This practice set contains high-yield board review questions covering key concepts in Hand Trauma & Infection. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 41
Topic: Hand Trauma & Infection
A 29-year-old professional athlete is diagnosed with an acute thumb UCL tear. An MRI is obtained to evaluate for a Stener lesion. What classic MRI appearance is highly specific for the presence of a Stener lesion?
Correct Answer & Explanation
. The 'yo-yo on a string' sign
Explanation
On MRI or ultrasound, a Stener lesion classically appears as a rounded mass of retracted ligament tissue proximal to the adductor aponeurosis, often referred to as the 'yo-yo on a string' sign.
Question 42
Topic: Hand Trauma & Infection
A 25-year-old skier falls while holding his ski pole and presents with ulnar-sided thumb pain. On examination, there is lack of a firm endpoint when a valgus stress is applied to the thumb metacarpophalangeal (MCP) joint in 30 degrees of flexion. Which of the following anatomical structures must be interposed to create a Stener lesion?
Correct Answer & Explanation
. Adductor pollicis aponeurosis
Explanation
A Stener lesion occurs when the distal end of the completely torn ulnar collateral ligament (UCL) displaces superficial to the adductor aponeurosis. This interposition prevents healing and is an absolute indication for operative repair.
Question 43
Topic: Hand Trauma & Infection
A patient with a diagnosed thumb UCL injury is deemed appropriate for non-operative management. What is the standard conservative protocol?
Correct Answer & Explanation
. Thumb spica immobilization for 4 to 6 weeks
Explanation
Incomplete tears of the UCL (Grades I and II) without a Stener lesion are treated with thumb spica cast or splint immobilization for 4 to 6 weeks to allow ligamentous healing.
Question 44
Topic: Hand Trauma & Infection
When evaluating a patient with a 'Gamekeeper's thumb,' how does the pathophysiology traditionally differ from a 'Skier's thumb'?
Correct Answer & Explanation
. Gamekeeper's thumb is caused by chronic, repetitive valgus stress
Explanation
Historically, 'Gamekeeper's thumb' refers to chronic attenuation of the UCL due to repetitive valgus forces (e.g., breaking the necks of game), whereas 'Skier's thumb' refers to an acute traumatic rupture.
Question 45
Topic: Hand Trauma & Infection
In the evaluation of a suspected Skier's thumb, valgus stress testing is performed to assess the integrity of the ulnar collateral ligament (UCL) complex. Which of the following statements regarding the biomechanical function of the thumb MCP joint ligaments is correct?
Correct Answer & Explanation
. The proper UCL is most taut in 30 degrees of MCP flexion.
Explanation
The proper UCL is the primary restraint to valgus stress when the thumb MCP joint is in 30 degrees of flexion, as it is most taut in this position. The accessory UCL and volar plate become the primary restraints when the MCP joint is in full extension.
Question 46
Topic: Hand Trauma & Infection
A 25-year-old female presents after a skiing accident with pain and swelling at the ulnar base of her right thumb. On examination, valgus stress testing reveals 40 degrees of laxity with the metacarpophalangeal (MCP) joint in 30 degrees of flexion, compared to 10 degrees on the contralateral thumb. There is no palpable end-point. MRI confirms a complete ligament rupture. During surgical repair, the torn proximal stump of the ligament is most likely to be found superficial to which of the following structures?
Correct Answer & Explanation
. Adductor pollicis aponeurosis
Explanation
This describes a Stener lesion, which occurs in 80% of complete proper UCL tears. The adductor pollicis aponeurosis becomes interposed between the torn UCL and its insertion, preventing spontaneous healing and necessitating surgical repair.
Question 47
Topic: Hand Trauma & Infection
A 40-year-old gamekeeper presents with a history of chronic pain and weakness in his right thumb. He has noticeable laxity of the thumb MCP joint on examination. Radiographs show no degenerative changes. He desires surgical intervention to improve his grip and pinch strength. In the setting of chronic UCL instability without arthrosis, what is the most appropriate surgical option?
Correct Answer & Explanation
. UCL reconstruction using a free tendon graft (e.g., palmaris longus)
Explanation
For chronic UCL insufficiency without osteoarthritis, the native ligament is usually attenuated and insufficient for direct repair. Reconstruction using a free tendon graft (such as palmaris longus) or an adductor advancement is indicated. Arthrodesis is reserved for cases with arthritis.
