Free Orthopedic Board Review Questions (2026) | Dr. Hutaif

Question 1

A 35-year-old male is brought to the trauma bay after a motorcycle accident. His blood pressure is 80/40 mmHg and heart rate is 130 bpm. A radiograph of the pelvis is obtained as part of the primary survey.

Assuming an Anteroposterior Compression Type III (APC III) pattern is confirmed with complete disruption of the anterior and posterior pelvic rings, what is the most likely anatomic source of life-threatening arterial hemorrhage in this specific injury pattern?

Explanation

In pelvic ring injuries, the vascular injury pattern closely correlates with the mechanism of injury. Anteroposterior compression (APC) injuries typically result in an increase in pelvic volume and stretch or tear anterior vascular structures, most commonly the internal pudendal or obturator arteries. Conversely, vertical shear or severe posterior ring disruptions are more closely associated with injuries to the superior gluteal artery. Prompt application of a pelvic binder reduces pelvic volume, promoting tamponade of venous bleeding (the most common overall source of bleeding in pelvic trauma), but arterial injuries often require angiography and embolization.

Question 2

A 12-year-old obese boy presents with a 3-week history of left knee pain and an antalgic gait. Examination reveals obligatory external rotation of the left hip upon flexion. Which of the following is considered an absolute indication for prophylactic in situ pinning of the asymptomatic contralateral hip in a patient with a Slipped Capital Femoral Epiphysis (SCFE)?

Explanation

Prophylactic pinning of the contralateral asymptomatic hip in SCFE is controversial but is universally recommended in patients with a high risk of subsequent contralateral slippage. Absolute indications for prophylactic contralateral pinning include underlying endocrine disorders (such as hypothyroidism, renal osteodystrophy, or growth hormone deficiency), prior radiation therapy, or presentation at an abnormally young age (typically under 10 years). While obesity and severe slip angles increase the mechanical risk, they are considered relative indications.

Question 3

A 45-year-old female falls on an outstretched hand and presents with a displaced intra-articular fracture of the distal radius. The injury imaging demonstrates volar displacement of a marginal fracture fragment with the carpus following the fragment.

In this type of fracture (volar Barton's), which of the following structures remains attached to the displaced volar marginal fragment, directly mediating the volar subluxation of the carpus?

Explanation

A volar Barton's fracture is a shear injury where the volar marginal articular fragment of the distal radius is displaced volarly. The strong volar radiocarpal ligaments, predominantly the radioscaphocapitate (RSC) and long radiolunate (LRL) ligaments, remain attached to this volar fragment. Because these ligaments tether the proximal carpal row to the distal radius, the carpus subluxates volarly along with the fracture fragment. Anatomic reduction and buttress plate fixation are required to restore joint congruity and stability.

Question 4

In the context of articular cartilage basic science, which structural zone contains the highest concentration of water and predominantly features collagen fibers oriented parallel to the articular surface to resist shear stress?

Explanation

The superficial zone (Zone I) of articular cartilage comprises the top 10-20% of the cartilage thickness. It possesses the highest water content and is characterized by flattened chondrocytes and type II collagen fibers that are oriented parallel to the joint surface, which is an architectural adaptation perfectly suited to resist shear forces. As you move deeper (Zone III), water content decreases, proteoglycan content increases, and collagen fibers are oriented perpendicularly to resist compressive loads.

Question 5

A 16-year-old female elite soccer player is scheduled to undergo an anterior cruciate ligament (ACL) reconstruction. During the preoperative discussion regarding graft choices, you inform her of the risks associated with different graft types. Which of the following graft options is associated with the highest rate of clinical failure and graft rupture in her specific demographic?

Explanation

Extensive literature, including large registry data (e.g., MOON cohort), demonstrates that allografts have a significantly higher failure rate compared to autografts when used in young, active patients (especially those under 25 years of age returning to cutting/pivoting sports). The higher failure rate is attributed to delayed graft incorporation, potential deleterious effects of the sterilization process, and slower biological remodeling.

Question 6

During a primary total hip arthroplasty (THA) using a posterior approach, the surgeon inadvertently places the acetabular component in excessive retroversion. Which of the following complications is this patient at greatest risk for developing postoperatively?

Explanation

Acetabular component version is critical to THA stability. The 'safe zone' described by Lewinnek suggests an optimal anteversion of 15 ± 10 degrees. Excessive retroversion of the acetabular component predisposes the hip to posterior impingement and subsequent posterior dislocation, particularly when the hip is placed in a position of flexion, adduction, and internal rotation. Conversely, excessive anteversion risks anterior dislocation.

Question 7

A 30-year-old male sustains a traumatic posterior shoulder dislocation during a seizure. Upon successful closed reduction in the emergency department, an MRI is obtained which reveals a reverse Hill-Sachs lesion. Which of the following best describes the precise anatomic location of this bony defect?

Explanation

A reverse Hill-Sachs lesion is an impaction fracture of the anteromedial aspect of the humeral head. It occurs during a posterior shoulder dislocation when the anterior aspect of the humeral head impacts against the hard posterior rim of the glenoid. In contrast, a classic Hill-Sachs lesion occurs during an anterior dislocation and is located on the posterolateral aspect of the humeral head.

Question 8

A 6-month-old infant is undergoing treatment with a Pavlik harness for developmental dysplasia of the hip (DDH). During a scheduled follow-up, the mother notes the child is no longer kicking the right leg. Physical examination confirms an absence of active knee extension on the right side. Which of the following specific positioning errors in the harness most likely caused this complication?

Explanation

The patient is presenting with a femoral nerve palsy, a known complication of the Pavlik harness. It is classically caused by hyperflexion of the hip (excessive hip flexion), which compresses the femoral nerve against the inguinal ligament. Treatment involves temporary cessation of harness use or adjusting the anterior straps to decrease flexion until function returns. In contrast, excessive hip abduction in the harness significantly increases the risk of avascular necrosis (AVN) of the femoral head.

Question 9

In the evaluation of a 60-year-old male presenting with bilateral hand clumsiness and gait instability, the examiner elicits a positive Hoffman's sign. What pathophysiologic entity does a positive Hoffman's sign suggest?

Explanation

Hoffman's sign is elicited by flipping the volar aspect of the distal phalanx of the middle finger; a positive response is a reflex flexion of the thumb and/or index finger. It is a sign of hyperreflexia and indicates an upper motor neuron (UMN) lesion, classically pointing to compression or dysfunction of the spinal cord in the cervical region (cervical myelopathy) above the C7 level.

