OITE Orthopedic Board Review MCQs: Hand, Wrist & Grafting

Orthopedic Board Review MCQs: Hand, Wrist & Grafting | Part 31

Comprehensive 100-Question Exam

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Question 1

A 25-year-old male presents with a persistent scaphoid nonunion 18 months after a cast-treated fracture. Imaging reveals a humpback deformity, an intrascaphoid angle of 65 degrees, and sclerosis with fragmentation of the proximal pole consistent with avascular necrosis (AVN). Which of the following is the most appropriate surgical treatment to achieve both structural restoration and biological healing?

Explanation

In cases of scaphoid nonunion with both proximal pole AVN and a humpback deformity, a free vascularized medial femoral condyle (MFC) corticocancellous bone graft is indicated. The MFC graft provides robust, independent blood supply necessary for a necrotic proximal pole and offers structural corticocancellous bone to correct the volar carpal collapse (humpback deformity). The 1,2-ICSRA graft often lacks sufficient structural integrity to reliably correct a humpback deformity and has a lower union rate in the presence of proximal pole fragmentation and AVN compared to the MFC graft.

Question 2

A 30-year-old manual laborer sustains a volar oblique amputation of the index fingertip, exposing the bone of the distal phalanx. Which of the following explains why a volar advancement flap (Moberg flap) is generally contraindicated in this digit?

Explanation

The Moberg volar advancement flap is ideally suited for the thumb because the thumb has an independent dorsal blood supply via the dorsal digital arteries arising from the radial artery. In the lesser digits (fingers), the dorsal skin relies heavily on dorsal branches arising from the volar proper digital arteries. Elevating and advancing a volar flap in the fingers typically requires division of these branches, leading to a high risk of dorsal skin ischemia and necrosis.

Question 3

A 62-year-old female with long-standing rheumatoid arthritis presents with an inability to actively flex the interphalangeal joint of her right thumb. Passive motion is intact. She has a history of a 'Mannerfelt-Norman lesion'. Which of the following best describes the pathoanatomy of this condition?

Explanation

The Mannerfelt-Norman syndrome refers to the spontaneous attrition rupture of the flexor pollicis longus (FPL) tendon (and sometimes the flexor digitorum profundus of the index and middle fingers) in rheumatoid arthritis patients. This is caused by friction over a bony spur on the volar aspect of the scaphoid. The spur forms secondary to rotatory subluxation of the scaphoid, causing the proximal pole to abrade the volar capsule and tendons.

Question 4

During the surgical release of a severe Dupuytren's contracture in the ring finger, the surgeon encounters the spiral cord. The neurovascular bundle in this area is at high risk of iatrogenic injury. Which of the following fascial structures is SPARED by the disease process and lies consistently dorsal to the neurovascular bundle?

Explanation

Cleland's ligament lies dorsal to the neurovascular bundle and is characteristically SPARED in Dupuytren's disease. The spiral cord is formed by the pathological involvement of the pretendinous band, spiral band, lateral digital sheet, and Grayson's ligament. The contraction of the spiral cord pulls the neurovascular bundle centrally, superficially, and proximally, placing it at high risk of injury during fasciectomy.

Question 5

A patient with low radial nerve palsy undergoes tendon transfer utilizing the flexor carpi radialis (FCR) to power the extensor digitorum communis (EDC). The excursion of the FCR is approximately 33 mm, whereas the EDC requires approximately 50 mm for full composite extension. By what primary mechanism does the patient achieve full active digital extension post-operatively?

Explanation

Tendon excursions in the forearm vary: wrist flexors/extensors have roughly 33 mm of excursion, common finger extensors 50 mm, and finger flexors 70 mm. Because the FCR (33 mm) has less excursion than the EDC (50 mm), it cannot provide full digital extension independently. Instead, patients achieve full digital extension by actively flexing the wrist (relying on intact volar flexors), which functionally increases the effective excursion of the transferred tendon through the tenodesis effect.

Question 6

A 40-year-old male is evaluated for chronic wrist pain. Radiographs reveal Scaphoid Nonunion Advanced Collapse (SNAC). Which of the following carpal articulations is typically the FIRST to demonstrate degenerative arthritic changes in a SNAC wrist?

Explanation

In a Scaphoid Nonunion Advanced Collapse (SNAC) wrist, the proximal scaphoid fragment typically remains attached to the lunate via the intact scapholunate interosseous ligament and maintains relative congruency with the radius. The distal fragment rotates and flexes, leading to abnormal kinematics and localized impingement. Consequently, the first joint to degenerate (Stage I SNAC) is the articulation between the distal scaphoid fragment and the radial styloid. The radiolunate joint is characteristically spared in both SNAC and SLAC (Scapholunate Advanced Collapse) patterns.

Question 7

In cases of massive peripheral nerve defects (e.g., > 6 cm gap) or poor soft-tissue beds (e.g., heavily irradiated or scarred), a free vascularized nerve graft is sometimes indicated. When a vascularized medial femoral condyle (MFC) bone graft or an adjacent free flap is harvested with an associated sensory nerve, what is the primary arterial pedicle supplying the MFC and its adjacent tissues?

Explanation

The primary vascular pedicle for the medial femoral condyle (MFC) free flap—which can include corticocancellous bone, periosteum, and occasionally skin or nerve components—is the descending genicular artery (DGA), specifically its articular and saphenous branches. If the DGA is absent or unsuitable, the superior medial genicular artery (SMGA) can sometimes serve as an alternative.

Question 8

A 45-year-old woman presents with persistent, vague volar forearm pain and paresthesias in her thumb, index, and middle fingers. She lacks nocturnal pain. Physical examination reveals a negative Phalen's test but a positive Tinel's sign over the proximal volar forearm. Which of the following specific physical exam findings differentiates Pronator Syndrome from Carpal Tunnel Syndrome (CTS)?

Explanation

Pronator syndrome is a proximal compression neuropathy of the median nerve. The palmar cutaneous branch of the median nerve, which supplies sensation to the thenar eminence, arises approximately 5 cm proximal to the transverse carpal ligament and travels superficial to it. Therefore, sensation over the thenar eminence is spared in Carpal Tunnel Syndrome (CTS) but can be decreased in Pronator Syndrome. Nocturnal pain is classic for CTS, while aching forearm pain exacerbated by activity is classic for Pronator Syndrome.

Question 9

When a large cortical bone autograft is utilized to reconstruct an upper extremity bony defect, it heals via a process termed creeping substitution. During which phase of this incorporation process is the mechanical and structural strength of the cortical bone graft at its WEAKEST?

Explanation

Cortical bone grafts incorporate via creeping substitution, which begins with osteoclastic resorption followed by osteoblastic bone formation. During the phase of revascularization and peak osteoclastic resorption (typically between 6 and 12 months, depending on the graft size), the graft becomes significantly porous. As a result, its mechanical and structural strength is at its lowest point, making it highly susceptible to fatigue fracture during this period.

Question 10

A 22-year-old rugby player presents with an inability to actively flex the distal interphalangeal (DIP) joint of his ring finger after grabbing an opponent's jersey. Radiographs reveal a bony fragment avulsed from the volar base of the distal phalanx. Surgical exploration demonstrates the flexor digitorum profundus (FDP) tendon is retracted into the palm, separate from the bony avulsion fragment. What is the correct classification of this injury?

Explanation

This is a Leddy and Packer Type IV Jersey finger. Type I involves FDP retraction to the palm (blood supply compromised, needs repair within 7-10 days). Type II involves retraction to the PIP joint level (held by vincula). Type III is a large bony avulsion that catches at the A4 pulley. Type IV is a bony avulsion fracture with concurrent avulsion of the FDP tendon directly off the bony fragment, allowing the tendon to retract further proximal than the fracture fragment.

Question 11

A patient undergoes a staged flexor tendon reconstruction utilizing a silicone (Hunter) rod for a severe Zone II injury. During the first stage, the rod is secured and left in place to stimulate the formation of a pseudo-sheath. Which of the following best describes the biological composition and functional property of the inner lining of this newly formed pseudo-sheath?

Explanation

The implantation of a silicone (Hunter) rod induces a foreign body reaction that forms a fibrous pseudo-sheath. The inner layer of this pseudo-sheath differentiates into a synovial-like mesothelial layer. This highly specialized lining actively secretes a mucin-like fluid rich in hyaluronic acid, which provides nutrition to the future tendon graft and creates a low-friction, gliding environment essential for the success of the second-stage tendon transfer.

Question 12

A 35-year-old female presents with persistent wrist pain. Radiographs reveal advanced Kienbock's disease. The lunate is significantly collapsed and fragmented, the carpal height ratio is decreased, and the scaphoid is flexed (cortical ring sign). Ulnar variance is neutral. Which of the following surgical interventions is generally CONTRAINDICATED in this specific stage of the disease?

Explanation

The patient has Lichtman Stage IIIB Kienbock's disease, defined by lunate fragmentation/collapse with secondary carpal instability (scaphoid flexion and decreased carpal height). Joint leveling procedures (like radial shortening osteotomy) are indicated for earlier stages (Stage II or IIIA, especially with negative ulnar variance) to unload the lunate. In Stage IIIB, because fixed carpal collapse and instability have already occurred, altering ulnar variance will not restore carpal mechanics or address the instability. Therefore, salvage procedures such as PRC, STT fusion, or SC fusion are required.

Question 13

You are performing a volar (Henry) approach to the distal radius for open reduction and internal fixation of a distal radius fracture. After developing the interval between the flexor carpi radialis (FCR) tendon and the radial artery, which muscle must be reflected from radial to ulnar to adequately expose the volar surface of the distal radius?

Explanation

During the volar Henry approach to the distal radius, the deep dissection involves elevating the pronator quadratus (PQ) muscle. The PQ is carefully elevated from its radial insertion (leaving a small cuff of tissue for later repair) and reflected ulnarly to expose the volar cortex of the distal radius. This protects the anterior interosseous nerve (AIN) and artery, which travel deep to the PQ.

Question 14

A 55-year-old male with a history of a remote distal radius fracture presents with difficulty extending his fingers and thumb, but normal sensory examination. He exhibits pain approximately 4 cm distal to the lateral epicondyle on resisted supination. Which structure is the most common site of compression for the nerve affected in this syndrome?

Explanation

The clinical presentation describes Posterior Interosseous Nerve (PIN) syndrome, characterized by weakness in thumb and finger extension without sensory loss (as the superficial radial nerve branches off proximal to the compression). The most common site of PIN compression is the Arcade of Frohse, which is the thickened proximal aponeurotic edge of the superficial head of the supinator muscle.

