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7. Hand and Wrist MCQs

Practice Set 46 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 901

Topic: 7. Hand and Wrist

A surgeon is preparing to elevate a reverse radial forearm flap for a large dorsal hand defect. The patient has undergone all necessary preoperative assessments, including a positive Allen's test. Which of the following steps is most consistent with the commonly preferred technique for flap elevation?

. Beginning the dissection distally, identifying the radial artery near the styloid, and proceeding proximally.
. Making an incision along the ulnar border of the skin paddle, dissecting subfascially, ligating the proximal radial artery, and proceeding distally.
. Elevating the flap in a suprafascial plane to preserve the paratenon of the flexor tendons.
. Dissecting the radial artery and its venae comitantes from the deep muscles before incising the skin paddle.
. Ligating the ulnar artery proximally to enhance retrograde flow through the radial artery.

Correct Answer & Explanation

. Making an incision along the ulnar border of the skin paddle, dissecting subfascially, ligating the proximal radial artery, and proceeding distally.

Explanation

Correct Answer: BThe case describes two main approaches for flap elevation, withproximal-to-distal dissection commonly preferred. This approach involves making an incision along the ulnar border of the planned skin paddle, dissecting subfascially (lifting skin, subcutaneous tissue, and deep fascia), identifying and ligating the radial artery at the proximal extent of the flap, and then meticulously dissecting distally, preserving the radial artery and its venae comitantes while ligating branches not supplying the flap.Option A is incorrect; this describes the distal-to-proximal approach, which is an alternative but not the 'commonly preferred' method as stated in the text.Option C is incorrect; the dissection is typically performed in asubfascialplane to ensure inclusion of the fasciocutaneous perforators that supply the flap. Preserving the paratenon is important for donor site skin graft take, but the flap itself is elevated subfascially.Option D is incorrect; the skin paddle is incised first, and the dissection proceeds to identify the vascular pedicle, not the other way around.Option E is incorrect; ligating the ulnar artery would be catastrophic, as the ulnar artery is the source of the retrograde flow to the radial artery via collateral circulation. This would lead to hand ischemia.

Question 902

Topic: 7. Hand and Wrist

A 60-year-old patient requires reconstruction of a thumb pulp defect with a sensate reverse radial forearm flap. During the flap harvest, which nerve is specifically identified and included with the flap to provide sensation to the reconstructed area, and what is the expected trade-off at the donor site?

. The median nerve; expected trade-off is loss of motor function in the thenar muscles.
. The ulnar nerve; expected trade-off is loss of sensation to the ulnar side of the hand.
. The superficial radial nerve; expected trade-off is sensory deficit in its native distribution on the dorsum of the donor hand.
. The lateral antebrachial cutaneous nerve; expected trade-off is weakness in elbow flexion.
. The posterior interosseous nerve; expected trade-off is loss of wrist and finger extension.

Correct Answer & Explanation

. The superficial radial nerve; expected trade-off is sensory deficit in its native distribution on the dorsum of the donor hand.

Explanation

Correct Answer: CFor sensate reconstruction with a reverse radial forearm flap, a segment of thesuperficial radial nerve (SRN)can be harvested with the flap. The SRN provides sensation to the dorsum of the hand and thumb, index, and middle fingers. The expected trade-off for harvesting the SRN is asensory deficit in its native distributionon the dorsum of the donor hand, which must be carefully considered and discussed with the patient.Option A is incorrect; the median nerve is a major nerve providing motor and sensory function to the hand, and its harvest would lead to severe functional impairment, not just thenar muscle loss, and it is not typically harvested with an RRFF.Option B is incorrect; the ulnar nerve is also a major nerve providing motor and sensory function, and its harvest is not part of an RRFF for sensate reconstruction.Option D is incorrect; the lateral antebrachial cutaneous nerve provides sensation to the radial forearm, but its harvest is not the primary method for providing sensation to a hand flap, and it does not affect elbow flexion.Option E is incorrect; the posterior interosseous nerve is a motor nerve supplying wrist and finger extensors, and its harvest would lead to significant motor deficits, not sensory, and it is not included in an RRFF.

Question 903

Topic: Wrist & Carpus

A 70-year-old patient with a history of diabetes and smoking undergoes a reverse radial forearm flap for coverage of an exposed distal radius fracture plate. On the first postoperative day, the flap appears dusky, swollen, and has sluggish capillary refill, despite adequate arterial Doppler signals. What is the most likely immediate complication, and what is the appropriate initial management?

