Orthopedic Board Review MCQs: Trauma, Hand & Elbow

Question 1

During surgical management of a terrible triad injury of the elbow, the coronoid is fixed, the radial head is replaced, and the lateral ulnar collateral ligament (LUCL) is repaired. On intraoperative fluoroscopic examination, the elbow persistently subluxates posteriorly when extended past 30 degrees. What is the most appropriate next step in management?

Explanation

In terrible triad injuries, the standard protocol involves fixing the coronoid, restoring the radial head, and repairing the lateral collateral ligament complex. If the elbow remains unstable in extension after these steps, it indicates medial collateral ligament (MCL) insufficiency. The current standard of care is to proceed with repair of the MCL (or application of a hinged external fixator). Leaving the elbow subluxated or merely casting it risks chronic instability and post-traumatic arthritis.

Question 2

A 40-year-old manual laborer presents with advanced Scaphoid Nonunion Advanced Collapse (SNAC). Radiographs demonstrate severe radioscaphoid and capitolunate arthritis, but the radiolunate joint space is well preserved. Which of the following surgical interventions is most appropriate?

Explanation

This patient has Stage 3 SNAC wrist, characterized by capitolunate arthritis in addition to radioscaphoid arthritis, with sparing of the radiolunate articulation. A proximal row carpectomy (PRC) is contraindicated because it relies on a healthy capitate articular surface to articulate with the lunate fossa of the radius. Scaphoid excision and four-corner fusion (capitate, lunate, hamate, triquetrum) is the procedure of choice as it fuses the arthritic midcarpal joint while preserving functional flexion/extension through the spared radiolunate joint.

Question 3

When performing an olecranon osteotomy for exposure of an intra-articular distal humerus fracture, what is the optimal technique to maximize construct stability and minimize nonunion?

Explanation

An apex-distal chevron osteotomy is the preferred technique. It provides intrinsic rotational stability due to the chevron shape and a large surface area for healing. The osteotomy should be directed to exit the articular surface at the 'bare area' (the non-articular portion of the greater sigmoid notch) to minimize damage to the articular cartilage of the proximal ulna.

Question 4

A 25-year-old sustains a volar laceration to the index finger in Zone II. Surgical exploration reveals complete transection of the FDS and FDP tendons. Following a 4-strand core repair of the FDP and an epitendinous repair, there is noticeable catching of the repair site on the A2 pulley during passive flexion, limiting glide. What is the most appropriate next step?

Explanation

Historically, preservation of the entire A2 and A4 pulleys was considered absolute to prevent bowstringing. However, modern flexor tendon repair protocols dictate that venting up to 50% or even 75% of the A2 pulley (typically the proximal or distal aspect) is acceptable and preferred to allow smooth tendon gliding and prevent triggering or repair rupture. 4-strand or 6-strand repairs are preferred for early active motion protocols, so downgrading to a weaker 2-strand repair is inappropriate.

Question 5

A 28-year-old man sustains a complete laceration of the ulnar nerve in the proximal arm. To maximize the chance of restoring intrinsic hand function before irreversible motor endplate loss occurs, a distal nerve transfer is planned. Which donor nerve is most commonly utilized for transfer to the deep motor branch of the ulnar nerve?

Explanation

For high ulnar nerve injuries, recovery of the intrinsic muscles of the hand is exceptionally poor due to the long distance the regenerating axons must travel. The standard 'supercharged' end-to-side or complete end-to-end nerve transfer involves taking the terminal branch of the anterior interosseous nerve (AIN) that innervates the pronator quadratus and transferring it to the deep motor branch of the ulnar nerve at the wrist.

Question 6

A 6-year-old boy presents for follow-up 6 weeks after closed reduction and casting of a Monteggia equivalent lesion. Radiographs reveal that the radial head is dislocated anteriorly, and the proximal ulna fracture has healed in apex-anterior angulation. What is the most appropriate management?

Explanation

A missed or chronic Monteggia fracture-dislocation in a child invariably stems from malreduction (angulation or length loss) of the ulna. The radial head cannot maintain reduction if the ulna length and alignment are not restored. Treatment requires a corrective osteotomy of the proximal ulna, combined with open reduction of the radial head. Radial head resection is contraindicated in children due to subsequent growth disturbances and wrist issues.

Question 7

A 24-year-old gymnast falls onto a hyperextended wrist. Imaging reveals a transverse fracture of the scaphoid waist and a transverse fracture of the capitate. Notably, the proximal capitate fragment is rotated 180 degrees. What is the classic eponym for this specific injury pattern?

Explanation

This injury pattern is classically known as scaphocapitate syndrome or Fenton's syndrome. The proposed mechanism involves extreme hyperextension of the wrist where the dorsal lip of the radius strikes the capitate causing a fracture, and the scaphoid fractures simultaneously. The proximal capitate fragment often rotates 90 to 180 degrees. Treatment requires open reduction and internal fixation of both fractures to prevent nonunion and avascular necrosis.

Question 8

A 35-year-old woman falls on her outstretched arm and sustains an isolated fracture of the capitellum. CT scan demonstrates a fracture in the coronal plane consisting primarily of a thin shell of articular cartilage with very minimal subchondral bone attached. According to the Bryan and Morrey classification, what type of fracture is this and what is the typical treatment if displaced?