Question 15

A 50-year-old patient undergoes an LRTI (Ligament Reconstruction and Tendon Interposition) arthroplasty utilizing the Flexor Carpi Radialis (FCR) for advanced thumb carpometacarpal (CMC) joint arthritis. Six months post-operatively, the patient reports new-onset, deep aching pain at the base of the thumb that limits pinch strength. Radiographs show proximal migration of the first metacarpal. What is the most likely cause of this patient's pain?

Explanation

A well-recognized complication of thumb CMC arthroplasty (such as trapeziectomy with or without LRTI) is subsidence (proximal migration) of the first metacarpal. If significant subsidence occurs, the base of the first metacarpal can impinge on the scaphoid (or distal radius/trapezoid), leading to pain, decreased grip/pinch strength, and loss of thumb length.

Question 16

During carpal instability evaluation, a VISI (Volar Intercalated Segment Instability) pattern is identified on lateral radiographs. This deformity is primarily initiated by the disruption of which intrinsic carpal ligament?

Explanation

A VISI (Volar Intercalated Segment Instability) pattern occurs primarily due to an injury to the Lunotriquetral (LT) interosseous ligament. Once disconnected from the extension force of the triquetrum, the lunate is allowed to rotate into volar flexion under the influence of the intact scaphoid. Conversely, DISI (Dorsal Intercalated Segment Instability) is caused by injury to the Scapholunate (SL) ligament.

Question 17

A patient with Ulnar Impaction Syndrome presents with chronic ulnar-sided wrist pain. Diagnostic arthroscopy reveals a Palmer Type 2C tear of the Triangular Fibrocartilage Complex (TFCC), characterized by a central perforation, chondromalacia of the ulnar head, and a complete tear of the lunotriquetral (LT) interosseous ligament. Ulnar variance is measured at +3 mm. What is the most appropriate surgical treatment?

Explanation

In a patient with Ulnar Impaction Syndrome and positive ulnar variance of +3 mm, especially in the presence of a concomitant lunotriquetral (LT) ligament tear (Palmer 2C), an ulnar shortening osteotomy (USO) is the treatment of choice. USO unloads the ulnocarpal joint and has the added biomechanical advantage of tightening the ulnocarpal ligaments (ulnolunate and ulnotriquetral), which helps stabilize the incompetent LT joint. The Wafer procedure is typically reserved for positive variance of <2 mm and does not tighten the ulnocarpal ligaments. Central TFCC tears (degenerative) are typically debrided, not repaired.

Question 18

A 40-year-old male requires an autologous nerve graft to bridge a 3 cm defect in the median nerve at the mid-forearm level. You choose to harvest the sural nerve. What essential biological component does this non-vascularized nerve autograft provide to facilitate axonal regeneration across the defect?

Explanation

A non-vascularized nerve autograft acts as a biological scaffold. The axons and myelin within the graft undergo Wallerian degeneration. However, the graft provides structurally intact endoneurial tubes (Schwann cell basal lamina) and viable Schwann cells (which survive via initial imbibition and later revascularization) that guide the regenerating axons from the proximal nerve stump to the distal stump.

Question 19

When utilizing Demineralized Bone Matrix (DBM) as a bone graft substitute to fill a benign bone cyst void in a metacarpal, its primary biological mechanism relies on osteoinductivity. Which specific components retained within the DBM are responsible for this osteoinductive property?

Explanation

Demineralized Bone Matrix (DBM) is created by acid extraction of the mineralized component of allograft bone, which exposes and preserves the non-collagenous proteins, specifically Bone Morphogenetic Proteins (BMPs). These BMPs induce local mesenchymal stem cells to differentiate into osteoblasts, providing the osteoinductive property. DBM lacks viable cells (so it is not osteogenic) and has poor structural integrity (minimal osteoconductivity compared to cancellous bone or synthetic ceramics).

Question 20

A surgeon is considering the use of an allograft tendon for a staged tendon reconstruction in the hand to bypass the morbidity of autograft harvest. Which of the following is an established disadvantage of using allograft tissue compared to autograft in flexor tendon reconstruction?

Explanation

Tendon allografts are primarily acellular collagen scaffolds. Because they lack living tenocytes initially, they rely entirely on cellular repopulation and creeping substitution from the host tissue. This process delays the biological remodeling phase, rendering the allograft mechanically weaker for a longer period compared to autografts, thereby increasing the risk of stretching or rupture during early active rehabilitation. Outright immunologic rejection is rare due to the relatively avascular and acellular nature of processed tendon allografts.

Question 21

A 24-year-old male presents with a persistent scaphoid nonunion 2 years after conservative management of a proximal pole fracture. MRI confirms avascular necrosis of the proximal pole. There is no evidence of carpal collapse or radiocarpal arthritis. Which of the following is the most appropriate grafting procedure to optimize the chance of union?

Explanation

For a proximal pole scaphoid nonunion with avascular necrosis and no arthritis, a vascularized bone graft is indicated. The free vascularized medial femoral condyle (MFC) graft has demonstrated superior union rates in this specific scenario compared to the pedicled 1,2 ICSRA graft, primarily because the MFC graft provides a robust, independent blood supply and structural corticocancellous bone. Non-vascularized grafts have an unacceptably high failure rate in the setting of AVN. Salvage procedures (PRC or 4-corner fusion) are reserved for cases with established arthritis (SLAC/SNAC wrist).

Question 22

Incorporation of bone grafts occurs through a process known as creeping substitution. Which of the following accurately describes the initial histological event distinguishing the incorporation of a cortical bone autograft from a cancellous bone autograft?

Explanation

The incorporation of bone autografts (creeping substitution) differs fundamentally between cortical and cancellous bone. Cancellous bone is rapidly revascularized and osteoblasts lay down new bone on the existing trabecular scaffold first (osteoblastic apposition), followed by remodeling. Cortical bone is denser, meaning it must first be revascularized and resorbed by osteoclasts via 'cutting cones' before new bone can be deposited by osteoblasts. This initial osteoclastic resorption makes cortical grafts temporarily weaker during the incorporation process.

Question 23

A 48-year-old manual laborer presents with chronic wrist pain after an untreated scapholunate injury 10 years ago. Radiographs reveal narrowing of the radioscaphoid joint and the capitolunate joint. The radiolunate joint is well preserved. Which of the following is the most appropriate definitive surgical intervention?

Explanation

This patient has Scapholunate Advanced Collapse (SLAC) Stage III, characterized by arthritis involving the radioscaphoid and capitolunate joints, while the radiolunate joint is characteristically spared. The treatment of choice is scaphoid excision and four-corner fusion (capitate, lunate, triquetrum, hamate). Proximal row carpectomy (PRC) is contraindicated in SLAC Stage III because it relies on articulating the capitate head with the lunate fossa; if the capitate head is arthritic (as in Stage III), PRC will lead to continued pain and failure.

Question 24

A 32-year-old woman presents with severe, excruciating pain in the tip of her left index finger, which is severely exacerbated by cold weather. On exam, there is pinpoint tenderness beneath the nail bed. Application of a tourniquet to the base of the finger completely relieves her pain during the examination. This specific physical exam finding is known as:

Explanation

The clinical picture is classic for a glomus tumor. Hildreth's sign is the relief of pain upon the application of a tourniquet to the ischemic digit, which is highly specific for a glomus tumor. Love's test refers to pinpoint pain reproducible by applying localized pressure (e.g., with the tip of a paperclip) over the lesion. Cold sensitivity is the third component of the classic triad for glomus tumors.

Question 25

In a patient with a chronic, irreversible radial nerve palsy, a standard tendon transfer procedure is planned to restore functional wrist and digit extension. To restore wrist extension, which of the following donor-recipient tendon transfers is most commonly utilized?

Explanation

The standard set of tendon transfers for a high radial nerve palsy includes: 1) Pronator teres (PT) to Extensor carpi radialis brevis (ECRB) to restore wrist extension; 2) Flexor carpi radialis (FCR) or Flexor carpi ulnaris (FCU) to Extensor digitorum communis (EDC) to restore finger extension; and 3) Palmaris longus (PL) to Extensor pollicis longus (EPL) to restore thumb extension. The ECRB is chosen over the ECRL for wrist extension because its central insertion at the base of the third metacarpal minimizes radial deviation during active wrist extension.

Question 26

Following a flexor tendon laceration in Zone II of the hand, careful repair and preservation of the flexor tendon sheath are required. To prevent bowstringing of the flexor tendons and significant loss of mechanical advantage, which two annular pulleys are the most critical to preserve or reconstruct?

Explanation

The flexor tendon sheath consists of 5 annular (A) and 3 cruciform (C) pulleys. The A2 pulley (located over the proximal phalanx) and the A4 pulley (located over the middle phalanx) are biomechanically the most critical for preventing bowstringing of the flexor tendons during digit flexion. Disruption of these pulleys leads to a significant decrease in the mechanical advantage and excursion efficiency of the tendons.

Question 27

A 55-year-old woman presents with a recurrent, fluid-filled mass on the dorsal aspect of the distal interphalangeal (DIP) joint of her right middle finger. She complains of progressive grooving of the adjacent fingernail. To minimize the risk of recurrence during surgical excision, which of the following must be included in the procedure?

Explanation

Mucous cysts of the DIP joint are typically associated with underlying osteoarthritis. They originate from the joint capsule and are often intimately related to marginal osteophytes. To minimize the risk of recurrence, surgical management must include not only excision of the cyst and its stalk communicating with the joint but also debridement/excision of the underlying osteophyte. Failure to remove the osteophyte is the most common cause of recurrence.

Question 28

A 26-year-old male presents with chronic wrist pain 3 years after a fall on an outstretched hand. Radiographs show a scaphoid waist nonunion with early degenerative changes localized strictly to the articulation between the radial styloid and the distal pole of the scaphoid. The midcarpal joint is preserved. This corresponds to which stage of Scaphoid Nonunion Advanced Collapse (SNAC), and what is the recommended bone-preserving treatment?

Explanation

SNAC Stage I is characterized by arthritis localized to the radioscaphoid joint, specifically between the radial styloid and the distal pole of the scaphoid. Treatment for Stage I involves a radial styloidectomy to remove the arthritic impingement, combined with scaphoid ORIF and bone grafting to address the nonunion. Stage II involves the scaphocapitate joint, and Stage III involves the periscaphoid joints and capitolunate joint.

Question 29

Recombinant human Bone Morphogenetic Protein-2 (rhBMP-2) is utilized as an osteoinductive graft substitute in spinal fusion and open tibia fractures. At the cellular level, BMP-2 initiates osteoblast differentiation by binding to which type of cell surface receptor to activate the SMAD signaling pathway?

Explanation

Bone Morphogenetic Proteins (BMPs) are members of the Transforming Growth Factor-beta (TGF-β) superfamily. They bind to distinct Type I and Type II cell surface receptors, which are both serine/threonine kinase receptors. Upon ligand binding, these receptors form a complex that phosphorylates intracellular SMAD proteins (specifically SMADs 1, 5, and 8), which then translocate to the nucleus to upregulate osteogenic genes like Runx2.