Question 10

A 22-year-old collegiate golfer presents with chronic, recalcitrant volar-ulnar wrist pain. A carpal tunnel radiograph view confirms a displaced fracture of the hook of the hamate. After 3 months of failed conservative management, surgical excision of the fractured fragment is planned. During the approach and excision, which nerve is anatomically at greatest risk of iatrogenic injury?

Explanation

The deep motor branch of the ulnar nerve travels in Guyon's canal and courses radially, tightly hooking around the base of the hook of the hamate to supply the intrinsic muscles of the hand (interossei, adductor pollicis, and the two ulnar lumbricals). Because of its intimate anatomic proximity to the hamate hook, it is at high risk of iatrogenic injury during surgical excision of the fragment.

Question 11

Demineralized bone matrix (DBM) is commonly used as a bone graft substitute in orthopedic procedures. Which of the following factors or pathways is primarily responsible for the unique osteoinductive properties of DBM?

Explanation

Bone graft materials can be osteogenic (contain live cells), osteoconductive (provide a scaffold), or osteoinductive (induce differentiation of stem cells into osteoblasts). Demineralized bone matrix (DBM) lacks live cells but contains the structural collagen matrix (osteoconductive) and retains the native proteinaceous growth factors of bone. The demineralization process exposes these native Bone Morphogenetic Proteins (BMPs), primarily conferring its osteoinductive capacity.

Question 12

A 65-year-old male with severe tricompartmental knee osteoarthritis undergoes total knee arthroplasty (TKA). During the trialing phase with the trial components in place, the knee is completely stable symmetrically in full extension, but demonstrates 5 mm of laxity to both varus and valgus stress when placed in 90 degrees of flexion. Which of the following intraoperative adjustments is the most appropriate to achieve a balanced knee?

Explanation

This scenario describes a 'loose flexion gap' and a 'stable extension gap'. If you simply increase the polyethylene thickness, the flexion gap will balance, but the extension gap will become too tight (leading to a flexion contracture). To specifically tighten the flexion gap without altering the extension gap, the surgeon must increase the posterior condylar offset. This is most effectively accomplished by upsizing the femoral component (which increases the anteroposterior dimension of the femur) and potentially using posterior augments if needed, thereby tensioning the collateral ligaments in flexion.

Question 13

A 40-year-old roofer falls from a ladder, landing axially on his right heel, sustaining a displaced, intra-articular fracture of the calcaneus. On the lateral radiograph of the foot, which of the following angle measurements is characteristically decreased due to the collapse of the posterior facet?

Explanation

Böhler's angle is formed by a line drawn from the highest point of the anterior process of the calcaneus to the highest point of the posterior facet, and a second line drawn from the posterior facet to the superior edge of the calcaneal tuberosity. The normal angle is 20 to 40 degrees. In intra-articular calcaneus fractures with depression of the posterior facet, Böhler's angle is characteristically decreased or flattened. Conversely, the crucial angle of Gissane typically increases in these injuries.

Question 14

A 24-year-old male sustains a humerus shaft fracture and presents with an associated radial nerve palsy. According to Seddon's classification of nerve injury, which term describes a nerve injury in which the axon and its myelin sheath are disrupted, causing Wallerian degeneration, but the endoneurium, perineurium, and epineurium remain structurally intact?

Explanation

According to Seddon's classification: Neuropraxia is a transient conduction block without axonal disruption; recovery is rapid and complete. Axonotmesis involves disruption of the axon and myelin sheath, leading to distal Wallerian degeneration, but the supporting connective tissue frameworks (endoneurium, perineurium, epineurium) remain intact, allowing for axonal regeneration at about 1 mm/day. Neurotmesis is a complete transection of the nerve including all connective tissue layers, requiring surgical repair for recovery.

Question 15

A 68-year-old female who underwent an uncemented total hip arthroplasty 10 years ago presents with new-onset thigh pain. Radiographs reveal massive focal areas of radiolucency (osteolysis) around the proximal femoral stem. At revision surgery, copious hypertrophic membrane is noted. Which of the following particulate debris types is the most potent biological stimulator of the macrophage-induced osteolytic cascade in this conventional bearing surface?

Explanation

Aseptic loosening secondary to osteolysis is the most common long-term mode of failure in conventional metal-on-polyethylene total hip arthroplasty. Submicron ultra-high-molecular-weight polyethylene (UHMWPE) wear particles are phagocytosed by macrophages. This triggers an intense foreign-body inflammatory response, causing the release of cytokines such as TNF-alpha, IL-1, IL-6, and PGE2, which subsequently activate osteoclasts (via the RANKL pathway), leading to periprosthetic bone resorption (osteolysis).

Question 16

A 6-year-old boy presents to the emergency department after falling from monkey bars. He has a visibly deformed left elbow. Radiographs confirm a displaced, posteromedial Gartland Type III supracondylar humerus fracture. On examination, the hand is pink and capillary refill is less than 2 seconds, but the radial pulse is completely non-palpable. What is the most appropriate next step in management?

Explanation

The clinical presentation of a 'pink, pulseless hand' in the setting of a displaced pediatric supracondylar humerus fracture represents a vascular urgency/emergency. The brachial artery is often kinked or tethered over the proximal fracture fragment rather than transected. The standard of care is to proceed emergently to the operating room for closed reduction and percutaneous pinning (CRPP). Reduction almost always restores the anatomic alignment and relieves the kinking of the vessel. Arteriography or open exploration is reserved for a hand that remains ischemic (white and pulseless) after adequate reduction and pinning.

Question 17

During a posterior (Kocher-Langenbeck) approach to the hip for a posterior wall acetabular fracture, the surgeon identifies the short external rotators. To avoid postoperative weakness in hip extension, an important nerve exiting the greater sciatic foramen immediately inferior to the piriformis muscle must be protected. What muscle does this nerve primarily supply?

Explanation

The nerve described is the inferior gluteal nerve. It exits the pelvis through the greater sciatic foramen inferior to the piriformis muscle, frequently in close association with the sciatic nerve. Its sole motor innervation is the gluteus maximus, which is the primary extensor of the hip. Injury to this nerve leads to an extension lurch or difficulty climbing stairs. The superior gluteal nerve (exiting above the piriformis) supplies the gluteus medius, gluteus minimus, and tensor fasciae latae.

