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 681
Topic: Wrist & Carpus
A 24-year-old female sustains a Galeazzi fracture. After achieving rigid anatomic internal fixation of the radius, intraoperative fluoroscopy and clinical examination demonstrate persistent, irreducible DRUJ dislocation in both supination and pronation. What is the most appropriate next step in management?
Correct Answer & Explanation
. Open exploration of the DRUJ and repair of the triangular fibrocartilage complex (TFCC)
Explanation
If the DRUJ remains irreducible or grossly unstable in all positions following rigid fixation of the radius, open exploration is required. The extensor carpi ulnaris (ECU) tendon is a classic anatomic block to DRUJ reduction in Galeazzi fractures.
Question 682
Topic: Wrist & Carpus
A 10-year-old child falls onto an outstretched hand, presenting with localized pain and swelling over the distal forearm and wrist. Radiographs show a fracture of the distal radial diaphysis. In the pediatric population, what is the most common anatomic injury pattern that represents a "Galeazzi equivalent" lesion?
Correct Answer & Explanation
. Distal ulnar physeal separation
Explanation
In pediatric patients, the ligaments of the DRUJ are often stronger than the open growth plates. Therefore, a Galeazzi equivalent fracture involves a distal radius fracture combined with a distal ulnar physeal separation rather than true DRUJ ligamentous disruption.
Question 683
Topic: Wrist & Carpus
Following anatomic rigid internal fixation of the radius for a classic Galeazzi fracture, the surgeon assesses the DRUJ. It is found to be unstable in pronation and neutral rotation, but anatomically reduced and stable in full supination. What is the most appropriate postoperative immobilization strategy?
Correct Answer & Explanation
. Immobilization in a long-arm splint or cast in full supination for 4 to 6 weeks
Explanation
If the DRUJ is reducible and stable in full supination following rigid fixation of the radius, non-operative management of the DRUJ is appropriate. A long-arm cast or splint in supination allows the volar radioulnar ligaments and TFCC to heal.
Question 684
Topic: 7. Hand and Wrist
A 45-year-old female presents with severe paresthesias in her right thumb, index, and middle fingers that consistently awaken her at night. Examination reveals profound thenar atrophy. Which muscle is typically innervated by the recurrent motor branch of the median nerve in this condition?
Correct Answer & Explanation
. Opponens pollicis
Explanation
The patient has severe carpal tunnel syndrome. The recurrent motor branch of the median nerve innervates the thenar muscles: opponens pollicis, abductor pollicis brevis, and the superficial head of the flexor pollicis brevis.
Question 685
Topic: 7. Hand and Wrist
A 50-year-old sedentary patient undergoes arthroscopic posterior labral repair and capsular plication for recurrent posterior subluxations. Post-operatively, the patient is placed in a sling. The rehabilitation protocol is initiated. Which of the following is a critical restriction during the initial 4-6 weeks of the post-operative rehabilitation protocol?
Correct Answer & Explanation
. Active internal rotation past neutral.
Explanation
Correct Answer: CThe case content emphasizes the critical restrictions during Phase 1 (Protection and Early Motion) of post-operative rehabilitation for posterior GH instability. It states: 'Avoid combined adduction, internal rotation, and flexion.' and specifically, 'No internal rotation past neutral for the first 4-6 weeks.' This restriction is crucial to protect the posterior capsulolabral repair from undue stress, as internal rotation combined with adduction and flexion is the position of posterior instability.Option A (Active external rotation beyond 30 degrees) is generally limited initially, but the primary restriction for posterior repair is internal rotation.Option B (Passive abduction beyond 120 degrees) is incorrect; PROM for abduction is typically allowed up to 90 degrees, and sometimes higher, but 120 degrees is often achievable passively.Option D (Passive flexion beyond 150 degrees) is incorrect; PROM for flexion is typically allowed to 90-120 degrees, but 150 degrees is often too aggressive initially.Option E (Any active elbow, wrist, or hand exercises) is incorrect; the protocol encourages active ROM exercises for the elbow, wrist, and hand to prevent stiffness and maintain circulation.
