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7. Hand and Wrist MCQs

Practice Set 38 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 741

Topic: 7. Hand and Wrist

A 68-year-old male is undergoing a regional fasciectomy for a severe Dupuytren's contracture of his left little finger. The surgeon has identified a spiral cord causing a significant PIP joint contracture. To minimize the risk of neurovascular injury during dissection, which of the following surgical principles, as described in the case, should the surgeon prioritize?

. Begin dissection directly over the densest part of the spiral cord to ensure complete excision.
. Use a nerve stimulator only after the cord has been fully excised to confirm nerve integrity.
. Always begin dissection on the ulnar side of the little finger, as the neurovascular bundle is typically displaced radially in this digit.
. Trace the neurovascular bundles proximally and distally into healthy tissue before approaching the area of dense scarring and cord involvement.
. Elevate skin flaps as thinly as possible to maximize exposure of the underlying fascia.

Correct Answer & Explanation

. Trace the neurovascular bundles proximally and distally into healthy tissue before approaching the area of dense scarring and cord involvement.

Explanation

Correct Answer: DExplanation:Option D is correct.The 'Detailed Surgical Approach / Technique' section, under 'Identification and Protection of Neurovascular Bundles,' states: 'Trace the neurovascular bundles proximally and distally into healthy tissue before approaching the area of dense scarring and cord involvement.' This allows for early identification and protection of the bundles before they become distorted and obscured by the pathological cords, significantly reducing the risk of injury.Option A is incorrect.Beginning dissection directly over the densest part of the spiral cord is dangerous because the neurovascular bundle is often displaced superficially and medially (ulnarly for the little finger) within or adjacent to the cord, making it highly susceptible to injury. The principle is to identify structures in healthy tissue first.Option B is incorrect.A nerve stimulator can be used to confirm nerve integrity, but it is most usefulduringdissection, especially in revision cases or when the nerve is difficult to identify, not just after excision. Its primary role is to aid in identification and protection, not just post-excision confirmation.Option C is incorrect.The surgical anatomy section states: 'For the Ring and Little Finger: The neurovascular bundle is typically displaced ulnarly and superficially.' Therefore, beginning dissection on the ulnar side of the little finger would be approaching the side where the bundle is most likely to be displaced and at highest risk. The text advises to 'Always begin dissection on the side of the digit where the neurovascular bundle is least likely to be involved or displaced by the cord. For the index and middle fingers, this is usually the ulnar side; for the ring and little fingers, the radial side.'Option E is incorrect.The text advises to 'Carefully elevate full-thickness skin flaps (containing subcutaneous fat) to expose the underlying diseased fascia. Handle skin edges gently to preserve their vascularity.' Elevating thin skin flaps can compromise their vascularity, increasing the risk of skin necrosis, a common complication.

Question 742

Topic: 7. Hand and Wrist
A 58-year-old male undergoes a regional fasciectomy for a severe Dupuytren's contracture of his right ring finger. Post-operatively, on day 3, he develops significant pain, swelling, and ecchymosis in the palm and digits, with some blistering of the skin flaps. The hand therapist notes decreased capillary refill in the ring finger. Based on the provided case information, what is the most likely complication and the appropriate initial management?
. Infection; initiate broad-spectrum oral antibiotics immediately.
. Complex Regional Pain Syndrome (CRPS); begin aggressive pain management and sympathetic blocks.
. Hematoma; elevate the hand, apply compression, and consider surgical evacuation if expanding.
. Nerve injury; observe for spontaneous resolution, as most are transient neuropraxias.
. Skin necrosis; dรฉbride necrotic tissue and prepare for skin grafting.

Correct Answer & Explanation

. Hematoma; elevate the hand, apply compression, and consider surgical evacuation if expanding.

Explanation

Correct Answer: C. The 'Complications & Management' table lists 'Hematoma' with symptoms including 'expanding or significantly painful' swelling, and notes that it can compromise skin flaps. The patient's symptoms of 'significant pain, swelling, and ecchymosis in the palm and digits, with some blistering of the skin flaps' are highly consistent with a post-operative hematoma. The decreased capillary refill suggests potential compromise of digital circulation due to pressure from the hematoma. Management includes 'Elevation, compression. If expanding or significantly painful, surgical evacuation, re-exploration for bleeding control.' Option A is incorrect. While infection is a possibility, the rapid onset (day 3) with significant ecchymosis and blistering is less typical for a primary infection, which usually manifests later with erythema, warmth, and purulent discharge. Hematoma can predispose to infection, but it is the more immediate and likely primary issue here. Option B is incorrect. CRPS typically presents with disproportionate pain, swelling, skin changes (trophic changes, color changes), and stiffness, but usually develops over a longer period (weeks to months) rather than acutely on day 3 with ecchymosis and blistering. The acute presentation points away from CRPS as the primary diagnosis. Option D is incorrect. While nerve injury is a risk, the primary symptoms described (swelling, ecchymosis, blistering, decreased capillary refill) are not typical for isolated nerve injury. Nerve injury would primarily manifest as sensory or motor deficits. While a hematoma could secondarily compress a nerve, the immediate concern is the hematoma itself. Option E is incorrect. While skin necrosis is a potential outcome of a severe hematoma compromising skin flap viability, it is a consequence, not the initial complication. The immediate issue is the hematoma causing the compromise. Management of skin necrosis would follow after addressing the hematoma and allowing time for tissue demarcation.