Question 30

A 35-year-old man presents with dorsal wrist pain. Radiographs demonstrate negative ulnar variance and sclerosis of the lunate with coronal fracture lines, but the lunate height is preserved and there is no fixed carpal collapse (Lichtman Stage IIIA Kienböck's disease). Which of the following is the most appropriate initial surgical management?

Explanation

In Kienböck's disease (avascular necrosis of the lunate), treatment depends on the Lichtman stage and ulnar variance. Stage IIIA involves lunate fragmentation/collapse without fixed carpal collapse. In a patient with negative ulnar variance, a joint leveling procedure (such as a radial shortening osteotomy) is the treatment of choice to decompress the lunate by shifting loads to the ulnocarpal joint. Salvage procedures (PRC, fusion) are reserved for Stage IIIB (with fixed carpal collapse) or Stage IV (radiocarpal arthritis).

Question 31

A 40-year-old carpenter presents with ulnar-sided wrist pain. Radiographs show a +3 mm ulnar variance with cystic changes in the lunate and ulnar head. MRI demonstrates a central perforation of the triangular fibrocartilage complex (TFCC). Arthroscopy confirms the TFCC tear but shows pristine, intact articular cartilage at the distal radioulnar joint (DRUJ). What is the most appropriate surgical treatment?

Explanation

This patient has Ulnar Impaction Syndrome with a large positive ulnar variance (+3 mm) and intact DRUJ cartilage. The gold standard treatment for ulnar impaction with intact DRUJ cartilage and >2mm of positive variance is an ulnar shortening osteotomy (USO). The arthroscopic wafer procedure is generally limited to patients with <2 mm of positive variance. The Darrach and Sauvé-Kapandji procedures are salvage operations indicated when there is concurrent DRUJ arthritis, which this patient does not have.

Question 32

A 25-year-old patient requires a sural nerve autograft to bridge a 4 cm median nerve defect in the forearm. Following the nerve grafting procedure, which of the following correctly describes a critical physiological phase that the graft must undergo to support host axonal regeneration?

Explanation

In a nerve autograft, the donor axons within the graft undergo Wallerian degeneration. The clearing of this axonal and myelin debris by macrophages is essential to create empty endoneurial tubes. The graft's viable Schwann cells then proliferate and guide the regenerating host axons from the proximal nerve stump through these endoneurial tubes toward the distal target. The graft's original axons do not survive or anastomose; they are cleared.

Question 33

A 42-year-old male with rheumatoid arthritis presents with a finger deformity characterized by PIP joint flexion and DIP joint hyperextension. Which of the following anatomical disruptions is the primary initiator of this specific deformity?

Explanation

This deformity (PIP flexion and DIP hyperextension) is a Boutonnière deformity. It is primarily initiated by the disruption or attenuation of the central slip of the extensor tendon at its insertion on the middle phalanx. This allows the lateral bands to subluxate volarly to the axis of rotation of the PIP joint, causing them to act as PIP flexors while continuing to exert extension force on the DIP joint.

Question 34

During a modified Brunelli tenodesis for a chronic scapholunate ligament dissociation, a tendon graft is utilized to reconstruct the vital dorsal scapholunate ligament and tether the scaphoid to prevent volar flexion. Which tendon is typically harvested or split to serve as the graft in this specific procedure?

Explanation

The modified Brunelli procedure (three-ligament tenodesis) uses a strip of the Flexor carpi radialis (FCR) tendon. The FCR strip is left attached distally at its insertion, passed from volar to dorsal through a bone tunnel in the distal pole of the scaphoid, routed across the dorsal radiocarpal capsule to the lunate (and often secured to the radius or radiocarpal ligaments), acting as a dynamic and static checkrein against scaphoid flexion and reconstructing the dorsal SL ligament.

Question 35

A 39-year-old butcher presents to the ER 48 hours after sustaining a small puncture wound to his right index finger. He exhibits signs of pyogenic flexor tenosynovitis. Which of the following is NOT one of Kanavel's cardinal signs for this condition?

Explanation

Kanavel's four cardinal signs of infectious flexor tenosynovitis are: 1) Finger held in slight resting flexion, 2) Fusiform (sausage-like) swelling of the digit, 3) Tenderness along the entire course of the flexor tendon sheath, and 4) Severe pain on passive extension of the digit. Pain with active flexion is not considered one of the specific cardinal signs, as passive extension is the hallmark test that stretches the inflamed sheath.

Question 36

When reconstructing a soft tissue defect on the volar surface of the hand, a surgeon must decide between a split-thickness skin graft (STSG) and a full-thickness skin graft (FTSG). Compared to an STSG, what is a major advantage of utilizing an FTSG in the hand?

Explanation

A full-thickness skin graft (FTSG) contains the entire epidermis and dermis. Because of the thicker dermis, it undergoes MORE primary contraction (immediate recoil upon harvest) but LESS secondary contraction (contracture during wound healing) compared to an STSG. Less secondary contraction is a significant advantage in the hand and joint surfaces to prevent flexion contractures. STSG requires less metabolic demand and survives better on poorer beds, but it shrinks and contracts significantly over time.

Question 37

A 50-year-old female with long-standing rheumatoid arthritis develops a swan neck deformity in her long finger. The intrinsic tightness test is positive. If left untreated, what is the primary structural pathology that permits the hyperextension at the PIP joint in a swan neck deformity?

Explanation

A swan neck deformity consists of PIP hyperextension and DIP flexion. The PIP hyperextension is permitted by the attenuation or stretching of the volar plate at the PIP joint. In RA, synovitis stretches this capsuloligamentous structure, allowing the dorsal extensor forces (often exacerbated by intrinsic tightness or MCP subluxation) to pull the joint into severe hyperextension. Volar subluxation of the lateral bands and central slip rupture cause Boutonnière deformity, not swan neck.

Question 38

A 28-year-old male sustains a high-energy fall onto an extended, ulnarly deviated wrist. Radiographs reveal a dorsal perilunate dislocation. According to Mayfield's progressive stages of perilunate instability, what is the correct anatomical sequence of ligamentous disruption?

Explanation

Mayfield described 4 stages of progressive perilunate instability surrounding the lunate (starting radially and progressing ulnarly). Stage I: Disruption of the Scapholunate (SL) ligament. Stage II: Disruption of the Capitolunate articulation (space of Poirier). Stage III: Disruption of the Lunotriquetral (LT) ligament (classic perilunate dislocation). Stage IV: Failure of the dorsal radiocarpal ligament allowing the lunate to dislocate volarly into the carpal tunnel.

Question 39

A 14-month-old child is undergoing surgical release for a simple, complete syndactyly between the long and ring fingers. To optimize functional outcome and prevent long-term flexion contractures as the child grows, which of the following surgical principles must be strictly adhered to?

Explanation

In syndactyly release, zig-zag (Bruner-type) or geometrically designed incisions must be used to prevent linear scar contracture as the child grows. Because the circumference of two separated fingers is greater than the circumference of the joined digits, there is always a shortage of skin. This lateral skin defect must be covered with full-thickness skin grafts (FTSG, usually from the groin or lower abdomen) to minimize secondary contraction. STSG contracts too much and leads to joint contractures.

Question 40

Demineralized bone matrix (DBM) is widely used in orthopedic surgery to supplement fusion masses. Which of the following best describes the biological property that distinguishes DBM from purely synthetic ceramic grafts (e.g., tricalcium phosphate)?

Explanation

Demineralized bone matrix (DBM) is processed allograft bone that has had the inorganic mineral phase removed, exposing the underlying collagen matrix and trapped growth factors. While it lacks structural strength and live cells (it is NOT osteogenic), it retains osteoinductive proteins, primarily Bone Morphogenetic Proteins (BMPs), which recruit and differentiate host mesenchymal stem cells into osteoblasts. Synthetic ceramics (like TCP) are purely osteoconductive scaffolds without osteoinductive properties.

Question 41

A 28-year-old man presents with a symptomatic proximal pole scaphoid nonunion with avascular necrosis, 2 years post-injury. You plan a vascularized medial femoral condyle (MFC) bone graft. What is the primary arterial supply to this corticocancellous graft?

Explanation

The medial femoral condyle (MFC) vascularized bone graft is primarily supplied by the descending genicular artery (DGA), which arises from the superficial femoral artery just proximal to the adductor hiatus. If the DGA is absent or unsuitable, the medial superior genicular artery (MSGA) provides a reliable secondary source of blood supply to the periosteum of the MFC.

Question 42

In a standard tendon transfer (modified Jones) for high radial nerve palsy, which of the following transfers is most universally utilized to restore functional wrist extension?

Explanation

The pronator teres (PT) is the classic and most mechanically advantageous donor muscle for restoring wrist extension, specifically transferred to the extensor carpi radialis brevis (ECRB). The ECRB is chosen over the ECRL because its central insertion at the base of the third metacarpal minimizes radial deviation during wrist extension.

Question 43

A 35-year-old carpenter sustains a volar thumb pulp amputation measuring 2.5 x 2.0 cm with exposed distal phalanx bone. Which of the following local flap options provides sensate coverage without significantly increasing the risk of interphalangeal (IP) joint flexion contracture?

Explanation

The First Dorsal Metacarpal Artery (FDMA) or Foucher flap provides sensate, single-stage coverage for large thumb defects. The Moberg advancement flap relies on both neurovascular bundles but is generally limited to defects of 1.5 cm or less; pushing its advancement past this limit highly risks a permanent thumb IP joint flexion contracture. V-Y flaps are for smaller defects, while cross-finger and thenar flaps are historically insensate unless specifically innervated.

Question 44

During a routine electrodiagnostic study for suspected carpal tunnel syndrome, the neurologist notes an anomalous innervation pattern consisting of a Martin-Gruber anastomosis. Which of the following best describes the anatomical pathway of this connection?

Explanation

A Martin-Gruber anastomosis is a common anatomical variant involving a neural connection from the median nerve (or its anterior interosseous branch) to the ulnar nerve in the forearm. It typically carries motor fibers that innervate intrinsic hand muscles. Riche-Cannieu is a median-to-ulnar connection in the hand; Marinacci is an ulnar-to-median connection in the forearm; Berrettini is a sensory ulnar-to-median connection in the hand.

Question 45

A 2-year-old child presents with bilateral absent thumbs and marked radial shortening. Laboratory tests reveal pancytopenia. Chromosomal breakage testing with diepoxybutane (DEB) is strongly positive. What is the inheritance pattern and primary cellular defect associated with this condition?

Explanation

The patient has Fanconi anemia, which typically presents with radial longitudinal deficiency (absent thumb/radius) and aplastic anemia (pancytopenia). It is inherited in an autosomal recessive pattern and is characterized by a failure in DNA interstrand cross-link repair. Diagnosis is confirmed by increased chromosomal breakage after exposure to clastogenic agents like DEB.

