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 1281
Topic: Nerve & Tendon
When utilizing a crossed-pinning technique (one medial and one lateral K-wire) for the fixation of a pediatric supracondylar humerus fracture, what is the most significant iatrogenic risk associated with the medial pin placement?
Correct Answer & Explanation
. Ulnar nerve injury
Explanation
Placement of a medial pin in supracondylar humerus fractures carries a recognized risk of iatrogenic ulnar nerve injury due to the nerve's posterior course in the cubital tunnel. To mitigate this, the elbow is often extended slightly from hyperflexion during medial pin insertion.
Question 1282
Topic: Nerve & Tendon
A 35-year-old carpenter underwent a primary flexor digitorum profundus (FDP) repair in his right ring finger one month ago. He now complains that he is entirely unable to make a full fist with his uninjured middle and small fingers. Which of the following biomechanical phenomena explains this presentation?
Correct Answer & Explanation
. Quadrigia effect
Explanation
The quadrigia effect occurs when the FDP tendon is over-advanced during repair. Because the FDP tendons to the middle, ring, and small fingers share a common muscle belly, over-tensioning one tendon restricts the excursion of the others.
Question 1283
Topic: 7. Hand and Wrist
A 28-year-old male sustains a minor twisting injury to his hand and presents with swelling and pain. Radiographs reveal a pathologic fracture through a central, expansile, lytic lesion in the proximal phalanx of the ring finger. Stippled calcifications are noted within the matrix. What is the recommended management after the fracture has healed?
Correct Answer & Explanation
. Curettage and bone grafting
Explanation
The clinical and radiographic presentation is classic for an enchondroma, the most common primary bone tumor of the hand. Once a pathologic fracture heals, the definitive treatment is curettage and bone grafting (or substitute) to prevent recurrence and structural failure.
Question 1284
Topic: Nerve & Tendon
A 22-year-old collegiate rugby player sustained an injury to his right ring finger when he violently grabbed an opponent's jersey. He is unable to actively flex the distal interphalangeal (DIP) joint. Ultrasound confirms a Type I Leddy-Packer avulsion, with the flexor digitorum profundus (FDP) tendon retracted into the palm. Within what timeframe must surgical repair ideally be performed to prevent permanent contracture and tendon necrosis?
Correct Answer & Explanation
. Within 7 to 10 days
Explanation
A Type I "Jersey finger" involves retraction of the FDP tendon into the palm, which disrupts the vincula and severely compromises the tendon's blood supply. Surgical repair must be performed within 7 to 10 days to prevent permanent tendon necrosis and fixed contracture.
Question 1285
Topic: Nerve & Tendon
A 30-year-old recreational basketball player sustained an untreated mallet injury to his middle finger eight months ago. He now presents complaining of a secondary finger deformity. Based on the pathophysiology of chronic mallet finger, which of the following deformities is he at greatest risk of developing?
Correct Answer & Explanation
. Swan neck deformity
Explanation
An untreated mallet finger leads to loss of terminal extensor tendon continuity. The extensor mechanism retracts proximally, concentrating extensor forces at the PIP joint. Over time, this stretches the volar plate, resulting in PIP hyperextension and DIP flexion (Swan neck deformity).
Question 1286
Topic: Nerve & Tendon
A 25-year-old chef sustains a knife laceration to the volar aspect of his palm at the level of the A1 pulley. During surgical exploration, both the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons are found cleanly transected. In which flexor tendon zone did this injury occur, and what is the current standard of care?
Correct Answer & Explanation
. Zone II; repair both FDP and FDS
Explanation
Zone II extends from the A1 pulley to the FDS insertion and contains both tendons within a tight fibro-osseous sheath. The current standard of care is the primary repair of both the FDS and FDP to optimize tendon gliding, preserve independent PIP joint flexion, and improve vascularity.