Question 743

Topic: 7. Hand and Wrist

A 72-year-old patient with a history of severe Dupuytren's contracture of the ring and little fingers, previously treated with multiple regional fasciectomies, presents with recurrent, aggressive disease. The skin over the affected areas is tightly adherent to the underlying cords and appears compromised. He has significant functional impairment due to persistent flexion deformities. Considering the patient's history and current presentation, which surgical technique is most appropriate to minimize future recurrence rates?

. Another regional fasciectomy, focusing on meticulous dissection.
. Percutaneous needle aponeurotomy (PNA) for a less invasive approach.
. Collagenase clostridium histolyticum (CCH) injection.
. Dermofasciectomy with full-thickness skin grafting.
. Open fasciotomy with McCash incision for secondary intention healing.

Correct Answer & Explanation

. Dermofasciectomy with full-thickness skin grafting.

Explanation

Correct Answer: DExplanation:Option D is correct.The 'Detailed Surgical Approach / Technique' section, under 'Dermofasciectomy,' states: 'This technique involves excising not only the diseased fascia but also the overlying skin. It is indicated for: Recurrent Dupuytren's disease with extensive skin involvement. Aggressive disease with rapid progression. Cases where the skin is tightly adherent to the underlying cords or compromised.' The patient's presentation of 'recurrent, aggressive disease,' 'skin over the affected areas is tightly adherent to the underlying cords and appears compromised,' and 'significant functional impairment' perfectly aligns with the indications for dermofasciectomy. The text also notes that this technique 'has a lower recurrence rate compared to standard fasciectomy.'Option A is incorrect.While meticulous dissection is always important, the patient has already undergone 'multiple regional fasciectomies' and has 'recurrent, aggressive disease' with compromised skin. Another regional fasciectomy is unlikely to provide a more definitive solution and would likely lead to further recurrence, as the skin itself is involved.Option B is incorrect.PNA is a less invasive technique suitable for isolated cords and less severe contractures, but it has significantly higher recurrence rates compared to fasciectomy and is not indicated for aggressive, recurrent disease with skin involvement.Option C is incorrect.CCH injection, similar to PNA, is for less severe cases and has higher recurrence rates. It is not appropriate for recurrent, aggressive disease with compromised skin.Option E is incorrect.Open fasciotomy involves simple division of cords without excision and carries a higher recurrence risk. While a McCash incision leaves the wound open to heal by secondary intention, which can minimize skin tension and hematoma, it does not address the underlying diseased fascia or the compromised skin in a way that reduces recurrence as effectively as dermofasciectomy.

Question 744

Topic: 7. Hand and Wrist

A 50-year-old male is scheduled for a regional fasciectomy for a Dupuytren's contracture of his right small finger. During pre-operative planning, the surgeon is reviewing the patient's history. Which of the following historical factors, if present, would be considered a significant risk factor for Dupuytren's contracture, as outlined in the case?

. History of carpal tunnel syndrome.
. Regular participation in repetitive manual labor.
. Chronic use of NSAIDs for arthritis.
. Diagnosed epilepsy managed with phenobarbital.
. Previous history of trigger finger release.

Correct Answer & Explanation

. Diagnosed epilepsy managed with phenobarbital.

Explanation

Correct Answer: DExplanation:Option D is correct.The 'Introduction & Epidemiology' section explicitly lists 'epilepsy (particularly with phenobarbital use)' as an associated risk factor for Dupuytren's contracture.Option A is incorrect.While carpal tunnel syndrome is a common hand condition, the case does not list it as a risk factor for Dupuytren's contracture.Option B is incorrect.The case states: 'While often linked anecdotally to repetitive manual labor, a clear causal relationship with occupational trauma remains debated in the literature, with most studies suggesting a weak or no direct association.' Therefore, regular participation in repetitive manual labor is not considered a strong or clear risk factor according to the provided text.Option C is incorrect.Chronic use of NSAIDs for arthritis is not mentioned as a risk factor for Dupuytren's contracture in the provided text.Option E is incorrect.Previous history of trigger finger release is not listed as a risk factor for Dupuytren's contracture. While both are hand conditions, they are distinct pathologies.