Question 46

A 40-year-old heavy laborer presents with severe, symptomatic post-traumatic distal radioulnar joint (DRUJ) osteoarthritis. He requires preservation of maximum grip strength and forearm rotation for work. Which of the following salvage procedures is designed to eliminate DRUJ pain while explicitly preserving the ulnocarpal ligament complex and carpal support?

Explanation

The Sauvé-Kapandji procedure involves arthrodesis of the DRUJ with a creation of a pseudoarthrosis in the distal ulnar metaphysis to allow forearm rotation. Because the ulnar head remains securely articulated and fused with the sigmoid notch, the ulnocarpal ligaments and triangular fibrocartilage complex (TFCC) attachments are preserved, maintaining ulnocarpal support and minimizing ulnar translation of the carpus. The Darrach procedure removes the distal ulna entirely, sacrificing this support.

Question 47

A 28-year-old aquarium worker presents with a slow-growing, erythematous, nodular lesion on his right index finger that recently ulcerated, following a minor abrasion sustained while cleaning a fish tank 3 weeks ago. What is the most appropriate culture medium and condition to identify the likely causative organism?

Explanation

The clinical scenario strongly suggests an atypical mycobacterial infection caused by Mycobacterium marinum ('fish tank granuloma'). This organism grows best at lower temperatures (30°C to 32°C) on mycobacterial specific media such as Lowenstein-Jensen or Middlebrook agar. Cultures incubated at standard body temperature (37°C) will frequently yield false-negative results.

Question 48

In the surgical management of Zone II flexor tendon lacerations, which of the following suture modifications most significantly increases the ultimate tensile strength of the repair, thereby safely permitting an early active motion protocol?

Explanation

The ultimate tensile strength of a flexor tendon repair is directly proportional to the number of core suture strands crossing the repair site. Moving from a 2-strand to a 4-strand or 6-strand repair significantly increases strength and gap resistance, which is critical for early active motion protocols. Dorsal placement (not volar) increases strength due to the cross-sectional geometry of the tendon. Epitendinous sutures add strength but less significantly than increasing core strands.

Question 49

When planning a reverse radial forearm flap for soft tissue coverage of a dorsal hand defect, the primary blood supply relies on retrograde flow through the radial artery. This reverse flow is anatomically sustained primarily via the anastomosis with which of the following structures?

Explanation

The reverse radial forearm flap is a distally based pedicled flap. Ligation of the radial artery proximally means the flap relies on retrograde flow. This flow is provided by the deep palmar arch, which is primarily formed by the terminal continuation of the radial artery after it passes through the anatomical snuffbox, anastomosing with the deep branch of the ulnar artery.

Question 50

A 25-year-old man sustains a severe traumatic brachial plexus injury resulting in an isolated, complete C5-C6 root avulsion. Six months post-injury, he has no active elbow flexion or shoulder abduction, but hand and wrist functions are normal. You plan an Oberlin transfer to restore elbow flexion. Which of the following describes the classic Oberlin transfer?

Explanation

The classic Oberlin transfer utilizes a redundant motor fascicle of the ulnar nerve (often the fascicle innervating the flexor carpi ulnaris) and transfers it directly to the motor branch of the biceps muscle to restore elbow flexion in upper trunk brachial plexus injuries. A 'double' Oberlin transfer also includes transferring a median nerve fascicle to the brachialis motor branch.

Question 51

In a patient with an isolated complete rupture of the scapholunate interosseous ligament (SLIL), which distinct anatomic region of the ligament is biomechanically the strongest and most critical for preventing pathologic diastasis between the scaphoid and lunate?

Explanation

The scapholunate interosseous ligament (SLIL) is a C-shaped ligament divided into dorsal, proximal (membranous), and volar regions. The dorsal region is composed of stout, transversely oriented collagen fibers and is biomechanically the thickest and strongest portion, making it the primary stabilizer of the scapholunate joint. Conversely, for the lunotriquetral (LT) ligament, the volar portion is the strongest.

Question 52

In the pathoanatomy of Dupuytren's disease, the 'spiral cord' is primarily responsible for the contracture of the proximal interphalangeal (PIP) joint and the resultant central, superficial, and proximal displacement of the neurovascular bundle. Which of the following normal fascial structures does NOT contribute to the formation of the spiral cord?

Explanation

The spiral cord in Dupuytren's disease is formed by diseased elements of four specific fascial structures: the pretendinous band, the spiral band, the lateral digital sheet, and Grayson's ligament. The natatory ligament contributes to the web space contractures but is not a component of the spiral cord.

Question 53

A 42-year-old woman complains of severe, paroxysmal pain at the tip of her left ring finger. The pain is exacerbated by cold weather. On examination, a subtle bluish discoloration is seen under the nail plate, and exquisite point tenderness is noted. Which of the following clinical tests is most specific for diagnosing this condition?

Explanation

The clinical presentation is classic for a glomus tumor (cold sensitivity, paroxysmal severe pain, point tenderness—the classic triad). The Hildreth test is highly specific for glomus tumors: the point tenderness is assessed, a tourniquet is inflated to create ischemia, and the tenderness disappears. Once the tourniquet is released, the pain and tenderness return.

Question 54

A 35-year-old laborer with advanced Scapholunate Advanced Collapse (SLAC) stage III wrist arthritis undergoes a four-corner arthrodesis (capitate, lunate, triquetrum, hamate) with scaphoid excision. To preserve postoperative wrist motion and ensure the success of this specific salvage procedure, which of the following joints MUST be radiographically free of advanced arthritic changes preoperatively?

Explanation

The four-corner fusion (capitate, lunate, triquetrum, hamate) creates a single carpal block that articulates exclusively with the radius via the radiolunate facet. Therefore, an absolute prerequisite for a successful four-corner fusion is an intact, cartilage-spared radiolunate joint. In SLAC wrist, the radiolunate joint is characteristically spared until the final stages, unlike the radioscaphoid joint, which degenerates early.

Question 55

Madelung deformity is a congenital dyschondrosteosis of the wrist characterized by a bowed, shortened radius and a dorsally prominent distal ulna. This deformity is the direct result of premature growth arrest of which specific anatomic portion of the distal radius physis?

Explanation

Madelung deformity arises from a partial premature closure or growth arrest of the volar-ulnar aspect of the distal radius physis. As the rest of the physis continues to grow, the distal articular surface of the radius tilts excessively in a volar and ulnar direction, leading to carpal subsidence and a relatively long, dorsally prominent distal ulna.

Question 56

A 28-year-old man sustains a Galeazzi fracture-dislocation (fracture of the distal third of the radius with associated distal radioulnar joint [DRUJ] disruption). Following rigid plate fixation of the radius, intraoperative assessment reveals that the DRUJ subluxates dorsally when the forearm is in pronation but completely reduces and is stable when the forearm is placed in supination. What is the most appropriate management of the DRUJ?

Explanation

In a classic Galeazzi fracture, after anatomic and rigid fixation of the radius, the DRUJ must be assessed. If the DRUJ reduces and is stable in a specific position (most commonly supination for a dorsal DRUJ dislocation), the standard of care is closed management with immobilization (sugar-tong splint or long arm cast) in that stable position (supination) for 4 to 6 weeks. Pinning or open repair is reserved for DRUJs that remain unstable in all positions of rotation or are irreducible.

Question 57

A 45-year-old woman presents with wrist pain and is diagnosed with Lichtman Stage IIIA Kienböck's disease (lunate sclerosis and collapse, but without fixed scaphoid rotation or carpal height loss). Radiographs reveal an ulnar-negative variance of 3 mm. Which of the following surgical interventions is most appropriate to halt progression and relieve pain?

Explanation

In early to intermediate Kienböck's disease (Lichtman Stages I, II, and IIIA) presenting with ulnar-negative variance, joint leveling procedures are the treatment of choice. A radial shortening osteotomy unloads the radiolunate fossa, redistributing compressive forces to the ulnocarpal articulation and halting the progression of lunate collapse. PRC or salvage fusions are reserved for Stage IIIB (fixed scaphoid rotation/carpal collapse) or Stage IV (pancarpal arthritis).

Question 58

During a corrective osteotomy for a distal radius malunion, a structural cortical bone graft is placed to maintain length. In contrast to cancellous bone grafts, which undergo rapid revascularization, cortical bone grafts incorporate primarily via a protracted process. What is the defining histologic sequence of this process?

Explanation

Cortical bone grafts lack the porous architecture for rapid revascularization seen in cancellous grafts. They primarily incorporate through 'creeping substitution,' a slow process where host osteoclasts first resorb the dead structural graft bone (creating cutting cones), followed immediately by host osteoblasts laying down new living bone matrix. This process temporarily weakens the graft before full incorporation occurs.

Question 59

A patient with an isolated low ulnar nerve palsy exhibits a pronounced claw deformity of the ring and small fingers. A Bouvier test is performed and is positive (the patient is able to actively extend the PIP joints when the examiner blocks the MCP joints in slight flexion). Based on this finding, which of the following procedures is most appropriate to dynamically correct the deformity?

Explanation

A positive Bouvier test indicates that the extensor apparatus over the PIP joint is intact and functional if the deforming hyperextension force at the MCP joint is eliminated. Therefore, an MCP flexion block procedure, such as the Zancolli lasso (transferring the flexor digitorum superficialis to the A1 pulley), will prevent MCP hyperextension, allowing the extrinsic extensors to effectively extend the PIP joints and dynamically correct the claw hand.

Question 60

A 32-year-old male sustains a high-energy volar Barton's fracture of the distal radius, characterized by a displaced volar marginal articular fragment. The carpus demonstrates associated volar subluxation. Which of the following robust radiocarpal ligaments remains firmly attached to this volar fragment, directly causing the carpus to translate volarly with the bone piece?

Explanation

A volar Barton's fracture involves a shear fracture of the volar articular margin of the distal radius. The strong extrinsic volar radiocarpal ligaments, including the radioscaphocapitate (RSC) and the long and short radiolunate ligaments, originate from this volar rim. When the rim fractures and displaces volarly, these intact ligaments pull the carpus along with the bone fragment, causing the characteristic volar subluxation of the wrist joint.

Question 61

A 25-year-old man presents with a symptomatic proximal pole scaphoid nonunion. MRI demonstrates avascular necrosis (AVN) of the proximal pole. The surgeon plans to perform a free vascularized bone graft using the medial femoral condyle. What is the primary arterial supply to this specific bone graft?

Explanation

The free vascularized medial femoral condyle (MFC) bone graft is commonly utilized for recalcitrant nonunions with AVN, such as proximal pole scaphoid nonunions. Its primary pedicle is the descending genicular artery (specifically the articular branch). The superior medial genicular artery can serve as an alternative if the descending genicular artery is absent or unsuitable.

