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7. Hand and Wrist MCQs

Practice Set 55 of 266

This practice set contains high-yield board review questions covering key concepts in 7. Hand and Wrist. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 1081

Topic: 7. Hand and Wrist

Which of the following complications is most frequently encountered during the non-operative management of a soft-tissue mallet finger with strict continuous splinting?

. Infection of the nail bed
. Skin maceration and ulceration over the dorsal DIP
. Complex regional pain syndrome
. Avascular necrosis of the distal phalanx
. Rupture of the flexor digitorum profundus (FDP)

Correct Answer & Explanation

. Skin maceration and ulceration over the dorsal DIP

Explanation

Skin maceration, pressure necrosis, and dorsal ulceration are the most common complications of continuous extension splinting for mallet fingers. Proper splint fitting and hygiene monitoring are essential to prevent this.

Question 1082

Topic: 7. Hand and Wrist

The terminal extensor tendon, which ruptures in a mallet finger injury, is formed anatomically by the convergence of which of the following structures over the middle phalanx?

. The central slip and the sagittal bands
. The conjoined lateral bands
. The oblique retinacular ligaments and transverse retinacular ligaments
. The lumbrical muscle tendons and interosseous muscle tendons
. The extensor digitorum communis and extensor indicis proprius

Correct Answer & Explanation

. The conjoined lateral bands

Explanation

The terminal extensor tendon inserts on the dorsal base of the distal phalanx. It is formed by the convergence of the two conjoined lateral bands over the distal third of the middle phalanx.

Question 1083

Topic: Hand Trauma & Infection

A 40-year-old gamekeeper presents with a history of chronic pain and weakness in his right thumb. He has noticeable laxity of the thumb MCP joint on examination. Radiographs show no degenerative changes. He desires surgical intervention to improve his grip and pinch strength. In the setting of chronic UCL instability without arthrosis, what is the most appropriate surgical option?

. Primary end-to-end repair of the UCL
. Thumb MCP joint arthrodesis
. UCL reconstruction using a free tendon graft (e.g., palmaris longus)
. Thumb CMC joint arthroplasty
. Adductor pollicis tenotomy

Correct Answer & Explanation

. UCL reconstruction using a free tendon graft (e.g., palmaris longus)

Explanation

For chronic UCL insufficiency without osteoarthritis, the native ligament is usually attenuated and insufficient for direct repair. Reconstruction using a free tendon graft (such as palmaris longus) or an adductor advancement is indicated. Arthrodesis is reserved for cases with arthritis.

Question 1084

Topic: Nerve & Tendon

In the pathogenesis of a swan neck deformity resulting from an untreated mallet finger, the initial flexed posture of the DIP joint leads to a biomechanical cascade. Which of the following best describes the primary anatomic change at the PIP joint?

. Attenuation of the central slip allowing the lateral bands to subluxate volarly
. Contracture of the oblique retinacular ligament pulling the PIP into flexion
. Proximal retraction of the extensor mechanism causing dorsal subluxation of the lateral bands
. Rupture of the volar plate at the PIP joint
. Hypertrophy of the lumbrical muscles

Correct Answer & Explanation

. Proximal retraction of the extensor mechanism causing dorsal subluxation of the lateral bands

Explanation

In an untreated mallet finger, the loss of terminal extensor tension causes the extensor mechanism to retract proximally. This concentrates extensor force at the central slip and causes dorsal displacement of the lateral bands, eventually stretching the volar plate and resulting in PIP hyperextension.

Question 1085

Topic: Hand Trauma & Infection
A 14-year-old boy falls while snowboarding and complains of thumb pain. Examination reveals significant swelling over the ulnar aspect of the thumb MCP joint and laxity with valgus stress testing. Radiographs show a displaced fracture through the epiphysis and exiting the articular surface of the ulnar base of the proximal phalanx. The proper UCL is functionally attached to this fragment. What is the most likely diagnosis?
. Stener lesion
. Gamekeeper's thumb with ligament attenuation
. Salter-Harris III equivalent of a Skier's thumb
. Bennett fracture
. Rolando fracture

Correct Answer & Explanation

. Salter-Harris III equivalent of a Skier's thumb

Explanation

In pediatric and adolescent patients with open physes, a valgus force to the thumb MCP joint typically causes a Salter-Harris III avulsion fracture of the proximal phalanx rather than a pure ligamentous rupture, because the physis is mechanically weaker than the proper UCL.