Question 1287
Topic: Nerve & Tendon
What neurovascular structure is in closest proximity to the probe in the arthroscopic view of the elbow shown in Figure 50? Review Topic
Correct Answer & Explanation
. Radial nerve
Explanation
The image shows a view of the radiocapitellar joint from an anterior medial portal. The radial nerve lies on the elbow capsule at the midportion of the capitellum. It is at risk for injury when capsular excision is performed in this region.
Question 1288
Topic: 7. Hand and Wrist
A 63-year-old woman is seen 10 weeks after sustaining a closed minimally displaced distal radius fracture. She has been in a short-arm cast and reports minimal pain but notes that she is having difficulty using her thumb. An extensor pollicis longus (EPL) tendon rupture is suspected. Which examination finding would confirm lack of EPL function?
Correct Answer & Explanation
. Inability to extend the thumb with the palm flat on a table
Explanation
EXPLANATION: As many as 5% of patients with a nondisplaced distal radius fracture experience EPL rupture. The extensor pollicis brevis (EPB) tendon often attaches to the extensor hood and sometimes continues more distally, providing weak metacarpophalangeal extension even in the setting of EPL disruption. However, because of the vector of its pull, the EPB cannot extend the thumb dorsal to the plane of the palm. A positive Froment sign is noted when flexion of the thumb interphalangeal joint with an attempted key pinch is caused by adductor pollicis weakness from ulnar nerve dysfunction. Compression of the median nerve in the carpal tunnel affects the recurrent motor branch of the abductor pollicis brevis, leading to thenar atrophy. The flexor pollicis longus tendon (FPL) is intact so the patient would not have difficulty flexing the thumb with the palm flat.
Question 1289
Topic: 7. Hand and Wrist
A 21-year-old man who was injured in a snowboarding accident 18 months ago now reports wrist pain. An MRI scan is shown in Figure 37. Based on the image findings, what is the most likely diagnosis?
Correct Answer & Explanation
. Scaphoid nonunion and osteonecrosis
Explanation
The coronal MRI scan of the wrist shows the scaphoid. There is a subtle fracture line with a step-off at the radial surface consistent with a nonunion. The signal intensity is markedly different between the two fragments of the scaphoid. This strongly suggests osteonecrosis. Preiser’s disease is osteonecrosis typically involving most or all of the scaphoid. Kienbock’s disease involves the lunate. Intraosseous ganglia are easily diagnosed on MRI but typically have a fluid-filled area surrounded by denser bone in the periphery. Scapholunate dissociation can be seen on MRI as an injury to the scapholunate ligament and widening of the scapholunate interval, neither of which is seen on this image.
Question 1290
Topic: 7. Hand and Wrist
To adequately expose the volar plate of the proximal interphalangeal joint of the finger, which of following pulleys is typically incised?
Correct Answer & Explanation
. Distal portion of C1, entire A3, and the proximal portion of C2
Explanation
Full exposure of the volar plate of the proximal interphalangeal joint of the finger is best accomplished by incision of the distal C1, A3, and proximal C2 pulleys; followed by gentle retraction of the flexor digitorum superficialis and profundus tendons. Sacrifice of the A3 pulley, although associated with some biomechanic disadvantage, can be tolerated without causing functionally limiting bowstringing of the flexor tendon. Sacrifice of even a portion of the A2 or A4 pulleys can decrease the biomechanic leverage provided by the flexor tendon sheath, leading to bowstringing of the flexor tendons.
Question 1291
Topic: 7. Hand and Wrist
A patient reports hyperesthesia over the base of the thenar eminence following volar locked plating of a distal radius fracture. A standard volar approach of Henry was used. What is the most likely cause of the hyperesthesia?
Correct Answer & Explanation
. Palmar cutaneous nerve injury
Explanation
The palmar cutaneous branch of the median nerve separates from the median nerve approximately 4 to 6 cm proximal to the wrist crease and travels between the median nerve and the flexor carpi radialis tendon. It supplies the skin of the thenar region. This nerve is at risk for injury with retraction of the digital flexor tendons in plating the distal radius. Wartenberg’s syndrome is compression of the superficial radial nerve which innervates the dorsum of the thumb and the first dorsal web space. Carpal tunnel syndrome causes dysesthesias of the thumb, index, and/or middle fingers. C7 radiculopathy affects the index and middle fingers.