Question 62

A 32-year-old carpenter sustains a severe volar forearm laceration resulting in a 4 cm segmental defect of the median nerve. After appropriate debridement, what is the most appropriate reconstructive strategy for this nerve gap?

Explanation

Autologous nerve cable grafting (e.g., using the sural nerve or medial antebrachial cutaneous nerve) remains the gold standard for peripheral nerve defects greater than 3 cm. Conduits and acellular nerve allografts are generally reserved for non-critical sensory nerves with gaps less than 3 cm due to poor outcomes in longer or mixed/motor nerve defects.

Question 63

During a two-stage flexor tendon reconstruction for a severe Zone II injury using a Hunter rod, the surgeon prepares for the second stage requiring an autologous tendon graft. Which of the following donor tendons is considered 'intrasynovial' and has been shown to result in fewer adhesions and improved gliding?

Explanation

Intrasynovial tendon grafts (such as the flexor digitorum longus or flexor digitorum superficialis) retain a synovial surface that limits postoperative adhesions and improves gliding excursion in Zone II reconstructions. Extrasynovial grafts (such as palmaris longus, plantaris, and extensor indicis proprius) lack this gliding surface and historically have a higher rate of adhesions.

Question 64

A hand surgeon plans a 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) vascularized bone graft for a scaphoid waist nonunion. Topographically, the vascular pedicle for this graft is located between which two extensor compartments?

Explanation

The 1,2 ICSRA vascularized bone graft is based on the 1,2 intercompartmental supraretinacular artery. This pedicle runs superficially in the fascia between the first dorsal extensor compartment (abductor pollicis longus, extensor pollicis brevis) and the second dorsal extensor compartment (extensor carpi radialis longus, extensor carpi radialis brevis).

Question 65

A 4-year-old boy presents to the emergency department after a clean, sharp amputation of the distal phalanx tip (Zone 1) of the long finger in a door hinge. The amputated part was kept clean and brought in on an ice slurry. What is the most appropriate management for the amputated digit?

Explanation

In children under 6 years of age, clean fingertip amputations distal to the distal interphalangeal joint (Zone 1) have an exceptionally high success rate when reattached as a non-vascularized composite graft (often referred to as 'cap' replacement). Microvascular replantation is technically challenging at this level in a toddler and often unnecessary given the success of composite grafting.

Question 66

A volar advancement (Moberg) flap is used to cover a 1.5 cm volar pulp defect on the thumb. This flap can be safely advanced in the thumb without causing dorsal skin necrosis, unlike in the lesser digits, due to which of the following anatomical characteristics?

Explanation

The Moberg flap involves elevating the entire volar skin and neurovascular bundles of the thumb. In the thumb, the dorsal skin has an independent blood supply (via dorsal branches of the radial artery). In the lesser digits, the dorsal skin is supplied by branches from the proper volar digital arteries; thus, raising a true Moberg flap in the fingers would devascularize the dorsal skin, leading to necrosis.

Question 67

A reverse radial forearm flap is planned for coverage of a complex dorsal hand wound. The venous drainage of this distally based flap relies primarily on which of the following mechanisms?

Explanation

The reverse radial forearm flap is a distally based pedicled flap. Its arterial supply relies on retrograde flow from the ulnar artery via the palmar arches to the radial artery. Venous drainage relies on retrograde flow through the venae comitantes of the radial artery. The blood bypasses venous valves through numerous communicating cross-branches between the paired venae comitantes.

Question 68

A 35-year-old man undergoes the Masquelet technique for a 4 cm segmental bone defect in his 3rd metacarpal following a crush injury. Six weeks after the initial placement of the polymethylmethacrylate (PMMA) spacer, he is ready for the second stage. What type of bone graft is most appropriate to place within the induced membrane?

Explanation

The Masquelet technique relies on a foreign body reaction to a PMMA spacer to create a pseudo-synovial induced membrane that is highly vascularized and secretes growth factors (VEGF, TGF-beta). In the second stage, the spacer is removed, and the void is packed with non-vascularized cancellous autograft. The membrane provides the necessary vascularity and osteoinductive factors to incorporate the cancellous graft.

Question 69

When performing a volar wedge bone graft (Russe technique) for a humpback scaphoid nonunion, it is critical to understand the scaphoid's blood supply. The primary intraosseous blood supply to the proximal 80% of the scaphoid enters the bone at which anatomical location?

Explanation

The scaphoid receives its primary blood supply (about 80%) from the dorsal carpal branch of the radial artery, which enters the bone at the dorsal ridge and flows retrogradely to supply the waist and proximal pole. The volar carpal branch supplies the remaining 20% (the distal pole) entering volar-distally. This retrograde flow is why proximal pole fractures have a high rate of AVN.

Question 70

A 40-year-old patient develops a severe, painful end-neuroma of the superficial radial nerve following a distal radius fracture surgery. Conservative management has failed. If surgical resection is pursued, what is considered an effective strategy to minimize the recurrence of a symptomatic neuroma when grafting is not planned?

Explanation

Excision of a painful end-neuroma often leads to recurrence if the nerve stump is left in a mobile or superficial area subject to mechanical irritation. Burying the freshly resected proximal nerve stump deep into a well-vascularized muscle belly (such as the brachioradialis or pronator quadratus for the SRN) is a widely accepted technique to prevent mechanical stimulation and symptomatic recurrence.

Question 71

A surgeon performs a cross-finger flap from the dorsum of the middle finger to reconstruct a volar soft tissue defect exposing the flexor tendon on the index finger. What is the most appropriate management of the donor site on the dorsum of the middle finger?

Explanation

When elevating a cross-finger flap from the dorsum of a donor digit, it is essential to leave the paratenon overlying the extensor tendon intact. The resulting donor site defect is then typically covered with a full-thickness (or thick split-thickness) skin graft placed directly onto the vascularized paratenon. Attempting to graft over bare tendon will result in graft failure and tendon desiccation.

Question 72

A 45-year-old active mechanic complains of severe ulnar-sided wrist pain and DRUJ instability 1 year after nonoperative treatment of a distal radius fracture. Radiographs show a distal radius malunion with 25 degrees of dorsal tilt and 5 mm of positive ulnar variance. What is the best surgical management?

Explanation

In a young, active patient with a symptomatic distal radius malunion causing secondary DRUJ incongruity and instability, the ideal treatment is to correct the primary deformity. A corrective opening wedge osteotomy of the distal radius with a structural bone graft and rigid fixation restores normal anatomy, corrects the relative positive ulnar variance, and realigns the DRUJ, thereby preserving joint mechanics.

Question 73

During surgery for a highly comminuted intra-articular distal radius fracture, the surgeon utilizes an osteoconductive bone graft substitute to fill a large metaphyseal void. Which of the following best defines the primary mechanism of osteoconduction?

Explanation

Bone graft properties are divided into osteoconduction, osteoinduction, and osteogenesis. Osteoconduction refers to the material's ability to act as a 3D physical scaffold or matrix for creeping substitution and ingrowth of host capillaries and osteoprogenitor cells. Osteoinduction (e.g., BMPs) recruits and stimulates cells to become osteoblasts. Osteogenesis (e.g., fresh autograft) directly supplies living bone-forming cells.

Question 74

A 30-year-old man with Lichtman Stage II Kienböck's disease undergoes a joint-leveling procedure and a pedicled vascularized bone graft from the dorsal distal radius based on the 4+5 Extensor Compartmental Artery (ECA). Anatomically, this vascular pedicle is harvested between which two extensor compartments?

Explanation

Pedicled vascularized bone grafts from the dorsal distal radius are a standard treatment for Kienböck's disease. The 4+5 ECA (extensor compartmental artery) graft is harvested from the dorsal radius with its pedicle lying between the fourth dorsal compartment (extensor digitorum communis, extensor indicis proprius) and the fifth dorsal compartment (extensor digiti minimi).

Question 75

A surgeon harvests the sural nerve to be used as a cable graft for a 5 cm ulnar nerve gap in the forearm. The patient must be informed preoperatively of which expected, unavoidable sensory deficit following this harvest?

Explanation

The sural nerve provides sensory innervation to the lateral and posterior aspect of the distal third of the leg, the lateral malleolus, the lateral aspect of the foot, and the lateral heel. Harvesting this nerve for grafting results in an unavoidable sensory deficit in these areas, which patients must be counseled about preoperatively.

Question 76

A structural tricortical bone graft is harvested from the anterior iliac crest to reconstruct a scaphoid nonunion. Postoperatively, the patient reports significant numbness and a burning sensation over the anterolateral aspect of his thigh. Which nerve was most likely injured during the graft harvest?

Explanation

The lateral femoral cutaneous nerve (LFCN) is at risk during anterior iliac crest bone graft harvest. It typically exits the pelvis under the inguinal ligament approximately 1-2 cm medial to the anterior superior iliac spine (ASIS). Injury to the LFCN results in meralgia paresthetica, characterized by pain, burning, and numbness over the anterolateral thigh. Staying at least 2-3 cm posterior to the ASIS during harvest minimizes this risk.

Question 77

A 28-year-old worker sustains a complete sharp amputation of his dominant index finger at the base of the proximal phalanx. The amputated digit is properly prepared in a watertight bag submerged in ice-water slush. What is the maximum acceptable cold ischemia time for replantation of a digit?

Explanation

Ischemia times vary based on the presence of muscle. Digits contain no muscle belly, making them highly resistant to ischemic necrosis. The maximum acceptable cold ischemia time for digits is widely cited as 24 hours (with some literature suggesting up to 30 hours). In contrast, for major limb amputations containing muscle (macro-replantation), the maximum cold ischemia time is 12 hours, and warm ischemia is 6 hours.

Question 78

A 24-year-old athlete presents 5 weeks after a 'jersey finger' injury (avulsion of the FDP tendon) of the ring finger. Surgical exploration reveals the FDP tendon is retracted into the palm with severe scarring, and primary repair is impossible. The flexor digitorum superficialis (FDS) is fully intact and functional. What is the most appropriate surgical option to restore stability to the distal finger?

Explanation

In a chronic Zone I FDP avulsion where the tendon cannot be primarily repaired but the FDS is completely intact and functional, attempting to pass a tendon graft through the intact FDS risks compromising the function of the FDS and causing stiffness of the PIP joint. The standard and most predictable reconstructive option is arthrodesis of the distal interphalangeal (DIP) joint (or FDP tenodesis) to provide a stable pinch.

Question 79

In the classic index finger pollicization (Buck-Gramcko technique) for a severely hypoplastic thumb, what does the index finger metacarpophalangeal (MCP) joint become in the newly constructed thumb?

