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 781
Topic: 7. Hand and Wrist
While most mallet finger injuries are successfully managed nonoperatively, certain clinical and radiographic features necessitate surgical intervention. Which of the following is considered an absolute indication for surgical fixation of a mallet finger?
Correct Answer & Explanation
. Volar subluxation of the distal phalanx on the lateral radiograph
Explanation
Volar subluxation of the distal phalanx is an absolute indication for surgical intervention (CRPP or ORIF) in bony mallet fingers. Surgery restores articular congruity and prevents early post-traumatic arthritis.
Question 782
Topic: 7. Hand and Wrist
A 60-year-old man undergoes fasciectomy for severe Dupuytren's contracture of the ring finger. During dissection of the proximal interphalangeal (PIP) joint, the neurovascular bundle is noted to be displaced by the spiral cord. What is the classic direction of neurovascular bundle displacement caused by the spiral cord?
Correct Answer & Explanation
. Volar, central, and proximal
Explanation
The spiral cord displaces the neurovascular bundle volarly, centrally (toward the midline of the digit), and proximally. It is formed by the pretendinous band, spiral band, lateral digital sheet, and Grayson's ligament.
Question 783
Topic: 7. Hand and Wrist
Biochemical analysis of a fascial cord excised from a patient with Dupuytren's contracture would most likely reveal which of the following abnormalities compared to normal palmar fascia?
Correct Answer & Explanation
. Increased ratio of Type III to Type I collagen
Explanation
In Dupuytren's disease, there is an overproliferation of myofibroblasts and an increase in the ratio of Type III to Type I collagen. Normal palmar fascia is composed predominantly of Type I collagen.
Question 784
Topic: 7. Hand and Wrist
During surgical excision of a Dupuytren's cord in the little finger, the surgeon carefully preserves a fascial structure that lies dorsal to the neurovascular bundle and is typically spared by the disease process. Which of the following structures is being preserved?
Correct Answer & Explanation
. Grayson's ligament
Explanation
Cleland's ligaments are located dorsal to the neurovascular bundle and are classically spared in Dupuytren's disease. In contrast, Grayson's ligaments are volar to the bundle and are frequently involved.
Question 785
Topic: 7. Hand and Wrist
A 65-year-old man receives a collagenase clostridium histolyticum injection for a Dupuytren's cord causing a 45-degree metacarpophalangeal (MCP) joint contracture of his small finger. Two weeks later, he presents unable to actively flex the distal interphalangeal joint of the small finger. Which of the following is the most likely cause?
Correct Answer & Explanation
. Flexor digitorum profundus rupture
Explanation
Flexor tendon rupture, particularly of the flexor digitorum profundus (FDP) of the small finger, is a known severe complication of collagenase injections if placed too deeply. The small finger is at highest risk due to the close proximity of the cord to the flexor sheath.
Question 786
Topic: 7. Hand and Wrist
A 32-year-old basketball player presents with a bony mallet finger of the long finger after a jamming injury. Radiographs show a dorsal intra-articular fracture involving 40% of the articular surface without volar subluxation of the distal phalanx. What is the most appropriate initial management?
Correct Answer & Explanation
. Continuous extension splinting of the DIP joint for 6-8 weeks
Explanation
Bony mallet fingers involving a large portion of the articular surface without volar subluxation of the distal phalanx can be successfully treated with continuous extension splinting. Studies show no significant functional difference between operative and nonoperative treatment in the absence of subluxation.
Question 787
Topic: Nerve & Tendon
A 45-year-old woman presents with a chronic, untreated mallet finger of 4 months duration. She has now developed a swan neck deformity. What is the primary pathophysiologic mechanism for the development of this deformity?
Correct Answer & Explanation
. Proximal retraction of the extensor mechanism concentrating extension force on the central slip
Explanation
In chronic mallet finger, the loss of terminal extensor continuity causes proximal retraction of the entire extensor mechanism. This concentrates extension forces on the central slip, leading to PIP joint hyperextension and a subsequent swan neck deformity.