Question 18

A 28-year-old male is admitted after a high-energy closed midshaft tibia fracture. Twelve hours post-injury, he complains of intractable leg pain that is not relieved by escalating doses of opioids. Pain is severely exacerbated by passive extension of the great toe. Intracompartmental pressure (ICP) monitoring is initiated. A fasciotomy is universally indicated when the 'Delta P' (difference between diastolic blood pressure and ICP) falls below what critical threshold?

Explanation

Acute compartment syndrome is a surgical emergency characterized by tissue perfusion pressures falling below that required for cellular viability. While absolute compartment pressures (e.g., >30-40 mmHg) have been used historically, the current gold standard is the 'Delta P' concept introduced by McQueen. A Delta P (Diastolic Blood Pressure minus Intracompartmental Pressure) of less than 30 mmHg is highly predictive of compartment syndrome and represents an absolute indication for emergent four-compartment fasciotomy.

Question 19

A 13-year-old male presents with chronic, dull anterior knee pain. Anteroposterior radiographs demonstrate a radiolucent line separating a bony fragment from the main body of the patella. According to the Saupe classification, which anatomic location represents the most common variant (Type III) of a bipartite patella?

Explanation

A bipartite patella results from failure of secondary ossification centers to fuse with the main body of the patella. It is usually asymptomatic but can become painful after trauma or due to overuse. The Saupe classification categorizes them by location: Type I is at the inferior pole (~5%), Type II is at the lateral margin (~20%), and Type III is at the superolateral pole. Type III is by far the most common, accounting for approximately 75% of all bipartite patellas.

Question 20

An 18-year-old elite baseball pitcher experiences a sudden 'pop' in his medial elbow during a fast pitch, followed by severe pain and an inability to continue throwing. An MRI confirms a complete rupture of the primary restraint to valgus stress. During ulnar collateral ligament (UCL) reconstruction, the surgeon must replicate the exact anatomic footprints of the anterior bundle. Which of the following describes the accurate native attachments of the anterior bundle of the UCL?

Explanation

The medial ulnar collateral ligament (UCL) consists of anterior, posterior, and transverse bundles. The anterior bundle is the primary restraint to valgus stress at the elbow during the late cocking and early acceleration phases of throwing. Its anatomical footprint originates on the anteroinferior, undersurface of the medial epicondyle (slightly posterior to the axis of rotation) and inserts distally on the sublime tubercle, which is located on the medial aspect of the coronoid process of the ulna.

Question 21

A 45-year-old male is involved in a motor vehicle collision. He is hemodynamically stable. An AP pelvis radiograph demonstrates symphysis pubis widening of 3.2 cm and widening of the anterior sacroiliac (SI) joints, but the posterior SI ligaments appear functionally intact.

According to the Young-Burgess classification, what is the most likely injury pattern and best definitive treatment?

Explanation

The clinical description of a symphysis pubis widening greater than 2.5 cm with disrupted anterior SI ligaments but intact posterior SI ligaments describes an Anteroposterior Compression (APC) Type II injury. In a hemodynamically stable patient, definitive treatment for an APC II injury typically requires anterior stabilization, most commonly via symphyseal plating, to restore the anterior tension band. APC III injuries involve complete posterior disruption and require both anterior and posterior fixation.

Question 22

A 30-year-old female presents with progressive knee pain. Radiographs reveal an eccentric, lytic lesion in the distal femoral epiphysis extending to the subchondral bone without a sclerotic margin. A biopsy is obtained and the histology is shown below.

If medical therapy is considered, which of the following best describes the targeted mechanism of action?

Explanation

The clinical and radiographic presentation is classic for a Giant Cell Tumor (GCT) of bone. In GCT, the true neoplastic cells are the mononuclear spindle cells, not the multinucleated giant cells. The neoplastic mononuclear cells secrete excessive RANKL, which recruits normal osteoclast precursors that fuse to form the characteristic giant cells, driving bone destruction. Denosumab is a monoclonal antibody that targets and binds RANKL, effectively inhibiting the recruitment and activation of the destructive giant cells.

Question 23

In the Ponseti method for the conservative management of congenital talipes equinovarus (clubfoot), manipulation and serial casting follow a specific sequence. Which of the following represents the correct sequential order of deformity correction?

Explanation

The Ponseti method uses the CAVE acronym to dictate the order of deformity correction: Cavus, Adductus, Varus, Equinus. The cavus is corrected first by elevating the first ray to align the forefoot with the hindfoot. Next, the adductus and varus are simultaneously corrected by abducting the forefoot with counter-pressure on the lateral aspect of the talar head. Equinus is addressed last, often requiring a percutaneous Achilles tenotomy.

Question 24

During an anterior cruciate ligament (ACL) reconstruction, a surgeon places the femoral tunnel excessively anterior (shallow) in the intercondylar notch. What biomechanical consequence will this have on the graft during knee range of motion?

Explanation

In ACL reconstruction, femoral tunnel malposition is the most common cause of graft failure. If the femoral tunnel is placed too anteriorly (i.e., shallow, away from the anatomical footprint and closer to the anterior cortex), the distance between the femoral and tibial tunnels increases as the knee flexes. This results in a graft that is excessively tight in flexion (limiting knee flexion or risking graft rupture) and lax in extension.

Question 25

During a total knee arthroplasty (TKA), after the initial bone cuts are made and trial components are inserted, the surgeon notes that the extension gap is perfectly balanced, but the flexion gap is excessively tight. Which of the following surgical maneuvers is the most appropriate next step to balance the knee?

Explanation

A tight flexion gap with a perfectly balanced extension gap requires a maneuver that only affects the flexion space. Downsizing the femoral component (using an anterior referencing system) will decrease the anteroposterior (AP) dimension of the femur, specifically reducing the posterior condylar offset. This selectively opens (increases) the flexion gap without altering the distal femoral cut, thus leaving the extension gap unchanged. Resecting more distal femur would affect only the extension gap. Releasing the posterior capsule affects the extension gap more than the flexion gap.

Question 26

A 25-year-old carpenter sustains a clean laceration to the volar middle phalanx of his index finger, dividing both the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons (Zone II). Primary repair is performed. Which of the following postoperative rehabilitation principles yields the best outcomes for minimizing adhesions while preventing rupture?

Explanation

Zone II flexor tendon repairs occur in "no man's land" where the FDS and FDP travel within a tight fibro-osseous sheath. Historically, strict immobilization led to dense adhesions and poor function. Current standards involve early controlled motion protocols. The classic protocols (Duran, Kleinert) use active extension and passive flexion to glide the tendons within the sheath without placing excessive active tension that could rupture the repair. (Note: Modern early active motion protocols exist but involve careful place-and-hold techniques, not "heavy resisted" flexion).