Question 48
Topic: Hand Trauma & Infection
A 14-year-old boy falls while snowboarding and complains of thumb pain. Examination reveals significant swelling over the ulnar aspect of the thumb MCP joint and laxity with valgus stress testing. Radiographs show a displaced fracture through the epiphysis and exiting the articular surface of the ulnar base of the proximal phalanx. The proper UCL is functionally attached to this fragment. What is the most likely diagnosis?
Correct Answer & Explanation
. Salter-Harris III equivalent of a Skier's thumb
Explanation
In pediatric and adolescent patients with open physes, a valgus force to the thumb MCP joint typically causes a Salter-Harris III avulsion fracture of the proximal phalanx rather than a pure ligamentous rupture, because the physis is mechanically weaker than the proper UCL.
Question 49
Topic: Hand Trauma & Infection
A 50-year-old male received a corticosteroid injection for a trigger middle finger 5 days ago. He now presents with severe throbbing pain, diffuse fusiform swelling of the digit, a semiflexed posture, and excruciating pain with passive extension. Which anatomical structure is the primary conduit for the proximal spread of this suspected infection?
Correct Answer & Explanation
. Flexor tendon sheath
Explanation
The patient exhibits Kanavel's cardinal signs of infectious pyogenic flexor tenosynovitis. The infection propagates longitudinally through the flexor tendon sheath, which in the middle finger can eventually rupture into the midpalmar space.
Question 50
Topic: Hand Trauma & Infection
A patient presents with a crush injury to the fingertip resulting in a deep laceration extending into the proximal nail fold area, involving the structure primarily responsible for 90% of nail plate volume and thickness. Injury to this specific structure is most likely to result in which permanent nail deformity?
Correct Answer & Explanation
. Split nail
Explanation
Correct Answer: CThe case explicitly states underSurgical Anatomy and Biomechanicsthat theGerminal Matrix (Proximal Matrix)is responsible for producing approximately 90% of the nail plate volume. It further notes that 'Injury to the germinal matrix often results in permanent nail deformities such as a split nail or an absent nail.' Therefore, a split nail is the most likely permanent deformity from an injury to this structure.Incorrect Options:A. Onycholysis:This is typically associated with injury to the sterile matrix, leading to non-adherence of the nail plate.B. Ridging/Dystrophy:While general nail dystrophy can occur from various injuries, ridging is more specifically linked to sterile matrix injury or chronic inflammation, not primarily germinal matrix laceration leading to a split.D. Hook nail (Pterygium Inversum):This is often associated with underlying bone malunion or specific nail bed scarring, not a direct consequence of germinal matrix laceration.E. Chronic paronychia:This is an inflammatory condition of the nail folds, often due to infection or irritation, not a direct deformity of the nail plate resulting from germinal matrix laceration.
Question 51
Topic: Hand Trauma & Infection
A patient sustains a laceration primarily affecting the sterile matrix of the nail unit. Based on the anatomical description, which of the following is the most likely long-term consequence of an inadequately repaired injury to this specific structure?
Correct Answer & Explanation
. Nail plate dystrophy, non-adherence, or onycholysis.
Explanation
Correct Answer: CUnder theSurgical Anatomy and Biomechanicssection, in theNail Bedsubsection, it states: 'Injury to the sterile matrix can lead to nail plate dystrophy, non-adherence, or onycholysis.' The sterile matrix provides adherence to the nail plate and contributes to its shape and contour.Incorrect Options:A. Complete absence of the nail plate:This is more likely with severe germinal matrix destruction.B. Permanent split nail:This is a classic consequence of germinal matrix injury.D. Pterygium formation:This is typically associated with eponychial fold injuries or severe scarring that causes the eponychium to adhere to the nail bed.E. Chronic paronychia:This is an inflammatory condition of the nail folds, not a direct consequence of sterile matrix laceration leading to nail plate deformity.
Question 52
Topic: Hand Trauma & Infection
A patient develops a severe acute paronychia that has progressed to a fluctuant abscess extending completely under the proximal eponychial fold. What is the standard surgical approach to adequately drain this without causing permanent nail deformity?
Correct Answer & Explanation
. Elevation of the eponychial fold and removal of the proximal third of the nail plate
Explanation
For an abscess extending under the eponychial fold (eponychia), adequate drainage requires gently elevating the eponychial fold and removing the proximal portion of the nail plate to prevent matrix damage and ensure proper outflow.