Question 788
Topic: 7. Hand and Wrist
A 48-year-old right-hand dominant male carpenter presents with a 6-month history of progressive left hand pain, cold intolerance, numbness, and episodic digital pallor and cyanosis primarily affecting the ring and small fingers. He frequently uses his left hypothenar region as an improvised hammer. Physical examination reveals mild hypothenar fullness, diminished left ulnar pulse, and a positive Allen's test for the ulnar artery. Which of the following is the most likely diagnosis?
Correct Answer & Explanation
. Hypothenar Hammer Syndrome
Explanation
Correct Answer: CThe patient's presentation is classic for Hypothenar Hammer Syndrome (HHS). Key features include:Occupational History:Repetitive blunt trauma to the hypothenar eminence (carpenter using hand as a hammer).Symptoms:Unilateral hand pain, cold intolerance, episodic digital pallor and cyanosis (ischemic symptoms) affecting the ulnar digits (ring and small fingers).Physical Exam:Hypothenar fullness, diminished ulnar pulse, and a positive Allen's test for the ulnar artery, indicating compromised ulnar artery flow.Why other options are incorrect:A. Primary Raynaud's Phenomenon:Typically bilateral, vasospastic, and lacks the specific history of trauma or a palpable hypothenar mass/diminished ulnar pulse. While cold intolerance is present, the unilateral nature and specific trauma history point away from primary Raynaud's.B. Ulnar Nerve Entrapment at Guyon's Canal (Type II):While ulnar nerve symptoms (numbness, weakness) are present, the primary and most prominent symptoms are vascular (cold intolerance, pallor/cyanosis). Ulnar nerve entrapment alone would not explain the digital ischemia or the positive Allen's test. While secondary nerve irritation can occur in HHS, it's not the primary diagnosis.D. De Quervain's Tenosynovitis:Involves pain and tenderness over the radial styloid, exacerbated by thumb and wrist movements, and a positive Finkelstein's test. It does not cause digital ischemia or ulnar nerve symptoms.E. Carpal Tunnel Syndrome:Involves median nerve compression, causing numbness and tingling in the thumb, index, middle, and radial half of the ring finger, often worse at night. It does not cause ulnar-sided digital ischemia or cold intolerance.
Question 789
Topic: 7. Hand and Wrist
During the clinical examination, an Allen's test is performed on the patient's left hand. Occlusion of the ulnar artery and release results in significantly delayed reperfusion (> 15 seconds) or absent reperfusion in the ring and small fingers, while radial artery occlusion and release shows normal reperfusion. What is the most accurate interpretation of this finding in the context of the patient's symptoms?
Correct Answer & Explanation
. There is significant compromise of the ulnar artery with inadequate collateral circulation from the radial artery to the ulnar digits.
Explanation
Correct Answer: C. The Allen's test is a crucial component of the vascular assessment in this case. The finding of significantly delayed or absent reperfusion in the ulnar digits after ulnar artery occlusion, despite normal radial artery flow, directly indicates severe compromise of the ulnar artery and insufficient collateral flow from the radial artery to adequately perfuse the ulnar side of the hand. This is a hallmark finding in Hypothenar Hammer Syndrome where the ulnar artery is often thrombosed or aneurysmal with intraluminal thrombus. Why other options are incorrect: A. The radial artery is occluded, leading to insufficient collateral flow: The case explicitly states that 'Radial artery occlusion and release showed normal reperfusion,' indicating a patent radial artery and good collateral flow from the ulnar artery to the radial digits. B. The ulnar artery is patent, but the superficial palmar arch is incomplete: The delayed/absent reperfusion after ulnar artery occlusion strongly suggests the ulnar artery itself is compromised, not merely an incomplete arch with a patent ulnar artery. D. The patient has a normal vascular supply to the hand, and symptoms are likely neuropathic: The positive Allen's test with delayed reperfusion directly contradicts a normal vascular supply and points to a significant vascular issue, which is the primary driver of the ischemic symptoms. E. This indicates a primary vasospastic disorder affecting the ulnar digits: While vasospasm can occur, the specific findings of a diminished ulnar pulse, palpable mass, and a positive Allen's test pointing to structural arterial compromise are more indicative of an obstructive vascular pathology rather than a purely vasospastic one.