Question 745

Topic: 7. Hand and Wrist

A 65-year-old male is 2 weeks post-regional fasciectomy for a severe Dupuytren's contracture of his left ring finger. He had a K-wire placed across his PIP joint, which was removed today. He is now entering the early mobilization and splinting phase of rehabilitation. According to the post-operative rehabilitation protocols, which of the following is a key component of his management at this stage?

. Discontinuation of all splinting to encourage full range of motion.
. Initiation of immediate, aggressive passive range of motion (PROM) by the therapist to overcome stiffness.
. Commencement of intensive hand therapy with custom-fabricated static extension night splinting.
. Return to full work and recreational activities to promote functional integration.
. Strict immobilization of the hand in a bulky dressing for another 4 weeks.

Correct Answer & Explanation

. Commencement of intensive hand therapy with custom-fabricated static extension night splinting.

Explanation

Correct Answer: CExplanation:Option C is correct.The 'Phase 2: Early Mobilization & Splinting (Weeks 1-3)' section states: 'Hand Therapy Commencement: Intensive hand therapy sessions (2-3 times per week) begin.' And 'Splinting: Night Splinting: A custom-fabricated, static extension splint (e.g., a volar thermoplastic splint) is provided and worn at night to maintain maximum extension of the MCP and PIP joints. This is crucial to counteract the tendency for re-contracture.' This aligns perfectly with the patient's stage of recovery and the recommended protocol.Option A is incorrect.Discontinuation of all splinting is not recommended at this early stage. Night splinting, in particular, is crucial to prevent re-contracture, as stated in the text.Option B is incorrect.While PROM may be introduced by the therapist, the text specifies 'Gentle, controlled PROM... ensuring not to disrupt wound healing or grafts.' 'Aggressive' PROM is generally avoided in the early phases due to the risk of wound dehiscence, hematoma, or increased inflammation. Early active range of motion (AROM) is emphasized first.Option D is incorrect.Return to full work and recreational activities is part of 'Phase 4: Return to Activity & Long-Term Management (Weeks 6-12+),' not the early mobilization phase (Weeks 1-3).Option E is incorrect.Strict immobilization in a bulky dressing is characteristic of the 'Phase 1: Immediate Post-Operative (Day 0 - Day 7).' By 2 weeks, the patient should be transitioning to early mobilization and splinting, not continued strict immobilization.

Question 746

Topic: 7. Hand and Wrist

A 40-year-old male presents with a new, firm nodule in his left palm, but he has no measurable flexion contracture of any digit, and his tabletop test is negative. He is concerned about the nodule and requests immediate treatment to prevent future contracture. Based on the provided case information, what is the most appropriate initial recommendation?

. Schedule for percutaneous needle aponeurotomy (PNA) to release the nodule.
. Prescribe collagenase clostridium histolyticum (CCH) injection into the nodule.
. Advise observation with regular follow-up, as not all nodules progress to contracture.
. Recommend immediate regional fasciectomy to excise the nodule and prevent progression.
. Initiate aggressive hand therapy and splinting to prevent contracture development.

Correct Answer & Explanation

. Advise observation with regular follow-up, as not all nodules progress to contracture.

Explanation

Correct Answer: CExplanation:Option C is correct.The 'Non-Operative Indications / Relative Contraindications' section explicitly states: 'Nodules without Contracture: The presence of palpable nodules without any measurable joint contracture is typically managed by observation, as not all nodules progress to contracture.' This patient fits this description perfectly, with a nodule but no contracture and a negative tabletop test.Option A is incorrect.PNA is used to release contracted cords, not isolated nodules without contracture. The text describes PNA for 'isolated cords, particularly MCP contractures.'Option B is incorrect.CCH injection is indicated for palpable cords with contractures, not for isolated nodules without contracture. The text mentions CCH for 'early disease stage' but specifically for 'significant contracture or functional impairment.'Option D is incorrect.Regional fasciectomy is a surgical procedure for established contractures that cause functional impairment or meet specific goniometric thresholds. It is not indicated for an isolated nodule without contracture.Option E is incorrect.Hand therapy and splinting are primarily used post-operatively or for managing existing contractures, not for preventing contracture development from an isolated nodule without any current contracture.

Question 747

Topic: 7. Hand and Wrist

During a regional fasciectomy for Dupuytren's contracture of the ring finger, the surgeon encounters a central cord causing a PIP joint contracture. According to the surgical anatomy described, what is the typical anatomical relationship of a central cord to the neurovascular bundles at the PIP level?

