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7. Hand and Wrist MCQs

Practice Set 186 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 3701

Topic: Nerve & Tendon

A patient presents with a chronic FDP rupture of the ring finger. He attempts to make a fist, and you observe active hyperextension of the DIP joint. This is known as:

. Boutonniere deformity.
. Swan neck deformity.
. Mallet finger.
. Lumbrical plus phenomenon.
. Quadriga effect.

Correct Answer & Explanation

. Lumbrical plus phenomenon.

Explanation

This is a classic description of the lumbrical plus phenomenon. In a chronic FDP rupture, the FDP tendon is slack or non-functional. When the patient attempts to flex the finger (activating the FDP muscle belly), the lumbrical muscle is pulled proximally, and its contraction (as it originates from the FDP tendon and inserts into the extensor mechanism) causes paradoxical extension of the DIP joint instead of flexion. This can be seen as active hyperextension of the DIP with attempted grip.

Question 3702

Topic: 7. Hand and Wrist

What surgical technique for FDP repair involves passing a suture through the distal tendon stump, out through the nail bed, and securing it over a button on the dorsal aspect of the nail?

. Modified Kessler suture.
. M-Tang suture.
. Bone anchor repair.
. Pull-out suture technique.
. Flexor profundus advancement.

Correct Answer & Explanation

. Pull-out suture technique.

Explanation

This is the classic description of a pull-out suture technique. It is often used for FDP avulsion repairs, especially when there is minimal bone for direct anchor fixation or when a bony fragment is small. The suture secures the tendon to the distal phalanx by passing through the bone and exiting dorsally, where it is tied over a button to hold the repair in place. The Modified Kessler and M-Tang are core suture techniques for direct tendon-to-tendon repair. Bone anchors are internal fixation devices. FDP advancement is a lengthening procedure.

Question 3703

Topic: 7. Hand and Wrist
In Leddy and Packer Type III Jersey finger, what is the significance of the bony avulsion fragment regarding tendon blood supply and timing of surgery?
. The bony fragment completely disrupts the vincula, making the injury highly urgent.
. The bony fragment protects the tendon's blood supply via retained vincula, allowing for delayed repair.
. The bony fragment increases the risk of tendon necrosis, necessitating immediate surgery.
. The bony fragment has no bearing on tendon blood supply or surgical timing.
. The bony fragment is usually too small to reattach, so the tendon is primarily repaired to the remaining phalanx.

Correct Answer & Explanation

. The bony fragment protects the tendon's blood supply via retained vincula, allowing for delayed repair.

Explanation

In a Type III Jersey finger, the bony avulsion fragment, typically from the distal phalanx, prevents further proximal retraction of the FDP tendon. Crucially, the vincula tendinum often remain attached to this fragment or the tendon itself, preserving the tendon's blood supply. This maintained vascularity allows for a less urgent surgical window, typically up to 3-4 weeks post-injury, without a significant increase in the risk of tendon necrosis or poor outcome, unlike a Type I injury. The fragment is usually reattached.

Question 3704

Topic: Nerve & Tendon

What is the expected long-term outcome regarding grip strength following a successful FDP repair for a Type I Jersey finger in a young, compliant patient?

. Complete restoration of pre-injury grip strength within 3 months.
. Significant permanent reduction in grip strength, even with good recovery.
. Near-normal grip strength can be achieved, but DIP flexion strength may be slightly reduced.
. Grip strength will be entirely dependent on the FDS tendon, as FDP function is lost.
. Increased grip strength due to compensatory hypertrophy of other flexors.

Correct Answer & Explanation

. Near-normal grip strength can be achieved, but DIP flexion strength may be slightly reduced.

Explanation

Following a successful FDP repair in a young, compliant patient, near-normal grip strength can typically be achieved. However, isolated DIP flexion strength, and potentially endurance, may remain slightly reduced compared to the uninjured contralateral digit due to some scarring, stiffness, or slight tendon shortening. Complete restoration is optimistic, but significant permanent reduction is too pessimistic for a successful repair. The FDP is crucial for grip, not fully compensated by FDS. Increased grip strength is not expected.

Question 3705

Topic: 7. Hand and Wrist

When performing an FDP repair, which of the following describes the potential issue of a 'too-tight' repair?

. Increased risk of re-rupture due to inadequate tendon coaptation.
. Resultant lack of full active flexion in the repaired digit.
. Quadriga effect, limiting flexion of adjacent digits.
. Insufficient blood supply to the tendon, leading to necrosis.
. Persistent pain at the distal phalanx due to bone anchor irritation.

Correct Answer & Explanation

. Quadriga effect, limiting flexion of adjacent digits.