Question 1086

Topic: 7. Hand and Wrist

A 55-year-old rheumatoid arthritis patient presents with bilateral spontaneous mallet finger deformities. There is no history of acute trauma. Radiographs reveal diffuse osteopenia and erosive changes at the radiocarpal and distal radioulnar joints. What is the most likely pathophysiologic mechanism for these specific mallet deformities?

. Rupture of the central slip leading to a boutonniere deformity that mimics a mallet finger
. Attrition rupture of the extensor tendons (Mannerfelt syndrome) at the wrist
. Spontaneous avulsion of the terminal tendon from the distal phalanx base
. Flexor tenosynovitis causing a fixed flexion contracture
. Subluxation of the extensor tendons into the intermetacarpal valleys

Correct Answer & Explanation

. Attrition rupture of the extensor tendons (Mannerfelt syndrome) at the wrist

Explanation

In a rheumatoid patient presenting with spontaneous loss of active digital extension, attrition rupture of the extensor tendons over a dorsally prominent distal ulna or Lister's tubercle (Mannerfelt syndrome/Vaughan-Jackson syndrome) must be suspected, starting typically with the extensor digiti minimi and moving radially.

Question 1087

Topic: 7. Hand and Wrist

A 32-year-old carpenter sustains a deep laceration to his dominant right hand, resulting in a full-thickness skin defect over the palmar aspect of his index finger, exposing the flexor digitorum profundus tendon. Intraoperatively, after meticulous debridement, the surgeon notes that the flexor tendon is completely denuded of its synovial sheath and appears glistening white and avascular. The surrounding subcutaneous tissue is also compromised. Which of the following is the MOST appropriate reconstructive option for this defect?

. A. Immediate application of a thin split-thickness skin graft (STSG) from the anterolateral thigh.
. B. Immediate application of a full-thickness skin graft (FTSG) from the groin crease.
. C. Application of a local or regional vascularized flap followed by potential secondary skin grafting.
. D. Application of an intermediate split-thickness skin graft (STSG) with a 1:3 meshing ratio.
. E. Primary closure of the wound with tension-free sutures after extensive undermining.

Correct Answer & Explanation

. C. Application of a local or regional vascularized flap followed by potential secondary skin grafting.

Explanation

Correct Answer: CThe case explicitly states that an exposed, bare flexor tendon, stripped of its synovial covering, is essentially avascular. The teaching case emphasizes that'An avascular structure cannot support a skin graft directly, making direct grafting onto bare flexor tendons an absolute contraindication. Such scenarios necessitate the interposition of a vascularized tissue layer (e.g., local flap, muscle flap, or paratenon graft from another site) before skin graft application.'Therefore, a vascularized flap is mandatory to provide a blood supply to the exposed tendon and create a suitable bed for potential secondary skin grafting or definitive coverage. Options A, B, and D involve direct skin grafting onto an avascular bed, which would inevitably lead to graft failure and tendon necrosis. Option E, primary closure, is contraindicated for a full-thickness skin defect with exposed vital structures, as it would create excessive tension and compromise the underlying tendon further, leading to potential dehiscence and infection.

Question 1088

Topic: 7. Hand and Wrist

A 60-year-old diabetic patient undergoes skin grafting for a dorsal hand wound with exposed extensor tendons (intact paratenon). On post-operative day 3, the patient complains of increasing pain, and examination reveals a dark, tense, non-blanching discoloration beneath a portion of the graft. The most likely immediate cause of this graft compromise is:

. A. Systemic infection leading to graft lysis.
. B. Inadequate revascularization due to poor recipient bed preparation.
. C. Hematoma or seroma formation beneath the graft.
. D. Excessive secondary contraction of the graft.
. E. Allergic reaction to the dressing materials.

Correct Answer & Explanation

. C. Hematoma or seroma formation beneath the graft.