Question 686
Topic: Nerve & Tendon
A 62-year-old patient is undergoing tension band wiring for a displaced olecranon fracture. During the posterior approach to the elbow, the surgical team must be particularly vigilant about identifying and protecting a specific neurovascular structure that is intimately associated with the medial aspect of the olecranon. Which of the following structures is at the highest risk of iatrogenic injury during this procedure?
Correct Answer & Explanation
. Ulnar nerve
Explanation
Correct Answer: DThe case clearly identifies the 'Ulnar Nerve' as the most critical neurovascular structure at risk during olecranon surgery. It courses posterior to the medial epicondyle, within the cubital tunnel, and is intimately associated with the medial aspect of the olecranon. Meticulous identification and protection or, if indicated, prophylactic decompression or anterior transposition, are paramount to prevent iatrogenic injury.Option A (Median nerve) and Option E (Brachial artery) are incorrectbecause these structures are located anterior to the elbow joint and are generally not at risk with a posterior approach to the olecranon.Option B (Radial nerve) is incorrectas the radial nerve and its branches (including the PIN) are located more laterally and anteriorly, primarily at risk during lateral or anterior approaches to the elbow, not a direct posterior approach to the olecranon.Option C (Posterior interosseous nerve - PIN) is incorrect. While a branch of the radial nerve, it is not directly in the surgical field for a posterior olecranon approach and is not the most vulnerable structure in this specific context.
Question 687
Topic: Nerve & Tendon
During posterior plating of an olecranon fracture, a surgeon utilizes an approach that elevates the flexor carpi ulnaris off the medial aspect of the ulna. Which nerve is at greatest direct risk of iatrogenic injury during this specific portion of the exposure?
Correct Answer & Explanation
. Ulnar nerve
Explanation
The ulnar nerve courses directly posterior to the medial epicondyle and rests adjacent to the medial aspect of the proximal ulna deep to the flexor carpi ulnaris. Medial dissection or misplaced retractors during olecranon plating place it at high risk.
Question 688
Topic: 7. Hand and Wrist
A 30-year-old male presents to the emergency department after a fall onto an outstretched hand (FOOSH). Radiographs demonstrate the lunate maintaining its normal articulation with the distal radius, but the capitate and the rest of the carpal bones are displaced dorsally relative to the lunate. The lunate appears to have lost its articulation with the capitate.
Correct Answer & Explanation
. Perilunate dislocation
Explanation
The description of the lunate remaining articulated with the radius while the capitate and other carpal bones are displaced dorsally relative to the lunate is the classic definition of a perilunate dislocation. In a true lunate dislocation, the lunate itself dislocates volarly, losing articulation with both the radius and the capitate.
Question 689
Topic: 7. Hand and Wrist
A patient presents with acute wrist pain after a fall. Initial standard radiographs are subtle, but a clenched-fist AP view of the wrist reveals a widened scapholunate interval (Terry Thomas sign).
Correct Answer & Explanation
. Scapholunate interosseous ligament disruption
Explanation
Correct Answer: DA widened scapholunate interval, especially on a clenched-fist AP view, is a hallmark of scapholunate dissociation. This represents Mayfield Stage I of perilunate instability, which primarily involves the disruption of the scapholunate interosseous ligament (SLIL). The SLIL is a critical intrinsic ligament for maintaining the stability of the proximal carpal row. While other ligaments may be involved in more advanced stages of perilunate instability, the SLIL is the initial and primary ligamentous injury in this scenario. Lunotriquetral ligament disruption leads to VISI (Volar Intercalated Segmental Instability). The other options are extrinsic ligaments or structures that are not the primary cause of isolated scapholunate widening.
Question 690
Topic: 7. Hand and Wrist
A 45-year-old male presents to the emergency department with an acute lunate dislocation following a high-energy fall. Clinical examination reveals acute onset paresthesias and numbness in the thumb, index, and middle fingers, along with a positive Tinel's sign over the carpal tunnel. The wrist is swollen and deformed.