Question 53
Topic: Hand Trauma & Infection
A 35-year-old carpenter presents with a swollen, erythematous index finger 48 hours after a puncture wound. When assessing for Kanavel's cardinal signs of pyogenic flexor tenosynovitis, which of the following is typically the earliest and most sensitive clinical indicator?
Correct Answer & Explanation
. Exquisite pain with passive extension of the digit
Explanation
Kanavel's four cardinal signs indicate pyogenic flexor tenosynovitis. Exquisite pain with passive extension of the involved digit is widely considered the earliest and most sensitive clinical sign of the infection.
Question 54
Topic: Hand Trauma & Infection
A 58-year-old female presents with a 3-month history of progressive swelling, tenderness, and intermittent purulent discharge from the proximal and lateral nail folds of her right index finger. She works as a dishwasher and reports frequent hand immersion in water. On examination, the nail folds are boggy and erythematous, with significant cuticle loss and mild nail plate discoloration. There is no acute fluctuance, but the symptoms have been refractory to multiple courses of oral antibiotics prescribed by her primary care physician. Which of the following is the most likely etiology and the primary predisposing factor for this patient's condition?
Correct Answer & Explanation
. C. Candida albicans colonization; prolonged moisture exposure
Explanation
Correct Answer: CThe patient's presentation of a 3-month history of insidious onset, boggy and erythematous nail folds, cuticle loss, nail plate discoloration, and prolonged exposure to moisture (dishwasher) is classic for chronic paronychia. Chronic paronychia is often multifactorial, but fungal colonization, primarily byCandida albicans, is a common etiology, especially in individuals with prolonged exposure to irritants or moisture, which disrupts the protective cuticle and creates a conducive environment for fungal growth. The refractory nature to oral antibiotics further supports a non-bacterial (e.g., fungal) cause.Incorrect Options:A. Staphylococcus aureus infection; nail biting:This describes acute paronychia, which typically has a rapid onset, is bacterial, and often associated with minor trauma like nail biting. The patient's chronic presentation and occupational exposure make this less likely.B. Streptococcus pyogenes infection; minor trauma:Similar to option A,Streptococcus pyogenesis a bacterial cause of acute paronychia, usually following minor trauma. This does not fit the chronic, insidious presentation.D. Pseudomonas aeruginosa infection; immunocompromise:While gram-negative organisms can cause paronychia, particularly in immunocompromised individuals,Pseudomonasis less common as a primary cause of chronic paronychia compared toCandidain this specific occupational context. The case does not mention immunocompromise.E. Viral (HSV) infection; aggressive manicuring:Herpetic whitlow (HSV infection) presents with characteristic vesicles and is typically acute, not chronic over months. Aggressive manicuring can predispose to acute bacterial paronychia, but not typically chronic fungal infections.
Question 55
Topic: Hand Trauma & Infection
A 32-year-old carpenter presents with an acute, painful, fluctuant swelling along the lateral nail fold of his left thumb, consistent with an acute paronychia with abscess formation. During incision and drainage, the surgeon makes a longitudinal incision parallel to the nail plate. Which of the following anatomical structures is most vulnerable to iatrogenic injury if the incision is made too deep or extends too far dorsally?
Correct Answer & Explanation
. D. Dorsal digital nerve
Explanation
Correct Answer: DThe dorsal branches of the proper digital nerves provide sensory innervation to the nail unit and are located dorsolateral to the nail folds. During incision and drainage procedures for paronychia, meticulous dissection is necessary to avoid iatrogenic injury to these nerves, which can lead to permanent paresthesia or dysesthesia. While the nail matrix is also vulnerable, the question specifies an incision that is 'too deep or extends too far dorsally,' which directly implicates the dorsal digital nerves.Incorrect Options:A. Proper digital artery:The proper digital arteries are located more volarly and laterally/medially along the digit, not typically directly dorsal to the nail fold where a paronychia incision is made.B. Flexor digitorum profundus tendon:This tendon is located on the volar aspect of the digit, deep within the flexor sheath, and is not at risk during a superficial incision for paronychia unless the infection has spread significantly and neglected.C. Nail matrix (germinal matrix):The nail matrix is located beneath the proximal nail fold (eponychium) and extends proximally. While it is vulnerable to injury, especially with transverse incisions or aggressive subungual dissection, an incision 'too deep or extending too far dorsally' from the lateral nail fold is more likely to injure the dorsal digital nerve first.E. Extensor tendon:The extensor tendon is located on the dorsal aspect of the digit, but typically more centrally and proximally than the immediate nail fold area. A superficial incision for paronychia is unlikely to directly injure the extensor tendon unless it is extremely deep and misdirected.