Explanation

Correct Answer: CThe teaching case states that 'Hematoma or Seroma' is 'The most common cause' of graft failure. It describes the clinical presentation as 'dark discoloration, tense swelling, palpable fluid under the graft.' The symptoms of increasing pain and a dark, tense, non-blanching discoloration on post-operative day 3 are highly indicative of a hematoma or seroma accumulating beneath the graft. This fluid collection mechanically lifts the graft off its vascularized bed, preventing imbibition and subsequent revascularization, leading to graft necrosis. While infection (A) can cause graft lysis, it typically presents later (Day 5-7) with purulence, fever, and spreading erythema. Inadequate revascularization (B) is a broader cause, but hematoma is a specific, common mechanism. Secondary contraction (D) occurs weeks to months after graft take, not on day 3. An allergic reaction (E) would typically present with erythema, pruritus, and rash, not a tense, dark discoloration of the graft itself.

Question 1089

Topic: 7. Hand and Wrist

A 28-year-old patient requires coverage for a large, irregularly shaped full-thickness skin defect on the dorsal aspect of the hand, extending across multiple digits. The underlying extensor tendons have viable paratenon. The surgeon decides to use a split-thickness skin graft (STSG). Which of the following statements regarding the use of a meshed STSG in this scenario is TRUE?

. A. Meshing significantly reduces secondary contraction, making it ideal for mobile joints.
. B. Meshing prevents the formation of seroma or hematoma by allowing fluid drainage.
. C. A 1:1 meshing ratio offers the greatest expansion and best cosmetic outcome.
. D. Meshed STSGs are inherently more durable and resistant to shear forces than unmeshed grafts.
. E. Meshing is primarily used to improve sensory recovery in the grafted area.

Correct Answer & Explanation

. B. Meshing prevents the formation of seroma or hematoma by allowing fluid drainage.

Explanation

Correct Answer: BThe teaching case explicitly lists the advantages of meshing: 'Allows the graft to expand, covering larger defects with less donor site harvest' and 'Creates fenestrations that facilitate drainage of seroma or hematoma from beneath the graft, which is particularly beneficial when covering an exposed tendon where fluid accumulation can compromise take.' Therefore, meshing helps prevent fluid accumulation. Option A is incorrect; meshing significantlyincreasessecondary contraction. Option C is incorrect; a 1:1 meshing ratio offers minimal expansion, and higher ratios (e.g., 1:3, 1:6) offer greater expansion but result in a less aesthetic 'cobblestone' appearance, not the best cosmetic outcome. Option D is incorrect; meshed STSGs are generally less durable and more prone to breakdown due to the interstices. Option E is incorrect; meshing does not primarily improve sensory recovery; FTSGs offer better sensory potential.

Question 1090

Topic: 7. Hand and Wrist

A 55-year-old patient undergoes successful full-thickness skin grafting to the dorsal aspect of the wrist. On post-operative day 6, during the first dressing change, the graft appears uniformly pink, adherent, and blanches with gentle pressure. The underlying wound bed is clean. Which of the following is the MOST appropriate next step in the rehabilitation protocol?

. A. Immediately initiate aggressive passive range of motion exercises for the wrist and fingers.
. B. Remove the splint and encourage full, unrestricted active use of the hand and wrist.
. C. Reapply a non-adherent dressing and a new splint, then begin controlled, gentle active range of motion for non-grafted joints and adjacent joints, as tolerated.
. D. Apply a compression garment directly over the graft to prevent secondary contraction.
. E. Administer a course of systemic corticosteroids to reduce inflammation and promote healing.

Correct Answer & Explanation

. C. Reapply a non-adherent dressing and a new splint, then begin controlled, gentle active range of motion for non-grafted joints and adjacent joints, as tolerated.

Explanation

Correct Answer: CThe teaching case outlines the post-operative rehabilitation protocol. In Phase 1, the first dressing change (Post-Op Day 5-7) is a critical evaluation point. If graft take is good (pink, blanching, adherent), the transition to Phase 2, Early Mobilization, begins. This phase involves 'Controlled Active Range of Motion (AROM)' for 'non-grafted joints and for joints adjacent to the graft that are not directly under tension.' The splint is reapplied to maintain protection. Option A, aggressive passive ROM, is too early and risks shear forces on the delicate, newly revascularized graft. Option B, unrestricted active use, is also premature and highly risks graft disruption. Option D, compression garments, are typically introduced later (after 2-3 weeks) for edema and scar management, not immediately after the first dressing change. Option E, systemic corticosteroids, are not indicated for routine graft healing and could impair wound healing and increase infection risk.