. It displaces the neurovascular bundle volarly and centrally/medially.
. It lies dorsal to the neurovascular bundles.
. It lies superficial to the flexor tendons but deep to the neurovascular bundles.
. It lies deep to the flexor tendons and neurovascular bundles.
. It is formed from the natatory ligaments and restricts abduction.

Correct Answer & Explanation

. It lies superficial to the flexor tendons but deep to the neurovascular bundles.

Explanation

Correct Answer: CExplanation:Option C is correct.The 'Surgical Anatomy & Biomechanics' section, under 'Central cords,' states: 'These cords arise directly from the palmar aponeurosis and extend distally along the central aspect of the digit, inserting into the middle phalanx. They directly cause PIP joint contracture and lie superficial to the flexor tendons but deep to the neurovascular bundles at the PIP level.' This directly describes the anatomical relationship.Option A is incorrect.This description ('displaces the neurovascular bundle volarly and centrally/medially') is characteristic of a spiral cord, which is noted as the most challenging anatomical distortion due to this displacement.Option B is incorrect.Cords that lie dorsal to the neurovascular bundles are retrovascular cords, which cause DIP joint contracture.Option D is incorrect.Central cords lie superficial to the flexor tendons, not deep to them.Option E is incorrect.This describes a natatory cord, which forms from natatory ligaments and restricts finger abduction, causing web space contracture, not PIP joint contracture from a central cord.

Question 748

Topic: 7. Hand and Wrist
A 32-year-old collegiate basketball player sustains a sudden, forceful flexion injury to his actively extended right long finger DIP joint while attempting to catch a ball. He presents immediately with an inability to actively extend the DIP joint, which rests in approximately 30 degrees of flexion. Passive extension to neutral is easily achieved. Radiographs are obtained and show no bony avulsion or fracture. According to the Doyle classification, what type of injury has this patient sustained?
. Type I
. Type II
. Type III
. Type IV
. Salter-Harris Type II

Correct Answer & Explanation

. Type I

Explanation

Correct Answer: A. The patient has sustained a Type I mallet finger injury. The case explicitly states that the injury results from 'disruption of the terminal extensor tendon without significant bony avulsion' and that 'Type I: Soft tissue avulsion of the terminal extensor tendon from its insertion on the distal phalanx.' The clinical presentation (inability to actively extend DIP, passive extension achievable, no bony avulsion on X-ray) perfectly matches the description of a soft tissue mallet finger, which is Doyle Type I. Incorrect Options: Type II: This involves a bony avulsion fracture of the dorsal aspect of the distal phalanx, involving less than 30% of the articular surface. The radiographs in this case explicitly show no bony avulsion. Type III: This involves a bony avulsion fracture of more than 30% of the articular surface, often associated with DIP joint subluxation. Again, no bony avulsion is present. Type IV: This refers to an epiphyseal fracture in children (Salter-Harris type I or II). The patient is a 32-year-old adult, making this classification inappropriate. Salter-Harris Type II: This is a specific type of epiphyseal fracture, which is a component of Doyle Type IV. It is not applicable to an adult patient with a purely soft tissue injury.

Question 749

Topic: 7. Hand and Wrist

A 48-year-old right-hand dominant construction worker presents with a chronic mallet finger of his left ring finger, sustained 5 months prior. He initially attempted splinting but was non-compliant due to work demands. Clinical examination reveals a persistent 25-degree extensor lag at the DIP joint, which is passively correctable to 5 degrees of hyperextension. He also exhibits a flexible hyperextension deformity of the PIP joint. Radiographs show no bony pathology. Which of the following is the most appropriate management strategy for this patient?

. Continue with continuous DIP extension splinting for another 8 weeks.
. Initiate a course of oral corticosteroids and aggressive hand therapy.
. Surgical repair of the terminal extensor tendon with K-wire fixation.
. DIP joint arthrodesis in a functional position.
. PIP joint volar plate tenodesis to address the hyperextension.

Correct Answer & Explanation

. Surgical repair of the terminal extensor tendon with K-wire fixation.