. Arterial occlusion; urgent re-exploration for vascular repair.
. Infection; immediate broad-spectrum antibiotics and wound debridement.
. Venous congestion; elevate the extremity, release tight sutures, and consider leeches.
. Hematoma formation; surgical evacuation and placement of a drain.
. Partial flap necrosis; conservative management with dressing changes.

Correct Answer & Explanation

. Venous congestion; elevate the extremity, release tight sutures, and consider leeches.

Explanation

Correct Answer: CThe clinical presentation of a dusky, swollen flap with sluggish capillary refill, despite adequate arterial Doppler signals, is highly indicative ofvenous congestion. This is a common complication, especially in patients with comorbidities like diabetes and smoking, which can affect microvascular health. The initial management for venous congestion includes elevating the extremity to promote venous outflow, releasing any tight sutures or dressings that might be causing external compression, and considering adjunctive measures like medicinal leeches or heparin paste to improve venous drainage.Option A is incorrect; arterial occlusion would typically present with a pale, cold, non-blanching flap with absent arterial Doppler signals, which contradicts the presence of adequate arterial signals.Option B is incorrect; while infection is a risk, the immediate presentation points more towards a vascular issue. Infection typically manifests later with signs of inflammation (redness, warmth, purulence).Option D is incorrect; hematoma formation can cause swelling and compromise flap viability, but the dusky appearance and sluggish capillary refill are more specific to venous congestion. While a hematoma could contribute, venous congestion is the more direct diagnosis based on the description.Option E is incorrect; partial flap necrosis is an outcome of prolonged vascular compromise (often venous congestion), not the immediate complication itself. The goal is to manage the congestion to prevent necrosis.

Question 904

Topic: 7. Hand and Wrist

A 25-year-old patient presents with a 4x5 cm full-thickness skin defect over the dorsal aspect of the proximal phalanx of the index finger, exposing the extensor tendon. The defect is too large for primary closure or a local flap. Considering the reconstructive ladder and the characteristics of the defect, which of the following reconstructive options would typically be considered a more complex alternative to the reverse radial forearm flap for this specific defect?

. Split-thickness skin graft.
. Full-thickness skin graft.
. Cross-finger flap.
. Anterolateral thigh (ALT) free flap.
. V-Y advancement flap.

Correct Answer & Explanation

. Anterolateral thigh (ALT) free flap.

Explanation

Correct Answer: DThe reverse radial forearm flap (RRFF) occupies a crucial rung on the reconstructive ladder, balancing between local flaps and free tissue transfer. For a 4x5 cm defect on the dorsal proximal phalanx, an RRFF would be a suitable option. AAnterolateral Thigh (ALT) free flapwould be considered a more complex alternative because it involves microsurgical free tissue transfer, requiring anastomosis of vessels at the recipient site. Free flaps are typically reserved for very large or complex defects involving multiple tissue types, or when regional pedicled flaps are not feasible or sufficient.Options A and B (Split-thickness and Full-thickness skin grafts) are incorrectbecause they are simpler options on the reconstructive ladder, suitable for smaller, well-vascularized beds without exposed critical structures. They would not provide robust coverage for an exposed extensor tendon.Option C (Cross-finger flap) is incorrectbecause while it is a regional flap, it is generally considered less complex than an RRFF and is limited in size and typically requires a two-stage procedure. It's often used for specific digital defects but might be too small or less versatile for a 4x5 cm defect exposing tendon.Option E (V-Y advancement flap) is incorrectbecause it is a local flap, suitable for smaller defects with sufficient adjacent healthy tissue, and would be insufficient for a 4x5 cm defect exposing tendon.

Question 905

Topic: 7. Hand and Wrist

A 32-year-old patient undergoes a reverse radial forearm flap for a complex hand injury. On the second postoperative day, the flap appears pale, cool to touch, and has absent capillary refill, with no audible Doppler signals over the pedicle. The patient also reports increasing pain. What is the most appropriate immediate course of action?

. Continue close observation and elevate the extremity further.
. Administer systemic antibiotics and apply warm compresses to the flap.
. Urgent re-exploration of the flap to assess for pedicle compromise.
. Apply medicinal leeches to the flap to improve venous outflow.
. Initiate aggressive hand therapy to promote circulation.