Question 1091

Topic: 7. Hand and Wrist
During the harvest of a full-thickness skin graft (FTSG) from the groin crease for a hand defect, the surgeon meticulously excises the graft. After harvest, the graft is placed dermal side up on a sterile surface. Which of the following steps is critical for ensuring successful graft take and should be performed next?
. Meshing the graft with a 1:3 ratio to allow for expansion and drainage.
. Making several small fenestrations in the graft to prevent seroma accumulation.
. Meticulously trimming away all subcutaneous fat from the undersurface of the dermis.
. Irrigating the graft with a dilute antibiotic solution to prevent infection.
. Stretching the graft to match the exact dimensions of the recipient defect.

Correct Answer & Explanation

. Meticulously trimming away all subcutaneous fat from the undersurface of the dermis.

Explanation

The teaching case describes the FTSG technique: 'Defatting the Graft (Crucial Step): Place the harvested FTSG, dermal side up, on a sterile firm surface... Using fine, sharp, curved iris scissors or a small #15 scalpel, meticulously trim away all subcutaneous fat from the undersurface of the dermis. This is a critical step; residual fat is avascular and will act as a barrier to revascularization, leading to graft failure.' Options A and B are incorrect for an FTSG at this stage. Meshing is typically for STSGs, and while fenestrations are made in unmeshed grafts, defatting is a more immediate and critical step after harvest for FTSGs. Option D, irrigating with antibiotics, is not a standard critical step for graft preparation. Option E, stretching the graft, should be avoided as it can damage the graft and is not the primary method for matching the defect; FTSGs are harvested slightly larger to account for primary contraction.

Question 1092

Topic: 7. Hand and Wrist

A 70-year-old patient with a history of chronic steroid use presents with a large, chronic ulcer on the dorsal aspect of the hand, exposing the extensor tendons with viable paratenon. The wound bed is marginal due to poor tissue quality. The surgeon plans for skin grafting. Considering the patient's comorbidities and wound characteristics, which of the following statements accurately reflects the biomechanical properties and take rate considerations for skin grafts?

. A. Full-thickness skin grafts (FTSGs) have a higher take rate than split-thickness skin grafts (STSGs) on marginal beds.
. B. Split-thickness skin grafts (STSGs) are more resistant to secondary contraction compared to FTSGs.
. C. Thinner STSGs require less oxygen and nutrients for survival, facilitating quicker revascularization and higher take rates.
. D. FTSGs offer superior durability but are more prone to blistering and breakdown than STSGs.
. E. The presence of hair follicles in FTSGs significantly impairs their take rate compared to STSGs.

Correct Answer & Explanation

. C. Thinner STSGs require less oxygen and nutrients for survival, facilitating quicker revascularization and higher take rates.

Explanation

Correct Answer: CThe teaching case states: 'Split-thickness skin grafts (STSGs) inherently possess a higher take rate compared to full-thickness skin grafts (FTSGs). This is due to their thinner nature, requiring less oxygen and nutrients for survival and facilitating quicker revascularization. This characteristic makes STSGs advantageous for marginal or less-than-ideally vascularized recipient beds.' Given the patient's chronic steroid use and marginal wound bed, a thinner STSG would be favored for its higher take rate. Option A is incorrect; STSGs have a higher take rate. Option B is incorrect; STSGs are highly susceptible to significant secondary contraction, whereas FTSGs demonstrate substantially less. Option D is incorrect; FTSGs are more robust and durable, while STSGs can be fragile and prone to blistering. Option E is incorrect; the presence of hair follicles is a cosmetic consideration for FTSGs but does not significantly impair their take rate.

Question 1093

Topic: 7. Hand and Wrist

A 40-year-old patient requires a full-thickness skin graft (FTSG) for a small, clean defect on the dorsal aspect of the index finger. The surgeon is planning the donor site. Which of the following donor sites is generally preferred for FTSGs in the hand due to its skin characteristics and ability for primary closure, while also offering a good color match?

. A. Anterolateral thigh.
. B. Scalp.
. C. Groin crease.
. D. Buttocks.
. E. Abdomen.

Correct Answer & Explanation

. C. Groin crease.