Explanation

Correct Answer: CThis patient presents with a chronic soft tissue mallet finger (5 months post-injury) with a significant persistent extensor lag (25 degrees) after failed non-operative management due to non-compliance. The case states, 'Surgical management for soft tissue mallet finger... is generally considered for: Failed Non-Operative Management: Persistent extensor lag of more than 15-20 degrees after an adequate course of continuous splinting (typically 8 weeks, followed by night splinting).' It also mentions 'Chronic Soft Tissue Mallet: Injuries presenting late (e.g., >3 months) with significant extensor lag and often associated scarring or tendon retraction.' Surgical repair, often involving direct reattachment with K-wire fixation for protection, is the most appropriate next step.Incorrect Options:Continue with continuous DIP extension splinting for another 8 weeks:This is unlikely to be effective for a chronic injury with a significant lag after failed initial attempts, especially given the patient's history of non-compliance. The window for successful primary splinting has passed.Initiate a course of oral corticosteroids and aggressive hand therapy:Corticosteroids are not indicated for tendon repair or chronic extensor lag. While hand therapy is crucial post-operatively, it cannot restore tendon integrity in a chronic, failed non-operative case.DIP joint arthrodesis in a functional position:While arthrodesis is a salvage option for severe, irreparable damage or persistent functional deficits, it is typically reserved for cases where tendon repair or reconstruction is not feasible or has failed. Given the description, a primary repair or reconstruction is still a viable and preferred option to preserve motion.PIP joint volar plate tenodesis to address the hyperextension:While the patient has a flexible PIP hyperextension (swan neck deformity), this is a secondary issue. The primary problem is the mallet finger. Addressing the mallet finger first is paramount, and the PIP deformity may resolve or become more manageable once DIP extension is restored. A PIP tenodesis alone would not address the underlying mallet deformity.

Question 750

Topic: 7. Hand and Wrist

A 28-year-old gymnast undergoes surgical repair for a chronic soft tissue mallet finger. During the dissection phase, a dorsal longitudinal incision is made over the DIP joint. As the surgeon carefully elevates the skin and subcutaneous tissue, which of the following structures is most vulnerable to iatrogenic injury and requires meticulous protection?

. Flexor digitorum profundus tendon
. Central slip of the extensor digitorum communis
. Dorsal digital nerves
. Triangular ligament
. Volar plate of the DIP joint

Correct Answer & Explanation

. Dorsal digital nerves

Explanation

Correct Answer: CThe case explicitly states under 'Detailed Surgical Approach / Technique' in the 'Dissection' section: 'Identify and protect the dorsal digital nerves, which are superficial and run along the sides of the digit. Using loupes is invaluable here.' These nerves are immediately beneath the skin and subcutaneous tissue and are highly susceptible to injury during initial dissection.Incorrect Options:Flexor digitorum profundus tendon:This tendon is located on the volar aspect of the distal phalanx and is not typically encountered or at risk during a dorsal approach for mallet finger repair.Central slip of the extensor digitorum communis:The central slip inserts on the middle phalanx and extends the PIP joint. While part of the extensor mechanism, it is more proximal and deeper than the dorsal digital nerves during a DIP joint repair.Triangular ligament:This ligament stabilizes the lateral bands at the DIP joint and is part of the deeper extensor mechanism. It is not as superficial as the dorsal digital nerves during the initial skin and subcutaneous dissection.Volar plate of the DIP joint:The volar plate is on the volar aspect of the DIP joint and is not directly exposed or at risk during a dorsal approach.

Question 751

Topic: 7. Hand and Wrist

A 60-year-old patient undergoes surgical repair of a chronic soft tissue mallet finger. Following the reattachment of the terminal extensor tendon to the distal phalanx, the surgeon places a transarticular K-wire as depicted in the image. What is the primary purpose of this K-wire fixation in the immediate post-operative period?

. To provide active range of motion for the DIP joint.
. To compress the tendon repair site for faster healing.
. To prevent volar subluxation of the lateral bands.
. To protect the tendon repair by maintaining the DIP joint in extension.
. To facilitate early strengthening exercises for the extensor mechanism.

Correct Answer & Explanation

. To protect the tendon repair by maintaining the DIP joint in extension.

Explanation

Correct Answer: DThe case states under 'Internal Fixation (K-wire)': 'After the tendon repair, transarticular K-wire fixation of the DIP joint is almost always performed to protect the repair and maintain the joint in the desired position during healing.' The desired position is full extension or slight hyperextension (0-10 degrees). The image clearly shows a K-wire maintaining the DIP joint in extension.Incorrect Options:To provide active range of motion for the DIP joint:K-wire fixation rigidly immobilizes the joint, preventing active motion, which is crucial for protecting the healing tendon.To compress the tendon repair site for faster healing:While some compression might occur, the primary purpose is not compression for healing but rather immobilization and protection from tension.To prevent volar subluxation of the lateral bands:The triangular ligament primarily prevents volar subluxation of the lateral bands. While K-wire fixation maintains overall joint alignment, its direct role is not specifically to prevent lateral band subluxation.To facilitate early strengthening exercises for the extensor mechanism:Strengthening exercises are initiated much later, typically in Phase 3 (Weeks 12+), after the K-wire has been removed and initial healing has occurred. Early strengthening would jeopardize the repair.