Question 27

A 45-year-old male presents with acute severe lower back pain, bilateral lower extremity weakness, saddle anesthesia, and urinary retention. MRI confirms a massive central L4-L5 disc herniation compressing the cauda equina. Current evidence suggests that surgical decompression is most strongly associated with improved recovery of bladder and motor function if performed within what timeframe from the onset of autonomic symptoms?

Explanation

Cauda equina syndrome is an orthopedic and neurosurgical emergency. While decompression should be performed as safely and quickly as possible, extensive meta-analyses (such as the landmark review by Ahn et al.) have demonstrated a significant difference in outcomes—specifically regarding the reversal of motor and autonomic (bladder/bowel) deficits—when surgical decompression is performed within 48 hours of the onset of symptoms, compared to after 48 hours.

Question 28

A 55-year-old patient with long-standing, poorly controlled diabetes presents with a unilaterally swollen, red, and warm foot. He denies pain or recent trauma. Radiographs reveal bone fragmentation, periarticular osteopenia, intra-articular debris, and subluxation at the midfoot. According to the Eichenholtz classification of Charcot arthropathy, which stage does this represent?

Explanation

The Eichenholtz classification describes the natural history of Charcot neuroarthropathy. Stage 0 is the clinical "red, hot, swollen" foot with normal x-rays. Stage 1 (Development/Fragmentation) is characterized by clinical inflammation and radiographic findings of bone fragmentation, debris, joint subluxation, and dislocation. Stage 2 (Coalescence) shows absorption of fine debris, early fusion of larger fragments, and decreased clinical swelling. Stage 3 (Reconstruction) features remodeling of bone ends, rounding of fragments, and decreased osteopenia without inflammation.

Question 29

When a diaphyseal fracture is treated with a perfectly applied lag screw and a neutralization plate (an absolute stability construct), bone healing primarily occurs through which of the following biological processes?

Explanation

Constructs that provide absolute stability (e.g., lag screw with neutralization plate, compression plating) reduce interfragmentary strain to less than 2%. This environment prevents the formation of a fracture callus (secondary healing) and instead allows for primary (direct) bone healing. This process occurs via the direct advancement of osteoclasts forming cutting cones across the fracture site, immediately followed by osteoblasts laying down new lamellar bone (Haversian remodeling).

Question 30

A 32-year-old male sustains a high-energy trauma to his left knee. Radiographs and CT scans reveal a bicondylar tibial plateau fracture with a transverse fracture line separating the metaphysis from the diaphysis. What is the correct Schatzker classification for this injury?

Explanation

The Schatzker classification is widely used for tibial plateau fractures. Schatzker I, II, and III are lateral plateau fractures (split, split-depression, pure depression). Schatzker IV involves the medial plateau. Schatzker V is a bicondylar fracture where the metaphysis remains in continuity with the diaphysis. Schatzker VI is defined by metaphyseal-diaphyseal dissociation (complete separation of the joint block from the shaft), typically due to high-energy trauma.

Question 31

The scaphoid bone is notorious for a high rate of avascular necrosis following a fracture due to its unique retrograde blood supply. Which of the following accurately describes the primary entry point and flow direction of the major intraosseous blood supply to the scaphoid?

Explanation

Approximately 70-80% of the scaphoid's blood supply is derived from the radial artery via branches that enter the scaphoid at the dorsal ridge, which is located distally. The intraosseous vascular flow is therefore retrograde, moving from distal to proximal. This anatomical reality means that fractures through the waist or proximal pole highly jeopardize the vascularity of the proximal fragment, significantly increasing the risk of delayed union, nonunion, and avascular necrosis.

Question 32

A 3-month-old infant is being treated with a Pavlik harness for developmental dysplasia of the hip (DDH). At the two-week follow-up, the parents report the baby has stopped kicking the affected leg. On examination, the hip remains reduced, but there is an absence of active knee extension. Which of the following complications has most likely occurred?

Explanation

Femoral nerve palsy is the most common nerve injury associated with the Pavlik harness, occurring in roughly 2% of cases. It is typically caused by excessive flexion of the hip (anterior straps too tight), which compresses the femoral nerve against the inguinal ligament or the rim of the pelvis. Clinically, it presents as an inability to actively extend the knee. Management involves altering the harness settings or temporarily discontinuing it to allow nerve recovery.

Question 33

A 65-year-old female who underwent a primary total hip arthroplasty (THA) 2 years ago presents with a loud "squeaking" noise coming from her hip when she bends down or climbs stairs. She has no pain and radiographs show perfectly fixed, well-positioned components. Her THA most likely utilized which of the following bearing surface combinations?

Explanation

Squeaking is a well-documented, specific complication associated with ceramic-on-ceramic (CoC) bearing surfaces in total hip arthroplasty. The exact etiology is multifactorial, including stripe wear, edge loading from micro-separation, component malposition (e.g., steep acetabular cup), or third-body wear. It is rarely associated with catastrophic failure if painless, but it can be highly annoying to the patient.

Question 34

A 22-year-old athlete sustains a high-energy knee dislocation (KD III) during a rugby match. It is reduced in the emergency department. The foot is warm and pink with palpable dorsalis pedis and posterior tibial pulses. An ankle-brachial index (ABI) is performed. According to contemporary trauma guidelines, at what ABI threshold is it universally indicated to perform an arterial duplex ultrasound or CT angiogram to rule out an intimal flap or popliteal artery injury?

Explanation

In the assessment of a knee dislocation, vascular injury (particularly to the popliteal artery) must be ruled out. While historically all knee dislocations underwent angiography, current protocols rely on the Ankle-Brachial Index (ABI). An ABI > 0.9 with normal palpable pulses is highly reassuring, and the patient can be observed with serial exams. An ABI < 0.9 is highly sensitive for an arterial injury and mandates further advanced imaging, such as a CT angiogram or arterial duplex ultrasound.

Question 35

A 78-year-old male falls from a standing height and sustains a fracture located at the junction of the base of the dens (odontoid process) and the body of C2, with 2 mm of posterior displacement. Based on the Anderson and D'Alonzo classification, what type of fracture is this, and what is its characteristic clinical challenge?