Question 1292
Topic: Nerve & Tendon
A 35-year-old man falls off of a roof and sustains an extra-articular supracondylar elbow fracture. He had normal sensation in all fingers after the injury and before undergoing surgery to repair the fracture. The ulnar nerve was not transposed but was inspected prior to wound closure. Ten days after surgery, the patient has numbness in his small finger and is unable to cross his fingers. His elbow range of motion is 40° to 100°. What is the next appropriate step in management?
Correct Answer & Explanation
. Continued observation
Explanation
This patient has an early postsurgical ulnar nerve palsy. The causes of this injury are laceration of the nerve during surgery, entrapment of the nerve in the fracture or hardware, or traction injury during surgery. If the orthopaedic surgeon is sure that the nerve was not lacerated at the end of the case or entrapped in the hardware, then the nerve is probably intact and will recover. Observation is the best treatment in this case because the nerve was checked before wound closure. Elbow splinting has not been shown to help with postsurgical nerve recovery. EMG findings may not be accurate this early following the injury.
Question 1293
Topic: 7. Hand and Wrist
An 18-year-old rugby player has had pain in his ring finger after missing a tackle 1 week ago. Examination reveals tenderness in the distal palm, and he is unable to actively flex the distal interphalangeal (DIP) joint. Radiographs are normal. What is the most appropriate management?
Correct Answer & Explanation
. Acute tendon repair
Explanation
DISCUSSION: Flexor digitorum profundus rupture or “rugger jersey finger” often occurs in the ring finger after the player misses a tackle and catches the digit on the shirt of the opposing player. Surgical repair is required for zone I-type injuries. REFERENCES: Moiemen NS, Elliot D: Primary flexor tendon repair in zone I. J Hand Surg Br 2000;25:78-84. Strickland JW: Flexor tendon injuries: I. Foundations of treatment. J Am Acad Orthop Surg 1995;3:44-54.
Question 1294
Topic: 7. Hand and Wrist
An otherwise healthy 35-year-old woman reports dorsal wrist pain and has trouble extending her thumb after sustaining a minimally displaced fracture of the distal radius 3 months ago. What is the next most appropriate step in management?
Correct Answer & Explanation
. Transfer of the extensor indicis proprius to the extensor pollicis longus tendon
Explanation
Extensor pollicis longus tendon rupture can occur after a fracture of the distal radius, even a minimally displaced one. Poor vascularity of the tendon within the third dorsal compartment is the suspected etiology, not the displaced fracture fragments. Tendon transfer will suitably restore active extension of the thumb interphalangeal joint.
Question 1295
Topic: 7. Hand and Wrist
A 24-year-old man who plays golf noted the immediate onset of pain on the ulnar side of his hand and has been unable to swing a club for the past 6 weeks after striking a tree root with his club during his golf swing. Examination reveals full motion of the wrist, diminished grip strength, and tenderness over the hypothenar region. A CT scan of the hand and wrist is shown in Figure 26. Management should consist of
Correct Answer & Explanation
. immobilization of the wrist until the fracture heals.
Explanation
DISCUSSION: Fractures of the hook of the hamate frequently are not identified in the acute phase. Because the fracture can be difficult to see on plain radiographs, the lack of findings can lead to a painful nonunion. A carpal tunnel view may show the fracture, but a CT scan will best detect the injury. Immobilization is the treatment of choice and will result in union in most patients unless the diagnosis is delayed. However, excision of the fragment may be necessary for patients who have nonunion, persistent pain, or ulnar nerve palsy. REFERENCES: Carroll RE, Lakin JF: Fracture of the hook of the hamate: Acute treatment. J Trauma 1993;34:803-805. Whalen JL, Bishop AT, Linscheid RL: Nonoperative treatment of acute hamate hook fractures. J Hand Surg Am 1992;17:507-511.