Question 790
Topic: Nerve & Tendon
Following the clinical examination, a Duplex Ultrasound (DUS) with Doppler Flow Study is performed. Given the suspected diagnosis and clinical findings, which of the following findings would be most consistent with Hypothenar Hammer Syndrome?
Correct Answer & Explanation
. A fusiform aneurysm of the ulnar artery within Guyon's canal with intraluminal thrombus and distal occlusion.
Explanation
Correct Answer: CThe DUS findings described in the case directly confirm the diagnosis of Hypothenar Hammer Syndrome: 'Demonstrated a fusiform aneurysm of the ulnar artery within Guyon's canal, measuring approximately 5mm in diameter, with evidence of intraluminal thrombus formation. Distal to the aneurysm, there was significant post-stenotic turbulent flow and a segment of complete occlusion of the ulnar artery.' This directly explains the patient's ischemic symptoms and the positive Allen's test.Why other options are incorrect:A. Evidence of ulnar nerve compression by a ganglion cyst within Guyon's canal:While ulnar nerve compression can occur, a ganglion cyst would be a primary cause of Guyon's canal syndrome, not HHS, and would not explain the arterial pathology or digital ischemia.B. Normal caliber ulnar artery with triphasic flow and no evidence of thrombus:This finding would rule out HHS, as the syndrome is characterized by ulnar artery pathology.D. Diffuse atherosclerotic changes throughout the palmar arch:While atherosclerosis can cause vascular disease, HHS is specifically related to focal trauma to the ulnar artery, often leading to aneurysm and thrombosis, rather than diffuse atherosclerotic changes, especially in a 48-year-old non-smoker without diabetes.E. Significant calcification within the ulnar artery wall, indicative of chronic vasculitis:Calcification is not a typical feature of HHS, which involves intimal injury, aneurysm, and thrombosis. Vasculitis would present differently and would be less likely given the specific trauma history.
Question 791
Topic: 7. Hand and Wrist
A Computed Tomography Angiography (CTA) is performed for pre-operative planning. Which of the following findings from the CTA would be most critical for determining the surgical strategy for arterial reconstruction?
Correct Answer & Explanation
. Precise delineation of the extent of the ulnar artery pathology (aneurysm and thrombotic occlusion) and assessment of collateral circulation.
Explanation
Correct Answer: CThe case states that CTA was indicated 'To precisely delineate the extent of the ulnar artery pathology, assess the full length of the vessel and its branches, evaluate collateral circulation, and provide a 3D anatomical map for surgical planning.' This information is crucial for determining the length of the arterial segment to be resected, the need for an interposition graft, and the suitability of the distal vessel for anastomosis, all of which directly impact the surgical strategy for arterial reconstruction.Why other options are incorrect:A. Absence of acute fractures or dislocations in the carpus:While important to rule out, this information is typically obtained from plain radiographs and does not directly guide arterial reconstruction strategy.B. The presence of mild edema in the surrounding soft tissues:This is a non-specific finding that indicates inflammation but does not provide the detailed anatomical information needed for vascular reconstruction.D. Increased signal intensity on T2-weighted images of the ulnar nerve:This finding is from MRI and indicates ulnar nerve irritation/compression, which might necessitate neurolysis, but it does not directly inform the arterial reconstruction technique or graft requirements.E. Sparse positive sharp waves and fibrillation potentials in intrinsic hand muscles:These are EMG findings, indicating mild denervation, and while relevant for assessing nerve function, they do not provide anatomical detail for arterial reconstruction.
Question 792
Topic: Nerve & Tendon
The patient's symptoms include both digital ischemia and mild ulnar nerve deficits. During the differential diagnosis process, it is crucial to distinguish Hypothenar Hammer Syndrome (HHS) from primary Ulnar Nerve Entrapment at Guyon's Canal. Which of the following features is most characteristic of HHS and helps differentiate it from isolated ulnar nerve entrapment?
Correct Answer & Explanation
. Digital pallor, cyanosis, cold intolerance, and a diminished ulnar pulse.