Explanation

An Anderson and D'Alonzo Type II odontoid fracture occurs at the base of the dens (the junction of the dens and the body of C2). It is the most common type of odontoid fracture. It poses a significant clinical challenge because it has a notoriously high rate of nonunion, especially in the elderly, due to a watershed blood supply in this region, limited cancellous bone contact, and difficult biomechanical stabilization. Type I is an apical avulsion, and Type III extends into the cancellous body of C2 (which generally heals well).

Question 36

A 35-year-old male presents with severe midfoot pain and swelling after falling from a horse with his foot caught in the stirrup. On an AP radiograph of the foot, widening is noted between the 1st and 2nd metatarsal bases, and a small "fleck sign" is observed. This pathognomonic "fleck" represents an avulsion of the Lisfranc ligament from the base of which anatomical structure?

Explanation

The Lisfranc ligament is a strong interosseous ligament that runs obliquely from the lateral aspect of the medial cuneiform to the medial base of the second metatarsal. The "fleck sign" on an AP radiograph is highly specific for a Lisfranc injury. It represents a bony avulsion of the Lisfranc ligament, typically avulsing from the base of the second metatarsal.

Question 37

Ultra-high molecular weight polyethylene (UHMWPE) undergoes cross-linking via gamma irradiation or electron beam radiation prior to use in modern total joint arthroplasty. While this process achieves the desired goal of decreasing osteolysis, it results in which of the following mechanical trade-offs?

Explanation

Highly cross-linking UHMWPE significantly increases its wear resistance, thereby drastically reducing the volume of wear debris generated and lowering the risk of periprosthetic osteolysis. However, the radiation process and subsequent thermal treatments (melting or annealing to eliminate free radicals and prevent oxidation) alter the crystalline structure. This mechanical trade-off results in decreased fracture toughness, reduced fatigue strength, and lowered ultimate tensile strength, making the material more susceptible to catastrophic failure in thin inserts or high-stress designs.

Question 38

A 55-year-old female who underwent open reduction and internal fixation of a distal radius fracture with a volar locking plate 9 months ago presents with a sudden inability to flex the interphalangeal (IP) joint of her thumb. Which of the following technical errors during the initial surgery is the most likely cause of this complication?

Explanation

The patient has sustained an iatrogenic rupture of the Flexor Pollicis Longus (FPL) tendon, which is a known complication of volar plating for distal radius fractures. The "watershed line" is a transverse ridge on the volar distal radius, marking the distal margin of the pronator fossa. If a plate is placed distal to this line, it sits prominently and rubs against the overlying flexor tendons (most commonly the FPL), leading to tenosynovitis, attrition, and eventual rupture. Dorsal screw over-penetration endangers the extensor tendons (e.g., EPL).

Question 39

A 52-year-old male undergoes a radiograph of his shoulder for chronic, dull pain. The x-ray reveals a destructive, intra-medullary lesion in the proximal humerus displaying "ring and arc" calcifications. CT scan reveals endosteal scalloping involving 80% of the cortical thickness. What is the most likely diagnosis?

Explanation

The radiographic presence of "ring and arc" or "popcorn" calcifications is the classic hallmark of a cartilaginous tumor matrix. In a patient over 40 years old, differentiating a benign enchondroma from a malignant chondrosarcoma can be difficult. However, pain at rest and imaging signs such as endosteal scalloping greater than 2/3 (66%) of the cortical thickness, cortical breakthrough, or an associated soft tissue mass are highly indicative of malignant transformation or a primary Chondrosarcoma.

Question 40

A 13-year-old obese male presents with left hip pain, an antalgic gait, and obligate external rotation upon hip flexion. Radiographs confirm a left-sided Slipped Capital Femoral Epiphysis (SCFE). The surgeon discusses in-situ pinning of the left hip and considers prophylactic pinning of the asymptomatic right hip. Which of the following is the most established indication for prophylactic fixation of the contralateral hip in SCFE?

Explanation

While prophylactic contralateral pinning in SCFE remains controversial for the idiopathic obese patient, it is strongly indicated and widely accepted in patients with underlying endocrinopathies (such as hypothyroidism, growth hormone deficiency, or panhypopituitarism) and in those with renal osteodystrophy. These systemic conditions place the patient at an exceptionally high risk (up to 100% in some series) for developing a contralateral slip. Younger age (e.g., girls < 10, boys < 12) or open triradiate cartilage are also relative indications, but endocrine disorders are the strongest and most universally accepted absolute indication.

Question 41

A 80-year-old male with a history of severe COPD and ischemic heart disease presents after a mechanical fall with neck pain. A CT scan of the cervical spine demonstrates a Type II odontoid fracture with 2 mm of displacement. What is the most appropriate initial management strategy for this patient?

Explanation

In elderly patients with Type II odontoid fractures, especially those with significant comorbidities, a rigid cervical collar is generally preferred. While nonunion rates are higher compared to surgical fixation, halo vest immobilization carries an unacceptably high mortality and morbidity rate in the elderly population.

Question 42

A 6-week-old infant is being treated with a Pavlik harness for developmental dysplasia of the left hip (DDH). At the 3-week ultrasound follow-up, the hip remains dislocated and cannot be reduced in the harness. What is the most appropriate next step in management?

Explanation

If a Pavlik harness fails to achieve reduction within 3 to 4 weeks, continuing it increases the risk of 'Pavlik harness disease' (excoriation, nerve palsy, and persistent posterior wear of the acetabulum). Transitioning to a rigid abduction brace is the recommended next step before attempting closed reduction under anesthesia.

Question 43

A 35-year-old female sustains a high-energy trauma resulting in an intra-articular distal femur fracture. CT imaging reveals a coronal plane fracture of the lateral femoral condyle (Hoffa fracture). Which of the following represents the optimal surgical approach and fixation strategy for this specific fragment?

Explanation

Hoffa fractures are coronal plane fractures of the femoral condyle. They are optimally addressed via a lateral (or anterolateral) arthrotomy to directly visualize the articular surface, stabilized with lag screws placed in an anterior-to-posterior direction, often supplemented with an anti-glide plate.

Question 44

A 24-year-old male presents with persistent radial-sided wrist pain 8 months after a fall. Imaging reveals a scaphoid proximal pole nonunion with humpback deformity. MRI confirms avascular necrosis of the proximal pole fragment. Which of the following graft options is most appropriate?

Explanation

A free medial femoral condyle (MFC) vascularized bone graft provides robust blood supply and structural support. It is the treatment of choice for scaphoid proximal pole nonunions complicated by both avascular necrosis and a humpback deformity requiring structural correction.