Correct Answer & Explanation
. Perform immediate closed reduction under adequate anesthesia
Explanation
Correct Answer: CAcute median nerve compression in the setting of a lunate dislocation is a surgical emergency. The volarly displaced lunate directly impinges on the median nerve within the unyielding carpal tunnel, and prolonged compression can lead to irreversible nerve damage. Therefore, the most appropriate immediate management step is prompt closed reduction under adequate anesthesia (e.g., regional block or conscious sedation) to decompress the median nerve and restore carpal alignment. While an MRI may be useful for surgical planning after reduction, and neurophysiologic studies are for chronic nerve issues, they are not initial emergency interventions. Corticosteroids are not a primary treatment for acute mechanical nerve compression, and a splint alone will not decompress the nerve.
Question 691
Topic: 7. Hand and Wrist
A 55-year-old female presents to the emergency department after a fall onto her outstretched hand. A true lateral radiograph of her wrist is obtained, as shown below.
Correct Answer & Explanation
. Spilled teacup sign
Explanation
Correct Answer: CThe image clearly demonstrates the lunate bone displaced volarly and rotated, losing its normal articulation with both the distal radius and the capitate. This classic appearance on a lateral wrist radiograph is known as the 'spilled teacup sign' and is pathognomonic for a true lunate dislocation. The Terry Thomas sign (widened scapholunate interval) and the piece of pie sign (triangular lunate on AP view) are associated with scapholunate dissociation or perilunate dislocations, but not the defining feature of a true lunate dislocation on a lateral view. The signet ring sign refers to a foreshortened, flexed scaphoid on an AP view. Positive ulnar variance refers to the relative length of the ulna compared to the radius, which is unrelated to this dislocation pattern.
Question 692
Topic: 7. Hand and Wrist
A 60-year-old patient presents with chronic wrist pain, stiffness, and weakness, 10 years after an inadequately treated perilunate injury. Radiographs show advanced degenerative changes characterized by arthritis between the scaphoid and radial styloid, progressing to the entire radioscaphoid joint, with relative sparing of the radiolunate joint.
Correct Answer & Explanation
. Scapholunate Advanced Collapse (SLAC) wrist
Explanation
The described pattern of progressive degenerative arthritis, particularly affecting the radioscaphoid joint with relative sparing of the radiolunate joint, is characteristic of Scapholunate Advanced Collapse (SLAC) wrist. SLAC wrist is a common long-term sequela of chronic scapholunate dissociation or inadequately treated perilunate injuries.
Question 693
Topic: 7. Hand and Wrist
A 38-year-old male undergoes successful closed reduction of an acute dorsal perilunate dislocation. Post-reduction plain radiographs appear to show satisfactory carpal alignment. However, the surgeon is concerned about potential occult injuries.
Correct Answer & Explanation
. Order a CT scan of the wrist
Explanation
Correct Answer: CAfter closed reduction of a perilunate or lunate dislocation, a CT scan of the wrist is highly recommended. It provides superior bony detail compared to plain radiographs, allowing for the identification of occult carpal fractures (e.g., scaphoid, triquetrum, radial styloid) that may have been missed, and for a more precise assessment of the accuracy of reduction and any residual carpal malalignment. While MRI can assess soft tissues, CT is generally preferred for immediate post-reduction evaluation of bony alignment and occult fractures. Ultrasound is not ideal for deep carpal bone assessment. Bone scintigraphy is for metabolic activity and not typically used for acute post-reduction assessment. Repeat plain radiographs alone may miss critical subtle findings.
Question 694
Topic: 7. Hand and Wrist
A patient with a history of a lunate dislocation develops progressive wrist pain and radiographic changes consistent with Kienböck's disease (avascular necrosis of the lunate). Which of the following best describes the vascular supply to the lunate?
Correct Answer & Explanation
. Branches from both radial and ulnar arteries forming dorsal and volar intraosseous networks
Explanation
The lunate's susceptibility to avascular necrosis (Kienböck's disease) after a dislocation or other trauma is primarily due to its precarious blood supply. The lunate receives its vascularity from branches of both the radial and ulnar arteries, which form dorsal and volar intraosseous networks that penetrate the bone.
Question 695
Topic: 7. Hand and Wrist
A 25-year-old male presents with an acute lunate dislocation after a fall. After administering adequate anesthesia (e.g., regional block), the surgeon prepares for closed reduction.
Correct Answer & Explanation
. Apply longitudinal traction to the hand, then hyperextend the wrist, followed by direct volar pressure on the lunate while simultaneously flexing the wrist.