Question 56
Topic: Hand Trauma & Infection
A 28-year-old healthcare worker presents with a painful, erythematous, and swollen right index fingertip. On examination, there are multiple clear vesicles clustered around the nail fold, some with a 'dewdrop on a rose petal' appearance. The patient reports a tingling sensation preceding the onset of the lesions. There is no fluctuance. Based on the clinical presentation, which of the following is the most appropriate initial management?
Correct Answer & Explanation
. C. Warm soaks and elevation, with consideration for antiviral medication
Explanation
Correct Answer: CThe clinical presentation of multiple clear vesicles, a 'dewdrop on a rose petal' appearance, and a preceding tingling sensation are classic signs of Herpetic Whitlow, a viral infection caused by HSV-1 or HSV-2. This condition is a crucial contraindication for incision and drainage, as surgical intervention can worsen the infection, promote viral dissemination, and lead to secondary bacterial superinfection. Management typically involves conservative measures such as warm soaks, elevation, pain control, and sometimes oral antiviral medications (e.g., acyclovir, valacyclovir) if initiated early in the course, especially in immunocompromised patients or for severe cases.Incorrect Options:A. Immediate incision and drainage with a No. 11 blade:This is absolutely contraindicated for Herpetic Whitlow and would be harmful. I&D is reserved for bacterial abscesses.B. Oral antibiotics targeting Staphylococcus aureus:Antibiotics are ineffective against viral infections. While secondary bacterial infection can occur, the primary treatment for Herpetic Whitlow is not antibiotics.D. Partial nail avulsion to decompress the subungual space:This is a surgical intervention for subungual abscesses, which are bacterial. It is inappropriate and harmful for Herpetic Whitlow.E. Referral for urgent MRI to rule out osteomyelitis:MRI is a high-level imaging study for complex infections or suspected osteomyelitis. It is not indicated as an initial step for a clear case of Herpetic Whitlow, which is a superficial viral infection.
Question 57
Topic: Hand Trauma & Infection
A 40-year-old diabetic patient presents with a severe acute paronychia involving both lateral nail folds and tracking proximally beneath the eponychium, forming a 'horseshoe' abscess. The surgeon plans for incision and drainage. Which of the following surgical techniques is most appropriate to drain the proximal subungual space while minimizing the risk of permanent nail matrix damage?
Correct Answer & Explanation
. B. Bilateral longitudinal incisions along the lateral nail folds combined with gentle eponychial elevation using a Freer elevator
Explanation
Correct Answer: BFor a horseshoe paronychia, the most appropriate and safest technique involves making bilateral longitudinal incisions on each lateral nail fold to drain the lateral abscesses. To drain the proximal subungual space without damaging the nail matrix, the eponychial fold is gently elevated off the nail plate using a blunt instrument like a Freer elevator. This allows for drainage of pus from beneath the eponychium while preserving the integrity of the nail matrix, which is crucial for preventing permanent onychodystrophy.Incorrect Options:A. A transverse incision across the eponychium (H-incision):Historically described, this technique is largely abandoned due to a very high risk of permanent nail matrix damage and subsequent severe onychodystrophy.C. Complete nail avulsion without addressing the eponychium:While complete nail avulsion may be necessary for a large subungual abscess, it does not directly address the pus tracking beneath the eponychium in a horseshoe configuration. Furthermore, if the eponychium is not elevated, the proximal abscess may remain undrained.D. A single central longitudinal incision through the eponychium and nail plate:Incising the eponychium directly carries a significant risk of damaging the underlying germinal matrix, leading to permanent nail deformity. This is generally avoided.E. Chemical ablation of the nail matrix with phenol:This is an aggressive technique primarily used for recalcitrant chronic fungal paronychia or ingrown toenails, aiming to destroy portions of the matrix. It is not indicated for acute bacterial horseshoe paronychia and would cause severe, permanent nail deformity.
Question 58
Topic: Hand Trauma & Infection
A 22-year-old male presents to the emergency department 3 days after sustaining a minor cut to his right middle finger, which has since become progressively painful, swollen, and erythematous. He now reports exquisite pain on passive extension of the digit, uniform swelling of the entire finger, and holds the finger in a semi-flexed posture. On palpation, there is tenderness along the flexor sheath. What is the most likely complication of his initial injury?