Correct Answer & Explanation

. Urgent re-exploration of the flap to assess for pedicle compromise.

Explanation

Correct Answer: CThe signs described (pale, cool, absent capillary refill, no Doppler signals, increasing pain) are classic indicators ofarterial occlusion or complete pedicle compromise. This is a surgical emergency requiring immediate intervention.Urgent re-exploration of the flapis mandatory to identify the cause of the vascular compromise (e.g., pedicle kinking, thrombosis, external compression) and attempt salvage through vascular revision or release of compression. Delay in re-exploration can lead to irreversible flap necrosis.Option A is incorrect; continued observation would lead to irreversible flap loss. Elevation is helpful for venous congestion but not for arterial occlusion.Option B is incorrect; antibiotics are for infection, which is not the primary issue here. Warm compresses might be used for vasospasm but are insufficient for complete arterial occlusion.Option D is incorrect; medicinal leeches are used for venous congestion, not arterial occlusion. They would be ineffective and potentially harmful in this scenario.Option E is incorrect; aggressive hand therapy is part of rehabilitation, not an immediate treatment for acute flap vascular compromise. Early mobilization could even worsen the situation if the pedicle is compromised.

Question 906

Topic: 7. Hand and Wrist

During preoperative evaluation for a reverse radial forearm flap, a modified Allen's test is performed. Upon release of the ulnar artery with continued radial artery compression, the hand regains its normal color in 14 seconds. What is the most appropriate management regarding the planned flap?

. Proceed with the RRFF as planned, as this is a normal finding.
. Proceed with the RRFF but plan for routine cephalic vein supercharging.
. Abort the RRFF and choose an alternative flap or perform angiography.
. Proceed with the RRFF and administer postoperative systemic vasodilators.
. Perform an ischemic preconditioning protocol before proceeding with the RRFF.

Correct Answer & Explanation

. Abort the RRFF and choose an alternative flap or perform angiography.

Explanation

Normal capillary refill during a modified Allen's test is typically under 7 seconds. A delayed refill of 14 seconds indicates inadequate ulnar collateral circulation via the palmar arches, making harvest of the radial artery unsafe.

Question 907

Topic: 7. Hand and Wrist

Which of the following is the most frequent long-term complication leading to patient dissatisfaction at the donor site following a radial forearm flap harvest?

. Median nerve palsy
. Neuroma or altered sensation in the superficial radial nerve distribution
. Ischemic contracture of the flexor pollicis longus
. Nonunion of the distal radius
. Loss of independent index finger flexion

Correct Answer & Explanation

. Neuroma or altered sensation in the superficial radial nerve distribution

Explanation

Injury to the superficial radial nerve is the most common sensory complication during radial forearm flap harvest. Dissection near the brachioradialis can inadvertently damage the nerve, leading to painful neuromas or troublesome paresthesias over the dorsal radial hand.

Question 908

Topic: 7. Hand and Wrist

During the elevation of a reverse radial forearm flap, the surgeon must be meticulous when dissecting the flap off the flexor carpi radialis (FCR) and brachioradialis tendons. What is the primary reason for this careful dissection?

. To prevent flexor tendon bowstringing at the wrist
. To preserve the paratenon for subsequent skin graft vascularization
. To avoid inadvertent injury to the median nerve
. To maintain arterial perforators to the underlying radius
. To prevent postoperative wrist flexion contractures

Correct Answer & Explanation

. To preserve the paratenon for subsequent skin graft vascularization

Explanation

The flap is elevated in the subfascial plane. Preserving the paratenon over the exposed tendons is critical to ensure a viable, vascularized bed for the split-thickness skin graft used to close the donor site.

Question 909

Topic: 7. Hand and Wrist

Following the inset of a reverse radial forearm flap for a dorsal hand defect, the flap appears cyanotic with dark, rapid bleeding from pinpricks. Which of the following is the most appropriate intraoperative maneuver to salvage the flap?