Explanation

During an index finger pollicization, the index metacarpal shaft is resected. The index metacarpal head acts as the new trapezium. The native index MCP joint is positioned to become the new carpometacarpal (CMC) joint of the thumb. Consequently, the index proximal interphalangeal (PIP) joint becomes the new thumb MCP joint, and the index DIP joint becomes the thumb IP joint.

Question 80

A 1-year-old child undergoes release of a simple complete syndactyly between the long and ring fingers. A full-thickness skin graft (FTSG) is preferred over a split-thickness skin graft (STSG) to cover the resulting lateral digit defects primarily because a FTSG:

Explanation

In syndactyly release, full-thickness skin grafts (FTSG) are favored over split-thickness skin grafts (STSG) because FTSGs undergo significantly less secondary contraction during the healing phase. This decreased secondary contracture is vital in the hand to prevent recurrent web creep and flexion contractures of the growing digits.

Question 81

A 35-year-old male undergoes a flexor tendon repair using the wide-awake local anesthesia no tourniquet (WALANT) technique. The surgeon injects a mixture of lidocaine and epinephrine. Forty-five minutes later, the patient's digit appears excessively pale, and the surgeon decides to reverse the vasoconstriction. Which of the following describes the mechanism of action of the most appropriate rescue agent?

Explanation

The rescue agent for epinephrine-induced digital ischemia is phentolamine. Phentolamine is a competitive, non-selective alpha-adrenergic receptor antagonist (blocking both alpha-1 and alpha-2 receptors). It effectively reverses the alpha-receptor-mediated vasoconstriction caused by epinephrine, restoring blood flow to the digit.

Question 82

In a patient with Stage III Scapholunate Advanced Collapse (SLAC) wrist, the radiolunate joint is characteristically spared from degenerative changes. Which of the following biomechanical or anatomic factors is the primary reason for this preservation?

Explanation

In SLAC wrist, the radiolunate joint is typically spared from osteoarthritis due to its congruent spherical articulation. When the scaphoid rotates into a flexed position, its elliptical proximal pole creates incongruous point-loading on the scaphoid fossa of the radius, leading to rapid degeneration (Stage I and II). The lunate, however, maintains a spherical, congruent relationship with the lunate fossa even when extended (DISI deformity), evenly distributing forces and sparing the cartilage.

Question 83

A surgeon plans to use a 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) vascularized bone graft for a scaphoid nonunion. During the dissection, the pedicle must be identified between the first and second dorsal extensor compartments. Which of the following pairs of tendons correctly defines the anatomic borders of these two compartments?

Explanation

The 1,2 ICSRA runs longitudinally along the dorsal retinaculum between the 1st and 2nd extensor compartments. The 1st compartment contains the Abductor Pollicis Longus (APL) and Extensor Pollicis Brevis (EPB). The 2nd compartment contains the Extensor Carpi Radialis Longus (ECRL) and Extensor Carpi Radialis Brevis (ECRB). Therefore, the interval is directly between the EPB (ulnar border of the 1st compartment) and ECRL (radial border of the 2nd compartment).

Question 84

A patient presents with an ulnar claw hand deformity following a laceration to the ulnar nerve at the wrist. The examiner performs the Bouvier test by passively preventing hyperextension of the metacarpophalangeal (MCP) joints, which subsequently allows the patient to actively extend the interphalangeal (IP) joints. A positive Bouvier test indicates the functional competence of which of the following structures?

Explanation

A positive Bouvier test occurs when blocking the MCP joint from hyperextending allows the long extensors to transmit force distally, resulting in IP joint extension. This indicates that the extrinsic extensor mechanism (central slip and lateral bands) is intact and functionally competent. It helps determine if a simple MCP stabilization procedure (e.g., Zancolli lasso or capsulodesis) will successfully correct the claw deformity.

Question 85

When utilizing cortical bone autograft for structural reconstruction in the upper extremity, it undergoes incorporation via a process known as creeping substitution. At approximately what time point post-implantation is a cortical autograft mechanically at its weakest?

Explanation

Cortical autograft heals by creeping substitution, where osteoclasts first resorb the bone (cutting cones) followed by osteoblasts laying down new bone. This initial resorptive phase increases graft porosity, making the cortical autograft mechanically weakest between 6 months and 1 year after implantation. It may take 1 to 2 years to regain its structural integrity.

Question 86

A surgeon chooses to use calcium phosphate cement to fill a metaphyseal void following the reduction of a distal radius fracture. Which of the following correctly describes a biomechanical or physical property of calcium phosphate cement?

Explanation

Calcium phosphate cement cures in vivo via an exothermic reaction into a hydroxyapatite-like structure. It is highly osteoconductive and provides excellent compressive strength (equivalent to or greater than cancellous bone), making it ideal for filling metaphyseal voids. However, it lacks tensile/shear strength and resorbs very slowly (often taking years), unlike calcium sulfate which resorbs rapidly.

Question 87

During surgical fasciectomy for severe Dupuytren's contracture of the ring finger, the surgeon isolates the neurovascular bundle to protect it. In the presence of a spiral cord, which of the following normal fascial structures is NOT a component of the spiral cord and thus typically spares the neurovascular bundle from dorsal displacement?

Explanation

The spiral cord in Dupuytren's disease is responsible for causing PIP joint contracture and displacing the neurovascular bundle centrally and superficially. It is formed by diseased tissue from four structures: the pretendinous band, spiral band, lateral digital sheet, and Grayson's ligament. Cleland's ligament is dorsal to the neurovascular bundle and is characteristically NOT involved in Dupuytren's disease.

Question 88

A 62-year-old female with long-standing rheumatoid arthritis presents with a sudden inability to actively flex the interphalangeal joint of her right thumb. She denies any preceding trauma. Radiographs reveal diffuse carpal advanced changes and prominent volar osteophytes. This presentation is most consistent with attritional rupture of the flexor pollicis longus (FPL) tendon. Which structure is the most likely source of attrition?

Explanation

This clinical scenario describes a Mannerfelt lesion (Mannerfelt-Norman syndrome), which is an attritional rupture of the flexor pollicis longus (FPL) tendon in patients with rheumatoid arthritis. It is most commonly caused by friction against a bony spur extending from the volar aspect of the scaphoid (often penetrating the floor of the carpal tunnel).

Question 89

A 45-year-old manual laborer with Stage III Kienböck's disease is evaluated for surgical intervention. The surgeon is considering a proximal row carpectomy (PRC). To ensure the success of a PRC, articular cartilage must be preserved on the lunate fossa of the radius and which other critical structure?

Explanation

Proximal row carpectomy (PRC) involves the excision of the scaphoid, lunate, and triquetrum. This converts the wrist into a simple hinge joint where the proximal pole of the capitate articulates directly with the lunate fossa of the distal radius. Therefore, PRC is strictly contraindicated if there is significant degenerative arthritis or cartilage loss at the proximal pole of the capitate.

Question 90

A 55-year-old female presents with inability to extend her thumb 6 weeks after a non-displaced distal radius fracture. The surgeon diagnoses an extensor pollicis longus (EPL) tendon rupture and plans an extensor indicis proprius (EIP) to EPL tendon transfer. During the harvest of the EIP tendon at the level of the metacarpal head, where is the EIP tendon located relative to the extensor digitorum communis (EDC) tendon of the index finger?

Explanation

During the surgical harvest for an EIP to EPL transfer, the Extensor Indicis Proprius (EIP) tendon is identified at the level of the index metacarpophalangeal (MCP) joint hood. The EIP tendon consistently lies ulnar and volar (deep) to the Extensor Digitorum Communis (EDC) tendon of the index finger.

Question 91

Bone morphogenetic proteins (BMPs) are commonly used as osteoinductive agents in bone grafting procedures. At the cellular level, BMPs initiate signal transduction by binding to cell surface receptors that possess which of the following intrinsic enzymatic activities?

Explanation

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-beta (TGF-β) superfamily. They bind to Type I and Type II transmembrane receptors that possess intrinsic serine/threonine kinase activity. Once activated, these receptors phosphorylate downstream intracellular signaling molecules called Smads (typically Smad 1, 5, and 8), which then translocate to the nucleus to regulate gene transcription.

Question 92

An 18-year-old male sustains a proximal pole scaphoid fracture. The high risk of avascular necrosis and nonunion in this region is primarily due to the unique retrograde intraosseous blood supply of the scaphoid. The predominant blood supply to the proximal 80% of the scaphoid enters the bone at which location?

Explanation

The scaphoid relies heavily on its retrograde blood supply. Approximately 70-80% of the scaphoid (including the entire proximal pole) is supplied by the dorsal carpal branch of the radial artery, which enters the non-articular dorsal ridge and flows proximally. The volar branches of the radial artery supply only the distal 20-30% at the region of the tuberosity.

Question 93

A patient presents with a 1.2 cm volar soft tissue defect over the distal phalanx of the thumb with exposed bone. A Moberg volar advancement flap is planned. Which of the following is a recognized disadvantage or common complication of this specific flap?

Explanation

The Moberg volar advancement flap is ideal for volar thumb defects up to 1.5 cm. It involves advancing the entire volar skin of the thumb along with both neurovascular bundles. Because the flap is advanced distally, it requires the interphalangeal (IP) joint to be flexed during healing, frequently resulting in a mild to moderate IP joint flexion contracture. Sensation is perfectly maintained and cortical misrepresentation (seen in heterodigital island flaps like the Littler flap) does not occur.

Question 94

A 32-year-old male is diagnosed with Kienböck's disease. Radiographs reveal sclerosis and fragmentation of the lunate, and the radioscaphoid angle measures 65 degrees, indicating fixed scaphoid rotation and carpal collapse. Which Lichtman stage best categorizes this presentation?

Explanation

Lichtman Stage IIIB Kienböck's disease is characterized by lunate fragmentation/collapse combined with fixed coronal rotation of the scaphoid (radioscaphoid angle > 60 degrees) and resulting carpal height collapse. Stage IIIA has lunate collapse but normal carpal alignment and scaphoid position. Stage IV involves secondary pancarpal osteoarthritis.

Question 95

A patient with a high radial nerve palsy requires tendon transfers to restore wrist, finger, and thumb extension. To restore wrist extension, the Pronator Teres (PT) is most commonly transferred to the Extensor Carpi Radialis Brevis (ECRB) rather than the Extensor Carpi Radialis Longus (ECRL). What is the primary biomechanical rationale for selecting the ECRB?

Explanation

The Pronator Teres (PT) is the standard transfer to restore wrist extension in radial nerve palsy. It is transferred to the ECRB rather than the ECRL because the ECRB inserts more centrally at the base of the third metacarpal. Transferring to the ECRL (which inserts on the second metacarpal) would result in a functionally limiting supination and excessive radial deviation moment during wrist extension.