Correct Answer & Explanation
. C. Flexor tenosynovitis
Explanation
Correct Answer: CThe patient's symptoms are classic for flexor tenosynovitis, characterized by Kanavel's cardinal signs: 1) uniform swelling of the digit, 2) semi-flexed posture of the digit, 3) exquisite tenderness along the flexor sheath, and 4) pain on passive extension of the digit. This is a severe hand infection that can rapidly lead to tendon necrosis and functional loss if not promptly treated with surgical drainage and intravenous antibiotics.Incorrect Options:A. Osteomyelitis of the distal phalanx:While osteomyelitis is a serious complication, it typically presents with more chronic symptoms, bone pain, and may not have the acute, specific signs of flexor tenosynovitis. X-rays would be needed for diagnosis.B. Septic arthritis of the DIP joint:Septic arthritis would involve pain and swelling primarily localized to the joint, with pain on both active and passive range of motion of that specific joint. While it can cause a semi-flexed posture, the uniform swelling of the entire digit and tenderness along the flexor sheath are more indicative of tenosynovitis.D. Deep space infection (e.g., thenar space):Deep space infections would present with swelling and tenderness localized to the specific deep space (e.g., thenar, midpalmar). While serious, they do not typically manifest with Kanavel's signs specific to the flexor sheath of a single digit.E. Recurrent paronychia:A paronychia is an infection of the nail folds. While the initial injury might have been a paronychia, the described progression with Kanavel's signs indicates a spread to the flexor sheath, which is a much more severe condition than a simple recurrent paronychia.
Question 59
Topic: Hand Trauma & Infection
A 65-year-old male with a history of hypertension and coronary artery disease requires incision and drainage for a subungual abscess of his right ring finger. The surgeon plans to use a digital block for anesthesia. Which of the following local anesthetic agents and additives is most appropriate for this procedure?
Correct Answer & Explanation
. C. 1% Lidocaine without epinephrine
Explanation
Correct Answer: CFor digital blocks, 1% or 2% lidocaine is a commonly used and effective local anesthetic. The crucial point is that epinephrine shouldneverbe used in a digital block. Epinephrine causes vasoconstriction, which can lead to digital ischemia and necrosis due to the end-arterial blood supply of the digits. While bupivacaine (Marcaine) provides longer duration, lidocaine is sufficient for most paronychia I&D procedures. The absence of epinephrine is the most critical factor.Incorrect Options:A. 1% Lidocaine with epinephrine:Incorrect due to the presence of epinephrine, which can cause digital ischemia.B. 0.5% Bupivacaine with epinephrine:Incorrect due to the presence of epinephrine.D. 2% Chloroprocaine with epinephrine:Incorrect due to the presence of epinephrine. Chloroprocaine is also less commonly used for digital blocks.E. 0.25% Marcaine with epinephrine:Incorrect due to the presence of epinephrine. Marcaine (bupivacaine) is a brand name for a long-acting anesthetic, but the epinephrine additive is the contraindication.
Question 60
Topic: Hand Trauma & Infection
A 35-year-old patient presents with an acute paronychia of the left index finger. The infection appears to have originated from a hangnail that disrupted the protective seal around the nail. Which specific anatomical structure, when compromised, most commonly serves as the initial portal of entry for bacteria in acute paronychia?
Correct Answer & Explanation
. D. Cuticle
Explanation
Correct Answer: DThe cuticle is a thin layer of keratinized epithelium that extends from the eponychium onto the nail plate, forming a crucial protective seal against external pathogens. Disruption of this seal, often due to minor trauma like a hangnail, nail biting, or aggressive manicuring, is a common initiator of acute paronychia, allowing bacteria to enter the potential space beneath the nail fold.Incorrect Options:A. Hyponychium:The hyponychium is the thickened skin beneath the free edge of the nail plate, providing a protective seal at the distal end. While it is a barrier, it is not the primary site of entry for typical paronychial infections originating from the nail folds.B. Nail plate:The nail plate itself is a hard, keratinized structure that is generally impervious to bacterial entry unless it is severely damaged or lifted.C. Nail matrix:The nail matrix is responsible for nail growth and is located beneath the eponychium. It is not a portal of entry but rather a structure vulnerable to damage if infection spreads or during improper surgical intervention.E. Sterile matrix:The sterile matrix is the distal portion of the nail bed that supports the nail plate. Like the germinal matrix, it is not a primary portal of entry for infection.
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