Question 752

Topic: Nerve & Tendon

A 50-year-old patient is 3 weeks post-operative from a surgical repair of a soft tissue mallet finger with transarticular K-wire fixation. He is currently in Phase 1 of his rehabilitation protocol. Which of the following instructions is most critical for the patient to adhere to during this phase?

. Begin gentle active DIP flexion exercises to prevent stiffness.
. Perform light resistive exercises for DIP extension.
. Ensure continuous immobilization of the DIP joint in full extension.
. Remove the K-wire daily for cleaning and reinsertion.
. Initiate scar massage over the surgical incision.

Correct Answer & Explanation

. Ensure continuous immobilization of the DIP joint in full extension.

Explanation

Correct Answer: CThe 'Post-Operative Rehabilitation Protocols' section, under 'Phase 1: Immobilization (Weeks 0-6)', states: 'The primary goal of this phase is to protect the surgically repaired terminal extensor tendon, allowing for initial healing... Crucial Principle: Absolutely no active or passive DIP joint flexion is permitted. The patient must be meticulously educated on this, particularly for activities of daily living.'Incorrect Options:Begin gentle active DIP flexion exercises to prevent stiffness:This is strictly prohibited in Phase 1 to protect the healing tendon. Active DIP flexion is only gradually introduced in Phase 3.Perform light resistive exercises for DIP extension:Strengthening exercises are part of Phase 3 (Weeks 12+), not Phase 1.Remove the K-wire daily for cleaning and reinsertion:K-wires are sterilely placed and remain in situ until removal by the surgeon, typically at 6 weeks. Daily removal would introduce infection risk and compromise fixation.Initiate scar massage over the surgical incision:Scar management is initiated in Phase 2 (Weeks 6-12) 'once the wound is well-healed', not in Phase 1 when the wound is still fresh.

Question 753

Topic: Nerve & Tendon

A 35-year-old patient presents with a chronic soft tissue mallet finger of 8 months duration. He has a 40-degree extensor lag at the DIP joint and has developed a fixed hyperextension deformity of the PIP joint, consistent with a swan neck deformity. He failed a prolonged course of non-operative management. Which of the following statements regarding the management of his swan neck deformity is most accurate?

. The swan neck deformity will spontaneously resolve once the mallet finger is surgically repaired.
. PIP flexion splinting alone will be sufficient to correct a fixed swan neck deformity.
. Addressing the mallet deformity is paramount, and the fixed swan neck may require additional procedures like PIP volar plate tenodesis or intrinsic release.
. The swan neck deformity is a contraindication to surgical repair of the mallet finger.
. The primary cause of the PIP hyperextension is laxity of the central slip, which should be shortened.

Correct Answer & Explanation

. Addressing the mallet deformity is paramount, and the fixed swan neck may require additional procedures like PIP volar plate tenodesis or intrinsic release.

Explanation

Correct Answer: CThe case discusses 'Swan Neck Deformity' as a complication, stating: 'This secondary deformity results from an imbalance in the extensor mechanism, with volar plate laxity at the PIP joint and overactivity of the central slip, leading to PIP hyperextension and compensatory DIP flexion. It can be a consequence of untreated or failed mallet finger.' For 'Fixed Deformity', it notes: 'Often requires complex reconstruction, including PIP volar plate tenodesis, intrinsic release, or PIP arthrodesis in severe, recalcitrant cases. Addressing the underlying mallet deformity (if not already done) is paramount.'Incorrect Options:The swan neck deformity will spontaneously resolve once the mallet finger is surgically repaired:While flexible swan neck deformities may improve, a 'fixed' deformity, as described, typically requires additional intervention beyond just mallet repair.PIP flexion splinting alone will be sufficient to correct a fixed swan neck deformity:PIP flexion splinting is indicated for 'flexible' deformities. A 'fixed' deformity implies structural changes that require more aggressive management, potentially surgical.The swan neck deformity is a contraindication to surgical repair of the mallet finger:A fixed swan neck deformity is listed as an 'Operative Indication' for mallet finger, often requiring a combined approach, not a contraindication.The primary cause of the PIP hyperextension is laxity of the central slip, which should be shortened:The case states the swan neck results from 'volar plate laxity at the PIP joint and overactivity of the central slip'. Shortening the central slip would exacerbate PIP hyperextension, as the central slip extends the PIP joint.

Question 754

Topic: 7. Hand and Wrist

In a soft tissue mallet finger (Doyle Type I), the characteristic flexion deformity of the DIP joint is primarily due to the unopposed action of which muscle-tendon unit?