Explanation

A 'too-tight' FDP repair, meaning the tendon is repaired with excessive tension or advanced too much, is a classic cause of the quadriga effect. Because the FDP tendons for the ring, middle, and small fingers share a common muscle belly (and the index finger's FDP is closely related), overtightening one tendon can prevent full excursion of the entire FDP muscle group. This leads to restricted flexion in the adjacent, healthy digits when the repaired finger attempts to flex. Lack of active flexion implies re-rupture or adhesions. Insufficient coaptation leads to gapping. Blood supply issues are from the injury itself.

Question 3706

Topic: 7. Hand and Wrist

What is the typical insertion point of the FDS tendon in the finger?

. Palmar base of the distal phalanx.
. Palmar aspect of the middle phalanx.
. Volar plate of the PIP joint.
. Dorsal aspect of the proximal phalanx.
. Distal phalanx of the thumb.

Correct Answer & Explanation

. Palmar aspect of the middle phalanx.

Explanation

The Flexor Digitorum Superficialis (FDS) tendon splits into two slips at the PIP joint, with the FDP passing through this decussation. The two slips of the FDS then re-unite to insert onto the palmar aspect of the middle phalanx of the four medial fingers. The FDP inserts onto the distal phalanx. The volar plate is a ligamentous structure. The dorsal aspect is for extensors. The thumb has its own flexor pollicis longus.

Question 3707

Topic: 7. Hand and Wrist
Which of the following represents the most challenging FDP avulsion injury to repair primarily, often requiring more complex solutions?
. Acute Type II injury with the tendon at the A3 pulley.
. Acute Type III injury with a large bony fragment.
. Acute Type V injury with a small intra-articular fracture.
. Chronic Type I injury with tendon retraction into the forearm.
. Acute Type I injury with minimal retraction and good tissue quality.

Correct Answer & Explanation

. Chronic Type I injury with tendon retraction into the forearm.

Explanation

A chronic Type I injury with the tendon retracted significantly into the forearm (often many centimeters) is the most challenging for primary repair. Over time, the retracted tendon shortens, undergoes degenerative changes, and dense adhesions form, making it impossible to bring the tendon to the distal phalanx without excessive tension. This scenario almost invariably requires staged tendon reconstruction with a graft, which is a much more complex procedure than repairing acute Type I, II, III, or V injuries. Acute injuries generally have better outcomes with primary repair.

Question 3708

Topic: Nerve & Tendon

When evaluating a patient for a Jersey finger, which finding on physical examination most strongly suggests the FDS tendon is still functional?

. Inability to actively flex the DIP joint.
. Intact cascade of all fingers at rest.
. Ability to actively flex the PIP joint while holding adjacent fingers in extension.
. Pain with passive extension of the DIP joint.
. Palpable tendon in the distal palm.

Correct Answer & Explanation

. Ability to actively flex the PIP joint while holding adjacent fingers in extension.

Explanation

The Flexor Digitorum Superficialis (FDS) is the primary flexor of the PIP joint. The most definitive test for FDS function is to stabilize the patient's adjacent fingers in full extension (to inactivate the FDP of those fingers, which share a common muscle belly) and then ask the patient to actively flex the PIP joint of the finger being tested. If the PIP joint flexes against resistance, the FDS is functional. Inability to flex the DIP suggests FDP rupture. Intact cascade is an FDP sign. Pain with passive extension is non-specific. Palpable tendon doesn't confirm function.

Question 3709

Topic: Nerve & Tendon

What is the most likely complication if the A2 pulley is inadvertently excised during FDP repair?

. Lumbrical plus phenomenon.
. Quadriga effect.
. Boutonniere deformity.
. Flexor tendon bowstringing.
. Increased risk of chronic pain.

Correct Answer & Explanation

. Flexor tendon bowstringing.

Explanation

The A2 pulley, along with the A4 pulley, is considered critical for maintaining the mechanical efficiency of the flexor tendons. Excision or rupture of the A2 pulley leads to 'bowstringing' of the flexor tendon, where the tendon lifts away from the bone during flexion, significantly reducing its mechanical advantage and causing a loss of grip strength and range of motion. Lumbrical plus and quadriga are related to tendon length/tension. Boutonniere involves the extensor mechanism. Chronic pain is a general complication, not specific to A2 excision.

Question 3710

Topic: 7. Hand and Wrist

Which of the following describes the 'no man's land' zone in flexor tendon surgery?

. The zone where flexor tendons emerge from the forearm into the palm.
. The zone of flexor tendons within the carpal tunnel.
. The zone from the distal palmar crease to the mid-portion of the middle phalanx (Zone II), notorious for high rates of adhesion formation.
. The zone proximal to the A1 pulley, where the lumbrical muscles originate.
. The zone where extensor tendons cross the MCP joints.

Correct Answer & Explanation

. The zone from the distal palmar crease to the mid-portion of the middle phalanx (Zone II), notorious for high rates of adhesion formation.