Explanation
Correct Answer: DThe most characteristic features of Hypothenar Hammer Syndrome that differentiate it from isolated ulnar nerve entrapment are the vascular symptoms and signs. These include digital pallor, cyanosis, cold intolerance, and a diminished ulnar pulse, all indicative of arterial compromise. The case explicitly highlights these as primary symptoms and findings.Why other options are incorrect:A. Intrinsic muscle atrophy and a positive Froment's sign:These are classic signs of significant ulnar nerve motor weakness, which can be present in both severe ulnar nerve entrapment and, to a milder degree, in HHS due to secondary nerve irritation. However, they are not specific to HHS and are more pronounced in primary nerve entrapment. The case notes 'No obvious clawing of the fingers or Froment's sign was present.'B. Paresthesia and numbness in the ulnar nerve distribution:These are common to both ulnar nerve entrapment and HHS (due to secondary nerve involvement) and therefore do not serve as a differentiating factor.C. A history of repetitive wrist flexion/extension:While repetitive movements can contribute to nerve entrapment, the specific history of using the hypothenar region as a 'hammer' (blunt trauma) is more indicative of HHS.E. Normal Allen's test with definite sensory deficits:A normal Allen's test would argue against significant ulnar artery compromise, making primary ulnar nerve entrapment more likely. In HHS, the Allen's test is typically positive (compromised ulnar flow).
Question 793
Topic: Nerve & Tendon
The Nerve Conduction Studies (NCS) and Electromyography (EMG) findings indicate a mild ulnar neuropathy at the wrist, with mildly reduced sensory nerve action potential (SNAP) amplitudes and sparse positive sharp waves in intrinsic muscles. Based on the overall clinical picture and imaging, what is the most likely etiology of this ulnar neuropathy?
Correct Answer & Explanation
. Secondary compression or irritation of the ulnar nerve by the adjacent ulnar artery aneurysm and surrounding edema.
Explanation
Correct Answer: CThe case explicitly states that the ulnar nerve appeared 'mildly compressed and displayed increased signal intensity on T2-weighted images proximal to the aneurysm, suggesting demyelination or irritation, but no definite nerve transection or severe structural damage.' The conclusion from NCS/EMG was that findings suggested 'a mild ulnar neuropathy at the wrist, likely secondary to external compression or irritation from the adjacent vascular pathology, rather than a primary severe ulnar nerve entrapment syndrome.' This indicates the neuropathy is a consequence of the vascular pathology.Why other options are incorrect:A. Primary ulnar nerve entrapment due to a space-occupying lesion unrelated to the artery:While possible, the primary pathology identified is the ulnar artery aneurysm, and the nerve symptoms are mild and secondary, making an unrelated primary entrapment less likely.B. A severe, isolated ulnar nerve transection at Guyon's canal:The NCS/EMG findings indicate 'mild' neuropathy, and MRI showed 'no definite nerve transection or severe structural damage,' ruling out a severe transection.D. A systemic vasculitis causing diffuse neuropathy:The patient has no history of autoimmune disease or other known vasculitis, and the symptoms are localized to one hand, making a diffuse systemic neuropathy less likely.E. Proximal ulnar nerve entrapment at the cubital tunnel:While cubital tunnel syndrome is common, the clinical examination (Tinel's sign over Guyon's canal, negative Phalen's) and imaging (aneurysm at Guyon's canal) localize the pathology to the wrist, not the elbow.
Question 794
Topic: Nerve & Tendon
The patient is classified as Type II Hypothenar Hammer Syndrome based on diagnostic findings. The decision is made to proceed with surgical intervention. Which of the following is the most compelling indication for surgical management in this patient?
Correct Answer & Explanation
. Persistent and worsening digital ischemia, symptomatic ulnar artery aneurysm with thrombus, and inadequate collateral circulation.