. Administer systemic heparin and observe for 30 minutes
. Ligate the radial artery to decrease excessive inflow
. Perform a venous supercharge by anastomosing a superficial flap vein to a dorsal hand vein
. Return the flap to the donor site and harvest a free flap
. Apply topical nitroglycerin paste and warm compresses

Correct Answer & Explanation

. Perform a venous supercharge by anastomosing a superficial flap vein to a dorsal hand vein

Explanation

Venous congestion is a significant complication of the reverse radial forearm flap. Anastomosing the cephalic vein or another superficial vein of the flap to a draining vein in the hand (supercharging) improves venous outflow and rescues congested flaps.

Question 910

Topic: Nerve & Tendon

A sensate reverse radial forearm flap is planned for a patient with a massive first web space defect. To provide protective sensation to the reconstructed area, which nerve should be included in the flap harvest for coaptation?

. Superficial radial nerve
. Lateral antebrachial cutaneous nerve
. Medial antebrachial cutaneous nerve
. Posterior antebrachial cutaneous nerve
. Palmar cutaneous branch of the median nerve

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve

Explanation

The lateral antebrachial cutaneous nerve courses with the cephalic vein and provides sensation to the radial aspect of the forearm. It is routinely included when a sensate radial forearm flap is required.

Question 911

Topic: 7. Hand and Wrist

A reverse radial forearm osteocutaneous flap is being harvested to reconstruct a composite first metacarpal defect. To minimize the risk of a postoperative radius fracture, the bone harvest should not exceed what maximum percentage of the radial cross-sectional diameter?

. 15%
. 20%
. 40%
. 60%
. 75%

Correct Answer & Explanation

. 40%

Explanation

When harvesting an osteocutaneous radial forearm flap, bone harvest should be strictly limited to a maximum of 30-40% of the radius cross-sectional diameter. Exceeding this amount significantly increases the risk of a pathologic radius fracture.

Question 912

Topic: 7. Hand and Wrist

A 45-year-old patient who underwent a reverse radial forearm flap 6 months ago presents with shooting pain radiating to the dorsoradial aspect of the hand when the donor site is tapped. Which nerve is most likely implicated in this complication?

. Median nerve
. Ulnar nerve
. Superficial branch of the radial nerve
. Lateral antebrachial cutaneous nerve
. Posterior interosseous nerve

Correct Answer & Explanation

. Superficial branch of the radial nerve

Explanation

The superficial branch of the radial nerve emerges beneath the brachioradialis in the distal third of the forearm. It is highly susceptible to injury or neuroma formation during the dissection and skin grafting of the donor site.

Question 913

Topic: 7. Hand and Wrist

The extended reach of the reverse radial forearm flap is determined by its pivot point. Anatomically, this pivot point relies on the anastomosis of the radial artery with which of the following structures?

. Superficial palmar arch
. Deep palmar arch
. Anterior interosseous artery
. Princeps pollicis artery
. Ulnar artery at the wrist crease

Correct Answer & Explanation

. Deep palmar arch

Explanation

The reverse radial forearm flap pivots distal to the radial styloid. Its viability and reach depend on the retrograde flow from the ulnar artery, which travels primarily through the deep palmar arch to the radial artery.

Question 914

Topic: 7. Hand and Wrist

A surgeon opts to perform a reverse adipofascial radial forearm flap instead of a standard fasciocutaneous flap for a dorsal wrist defect. What is the primary advantage of this modification?

. Enhanced sensory recovery at the recipient site
. Ability to include a larger bony segment
. Direct primary closure of the donor site
. Improved venous drainage without supercharging
. Increased resistance to postoperative deep space infection

Correct Answer & Explanation

. Direct primary closure of the donor site

Explanation

The adipofascial variation of the radial forearm flap spares the overlying forearm skin. This allows for primary closure of the donor site, significantly reducing donor site morbidity compared to skin grafting over exposed paratenon.

Question 915

Topic: 7. Hand and Wrist

A 60-year-old male smoker with peripheral vascular disease undergoes a reverse radial forearm flap. Postoperatively, he develops severe digital ischemia in the affected hand. Which underlying anatomic factor most likely precipitated this complication?

. Incomplete superficial palmar arch
. Hypercoagulable state due to smoking
. Venous congestion of the flap
. Superficial radial nerve injury
. Failure of the skin graft at the donor site

Correct Answer & Explanation

. Incomplete superficial palmar arch

Explanation

Ligation of the radial artery leaves the hand entirely dependent on the ulnar artery. An incomplete superficial palmar arch, especially in a vasculopathic patient, can lead to severe hand ischemia when the radial artery is sacrificed.