Explanation

'No man's land' refers to Zone II of the flexor tendon system, which extends from the distal palmar crease to the mid-portion of the middle phalanx. This zone is particularly challenging for flexor tendon repairs due to the close proximity of both FDS and FDP tendons within a confined fibro-osseous sheath, making it highly susceptible to adhesion formation and poor gliding post-repair. While surgical techniques and rehabilitation have improved outcomes, it remains a challenging zone.

Question 3711

Topic: 7. Hand and Wrist

Which of the following is a recognized complication of an untreated or chronically missed Monteggia fracture, leading to late reconstructive challenges?

. Madelung's deformity
. Post-traumatic arthrosis of the radiocapitellar joint
. Carpal tunnel syndrome
. Anterior interosseous nerve syndrome
. De Quervain's tenosynovitis

Correct Answer & Explanation

. Post-traumatic arthrosis of the radiocapitellar joint

Explanation

Untreated or chronically missed Monteggia fractures, especially with persistent radial head dislocation, inevitably lead to degenerative changes and post-traumatic arthrosis of the radiocapitellar joint. The abnormal articulation and altered biomechanics result in cartilage wear, pain, stiffness, and progressive loss of function. This is a significant challenge in late reconstructive surgery. Madelung's deformity is a growth disturbance of the distal radius, carpal tunnel syndrome is median nerve compression at the wrist, AIN syndrome is a specific median nerve motor palsy, and De Quervain's is a wrist tenosynovitis; none are primary sequelae of chronic Monteggia.

Question 3712

Topic: Nerve & Tendon

After ORIF of an adult Monteggia fracture, the patient complains of numbness in the small finger and medial half of the ring finger. What nerve injury should be suspected?

. Radial nerve
. Median nerve
. Posterior interosseous nerve
. Anterior interosseous nerve
. Ulnar nerve

Correct Answer & Explanation

. Ulnar nerve

Explanation

Numbness in the small finger and the medial half of the ring finger, along with weakness of intrinsic hand muscles (interossei, adductor pollicis), indicates an ulnar nerve injury. While PIN injury is most common with the Monteggia fracture itself, iatrogenic ulnar nerve injury can occur during surgical approaches to the medial or posterior elbow, or due to prolonged traction or compression during surgery. Assessment of nerve function is crucial both pre- and post-operatively.

Question 3713

Topic: Nerve & Tendon

During surgical exposure for an olecranon fracture, the ulnar nerve is identified. What is the most appropriate management strategy if the nerve is found to be intact but compressed by surrounding hematoma or scar tissue, especially in a fracture requiring internal fixation?

. No intervention, close the wound
. Neurolysis in situ
. Anterior transposition of the ulnar nerve
. Posterior interosseous nerve release
. Immediate nerve graft

Correct Answer & Explanation

. Anterior transposition of the ulnar nerve

Explanation

If the ulnar nerve is found to be compressed or at high risk of post-operative compression/irritation (e.g., due to hardware placement or significant swelling, or pre-existing cubital tunnel syndrome), anterior transposition (C) is often performed prophylactically or therapeutically. This moves the nerve out of the cubital tunnel and into a less constrained anterior position, reducing the risk of neuropathy. Neurolysis in situ (B) may be considered for milder cases but is less definitive if significant risk factors for ongoing compression are present. No intervention (A) would be inappropriate if compression is present or anticipated. Posterior interosseous nerve release (D) is for radial nerve issues. Immediate nerve graft (E) is for transected nerves.

Question 3714

Topic: Nerve & Tendon

During a posterior approach to the elbow for olecranon fracture fixation, the ulnar nerve is typically located in which anatomical relationship to the medial epicondyle?

. Anterior and lateral
. Posterior and lateral
. Anterior and medial
. Posterior and medial
. Directly over the olecranon tip

Correct Answer & Explanation

. Posterior and medial

Explanation

The ulnar nerve runs in the cubital tunnel, which is located posterior and medial (D) to the medial epicondyle of the humerus. This makes it vulnerable to injury during a posterior surgical approach to the olecranon, requiring careful identification and protection.

Question 3715

Topic: Nerve & Tendon

What specific maneuver is critical to perform during the closure of a posterior approach for olecranon fracture fixation, especially if the ulnar nerve was exposed or transposed?

. Ensure full elbow extension
. Perform passive varus stress test
. Check for tension-free closure over the ulnar nerve
. Apply immediate full active flexion
. Tighten triceps repair aggressively

Correct Answer & Explanation

. Check for tension-free closure over the ulnar nerve

Explanation

Ensuring a tension-free closure over the ulnar nerve (C) is paramount to prevent post-operative nerve irritation or entrapment. If the nerve has been transposed, it must be placed in a bed of soft tissue and not directly beneath skin or fascia under tension. Aggressive tightening of the triceps repair (E) can cause undue tension. The other options are not directly related to ulnar nerve protection during closure.