Question 45

During an anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BTB) autograft, which component represents the weakest link of the graft construct during the first 6 weeks postoperatively?

Explanation

In the early postoperative period (first 6-8 weeks) following ACL reconstruction, the weakest link in the construct is typically the fixation site. For a BTB graft, the tibial interference screw interface is the weakest point due to the lower bone mineral density in the proximal tibia compared to the distal femur.

Question 46

A 14-year-old boy presents with progressive distal thigh pain. Imaging shows a highly aggressive mixed lytic and sclerotic lesion in the distal femoral metaphysis with a 'sunburst' periosteal reaction. Biopsy reveals malignant cells producing osteoid matrix. Which of the following genetic alterations is most commonly associated with this tumor?

Explanation

The clinical presentation and histology confirm osteosarcoma, which is characterized by malignant spindle cells producing osteoid. Osteosarcoma is frequently associated with mutations in critical tumor suppressor genes, primarily RB1 and TP53.

Question 47

In total hip arthroplasty, the choice of bearing surface impacts longevity. Which of the following bearing surface combinations exhibits the lowest volumetric wear rate in laboratory simulator testing?

Explanation

Ceramic-on-ceramic bearing surfaces demonstrate the lowest volumetric wear rates in simulator studies, typically measuring less than 1 cubic millimeter per million cycles. However, they carry unique risks, including component fracture and squeaking.

Question 48

A 28-year-old male is admitted with a highly comminuted tibial shaft fracture. He complains of pain out of proportion to the injury. Which of the following physiological thresholds is the most accurate and absolute indication for performing a fasciotomy for acute compartment syndrome?

Explanation

A delta pressure (defined as Diastolic Blood Pressure minus Compartment Pressure) of less than 30 mmHg is the most reliable and validated threshold for diagnosing acute compartment syndrome. Relying on absolute pressures alone can lead to unnecessary fasciotomies or missed diagnoses depending on systemic blood pressure.

Question 49

A 55-year-old male with poorly controlled diabetes presents with a swollen, erythematous, and warm foot. He denies trauma and reports minimal pain. Radiographs demonstrate acute periarticular fragmentation and subluxation at the tarsometatarsal joint. According to the Eichenholtz classification, what is the standard of care for this acute phase?

Explanation

The clinical picture represents the acute fragmentation phase (Eichenholtz stage I) of Charcot arthropathy. The standard initial management is strict immobilization and offloading, typically with a total contact cast, to prevent further deformity while the acute inflammatory process subsides.

Question 50

During the process of secondary fracture healing, a critical transition from soft callus to hard callus occurs. During which phase of healing does this primarily take place, and what is the primary type of collagen synthesized as the matrix matures?

Explanation

The transition from soft to hard callus occurs during the reparative phase of secondary fracture healing. Through the process of endochondral ossification, the cartilaginous matrix (rich in Type II collagen) is replaced by woven bone (rich in Type I collagen).

Question 51

A 12-year-old boy undergoes an uncomplicated in situ pinning for an unstable slipped capital femoral epiphysis (SCFE). Six months later, he develops acute, severe hip stiffness and a pronounced antalgic gait. Radiographs reveal a uniform and rapid narrowing of the joint space. What is the most likely diagnosis?

Explanation

Chondrolysis is a severe complication following SCFE, characterized by acute, painful stiffness and rapid, uniform loss of the articular cartilage space on radiographs. It is strongly associated with unrecognized hardware penetration into the joint space during pinning.

Question 52

A 40-year-old male arrives in the trauma bay in hemorrhagic shock following a crush injury. Radiographs show a widened symphysis pubis and disrupted posterior sacroiliac ligaments (APC-III). When applying a circumferential pelvic binder to stabilize the pelvis, over which anatomic landmarks must the binder be centered?

Explanation

A pelvic binder must be centered directly over the greater trochanters to effectively close the pelvic ring volume and stabilize an 'open book' fracture pattern. Misplacing the binder proximally over the iliac crests is ineffective and can paradoxically widen the true pelvis.

Question 53

A 28-year-old carpenter sustains a deep volar laceration to his right index finger exactly at the level of the distal interphalangeal (DIP) joint crease. Examination shows inability to flex the DIP joint, but proximal interphalangeal (PIP) joint flexion remains intact against resistance. This injury corresponds to which flexor tendon zone?

Explanation

Zone I flexor tendon injuries occur distal to the insertion of the flexor digitorum superficialis (FDS). These injuries involve isolated transection of the flexor digitorum profundus (FDP), resulting in loss of DIP flexion while PIP flexion is spared.

Question 54

During a primary posterior-stabilized total knee arthroplasty, trial reduction reveals that the knee is completely balanced in full extension but excessively tight in 90 degrees of flexion, limiting range of motion. Which of the following technical adjustments is most appropriate to balance this knee?

Explanation

A knee that is balanced in extension but tight in flexion represents an isolated tight flexion gap. Appropriate adjustments to increase the flexion gap without affecting the extension gap include increasing the posterior tibial slope, downsizing the femoral component, or anteriorly translating the femoral component.

Question 55

A 21-year-old football player undergoes an MRI for recurrent anterior shoulder instability. The MRI reveals an avulsion of the anterior labrum where the labrum and the intact periosteum are stripped and displaced medially along the glenoid neck. What is the specific eponym for this pathology?

Explanation

An ALPSA (Anterior Labroligamentous Periosteal Sleeve Avulsion) lesion involves the anterior labrum being stripped from the glenoid rim along with an intact periosteal sleeve, displacing medially. In contrast, a classic Bankart lesion involves a torn periosteum.

Question 56

A 65-year-old male is diagnosed with multiple myeloma and presents with hypercalcemia and extensive 'punched-out' lytic bone lesions. What is the primary molecular mechanism responsible for this accelerated osteolysis?

Explanation

Myeloma cells induce osteolytic lesions primarily by disrupting bone homeostasis; they secrete factors that upregulate RANKL and downregulate osteoprotegerin (OPG) in the marrow microenvironment, leading to overwhelming osteoclast activation and bone resorption.

Question 57

A 4-month-old infant is being treated with a Pavlik harness for developmental dysplasia of the hip (DDH). At the follow-up visit, the parents report the infant is no longer kicking the right leg actively. Examination reveals an inability to actively extend the right knee. Which of the following positioning errors is most likely responsible for this complication?