Explanation
Correct Answer: CThe case explicitly outlines the critical factors for surgical decision-making:Persistent and Worsening Digital Ischemia:'The patient's symptoms of cold intolerance, intermittent pallor/cyanosis, and trophic changes were progressive and indicative of critical arterial insufficiency.'Symptomatic Ulnar Artery Aneurysm with Thrombus:'The presence of a palpable, tender, pulsatile mass, confirmed by DUS and CTA to be an ulnar artery aneurysm with significant intraluminal thrombus, presented a clear risk of further distal embolization and complete digital necrosis.'Inadequate Collateral Circulation:'The positive Allen's test and CTA findings confirmed insufficient collateral flow from the radial artery to adequately perfuse the ulnar digits.'These three factors combined represent a clear and urgent indication for surgical intervention to restore perfusion and prevent further tissue loss.Why other options are incorrect:A. Mild ulnar nerve paresthesia and numbness:While present, the nerve symptoms are described as 'mild' and secondary. Isolated mild neuropathy would typically be managed conservatively first.B. The patient's desire to return to carpentry without activity modification:While a factor in patient counseling, it is not a medical indication for surgery. Activity modification is often part of long-term management.D. A positive Tinel's sign over Guyon's canal:This indicates nerve irritation but, similar to mild paresthesia, is not a standalone compelling indication for surgery, especially when compared to critical ischemia.E. The presence of well-controlled hypertension and hyperlipidemia:These are comorbidities that need management but are not indications for hand surgery.
Question 795
Topic: 7. Hand and Wrist
Immediately post-operatively, the patient is in the recovery room. Which of the following is the most critical aspect of monitoring and management to ensure the success of the arterial reconstruction?
Correct Answer & Explanation
. Continuous monitoring of digital perfusion (color, temperature, capillary refill) and Doppler auscultation of the graft site.
Explanation
Correct Answer: CThe 'Post-Operative Protocol & Rehabilitation' section emphasizes: 'Continuous monitoring of digital perfusion (color, temperature, capillary refill) of the left ring and small fingers is paramount. Doppler auscultation of the graft site and distal arterial flow performed hourly initially, then every 4 hours. Any signs of compromise (pallor, cyanosis, delayed capillary refill, cold digits, loss of Doppler signal) warrant immediate re-exploration.' This is critical for detecting early graft thrombosis or compromise, which can lead to limb-threatening ischemia.Why other options are incorrect:A. Aggressive physical therapy to restore range of motion:Early aggressive physical therapy could jeopardize the delicate microvascular anastomoses and lead to graft failure. Gentle ROM is initiated later.B. Strict immobilization of the entire upper extremity for 6 weeks:While the wrist is splinted in a neutral position for 1-2 weeks, prolonged strict immobilization is not indicated and can lead to stiffness.D. Immediate initiation of full weight-bearing activities:This is contraindicated as it would place excessive stress on the surgical site and graft, risking failure.E. Discontinuation of all antiplatelet or anticoagulant medications:The case states: 'Systemic heparinization maintained for 24-48 hours, followed by transition to oral antiplatelet therapy (e.g., Aspirin 81-325mg daily) for at least 3-6 months.' Antiplatelet/anticoagulant therapy is essential to maintain graft patency.
Question 796
Topic: 7. Hand and Wrist
A potential pitfall in managing patients with suspected Hypothenar Hammer Syndrome is misdiagnosis. Which of the following scenarios best illustrates a common pitfall that could lead to inappropriate treatment?
Correct Answer & Explanation
. Attributing all symptoms solely to ulnar nerve entrapment and proceeding with nerve decompression without vascular imaging.
Explanation
Correct Answer: BThe 'Pitfalls' section explicitly lists: 'Misdiagnosis: Missing HHS and attributing symptoms solely to ulnar nerve entrapment or systemic vasculitis can lead to inappropriate treatment and worsening ischemia.' And 'Inadequate Vascular Workup: Proceeding to surgery for "Guyon's canal syndrome" without proper vascular imaging can lead to unexpected vascular findings, requiring aborting the initial plan or performing an inadequate intervention.' This scenario directly reflects these pitfalls, as treating only the nerve without addressing the underlying vascular pathology would be inadequate and potentially harmful.Why other options are incorrect:A. Performing a detailed occupational history and a meticulous Allen's test, followed by Duplex Ultrasound:These are 'Pearls' and represent appropriate diagnostic steps for HHS.C. Utilizing CTA for pre-operative planning to delineate the extent of arterial pathology and collateral circulation:This is a 'Pearl' and a crucial step for successful surgical planning in HHS.D. Prescribing antiplatelet therapy and advising activity modification for mild, non-progressive symptoms:This is appropriate conservative management for mild cases of HHS, as mentioned in the 'Management' section of the differential diagnosis table.E. Referring the patient to a hand therapist for early, gentle range of motion exercises post-operatively:This is part of the recommended 'Early Rehabilitation' protocol and is a 'Pearl' for post-operative care.