Question 96

A 40-year-old male sustains a complete laceration of the ulnar nerve near the elbow. Examination reveals profound weakness of the intrinsic hand muscles but relatively mild clawing of the ring and small fingers compared to a patient with an ulnar nerve injury at the wrist. This phenomenon is commonly known as the 'Ulnar Paradox.' What is the anatomic basis for this presentation?

Explanation

The 'Ulnar Paradox' states that a high ulnar nerve injury produces a less severe claw hand deformity than a low ulnar nerve injury. The claw deformity (MCP hyperextension, IP flexion) is driven by the unopposed action of the extensor digitorum communis and the flexor digitorum profundus (FDP) when the lumbricals are paralyzed. In a high injury, the ulnar-innervated FDP to the ring and small fingers is also paralyzed, removing the strong flexor force at the IP joints and thereby softening the claw appearance.

Question 97

Following primary repair of an acute Zone II flexor tendon laceration, the healing tendon progresses through inflammatory, fibroblastic, and remodeling phases. During the fibroblastic (proliferation) phase, which collagen type is predominantly synthesized initially by fibroblasts before being gradually replaced in the remodeling phase?

Explanation

Tendon healing in the initial fibroblastic (proliferative) phase, which spans approximately days 5 to 28, is characterized by the production of Type III collagen. This forms a disorganized, mechanically weak matrix. During the subsequent remodeling phase, this Type III collagen is gradually replaced by the stronger, longitudinally oriented Type I collagen, increasing the tendon's tensile strength.

Question 98

A surgeon incorporates calcium sulfate pellets as a bone graft substitute to fill a benign bone cyst defect in the hand. Three weeks postoperatively, the patient presents with non-purulent, serous drainage from the wound. Inflammatory markers are normal and cultures are negative. What is the most likely cause of this drainage?

Explanation

Calcium sulfate is an osteoconductive bone graft substitute known for its very rapid absorption rate, which often outpaces new bone formation. Its dissolution can create a localized hyperosmotic environment, drawing fluid into the area and resulting in a sterile, serous wound exudate in up to 30% of patients. It does not set with an exothermic reaction (unlike calcium phosphate or PMMA).

Question 99

During flexor tendon reconstruction, it is critical to preserve or reconstruct specific pulleys to prevent bowstringing of the tendon and significant loss of active flexion arc. Which two pulleys are considered the most critical for preventing bowstringing, and from what anatomical structures do they primarily originate?

Explanation

The A2 and A4 pulleys are mechanically the most crucial pulleys for maintaining tendon apposition to the bone and preventing bowstringing. These are the diaphyseal pulleys, arising broadly and robustly from the periosteum of the proximal phalanx (A2) and middle phalanx (A4). The A1, A3, and A5 are joint pulleys and arise from the volar plates.

Question 100

In the process of Wallerian degeneration following a severe peripheral nerve injury in the upper extremity, the distal nerve segment undergoes organized cellular changes to prepare for potential regenerating axons. Which specialized cells are primarily responsible for clearing myelin debris and subsequently proliferating to form the parallel arrays known as 'Bands of Büngner'?

Descending genicular artery
Medial superior genicular artery
Inferior medial genicular artery
Popliteal artery
Deep femoral artery

Correct Answer: Descending genicular artery

Explanation:

Question 42:

In a standard tendon transfer (modified Jones) for high radial nerve palsy, which of the following transfers is most universally utilized to restore functional wrist extension?

Options:

Pronator teres to extensor carpi radialis brevis
Flexor carpi ulnaris to extensor digitorum communis
Palmaris longus to extensor pollicis longus
Flexor digitorum superficialis to extensor carpi radialis longus
Flexor carpi radialis to extensor digitorum communis

Correct Answer: Pronator teres to extensor carpi radialis brevis

Explanation:

Question 43:

Options:

Moberg advancement flap
First dorsal metacarpal artery (FDMA) island flap
V-Y advancement (Atasoy) flap
Thenar flap
Cross-finger flap

Correct Answer: First dorsal metacarpal artery (FDMA) island flap

Explanation:

Question 44:

Options:

Median nerve to ulnar nerve connection in the forearm
Ulnar nerve to median nerve connection in the forearm
Motor branch of the median nerve to the deep branch of the ulnar nerve in the hand
Sensory connection between the ulnar and median nerves in the palmar surface of the digits
Superficial radial nerve to the dorsal sensory branch of the ulnar nerve

Correct Answer: Median nerve to ulnar nerve connection in the forearm

Explanation:

Question 45:

Options:

Autosomal recessive; defect in DNA interstrand cross-link repair
Autosomal dominant; defect in fibroblast growth factor receptor 3
X-linked recessive; defect in type 1 collagen synthesis
Autosomal recessive; mutation in the SHH (Sonic Hedgehog) gene
Autosomal dominant; defect in DNA mismatch repair

Correct Answer: Autosomal recessive; defect in DNA interstrand cross-link repair

Explanation:

Question 46:

Options:

Sauvé-Kapandji procedure
Darrach procedure
Hemiresection interposition arthroplasty (Bowers)
Distal ulna prosthetic replacement
Ulnar shortening osteotomy

Correct Answer: Sauvé-Kapandji procedure

Explanation:

Question 47:

Options:

Lowenstein-Jensen agar at 30°C to 32°C
Blood agar at 37°C
Viral transport media at 37°C
Sabouraud dextrose agar at 25°C
Chocolate agar at 37°C

Correct Answer: Lowenstein-Jensen agar at 30°C to 32°C

Explanation:

Question 48:

Options:

Increasing the number of core suture strands crossing the repair site
Changing from a grasping to a locking core suture configuration
Placing the core suture entirely in the volar half of the tendon
Increasing the caliber of the epitendinous suture from 6-0 to 5-0
Utilizing a braided absorbable core suture instead of monofilament non-absorbable

Correct Answer: Increasing the number of core suture strands crossing the repair site

Explanation:

Question 49:

Options:

Deep palmar arch
Superficial palmar arch
Anterior interosseous artery
Posterior interosseous artery
Princeps pollicis artery

Correct Answer: Deep palmar arch

Explanation:

Question 50:

Options:

Transfer of an expendable ulnar nerve fascicle to the biceps motor branch
Transfer of the medial pectoral nerve to the musculocutaneous nerve
Transfer of three intercostal nerves directly to the musculocutaneous nerve
Transfer of the spinal accessory nerve to the suprascapular nerve
Transfer of a median nerve fascicle to the axillary nerve

Correct Answer: Transfer of an expendable ulnar nerve fascicle to the biceps motor branch

Explanation:

Question 51:

Options:

Dorsal region
Volar region
Proximal (membranous) region
Central region
Palmar radiocarpal region

Correct Answer: Dorsal region

Explanation:

Question 52:

Options:

Natatory ligament
Pretendinous band
Spiral band
Lateral digital sheet
Grayson's ligament

Correct Answer: Natatory ligament

Explanation:

Question 53:

Options:

Hildreth test
Phalen's test
Finkelstein's test
Tinel's sign
Grind test

Correct Answer: Hildreth test

Explanation:

Question 54:

Options:

Radiolunate joint
Radioscaphoid joint
Lunotriquetral joint
Distal radioulnar joint
Capitohamate joint

Correct Answer: Radiolunate joint

Explanation:

Question 55:

Options:

Volar-ulnar portion
Dorsal-ulnar portion
Volar-radial portion
Dorsal-radial portion
Central portion

Correct Answer: Volar-ulnar portion

Explanation:

Question 56:

Options:

Immobilization of the forearm in supination for 4 to 6 weeks
Immobilization of the forearm in pronation for 4 to 6 weeks
Immediate open reduction and primary repair of the triangular fibrocartilage complex (TFCC)
Transfixion pinning of the DRUJ with the forearm in neutral rotation
Resection of the distal ulna (Darrach procedure)

Correct Answer: Immobilization of the forearm in supination for 4 to 6 weeks

Explanation:

Question 57:

Options:

Radial shortening osteotomy
Proximal row carpectomy
Scaphoid-trapezium-trapezoid (STT) fusion
Lunate excision and capitate shortening
Total wrist arthrodesis

Correct Answer: Radial shortening osteotomy

Explanation:

Question 58:

Options:

Osteoclastic resorption of host bone followed by osteoblastic new bone formation (creeping substitution)
Direct intramembranous ossification from surviving transplanted osteoprogenitor cells
Endochondral ossification beginning with a cartilaginous intermediate
Rapid neoangiogenesis leading to direct osteoblast differentiation from endothelial cells
Formation of woven bone directly bridging the fracture gap without prior resorption

Correct Answer: Osteoclastic resorption of host bone followed by osteoblastic new bone formation (creeping substitution)

Explanation:

Question 59:

Options:

Zancolli lasso procedure (FDS to A1 pulley transfer)
Extensor indicis proprius to extensor pollicis longus transfer
Pronator teres to extensor carpi radialis brevis transfer
Brachioradialis to flexor pollicis longus transfer
Flexor carpi ulnaris to extensor digitorum communis transfer

Correct Answer: Zancolli lasso procedure (FDS to A1 pulley transfer)

Explanation:

Question 60:

Options:

Radioscaphocapitate ligament
Dorsal radiocarpal ligament
Scapholunate interosseous ligament
Lunotriquetral interosseous ligament
Dorsal intercarpal ligament

Correct Answer: Radioscaphocapitate ligament

Explanation:

Question 61:

Options:

Descending genicular artery
Superior medial genicular artery
Inferior medial genicular artery
Popliteal artery direct branches
Sural artery

Correct Answer: Descending genicular artery

Explanation:

Question 62:

Options:

Primary end-to-end repair under tension
Use of a synthetic polyglycolic acid nerve conduit
Bridging with an acellular nerve allograft
Reconstruction using an autologous nerve cable graft
End-to-side neurorrhaphy to the ulnar nerve

Correct Answer: Reconstruction using an autologous nerve cable graft

Explanation:

Question 63:

Options:

Palmaris longus
Plantaris
Extensor indicis proprius
Flexor digitorum longus
Extensor digiti minimi

Correct Answer: Flexor digitorum longus

Explanation:

Question 64:

Options:

First and Second
Second and Third
Third and Fourth
Fourth and Fifth
Fifth and Sixth

Correct Answer: First and Second

Explanation:

Question 65:

Options:

Terminalization of the digit and primary closure
Volar V-Y advancement flap
Cross-finger flap from the adjacent digit
Reattachment as a non-vascularized composite graft
Microvascular replantation with vein grafting

Correct Answer: Reattachment as a non-vascularized composite graft

Explanation:

Question 66:

Options:

The absence of Cleland's ligaments in the thumb
The independent dorsal blood supply to the thumb skin
The superficial location of the princeps pollicis artery
The increased elasticity of the volar thumb fascia
The complete separation of the flexor pollicis longus sheath

Correct Answer: The independent dorsal blood supply to the thumb skin

Explanation:

Question 67:

A reverse radial forearm flap is planned for coverage of a complex dorsal hand wound. The venous drainage of this distally based flap relies primarily on which of the following mechanisms?