Explanation

Correct Answer: CThe teaching case lists common FTSG donor sites: 'Common FTSG donor sites include the groin crease, volar forearm, hypothenar eminence, supraclavicular fossa, and postauricular region. Prioritize concealment of the donor scar and minimize functional deficit.' The groin crease is a well-established donor site for FTSGs, offering skin that is relatively thin, pliable, and often provides a good color match for the hand, while allowing for primary closure of the donor site. Options A, B, D, and E are typically used for split-thickness skin grafts (STSGs) due to their larger surface area and the ability of STSG donor sites to heal by re-epithelialization, but they are generally not preferred for FTSGs due to thickness, hair-bearing status, or less ideal color match for the hand.

Question 1094

Topic: 7. Hand and Wrist

A 25-year-old patient sustains a degloving injury to the dorsal hand, resulting in a large full-thickness skin defect. The underlying extensor tendons are exposed but retain viable paratenon. The surgeon plans for an intermediate split-thickness skin graft (STSG). Which of the following physiological events is primarily responsible for the initial survival of the graft in the first 24-48 hours post-application?

. A. Active revascularization by host capillaries invading the graft.
. B. Establishment of lymphatic drainage within the graft.
. C. Passive absorption of tissue fluid and nutrients from the recipient bed (Imbibition).
. D. Direct nerve regeneration from the recipient bed into the graft.
. E. Primary contraction of the graft due to elastic fiber recoil.

Correct Answer & Explanation

. C. Passive absorption of tissue fluid and nutrients from the recipient bed (Imbibition).

Explanation

Correct Answer: CThe teaching case describes the biological integration of a skin graft: '1.Imbibition (0-48 hours):The freshly applied graft survives by passively absorbing tissue fluid, including plasma and nutrients, from the underlying wound bed. The graft appears pale and slightly edematous.' This initial phase is crucial for the graft's survival before a new blood supply is established. Option A, active revascularization (Inosculation and Revascularization), occurs later (2-7 days and beyond). Option B, lymphatic drainage, also commences later. Option D, nerve regeneration, is a much later and often incomplete process. Option E, primary contraction, is an immediate physical property of the graft upon harvest, not a physiological mechanism of survival post-application.

Question 1095

Topic: 7. Hand and Wrist
A 50-year-old patient undergoes skin grafting for a complex hand wound. Following the application and securing of the graft, the surgeon proceeds with dressing and immobilization. Which of the following components is critical for the immediate post-application dressing to ensure graft survival?
. Application of a topical antibiotic ointment directly onto the graft to prevent infection.
. A bulky, absorbent outer dressing without any direct pressure on the graft.
. A bolster dressing (tie-over or stent) providing continuous, gentle pressure and immobilization.
. Immediate initiation of active range of motion exercises to prevent stiffness.
. Leaving the graft exposed to air to promote drying and prevent maceration.

Correct Answer & Explanation

. A bolster dressing (tie-over or stent) providing continuous, gentle pressure and immobilization.

Explanation

The teaching case emphasizes the importance of the immediate post-application dressing: 'The immediate post-application dressing is paramount for graft survival, providing immobilization and gentle, continuous pressure.' It specifically details the 'Bolster Dressing (Tie-Over or Stent Dressing): This provides critical, continuous, gentle pressure to the graft and ensures its immobilization.' This pressure maintains uniform graft contact with the recipient bed, preventing hematoma/seroma formation and shear forces. Option A, topical antibiotic ointment, is generally not recommended directly on the graft as it can interfere with imbibition and revascularization. Option B, a bulky dressing without direct pressure, is insufficient to prevent fluid accumulation or shear. Option D, immediate active range of motion, is strictly contraindicated as it would disrupt the delicate graft. Option E, leaving the graft exposed to air, would lead to desiccation and graft failure.

Question 1096

Topic: 7. Hand and Wrist

A 52-year-old female presents with a 6-month history of painful clicking and locking in her right ring finger, particularly noticeable in the mornings. She reports difficulty making a full fist and extending the digit. Physical examination reveals a palpable, tender nodule at the base of the ring finger, consistent with the A1 pulley, and a characteristic 'triggering' sensation during active flexion and extension. Her medical history is significant for Type 2 Diabetes Mellitus, managed with oral medications. She has failed two corticosteroid injections into the flexor sheath over the past 3 months. Based on the epidemiological data presented in the case, which of the following statements regarding her condition is most accurate?

. Her diabetes mellitus is a minor contributing factor, with repetitive strain being the primary etiology.
. The incidence of trigger finger is typically higher in men than women, making her presentation atypical.
. The ring finger is the least commonly affected digit, suggesting an unusual presentation.
. Her diabetes significantly increases her risk of recurrence and severity, and is the most strongly linked comorbidity.
. Bilateral involvement is rare, making the likelihood of future involvement in her left hand very low.