Explanation
Correct Answer: BThe classic and most effective maneuver for closed reduction of an acute lunate dislocation involves a specific sequence. First, longitudinal traction is applied to the hand to distract the carpal bones. Second, the wrist is hyperextended to 'unlock' the lunate from its displaced position (often from under the capitate). Third, while maintaining traction and hyperextension, direct volar pressure is applied over the dislocated lunate, and the wrist is simultaneously flexed. This maneuver guides the lunate back into its anatomical position within the lunate fossa of the radius. The other options describe incorrect or ineffective sequences for reducing a volarly dislocated lunate.
Question 696
Topic: 7. Hand and Wrist
A lateral wrist radiograph of a patient with chronic wrist pain and a history of a missed wrist injury is shown. The scapholunate angle measures 75 degrees (normal 30-60 degrees), and the capitolunate angle is 40 degrees (normal <30 degrees). What is the most likely diagnosis?
Correct Answer: C. The radiographic findings of an increased scapholunate angle (>60 degrees) and an increased capitolunate angle (>30 degrees) on a lateral radiograph, indicating a dorsal tilt or extension of the lunate, are characteristic of Dorsal Intercalated Segmental Instability (DISI). This pattern is most commonly associated with chronic scapholunate ligament disruption, often a sequela of a missed or inadequately treated perilunate injury. Volar Intercalated Segmental Instability (VISI) would show a volar tilt of the lunate. SLAC wrist is a pattern of degenerative arthritis, not the instability pattern itself. Lunotriquetral dissociation typically leads to VISI. Carpal bossing is an osteophyte formation, not an instability pattern.
Question 697
Topic: 7. Hand and Wrist
A 50-year-old patient presents 4 months after a lunate dislocation with persistent wrist pain, stiffness, and ongoing median nerve paresthesias. Closed reduction attempts at an outside facility have failed, and current radiographs confirm irreducible volar displacement of the lunate.
Correct Answer & Explanation
. Combined dorsal and volar approach for open reduction, ligament repair, and nerve decompression
Explanation
Correct Answer: CFor a subacute to chronic (4 months) and irreducible lunate dislocation with persistent median nerve symptoms, a combined dorsal and volar surgical approach is typically indicated. The volar approach is crucial for decompressing the median nerve, which is compressed by the volarly displaced lunate and surrounding edema/fibrosis. It also allows for the repair or reconstruction of essential volar ligaments. The dorsal approach provides optimal visualization and access for achieving anatomical reduction of the lunate (which is volarly displaced but needs to be pushed dorsally into place) and for repairing dorsal ligamentous injuries. A dorsal approach alone would not adequately address the median nerve compression. A volar approach alone would make reduction of the lunate challenging. Proximal row carpectomy or wrist arthrodesis are salvage procedures usually reserved for very chronic cases with significant arthrosis or failed reconstructive attempts, not as the primary approach for an irreducible subacute dislocation where reduction and repair are still feasible.
Question 698
Topic: Nerve & Tendon
A 72-year-old patient is undergoing a total shoulder arthroplasty in the beach chair position. During the procedure, the anesthesia team reports a significant drop in blood pressure. The surgeon is concerned about potential complications related to patient positioning. Which of the following neurological complications is a rare but serious risk associated with the beach chair position, particularly with sustained hypotension?
Correct Answer & Explanation
. D. Posterior ischemic optic neuropathy (PION)
Explanation
Correct Answer: DWhile the case study mentions 'Risk of Cerebral Hypoperfusion' and 'Neck and Head Positioning: Requires careful padding and stabilization to prevent nerve palsy (e.g., brachial plexus, ulnar nerve) or pressure injuries,' it does not explicitly list Posterior Ischemic Optic Neuropathy (PION). However, PION is a well-recognized, albeit rare, and devastating complication associated with the beach chair position, especially in the context of prolonged surgery, significant blood loss, and sustained hypotension. It results from inadequate perfusion to the optic nerve. The question asks for a 'rare but serious risk associated with the beach chair position, particularly with sustained hypotension.' Ulnar nerve palsy (A) and brachial plexus neuropraxia (B) are more commonly associated with direct pressure or stretch from improper limb/neck positioning, not primarily hypotension. Spinal cord injury (C) is extremely rare and typically related to direct trauma or pre-existing spinal conditions, not the beach chair position itself. Sciatic nerve palsy (E) is a lower extremity nerve injury, not typically associated with shoulder surgery in the beach chair position.