. Extensor digitorum communis (EDC) tendon
. Flexor digitorum superficialis (FDS) tendon
. Flexor digitorum profundus (FDP) tendon
. Lumbrical muscles
. Interossei muscles

Correct Answer & Explanation

. Flexor digitorum profundus (FDP) tendon

Explanation

Correct Answer: CThe 'Surgical Anatomy & Biomechanics' section states: 'In a soft tissue mallet injury (Type I), the terminal extensor tendon is ruptured from its insertion, disrupting the extensor moment arm at the DIP joint. This disruption leaves the DIP joint extension unopposed, and the powerful pull of theflexor digitorum profundus (FDP)tendon, which inserts on the volar aspect of the distal phalanx, creates the characteristic flexion deformity.'Incorrect Options:Extensor digitorum communis (EDC) tendon:The EDC contributes to the extensor mechanism, but its terminal tendon is ruptured in a mallet finger, leading to loss of extension, not flexion.Flexor digitorum superficialis (FDS) tendon:The FDS tendon inserts on the middle phalanx and primarily flexes the PIP joint, not the DIP joint.Lumbrical muscles:Lumbricals contribute to MCP flexion and PIP/DIP extension, not DIP flexion.Interossei muscles:Interossei also contribute to MCP flexion and PIP/DIP extension, not DIP flexion.

Question 755

Topic: Nerve & Tendon

A 22-year-old athlete presents with an acute soft tissue mallet finger of the ring finger. He has full passive DIP extension and an active extensor lag of 35 degrees. He is highly motivated and compliant. Based on the case, what is the most appropriate initial management strategy and its critical success factor?

. Immediate surgical repair with K-wire fixation, with the critical factor being early active DIP motion.
. Continuous immobilization of the DIP joint in full extension for 6-8 weeks, with the critical factor being patient compliance.
. Dynamic splinting of the DIP joint to gradually restore extension, with the critical factor being aggressive strengthening.
. PIP joint immobilization to prevent swan neck deformity, with the critical factor being early return to sport.
. Oral anti-inflammatory medications and rest, with the critical factor being pain control.

Correct Answer & Explanation

. Continuous immobilization of the DIP joint in full extension for 6-8 weeks, with the critical factor being patient compliance.

Explanation

Correct Answer: BThe 'Indications & Contraindications' section, under 'Non-Operative Indications', states: 'The vast majority of acute soft tissue mallet injuries (Doyle Type I) are successfully managed non-operatively. The core principle is continuous immobilization of the DIP joint in full extension or slight hyperextension (0-10 degrees) for a prolonged period, typically 6 to 8 weeks, followed by a gradual weaning phase. The PIP joint should be left free to allow full range of motion.' It also lists 'Patient Compliance' as a key factor. The 'Summary of Key Literature / Guidelines' reinforces this: 'continuous immobilization of the DIP joint in extension (or slight hyperextension) for 6-8 weeks... remains the gold standard for acute soft tissue injuries. Studies... underscore the high success rates (typically 80-90%) with proper splinting and patient compliance. The critical factor is continuous wear.'Incorrect Options:Immediate surgical repair with K-wire fixation, with the critical factor being early active DIP motion:Surgical repair is generally reserved for failed non-operative management or specific complex cases, not acute, compliant patients. Early active DIP motion is contraindicated post-surgery.Dynamic splinting of the DIP joint to gradually restore extension, with the critical factor being aggressive strengthening:Dynamic splinting is not the initial treatment for acute mallet finger. Continuous static immobilization is preferred. Aggressive strengthening is for later phases.PIP joint immobilization to prevent swan neck deformity, with the critical factor being early return to sport:The PIP joint should be left free to allow full range of motion during DIP splinting. Early return to sport is not the critical factor for healing.Oral anti-inflammatory medications and rest, with the critical factor being pain control:While pain control is important, this alone does not address the mechanical disruption of the tendon. Immobilization is the primary treatment.

Question 756

Topic: Nerve & Tendon

A 65-year-old patient undergoes surgical repair for a chronic soft tissue mallet finger. Six months post-operatively, despite adherence to the rehabilitation protocol, he presents with a persistent 20-degree extensor lag at the DIP joint and significant loss of DIP flexion, limiting his ability to grasp small objects. Which of the following complications is most likely contributing to his current functional deficit, and what is a potential salvage strategy for the persistent extensor lag?

. Infection; Salvage with immediate K-wire removal and antibiotics.
. Nail deformity; Salvage with nail bed revision.
. Extensor lag / Re-rupture; Salvage with revision surgery (e.g., repeat repair, tenodesis, or DIP fusion).
. Hypersensitivity/CRPS; Salvage with sympathetic blocks.
. Skin necrosis; Salvage with local flap coverage.