Explanation

Femoral nerve palsy is a known complication of the Pavlik harness, typically caused by excessive hip flexion. It generally resolves with temporary adjustment or removal of the harness.

Question 58

A 28-year-old male presents with a slowly enlarging, painful mass around his knee joint. An MRI demonstrates a soft tissue mass adjacent to the joint capsule, and biopsy confirms synovial sarcoma. Which of the following chromosomal translocations is highly specific for this diagnosis?

Explanation

Synovial sarcoma is characterized by the t(X;18)(p11;q11) translocation, resulting in the SYT-SSX fusion gene. This molecular marker is present in over 90% of cases.

Question 59

During a primary posterior-stabilized total knee arthroplasty (TKA), the surgeon finds the knee to be symmetrically balanced in extension but significantly tight in flexion. Which of the following intraoperative adjustments is most appropriate to resolve this specific mismatch?

Explanation

A knee that is tight in flexion but balanced in extension requires an increase in the flexion gap without altering the extension gap. Downsizing the femoral component using anterior referencing reduces the posterior condylar offset, effectively increasing the flexion gap.

Question 60

A 22-year-old athlete undergoes an anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft. Postoperatively, he lacks 15 degrees of terminal extension but can flex to 140 degrees. What is the most likely intraoperative technical error causing this complication?

Explanation

An anteriorly placed tibial tunnel can cause roof impingement, leading to a loss of full knee extension. Conversely, a femoral tunnel placed too anteriorly typically results in a graft that is tight in flexion.

Question 61

A 35-year-old male sustains a closed tibia fracture and is admitted for observation. Several hours later, he complains of severe pain out of proportion to the injury. Which of the following clinical parameters is the most reliable objective indicator for emergent fasciotomy?

Explanation

A Delta P (diastolic blood pressure minus compartment pressure) of 30 mmHg or less is widely considered the threshold for diagnosing acute compartment syndrome and mandates emergent fasciotomy. Loss of pulses is a late and unreliable sign of compartment syndrome.

Question 62

Bone morphogenetic proteins (BMPs) play a critical role in bone healing and formation by initiating an intracellular signaling cascade. Which of the following intracellular proteins directly mediate the canonical signaling pathway of BMPs to regulate gene transcription in osteoblasts?

Explanation

BMPs bind to serine/threonine kinase receptors, leading to the phosphorylation of receptor-regulated SMADs (SMAD 1, 5, and 8). These form a complex with SMAD 4 to enter the nucleus and regulate osteogenic gene transcription.

Question 63

A 40-year-old male is involved in a high-speed motor vehicle collision. CT of the cervical spine reveals bilateral pars interarticularis fractures of C2 with 4 mm of anterior translation of C2 on C3 and severe C2-C3 intervertebral disc disruption (Effendi Type II Hangman's fracture). What is the classic mechanism of injury for this fracture pattern?

Explanation

A classic Hangman's fracture (traumatic spondylolisthesis of the axis) occurs via a mechanism of hyperextension and axial distraction. This mechanism was historically seen in judicial hangings and is now commonly associated with sudden deceleration in motor vehicle accidents.

Question 64

A 30-year-old male sustains a forced dorsiflexion injury to his foot. Radiographs reveal a talar neck fracture with subluxation of the subtalar joint and a preserved tibiotalar joint. Based on the Hawkins classification, what is the approximate risk of developing avascular necrosis (AVN) of the talar body?

Explanation

This is a Hawkins type II talar neck fracture, which involves subluxation or dislocation of the subtalar joint. The risk of AVN is approximately 20-50%, compared to 0-10% for type I and >90% for type III.

Question 65

A 6-year-old girl falls off monkey bars and sustains a significantly displaced extension-type supracondylar humerus fracture. On examination, she is unable to flex the interphalangeal joint of her thumb and the distal interphalangeal joint of her index finger. Which nerve is most likely injured?

Explanation

The anterior interosseous nerve (AIN), a branch of the median nerve, is the most commonly injured nerve in extension-type supracondylar humerus fractures. It innervates the flexor pollicis longus and the flexor digitorum profundus to the index and long fingers.

Question 66

A 15-year-old boy presents with pain and swelling over his distal femur. A biopsy reveals small blue round cells. Cytogenetic testing demonstrates a t(11;22) chromosomal translocation. Which fusion gene is pathognomonic for this patient's diagnosis?

Explanation

The t(11;22) translocation results in the EWS-FLI1 fusion protein, which is diagnostic for Ewing sarcoma. This malignant bone tumor typically presents with a destructive lesion and an 'onion skin' periosteal reaction.

Question 67

A 25-year-old female athlete is 6 months post-anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft. She complains of a mechanical block to terminal knee extension and an audible clunk. MRI shows a focal fibrovascular nodule anterior to the tibial insertion of the graft. What is the most likely diagnosis?

Explanation

A cyclops lesion is a localized form of anterior arthrofibrosis that typically presents with a mechanical block to terminal knee extension after ACL reconstruction. Treatment consists of arthroscopic excision.

Question 68

A 65-year-old male presents with deteriorating handwriting, clumsiness in his hands, and a wide-based gait. On examination, rapidly flicking the distal phalanx of the middle finger downward produces involuntary flexion of the thumb and index finger. What does this physical sign indicate?

Explanation

The Hoffmann sign evaluates for upper motor neuron hyperreflexia and is strongly suggestive of cervical spondylotic myelopathy. It is considered the upper extremity equivalent of the Babinski reflex.

Question 69

A 45-year-old female with severe, refractory carpal tunnel syndrome undergoes an open carpal tunnel release. During the procedure, the surgeon inadvertently cuts the transverse carpal ligament too far radially. Which anatomical structure is at greatest risk of iatrogenic injury?

Explanation

The recurrent motor branch of the median nerve supplies the thenar muscles and typically branches off the radial aspect of the median nerve. Dividing the ligament too far radially places this critical motor branch at high risk.

Question 70

A 55-year-old active male underwent a total hip arthroplasty (THA) using a ceramic-on-ceramic bearing surface. Two years postoperatively, he complains of an audible squeaking sound from his hip during walking, but denies any pain. Radiographs show no loosening. What is the most likely biomechanical cause of the squeaking?

Explanation

Squeaking in ceramic-on-ceramic total hips is primarily associated with edge loading, often resulting from a malpositioned acetabular cup (e.g., vertical inclination). While often painless, it can increase the risk of component wear or catastrophic fracture.