Correct Answer & Explanation

. Her diabetes significantly increases her risk of recurrence and severity, and is the most strongly linked comorbidity.

Explanation

Correct Answer: DThe case explicitly states that "Diabetes mellitus is the most strongly linked condition, increasing the risk by two to ten-fold, with higher incidence, severity, and recurrence rates in diabetic patients." This directly supports option D. Her history of failed injections and persistent symptoms aligns with the increased severity and recurrence often seen in diabetic patients.Option A is incorrectbecause while repetitive strain can contribute, diabetes mellitus is highlighted as the most strongly linked systemic comorbidity, significantly increasing risk and severity, making it more than a 'minor' factor.Option B is incorrectbecause the case states a "predilection for women (female-to-male ratio of approximately 2:1)," making her presentation typical for gender, not atypical.Option C is incorrectbecause the case lists the most frequently affected digits in descending order as "the thumb, ring finger, middle finger, little finger, and index finger." The ring finger is the second most commonly affected digit, not the least.Option E is incorrectbecause "Bilateral involvement is observed in approximately 20-30% of cases," which is a significant percentage, making the likelihood of future involvement in the contralateral hand not 'very low' but rather a notable possibility.

Question 1097

Topic: Nerve & Tendon

A 48-year-old carpenter presents with a painful locking sensation in his right middle finger. He points to the base of his finger in the palm as the site of discomfort. During surgical planning for an A1 pulley release, the surgeon must accurately identify the anatomical location of the A1 pulley. For the middle finger, where is the A1 pulley consistently situated relative to the palmar creases?

. Distal to the distal interphalangeal (DIP) joint crease.
. Proximal to the metacarpophalangeal (MCP) joint crease.
. Beneath the proximal palmar crease.
. Overlying the volar plate of the proximal interphalangeal (PIP) joint.
. Originating from the proximal half of the proximal phalanx.

Correct Answer & Explanation

. Beneath the proximal palmar crease.

Explanation

Correct Answer: CThe case explicitly states: "For the middle and ring fingers, the A1 pulley is consistently situated beneath the proximal palmar crease." This is a direct recall of the anatomical landmark provided for surgical planning.Option A is incorrectas the A1 pulley is at the MCP joint level, far proximal to the DIP joint crease.Option B is incorrectas the A1 pulley is at the MCP joint level, which is typically marked by the proximal palmar crease, not necessarily proximal to it for the middle finger. For the thumb, it's proximal to the MCP joint crease, and for the index finger, slightly more proximal to the crease, but for the middle finger, it's beneath the crease itself.Option D is incorrectas the A3 pulley overlies the volar plate of the PIP joint, not the A1 pulley.Option E is incorrectas the A2 pulley originates from the proximal half of the proximal phalanx, not the A1 pulley.

Question 1098

Topic: Nerve & Tendon

A 60-year-old woman reports a 'catching' and 'snapping' sensation in her left ring finger when she tries to extend it after making a fist. This has progressed to the point where she sometimes needs to use her other hand to straighten the finger. The underlying biomechanical pathology responsible for this 'triggering' phenomenon, as described in the case, primarily involves:

. Inflammation and thickening of the A2 pulley, restricting tendon glide.
. A rupture of the flexor digitorum superficialis (FDS) tendon, causing loss of smooth movement.
. A size mismatch between the flexor tendons and the A1 pulley, due to tenosynovial hypertrophy and nodule formation.
. Degenerative changes within the metacarpophalangeal (MCP) joint, leading to mechanical obstruction.
. Compression of the digital nerves within the carpal tunnel, causing referred pain and stiffness.

Correct Answer & Explanation

. A size mismatch between the flexor tendons and the A1 pulley, due to tenosynovial hypertrophy and nodule formation.