Question 797
Topic: Nerve & Tendon
A 29-year-old G1 P0 woman, 7 months pregnant, presents with bilateral thumb numbness, worse at night. On examination, direct compression over the median nerve at the carpal tunnel for 30 seconds elicits paresthesias in the median nerve distribution. This maneuver is known as the Durkan test. Which of the following statements regarding the Durkan test is most accurate?
Correct Answer & Explanation
. Its approximate sensitivity and specificity are 90%.
Explanation
Correct Answer: CThe Durkan test involves direct compression over the median nerve at the carpal tunnel for approximately 30 seconds, with a positive result being the onset of paresthesias or pain in the median nerve distribution. The discussion explicitly states that its approximate sensitivity and specificity are 90%. This makes option C correct.Option A is incorrectbecause the Durkan test specifically assesses median nerve compression, not ulnar nerve compression.Option B is incorrectbecause sustained wrist flexion is characteristic of the Phalen test, not the Durkan test. The Durkan test involves direct compression.Option D is incorrectbecause the discussion states that the sensitivity and specificity of the Durkan test are generally thought to begreaterthan that for the Phalen test.Option E is incorrectbecause a positive Durkan test indicates median nerve compression, which can cause paresthesias or pain, but it does not directly indicate thenar muscle atrophy. While chronic median nerve compression can lead to atrophy, the test itself is for sensory symptoms.
Question 798
Topic: 7. Hand and Wrist
A 29-year-old G1 P0 woman, 7 months pregnant, is diagnosed with carpal tunnel syndrome. She reports no prior symptoms. Based on current understanding, what is the approximate incidence of carpal tunnel syndrome symptoms among pregnant women?
Correct Answer & Explanation
. Approximately 25%
Explanation
Correct Answer: CThe discussion explicitly states that carpal tunnel syndrome during pregnancy is common and is believed to occur in approximately 25% of pregnant women. This makes option C the correct answer.Options A, B, D, and E are incorrectas they do not match the stated incidence of approximately 25%.
Question 799
Topic: 7. Hand and Wrist
The patient's symptoms of carpal tunnel syndrome are attributed to her pregnancy. What is the primary pathophysiological mechanism underlying carpal tunnel syndrome in the later stages of pregnancy?
Correct Answer & Explanation
. Whole body edema causing swelling within the carpal tunnel.
Explanation
Correct Answer: CThe discussion clearly states that the etiology of carpal tunnel syndrome during pregnancy appears to be related to "whole body edema during the later phases of pregnancy, which in turn causes swelling within the carpal tunnel." This increased pressure within the carpal tunnel compresses the median nerve, leading to symptoms.Option A is incorrectas increased muscle mass is not a recognized cause of pregnancy-induced CTS.Option B is incorrectas while hormonal changes are involved in pregnancy, the direct mechanism described is edema, not direct demyelination.Option D is incorrectas while altered posture might occur, the primary mechanism cited is edema, not repetitive strain.Option E is incorrectas the primary mechanism is mechanical compression due to swelling, not primarily decreased blood flow from vascular compression, although nerve compression can secondarily affect microcirculation.
Question 800
Topic: 7. Hand and Wrist
A 29-year-old, 7 months pregnant woman is diagnosed with carpal tunnel syndrome. She is managed conservatively. What is the most likely long-term outcome for her carpal tunnel syndrome symptoms following delivery?
Correct Answer & Explanation
. Symptoms will improve and/or resolve following delivery.
Explanation
Correct Answer: CThe discussion states that "most women with this problem can be treated conservatively with the expectation that symptoms will improve and/or resolve following delivery." This indicates a favorable prognosis post-partum for pregnancy-induced carpal tunnel syndrome.Option A is incorrectas the expectation is improvement/resolution, not indefinite persistence requiring surgery.Option B is incorrectas symptoms are expected to improve, not worsen, after delivery.Option D is incorrectas the natural history is improvement, not remaining unchanged.Option E is incorrectas there is a clear expected pattern of resolution post-delivery.
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