Question 3716

Topic: Nerve & Tendon

Besides early controlled range of motion, what other intra-operative technique is crucial to minimize post-operative elbow stiffness following olecranon fracture fixation?

. Prolonged tourniquet time
. Aggressive periosteal stripping
. Meticulous anatomical reduction of the articular surface
. Oversized hardware
. Routine prophylactic ulnar nerve transposition

Correct Answer & Explanation

. Meticulous anatomical reduction of the articular surface

Explanation

Meticulous anatomical reduction of the articular surface (C) is critical. A smooth, congruent joint surface minimizes friction, prevents abnormal contact stresses, and allows for smoother motion, significantly reducing the risk of post-traumatic arthritis and subsequent stiffness. Prolonged tourniquet time (A) and aggressive periosteal stripping (B) can increase tissue damage and lead to stiffness and heterotopic ossification. Oversized hardware (D) can itself be prominent and restrict motion. Routine prophylactic ulnar nerve transposition (E) is performed to prevent nerve symptoms, not primarily stiffness, although avoiding nerve irritation can facilitate rehabilitation.

Question 3717

Topic: Nerve & Tendon
All of the following are potential contributing factors to elbow stiffness following an olecranon fracture EXCEPT:
. Prolonged immobilization
. Heterotopic ossification
. Complex intra-articular comminution
. Aggressive early active range of motion within pain limits
. Ulnar nerve entrapment

Correct Answer & Explanation

. Aggressive early active range of motion within pain limits

Explanation

Aggressive early active range of motion within pain limits is actually a preventative measure against stiffness, as controlled motion helps maintain joint mobility and cartilage health. Therefore, it is not a contributing factor to stiffness. Prolonged immobilization, heterotopic ossification, and complex intra-articular comminution are all well-known causes of elbow stiffness. Ulnar nerve entrapment can cause pain and limit participation in rehabilitation, thereby indirectly contributing to stiffness.

Question 3718

Topic: Nerve & Tendon

Which peripheral nerve is most commonly injured in association with olecranon fractures or during their surgical repair?

. Radial nerve
. Median nerve
. Ulnar nerve
. Musculocutaneous nerve
. Anterior interosseous nerve

Correct Answer & Explanation

. Ulnar nerve

Explanation

The ulnar nerve (C) is located in the cubital tunnel posterior to the medial epicondyle, making it highly susceptible to injury during olecranon fractures (due to direct trauma, displacement of fragments, or hematoma) and during surgical approaches (due to retraction, direct injury, or hardware impingement). It is by far the most commonly involved nerve in this setting.

Question 3719

Topic: Nerve & Tendon

Which factor makes the posterior aspect of the elbow particularly prone to hardware prominence and subsequent irritation after olecranon fracture fixation?

. High vascularity of the olecranon
. Lack of significant muscle or subcutaneous tissue coverage
. Presence of the ulnar nerve in the cubital tunnel
. Frequent flexion and extension movements of the elbow
. High incidence of infection

Correct Answer & Explanation

. Lack of significant muscle or subcutaneous tissue coverage

Explanation

The posterior aspect of the elbow (over the olecranon) has very little subcutaneous tissue or muscle coverage, making it particularly susceptible to hardware prominence and irritation (B). Even well-placed hardware can be felt directly under the skin, leading to pain, bursitis, or skin breakdown, often necessitating removal once the fracture has healed. While frequent movement (D) can exacerbate symptoms, the lack of soft tissue is the primary anatomical reason for prominence.

Question 3720

Topic: 7. Hand and Wrist

What is the typical presentation of a patient experiencing a delayed union of a both bones forearm fracture, 6 months post-ORIF?

. Sudden onset of severe pain, fever, and purulent discharge.
. Progressive stiffness, skin changes, and hyperalgesia (CRPS).
. Persistent pain with activity, localized tenderness, and possibly loosening of hardware on radiographs.
. Acute loss of forearm rotation with a palpable 'clunk' in the wrist.
. Neurovascular compromise distal to the fracture site.

Correct Answer & Explanation

. Persistent pain with activity, localized tenderness, and possibly loosening of hardware on radiographs.

Explanation

A delayed union (Option C) typically presents as persistent pain with activity, localized tenderness at the fracture site, and often, radiographs showing persistent fracture lines with absent or insufficient bridging callus, and sometimes signs of hardware loosening or breakage due to cyclic loading. Sudden pain and discharge (A) suggest infection. Progressive stiffness and skin changes (B) suggest CRPS. Loss of rotation with a clunk (D) might indicate DRUJ instability or synostosis in late stages. Neurovascular compromise (E) is an acute complication.

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