Correct Answer & Explanation

. Extensor lag / Re-rupture; Salvage with revision surgery (e.g., repeat repair, tenodesis, or DIP fusion).

Explanation

Correct Answer: CThe 'Complications & Management' table lists 'Extensor Lag / Re-rupture' as 'Most common (5-20%), higher in chronic cases'. The explanation further states: 'Recurrent extensor lag is the most frequent reason for dissatisfaction post-surgery... For persistent, functionally significant lag, revision surgery may be considered. Options include repeat direct repair, tendon advancement (if proximal tissue allows), tenodesis (using a portion of the lateral band or a small palmaris longus graft), or, in cases of severe, irreparable damage with significant functional impairment, DIP joint arthrodesis (fusion) in a functional position.'Incorrect Options:Infection; Salvage with immediate K-wire removal and antibiotics:While infection is a complication, the primary issue described is persistent extensor lag and stiffness, not signs of active infection. K-wires are typically removed at 6 weeks, not 6 months.Nail deformity; Salvage with nail bed revision:Nail deformity is often cosmetic and does not typically cause a 20-degree extensor lag or significant loss of DIP flexion.Hypersensitivity/CRPS; Salvage with sympathetic blocks:CRPS is rare and presents with a constellation of symptoms (pain, swelling, skin changes) beyond just extensor lag and stiffness.Skin necrosis; Salvage with local flap coverage:Skin necrosis is an acute wound healing complication, not a chronic issue presenting 6 months post-op with extensor lag and stiffness.

Question 757

Topic: 7. Hand and Wrist

During a regional fasciectomy for a severe Dupuytren's contracture of the ring finger, the surgeon carefully dissects the diseased fascia causing the proximal interphalangeal (PIP) joint flexion deformity. The neurovascular bundle is at risk due to displacement by the spiral cord. In which direction is the neurovascular bundle characteristically displaced at the level of the proximal phalanx?

. Dorsal, lateral, and distal
. Central, superficial, and proximal
. Central, deep, and distal
. Lateral, deep, and proximal
. Dorsal, central, and superficial

Correct Answer & Explanation

. Central, superficial, and proximal

Explanation

The spiral cord is a diseased progression of normal fascial structures that displaces the neurovascular bundle centrally, superficially (volar), and proximally. This anatomical distortion places the digital nerve at high risk for iatrogenic transection during surgical release.

Question 758

Topic: Nerve & Tendon

A 24-year-old athlete presents with an acute soft-tissue mallet deformity of his long finger after jamming it during a basketball game. Radiographs are negative for any fracture. What is the gold standard initial management for this injury?

. Nighttime-only extension splinting for 6 weeks
. Continuous DIP joint extension splinting for 6 to 8 weeks
. Surgical repair of the terminal extensor tendon
. Continuous DIP and PIP joint extension splinting for 6 weeks
. Closed reduction and percutaneous pinning of the DIP joint

Correct Answer & Explanation

. Continuous DIP joint extension splinting for 6 to 8 weeks

Explanation

The primary treatment for an acute soft-tissue mallet finger is continuous, uninterrupted extension splinting of the DIP joint for 6 to 8 weeks. The PIP joint should be left free to allow active range of motion and prevent stiffness.

Question 759

Topic: 7. Hand and Wrist

A researcher is studying the histological properties of surgical specimens excised from patients with Dupuytren's disease. Which of the following cell types is considered the primary driver of the proliferative phase and resulting tissue contracture in this condition?

. Osteoblast
. Chondrocyte
. Myofibroblast
. Macrophage
. Schwann cell

Correct Answer & Explanation

. Myofibroblast

Explanation

The myofibroblast is the hallmark cell responsible for the pathogenesis of Dupuytren's contracture. These cells have characteristics of both fibroblasts and smooth muscle cells, generating the contractile forces that lead to digital deformities.

Question 760

Topic: 7. Hand and Wrist

A 35-year-old construction worker sustained a crush injury to his left index finger. Radiographs reveal a bony mallet injury with an avulsion fracture involving 60% of the dorsal articular surface of the distal phalanx and associated volar subluxation of the distal phalanx. What is the most appropriate definitive management?

. Continuous DIP extension splinting for 8 weeks
. Buddy taping to the adjacent long finger
. Surgical intervention (e.g., extension block pinning or ORIF)
. Primary DIP joint arthrodesis
. Physical therapy for early active range of motion

Correct Answer & Explanation

. Surgical intervention (e.g., extension block pinning or ORIF)

Explanation

Surgical intervention is indicated for bony mallet fingers when there is volar subluxation of the distal phalanx or when the fracture involves greater than 30-50% of the articular surface. Extension block pinning or open reduction and internal fixation can restore articular congruity.

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