Question 1296
Topic: Nerve & Tendon
Figures 55a through 55c are the clinical photograph and radiographs of a 5-year-old boy who fell and injured his right elbow. His radial pulse is thready. Which neurologic deficit most commonly is associated with this injury?
Correct Answer & Explanation
. Inability to flex the thumb interphalangeal (IP) joint
Explanation
DISCUSSION: This injury is a type III supracondylar humerus fracture with posterolateral displacement. The area of ecchymosis is anteromedial, corresponding to the proximal spike of the humeral metaphysis. The brachial artery is likely tented over this spike, leading to diminished perfusion. The median nerve also resides in this area, and any neurological deficit is likely in its most vulnerable fibers, those of the anterior interosseous nerve (AIN). The AIN contains no sensory fibers, and its motor function involves flexion of both the thumb IP joint and the index distal IP joint. First dorsal web space anesthesia and an inability to extend the fingers would indicate radial nerve neuropraxia, which would be more likely with posteromedially displaced fractures and lead to anterolateral ecchymosis. Finger abduction is controlled by the ulnar nerve, which most often is injured in flexion injuries and iatrogenically by medially placed pins.
Question 1297
Topic: 7. Hand and Wrist
The comparative outcomes of needle aponeurotomy (NA) and collagenase Clostridium histolyticum (CCH) use in the treatment of Dupuytren contracture indicate that patients treated with CCH have
Correct Answer & Explanation
. greater direct costs.
Explanation
NA and CCH are the treatment options for Dupuytren contracture. The treatments of MCP contractures with NA and CCH were compared in two randomized trials that showed equivalent outcomes at 12 months, based on correction and Unité Rhumatologique des Affections de Main (URAM) scores. A recent retrospective study showed reintervention rates at 2 years of 24% for NA and 41% for CCH. At 5 years, the rates were 61% for NA and 55% for CCH. Standardized direct costs for NA and CCH were $624 and $4,189, respectively. Including all reinterventions, the cumulative costs per digit at 5 years after NA and CCH were $1,540 and $5,952, respectively. A 2-year follow-up by Strömberg showed no difference in range of motion or patient-reported outcomes.
. Sabapathy et al. review replantation surgery in the upper extremity. They discuss that a “functional extremity” could be reconstructed at the upper-arm level in 22% to 34%, at the proximal forearm level in 30% to 41%, and at the distal forearm level in 56% to 80% of cases.
Explanation
outcomes than above the elbow replantations.A 45-year-old carpenter sustained a table saw injury to his right hand while at work earlier today. Evaluation in the Emergency Department reveals the defect depicted in Figure A. An island volar advancement flap was selected for wound closure. What is the largest defect that could be covered with this technique?less than 1 cm1.5 cm
Question 1299
Topic: Nerve & Tendon
Which method of flexor tendon repair that necessitates excursion through the A2 pulley allows for the most thorough assessment of tendon gliding?
Correct Answer & Explanation
. Strand repair with 6-0 epitendinous suture with Bier block anesthesia
Explanation
EXPLANATION: Wide-awake repair under only local anesthesia, regardless of the technique, allows direct inspection of the tendon repair and active excursion. Regional anesthesia and Bier block anesthesia do not allow active motion (Bier block necessitates continued use of a tourniquet, which limits muscle function). The A2 pulley should be preserved, especially the distal 50%, to maintain tendon function. All of the listed techniques for suture repair are acceptable options.
Question 1300
Topic: Nerve & Tendon
A 20-year-old college pitcher reports medial elbow pain after 3 innings of hard throwing. He recalls no injury and reports no pain with light throwing. The examination shown in the clinical photograph in Figure 48 reproduces the elbow pain. What is the most likely diagnosis? Review Topic
Correct Answer & Explanation
. Medial collateral ligament injury
Explanation
The milking test, as seen in the photograph, elicits pain when a tear is present in the medial collateral ligament. Complete rupture is possible but unlikely when there is no history of trauma and the patient is able to throw pain-free for several innings. Subluxation of the ulnar nerve and triceps tendon subluxation present as a painful snapping over the medial aspect of the elbow.
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