Question 71

A 30-year-old male is admitted with a closed tibial shaft fracture. Overnight, he develops disproportionate leg pain. His blood pressure is 120/80 mmHg. Intra-compartmental pressure monitoring reveals a pressure of 45 mmHg in the anterior compartment. What is the patient's delta pressure, and what is the indicated management?

Explanation

Delta pressure is calculated as diastolic blood pressure minus intra-compartmental pressure (80 - 45 = 35 mmHg). A delta pressure of less than or equal to 30 mmHg is the classic threshold for acute compartment syndrome, but clinical signs combined with a narrowing delta pressure strongly indicate the need for fasciotomy.

Question 72

A 40-year-old male suffers an acute Achilles tendon rupture playing basketball. He elects for non-operative management utilizing an early functional rehabilitation protocol. Compared to acute operative repair, this non-operative protocol is associated with which of the following outcomes?

Explanation

Recent high-quality evidence demonstrates that non-operative management with early functional bracing yields re-rupture rates equivalent to surgical repair. It provides the added benefit of avoiding surgical complications such as infection and wound breakdown.

Question 73

A 3-month-old female is being treated with a Pavlik harness for developmental dysplasia of the hip (DDH). At her 2-week follow-up, the mother notes the infant is no longer kicking her leg on the treated side. Examination reveals a lack of active knee extension. What is the most appropriate next step in management?

Explanation

A lack of active knee extension in a Pavlik harness indicates a femoral nerve palsy caused by hyperflexion of the hip. The standard of care is to remove the harness to decompress the nerve, which typically results in spontaneous recovery.

Question 74

Articular cartilage is divided into distinct structural zones. Which zone contains the highest concentration of water, the lowest concentration of proteoglycans, and collagen fibers arranged parallel to the articular surface?

Explanation

The superficial zone of articular cartilage is specifically adapted to resist shear forces, featuring high water content, low proteoglycans, and parallel-oriented Type II collagen fibers.

Question 75

A 35-year-old female presents with a destructive, expansile lytic lesion in her distal femur that extends to the subchondral bone. Biopsy confirms a Giant Cell Tumor (GCT) of bone. Denosumab therapy is initiated to reduce tumor size prior to intralesional curettage. Denosumab exerts its effect by directly binding to and inhibiting which of the following molecules?

Explanation

Denosumab is a fully human monoclonal antibody that binds directly to RANKL (Receptor Activator of Nuclear factor Kappa-B Ligand). This prevents RANKL from activating RANK on osteoclasts, severely inhibiting their bone-resorbing activity in Giant Cell Tumors.

Question 76

A 22-year-old male requires arthroscopic stabilization for recurrent anterior shoulder instability. Advanced imaging calculates his glenoid bone loss at 10%, but identifies an 'off-track' Hill-Sachs lesion. Which of the following procedures is indicated in addition to an arthroscopic Bankart repair to prevent engagement of the defect?

Explanation

An 'off-track' Hill-Sachs lesion will engage the anterior glenoid rim during abduction and external rotation, causing failure of an isolated Bankart repair. A Remplissage procedure (tenodesis of the infraspinatus into the humeral defect) makes the defect extra-articular, preventing engagement.

Question 77

A 45-year-old male involved in a motor vehicle collision sustains a high-energy, bicondylar tibial plateau fracture. CT imaging demonstrates a large, displaced posteromedial fragment. What is the optimal surgical approach to directly visualize and buttress this specific fragment?

Explanation

Posteromedial tibial plateau fragments occur secondary to vertical shear forces and require stable anti-glide or buttress plating. A posteromedial approach allows direct visualization and perpendicular plate application to neutralize these shear forces.

Question 78

A 68-year-old male complains of bilateral posterior leg pain and heaviness that worsens with walking and standing. He notes significant relief when sitting or leaning forward on a shopping cart. Peripheral pulses are 2+ bilaterally. What is the primary pathophysiological mechanism underlying his symptoms?

Explanation

This presentation is classic for neurogenic claudication due to central lumbar spinal stenosis. Leaning forward (lumbar flexion) increases the cross-sectional area of the central canal, transiently relieving pressure on the neural elements.

Question 79

A 25-year-old male falls on an outstretched hand and sustains a displaced fracture through the proximal pole of the scaphoid. This specific fracture pattern carries a notoriously high risk of nonunion and avascular necrosis. This complication is primarily due to the dominant intraosseous blood supply flowing in which direction?

Explanation

The scaphoid receives 70-80% of its blood supply from the dorsal carpal branch of the radial artery, which enters at the dorsal ridge and flows retrogradely (distal to proximal). Proximal pole fractures disrupt this retrograde flow, heavily predisposing the fragment to ischemia.

Question 80

A 70-year-old male presents with aseptic loosening 15 years after a total knee arthroplasty. Radiographs show extensive scalloping and periprosthetic osteolysis. The primary biological mediator of this osteolysis is the activation of which specific cell type by submicron particulate debris?

Explanation

Aseptic loosening secondary to osteolysis is driven by macrophages that phagocytose submicron wear debris (especially polyethylene). The activated macrophages release pro-inflammatory cytokines (TNF-alpha, IL-1, IL-6), stimulating aggressive osteoclastic bone resorption.

Question 81

A 28-year-old male sustains a high-energy injury resulting in a nearly vertical femoral neck fracture. According to the Pauwels classification, Type III fractures have a high rate of nonunion and fixation failure primarily due to which biomechanical factor?

Explanation

The Pauwels classification evaluates the angle of the fracture line relative to the horizontal. Type III fractures (>50 degrees) are steep and vertical, which translates axial loads into massive shear forces, causing varus instability and increasing nonunion risk.

Question 82

An 8-year-old boy presents with an antalgic gait and is diagnosed with Legg-Calve-Perthes disease. Radiographs are utilized to determine the Herring Lateral Pillar classification. A significantly poorer long-term prognosis is most strongly associated with involvement of what percentage of the lateral pillar height?

Explanation

The Herring Lateral Pillar classification is strongly prognostic in Legg-Calve-Perthes. Group C is defined by >50% loss of lateral pillar height and carries the poorest prognosis, with a high likelihood of asynchronous healing and early degenerative joint disease.

Updated Orthopedic Review | Dr Hutaif General Orthopedi -...

100 Random Orthopedic MCQs for Board Prep (2026 Update)

Key Takeaway

100 Random Orthopedic MCQs for Board Prep (2026 Update)

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