Explanation

Correct Answer: CThe case clearly describes the biomechanics of triggering: "The pathological process in stenosing tenosynovitis involves an imbalance between the volume of the flexor tendon and the caliber of the A1 pulley tunnel. Chronic irritation, repetitive strain, or systemic conditions lead to tenosynovial inflammation and hypertrophy, predominantly affecting the FDS tendon. This results in the formation of a palpable nodule..." This nodule then catches on the proximal edge of the A1 pulley during extension.Option A is incorrectbecause the A1 pulley is the primary pulley implicated in trigger finger, not the A2 pulley.Option B is incorrectbecause trigger finger involves a restriction of tendon glide due to a nodule, not a tendon rupture, which would typically result in loss of flexion.Option D is incorrectbecause while chronic triggering can lead to a fixed flexion deformity of the MCP joint, the primary pathology is tendon and pulley-related, not primarily degenerative changes within the joint itself causing the initial triggering.Option E is incorrectbecause carpal tunnel syndrome involves median nerve compression at the wrist, and while it can be associated with trigger finger, it does not directly cause the mechanical triggering phenomenon in the digit.

Question 1099

Topic: Nerve & Tendon

During an open A1 pulley release for a trigger index finger, a surgeon is meticulously dissecting through the subcutaneous tissue and palmar fascia. The proper digital nerves and arteries are identified and retracted. According to the case, which specific digital nerve is particularly vulnerable during this procedure for the index finger?

. The ulnar digital nerve of the index finger.
. The radial digital nerve of the index finger.
. The common digital nerve to the index and middle fingers.
. The median nerve proper.
. The ulnar digital nerve of the middle finger.

Correct Answer & Explanation

. The radial digital nerve of the index finger.

Explanation

Correct Answer: BThe case states: "The proper digital nerves... course along the radial and ulnar aspects of the flexor tendon sheath, superficial to the A1 pulley. They are particularly vulnerable during surgical approaches to the A1 pulley, especially the radial digital nerve of the index finger and the ulnar digital nerve of the little finger, as they are often more volar." Therefore, for the index finger, the radial digital nerve is highlighted as particularly vulnerable.Option A is incorrectbecause while the ulnar digital nerve of the index finger is present, the radial digital nerve is specifically mentioned as more vulnerable due to its often more volar position.Option C is incorrectbecause the common digital nerves are more proximal in the palm and divide into proper digital nerves before reaching the A1 pulley level.Option D is incorrectbecause the median nerve proper is a major nerve in the forearm and wrist, not directly at the A1 pulley level in the digit.Option E is incorrectbecause the question specifically asks about the index finger, not the middle finger.

Question 1100

Topic: Nerve & Tendon

A 35-year-old mother presents with a 9-month history of painful locking of her right thumb, which she describes as interfering significantly with her ability to care for her infant. She has a palpable nodule at the base of her thumb and a fixed flexion deformity of the MCP joint, requiring passive manipulation to extend. She has undergone two corticosteroid injections, with only temporary relief lasting less than 2 weeks each time. Based on the provided indications, what is the most appropriate next step in her management?

. A third corticosteroid injection, as injections are the first-line treatment.
. Referral for occupational therapy and splinting to reduce repetitive strain.
. Surgical release of the A1 pulley, given her persistent symptoms and fixed deformity.
. Observation, as trigger thumb in younger patients often resolves spontaneously.
. Further diagnostic imaging, such as an MRI, to rule out other pathologies.

Correct Answer & Explanation

. Surgical release of the A1 pulley, given her persistent symptoms and fixed deformity.

Explanation

Correct Answer: CThe case outlines several operative indications, including: "Failure of Non-Operative Management: Persistent, symptomatic triggering, locking, or pain despite adequate trials of corticosteroid injections (typically 1-2 injections)..." and "Fixed Flexion Deformity: Established contracture of the MCP joint secondary to chronic triggering, making passive extension difficult or incomplete." This patient has failed two injections, has persistent debilitating symptoms, and a fixed flexion deformity, all strong indications for surgical release.Option A is incorrectbecause the case states that typically 1-2 injections are tried, and repeated injections (more than 2-3) are generally not recommended due to potential tendon weakening or skin atrophy. She has already failed two.Option B is incorrectbecause while therapy and splinting are part of conservative management, she has already failed injections and has a fixed deformity, indicating a need for more definitive treatment.Option D is incorrectbecause while childhood trigger thumb can sometimes self-resolve, this patient is an adult (35 years old) and has a fixed deformity, which warrants surgical intervention, not observation.Option E is incorrectbecause the diagnosis of trigger finger/thumb is primarily clinical, and imaging is generally not required for typical presentations. Her symptoms and physical exam findings are classic.

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