Options:

Retrograde flow through the cephalic vein bypassing functional valves
Antegrade flow through the basilic vein via the palmar arch
Retrograde flow through the venae comitantes of the radial artery
Retrograde flow through the median cubital vein
Collateral drainage via the dorsal venous arch of the hand

Correct Answer: Retrograde flow through the venae comitantes of the radial artery

Explanation:

Question 68:

Options:

Non-vascularized cortical strut allograft
Non-vascularized cancellous autograft
Free vascularized fibular graft
Demineralized bone matrix (DBM) with BMP-2 alone
Synthetic hydroxyapatite blocks

Correct Answer: Non-vascularized cancellous autograft

Explanation:

Question 69:

Options:

Volar proximal pole
Volar distal pole
Dorsal ridge
Proximal articular surface
Scaphotrapeziotrapezoid joint capsule

Correct Answer: Dorsal ridge

Explanation:

Question 70:

Options:

Ligation of the nerve end and placing it in the subcutaneous fat
Chemical ablation with phenol at the resection stump
Capping the nerve stump with a silicone tube
Transposition and deep burial of the nerve stump into the brachioradialis muscle
Performing a side-to-side anastomosis to the intact median nerve

Correct Answer: Transposition and deep burial of the nerve stump into the brachioradialis muscle

Explanation:

Question 71:

Options:

Primary closure by wide undermining
Split-thickness skin graft over bare bone
Full-thickness skin graft over preserved paratenon
Healing by secondary intention
Coverage with a local rotational flap

Correct Answer: Full-thickness skin graft over preserved paratenon

Explanation:

Question 72:

Options:

Darrach procedure
Sauvé-Kapandji procedure
Ulnar shortening osteotomy
Distal radius corrective osteotomy with structural bone graft and volar plating
Hemiresection interposition arthroplasty (Bowers procedure)

Correct Answer: Distal radius corrective osteotomy with structural bone graft and volar plating

Explanation:

Question 73:

Options:

Recruitment of mesenchymal stem cells via BMPs
Providing a physical scaffold for host bone ingrowth
Supplying viable osteoblasts to the defect site
Inducing a sterile inflammatory response to stimulate angiogenesis
Generating a piezoelectric effect under mechanical load

Correct Answer: Providing a physical scaffold for host bone ingrowth

Explanation:

Question 74:

Options:

First and Second
Second and Third
Third and Fourth
Fourth and Fifth
Fifth and Sixth

Correct Answer: Fourth and Fifth

Explanation:

Question 75:

Options:

Loss of sensation over the medial malleolus
Loss of sensation over the lateral aspect of the foot and lateral heel
Loss of sensation over the first web space of the foot
Loss of sensation over the plantar aspect of the heel
Loss of sensation over the anterior ankle

Correct Answer: Loss of sensation over the lateral aspect of the foot and lateral heel

Explanation:

Question 76:

Options:

Ilioinguinal nerve
Iliohypogastric nerve
Lateral femoral cutaneous nerve
Femoral nerve
Genitofemoral nerve

Correct Answer: Lateral femoral cutaneous nerve

Explanation:

Question 77:

Options:

6 hours
12 hours
24 hours
36 hours
48 hours

Correct Answer: 24 hours

Explanation:

Question 78:

Options:

Free vascularized toe transfer
Two-stage flexor tendon grafting using palmaris longus
Excision of the FDS and one-stage flexor tendon grafting
DIP joint arthrodesis
Primary end-to-end repair using a bridging allograft

Correct Answer: DIP joint arthrodesis

Explanation:

Question 79:

In the classic index finger pollicization (Buck-Gramcko technique) for a severely hypoplastic thumb, what does the index finger metacarpophalangeal (MCP) joint become in the newly constructed thumb?

Options:

Interphalangeal (IP) joint
Metacarpophalangeal (MCP) joint
Carpometacarpal (CMC) joint
Scaphotrapezial joint
Radiocarpal joint

Correct Answer: Carpometacarpal (CMC) joint

Explanation:

Question 80:

Options:

Has a higher rate of initial 'take' over avascular structures
Decreases the risk of secondary contracture
Requires less meticulous defatting of the graft
Prevents the need for a tie-over bolster dressing
Provides better sensory reinnervation for two-point discrimination

Correct Answer: Decreases the risk of secondary contracture

Explanation:

Question 81:

Options:

Non-selective beta-adrenergic receptor agonist
Selective alpha-1 adrenergic receptor agonist
Non-selective alpha-adrenergic receptor antagonist
Direct smooth muscle relaxant via nitric oxide donation
Selective beta-2 adrenergic receptor antagonist

Correct Answer: Non-selective alpha-adrenergic receptor antagonist

Explanation:

Question 82:

Options:

The robust interosseous blood supply to the lunate
The shielding effect of the intact triangular fibrocartilage complex (TFCC)
The elliptical articulation of the radiolunate joint that disperses sheer stress
The congruent spherical articulation of the radiolunate joint
The absence of rotational forces on the lunate following scapholunate dissociation

Correct Answer: The congruent spherical articulation of the radiolunate joint

Explanation:

Question 83:

Options:

Abductor pollicis longus and extensor pollicis longus
Extensor pollicis brevis and extensor carpi radialis longus
Extensor carpi radialis brevis and extensor pollicis longus
Extensor digitorum communis and extensor digiti minimi
Abductor pollicis longus and extensor pollicis brevis only

Correct Answer: Extensor pollicis brevis and extensor carpi radialis longus

Explanation:

Question 84:

Options:

Lumbricals
Palmar interossei
Extensor mechanism (central slip and lateral bands)
Flexor digitorum profundus
Sagittal bands

Correct Answer: Extensor mechanism (central slip and lateral bands)

Explanation:

Question 85:

Options:

2 to 4 weeks
6 to 12 months
18 to 24 months
3 to 5 years
It maintains consistent mechanical strength throughout the incorporation process

Correct Answer: 6 to 12 months

Explanation:

Question 86:

Options:

It cures via an endothermic reaction, protecting surrounding tissue
It provides high tensile and shear strength
It is rapidly resorbed within 4 to 6 weeks, matching the rate of new bone formation
It cures via an exothermic reaction and provides high compressive strength
It is primarily osteoinductive, promoting cell differentiation

Correct Answer: It cures via an exothermic reaction and provides high compressive strength

Explanation:

Question 87:

Options:

Pretendinous band
Spiral band
Cleland's ligament
Grayson's ligament
Lateral digital sheet

Correct Answer: Cleland's ligament

Explanation:

Question 88:

Options:

Volar lip of the distal radius
Hook of the hamate
Tubercle of the trapezium
Volar spur of the scaphoid
Pisiform

Correct Answer: Volar spur of the scaphoid

Explanation:

Question 89:

Options:

Distal pole of the scaphoid
Proximal pole of the capitate
Trapezoid
Hamate
Triquetrum

Correct Answer: Proximal pole of the capitate

Explanation:

Question 90:

Options:

Radial and dorsal
Ulnar and volar
Ulnar and dorsal
Radial and volar
Directly superficial

Correct Answer: Ulnar and volar

Explanation:

Question 91:

Options:

Tyrosine kinase
Serine/threonine kinase
Guanylyl cyclase
Phospholipase C
Adenylyl cyclase

Correct Answer: Serine/threonine kinase

Explanation:

Question 92:

Options:

Volar tubercle via branches of the superficial palmar arch
Dorsal ridge via branches of the radial artery
Distal articular surface via the deep palmar arch
Scapholunate interosseous ligament via the anterior interosseous artery
Proximal pole via direct branches from the ulnar artery

Correct Answer: Dorsal ridge via branches of the radial artery

Explanation:

Question 93:

Options:

Loss of protective sensation at the fingertip
Cortical misrepresentation of sensory input
Interphalangeal joint flexion contracture
Necessity of a secondary skin graft on the volar surface
Venous congestion due to retrograde flow

Correct Answer: Interphalangeal joint flexion contracture

Explanation:

Question 94:

Options:

Stage II
Stage IIIA
Stage IIIB
Stage IV
Stage I

Correct Answer: Stage IIIB

Explanation:

Question 95:

Options:

The ECRB has a longer excursion profile matching the PT
Transfer to the ECRL produces excessive radial deviation during extension
The ECRB tendon is located superficial to the superficial branch of the radial nerve
The ECRB is a primary flexor of the MCP joints, augmenting grip strength
The ECRB is less likely to undergo attritional rupture over the Lister tubercle

Correct Answer: Transfer to the ECRL produces excessive radial deviation during extension

Explanation:

Question 96:

Options:

Cross-innervation from the median nerve via a Martin-Gruber anastomosis
Intact extensor digitorum communis compensating for lumbrical loss
Simultaneous denervation of the flexor digitorum profundus to the ring and small fingers
Spasticity of the palmar interossei pulling the proximal phalanx into flexion
Preservation of the deep motor branch of the ulnar nerve at the wrist

Correct Answer: Simultaneous denervation of the flexor digitorum profundus to the ring and small fingers

Explanation:

Question 97:

Options:

Type I collagen
Type II collagen
Type III collagen
Type IV collagen
Type IX collagen

Correct Answer: Type III collagen

Explanation:

Question 98:

Options:

Exothermic necrosis of surrounding soft tissue during setting
Allergic reaction to the carrier matrix
Rapid dissolution of calcium sulfate leading to a hyperosmotic serous effusion
Undiagnosed low-grade mycobacterial infection
Premature weight-bearing causing micromotion and inflammatory exudate

Correct Answer: Rapid dissolution of calcium sulfate leading to a hyperosmotic serous effusion

Explanation:

Question 99:

Options:

A1 and A3 pulleys; arising from the volar plates of the MCP and PIP joints
A2 and A4 pulleys; arising from the volar plates of the PIP and DIP joints
A2 and A4 pulleys; arising from the periosteum of the proximal and middle phalanges
A1 and A5 pulleys; arising from the periosteum of the metacarpal and distal phalanx
A3 and A5 pulleys; arising from the interosseous intrinsic fascial bands

Correct Answer: A2 and A4 pulleys; arising from the periosteum of the proximal and middle phalanges

Explanation:

Question 100:

Options:

Fibroblasts
Macrophages
Schwann cells
Astrocytes
Oligodendrocytes

Correct Answer: Schwann cells

AAOS & ABOS Upper Extremity MCQs (Set 4): Shoulder, Elbow, Wrist, Hand & Nerve Review | 2025-2026 Boards

Orthopedic Board Review MCQs: Hand, Wrist & Grafting | Part 31

Key Takeaway

Orthopedic Board Review MCQs: Hand, Wrist & Grafting | Part 31

Chapter Index