Question 916

Topic: 7. Hand and Wrist



A patient presents with a soft tissue defect over the distal interphalangeal joint of the middle finger. A reverse radial forearm flap is considered. What limits the utility of this flap for this specific defect?

. Inadequate venous drainage at the distal phalanx level
. The maximum distal reach of the standard flap is typically limited to the proximal phalanx
. High risk of radial artery thrombosis when spanning the MCP joints
. Inability to provide a sensate flap for the digit
. The thickness of the flap precludes its use on any part of the fingers

Correct Answer & Explanation

. The maximum distal reach of the standard flap is typically limited to the proximal phalanx

Explanation

The standard reverse radial forearm flap relies on a pivot point near the anatomic snuffbox. Its maximum distal reach is generally limited to the dorsum of the hand, the thumb, and the proximal phalanges, making it unsuitable for a DIP joint defect without vein grafting.

Question 917

Topic: 7. Hand and Wrist

A 42-year-old male undergoes a reverse radial forearm flap for a dorsal hand defect. Intraoperatively, the cephalic vein is not anastomosed to a local hand vein. How does venous blood primarily drain from this distally based pedicled flap?

. Through retrograde flow via the cephalic vein.
. Through retrograde flow via valveless communicating branches between the venae comitantes.
. Through capillary diffusion into the recipient bed.
. Through antegrade flow in the basilic vein.
. Through collateral flow via the deep palmar arch.

Correct Answer & Explanation

. Through retrograde flow via valveless communicating branches between the venae comitantes.

Explanation

Venous drainage in a distally based radial forearm flap without superficial venous supercharging relies on retrograde flow through the venae comitantes. Blood bypasses the venous valves via valveless communicating transverse branches between the comitantes.

Question 918

Topic: 7. Hand and Wrist

To achieve maximum distal reach for a reverse radial forearm flap without compromising its primary vascular supply, what is the most distal anatomical landmark for the flap's pivot point?

. The proximal edge of the transverse carpal ligament.
. The anatomical snuffbox.
. The bifurcation of the radial artery.
. The superficial palmar arch.
. The junction of the brachioradialis and flexor carpi radialis tendons.

Correct Answer & Explanation

. The anatomical snuffbox.

Explanation

The pivot point for a reverse radial forearm flap is typically at the anatomical snuffbox, just distal to the radial styloid. Dissection beyond this point risks injuring the communicating branches to the deep palmar arch, which provide the retrograde blood supply.

Question 919

Topic: 7. Hand and Wrist

A surgeon plans to harvest a sensate reverse radial forearm flap to reconstruct a palmar hand defect. Which nerve should be co-apted to a recipient digital nerve to restore protective sensation to the flap?

. Superficial branch of the radial nerve
. Medial antebrachial cutaneous nerve
. Lateral antebrachial cutaneous nerve
. Posterior antebrachial cutaneous nerve
. Palmar cutaneous branch of the median nerve

Correct Answer & Explanation

. Lateral antebrachial cutaneous nerve

Explanation

The lateral antebrachial cutaneous nerve (LABC) travels within the subcutaneous tissue of the radial forearm and is routinely included to provide protective sensation in a sensate reverse radial forearm flap. The superficial branch of the radial nerve should generally be preserved to maintain dorsal hand sensation.

Question 920

Topic: 7. Hand and Wrist

Intraoperatively, following the transfer of a reverse radial forearm flap to the dorsal hand, the flap appears excessively blue and engorged with a brisk, dark capillary bleed. The arterial anastomosis is patent. What is the most reliable surgical method to salvage the flap?

. Systemic administration of heparin and dextran
. Venous supercharging by anastomosing the proximal cephalic vein of the flap to a superficial vein at the recipient site
. Elevating the extremity above heart level and applying warm compresses
. Performing multiple needle punctures to allow continuous passive drainage
. Revising the arterial pedicle to reduce excessive inflow

Correct Answer & Explanation

. Venous supercharging by anastomosing the proximal cephalic vein of the flap to a superficial vein at the recipient site

Explanation

Venous congestion is a recognized complication of the reverse radial forearm flap due to valvular resistance in the venae comitantes. Anastomosing the proximally divided cephalic vein (or a large superficial vein) of the flap to a dorsal hand vein provides antegrade venous drainage and reliably relieves congestion.

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