Question 699
Topic: Wrist & Carpus
A 68-year-old female presents to the emergency department after a low-energy fall onto an outstretched hand. Radiographs reveal a dorsally displaced, comminuted, intra-articular distal radius fracture with 15 degrees of dorsal angulation, 8 mm of radial shortening, and a 3 mm intra-articular step-off involving the lunate fossa. She has no neurovascular deficits. Given her age and fracture characteristics, which of the following findings, if present on a pre-operative CT scan, would be MOST critical to address to prevent long-term post-traumatic arthritis and DRUJ instability?
Correct Answer & Explanation
. A displaced die-punch fragment involving the lunate fossa.
Explanation
Correct Answer: CThe case emphasizes that intra-articular step-off or gap of >1-2 mm is strongly correlated with the development of post-traumatic arthritis. A displaced die-punch fragment, especially involving the lunate fossa, directly contributes to this articular incongruity. The lunate fossa is a critical load-bearing surface, and failure to anatomically reduce a displaced die-punch fragment will lead to altered joint mechanics, progressive cartilage wear, and ultimately, post-traumatic arthritis. While other factors like radial shortening and dorsal angulation contribute to overall wrist dysfunction, direct articular incongruity is the most potent predictor of arthritis. DRUJ instability is often secondary to radial length loss or TFCC injury, but a poorly reduced articular surface can also indirectly affect DRUJ mechanics. A pre-operative CT scan is highly recommended for all displaced intra-articular fractures to precisely identify such fragments and guide surgical reduction to restore articular congruity.Option A (Comminution of the radial styloid) is important for radial length and inclination but less directly impactful on articular congruity than a displaced die-punch fragment.Option B (Non-displaced ulnar styloid fracture) is common and often does not require specific intervention unless associated with gross DRUJ instability, which is not implied by 'non-displaced'.Option D (Mild osteopenia) is a patient factor influencing fixation strategy but not a specific fracture characteristic that directly causes post-traumatic arthritis or DRUJ instability in the same way as articular incongruity.Option E (Non-displaced scaphoid waist fracture) is an associated injury that needs management but, if non-displaced, is less immediately critical for preventing post-traumatic arthritis of the radiocarpal joint than a displaced intra-articular fragment of the distal radius itself.
Question 700
Topic: 7. Hand and Wrist
A 35-year-old male sustains a high-energy distal radius fracture with significant dorsal comminution and loss of volar tilt. He is scheduled for open reduction and internal fixation via a volar Henry approach. During the approach, after incising the forearm fascia, the surgeon identifies the flexor carpi radialis (FCR) tendon. Which of the following statements accurately describes the next critical step in the approach and the anatomical structures to be protected?
Correct Answer & Explanation
. The FCR tendon is retracted ulnarly, and the radial artery is identified and protected radially.
Explanation
Correct Answer: CThe image provided illustrates the volar Henry approach. The case describes the internervous plane for the volar Henry approach: 'The most common interval utilizes the plane between the flexor carpi radialis (FCR) tendon (retracted ulnarly) and the radial artery (retracted radially).' This means the FCR tendon is retracted towards the ulnar side of the forearm, and the radial artery, which courses dorsoradially, is identified and protected by retracting it towards the radial side. The median nerve lies ulnar to the FPL, deeper in the carpal tunnel, and is not the primary structure identified in this specific internervous plane. The palmar cutaneous branch of the median nerve, which courses radially to the FCR tendon, also needs protection during the initial skin and subcutaneous dissection.Option A is incorrect because the FCR is typically retracted ulnarly, and the radial artery is retracted radially.Option B is incorrect because the median nerve is ulnar to the FPL, not radially to the FCR in this interval.Option D is incorrect because the FCR is retracted ulnarly, and the FPL is typically deeper and more ulnar, not the primary structure in this specific interval.Option E is incorrect; the FCR tendon is a landmark and is retracted, not incised, to access the deeper structures.
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