Explanation

Bryan and Morrey Type II capitellar fractures (Kocher-Lorenz) are 'uncapital' shear fractures involving a thin sliver of articular cartilage with little subchondral bone. Because of the lack of bone stock, they are extremely difficult to fix with standard screws. Treatment typically involves either excision of the fragment or fixation with very small bioabsorbable pins or resorbable darts. Type I (Hahn-Steinthal) fractures have a large segment of subchondral bone and are amenable to headless screw fixation.

Question 9

A 22-year-old man presents with severe crush injury to his right forearm and is diagnosed with acute compartment syndrome. A volar approach for fasciotomy (extensile Henry approach) is planned. During deep dissection, which critical neurovascular structure must be carefully protected as it passes between the two heads of the pronator teres?

Explanation

The median nerve classically runs between the humeral and ulnar heads of the pronator teres muscle in the proximal forearm. During the volar forearm fasciotomy (which utilizes the Henry approach extending from the distal humerus to the wrist), careful identification and release of the pronator teres aponeurosis and the FDS arch is necessary to thoroughly decompress the deep volar compartment and prevent secondary median nerve entrapment.

Question 10

A 28-year-old carpenter amputates the tip of his right index finger. Examination reveals a volar oblique amputation with 4 mm of exposed distal phalanx bone. The nail bed is largely intact dorsally. Which of the following is the most appropriate reconstructive option for providing durable, sensate coverage?

Explanation

A volar oblique fingertip amputation with exposed bone requires soft tissue coverage, as healing by secondary intention is inappropriate for exposed bone >1-2 cm or prominent bone. The cross-finger flap is the workhorse for volar oblique amputations in the fingers, transferring dorsal skin from an adjacent digit. The Moberg flap is largely restricted to the thumb due to its independent dorsal blood supply. Atasoy and Kutler flaps are best for transverse or dorsal oblique amputations.

Question 11

A 30-year-old male sustains a closed, isolated, transverse shaft fracture of the second metacarpal (index finger) of his dominant hand. Radiographs show 25 degrees of apex dorsal angulation and no rotational deformity. What is the most appropriate treatment?

Explanation

The carpometacarpal (CMC) joints of the index and long fingers are highly rigid, offering virtually no compensatory motion in the sagittal plane. Therefore, fractures of the 2nd and 3rd metacarpals tolerate very little apex dorsal angulation (acceptable limits are typically <10 to 15 degrees). An angulation of 25 degrees will lead to a painful grip and a pseudoclaw deformity. Operative intervention (ORIF or CRPP, but ORIF is definitive for 25 deg in the 2nd MC) is indicated. In contrast, the 4th and 5th metacarpals tolerate much greater angulation (up to 30-40+ degrees) due to their mobile CMC joints.

Question 12

Six months following open reduction and internal fixation of a distal radius fracture with a volar locking plate, a 55-year-old woman is unable to actively flex the interphalangeal joint of her thumb. Which of the following technical errors during the index procedure is the most likely cause of this complication?

Explanation

Rupture of the flexor pollicis longus (FPL) tendon is a well-recognized complication of volar plating of the distal radius. It is most commonly caused by hardware prominence distal to the watershed line (the most volar margin of the radius). The tendon glides over the sharp distal edge of the plate, leading to attritional rupture. Placement proximal to the watershed line is the correct technique to avoid this. Long distal screws would cause extensor tendon rupture, not flexor.

Question 13

A 42-year-old man falls from a ladder, sustaining a comminuted, un-reconstructible radial head fracture. Intraoperatively, after radial head excision, he is noted to have significant longitudinal translation of the radius. Examination of the wrist reveals dorsal prominence and gross instability of the distal ulna. What is the most appropriate definitive management of the elbow and wrist?

Explanation

This is a classic Essex-Lopresti injury, characterized by a radial head fracture, tear of the interosseous membrane, and disruption of the distal radioulnar joint (DRUJ). Because the central band of the IOM is incompetent, the radial head acts as the primary constraint to proximal migration of the radius. Radial head resection alone is strictly contraindicated as it leads to severe proximal migration of the radius and ulnocarpal impaction. Treatment mandates radial head replacement to restore longitudinal stability and stabilization of the DRUJ (usually by pinning the wrist in supination for 4-6 weeks).

Question 14

A 34-year-old agricultural worker is caught in a tractor power take-off, sustaining a Gustilo-Anderson Type IIIB open fracture of the humeral shaft with gross soil contamination. In addition to prompt surgical debridement, what is the most appropriate initial intravenous antibiotic regimen according to current trauma guidelines?

Explanation

For severe open fractures (Gustilo III), standard prophylaxis involves a first-generation cephalosporin (Cefazolin) for Gram-positive coverage and an aminoglycoside (Gentamicin) for Gram-negative coverage. When an injury occurs in an agricultural setting or involves gross soil contamination, there is a high risk of Clostridium infection. Therefore, high-dose Penicillin G must be added to the regimen for anaerobic coverage to prevent gas gangrene.

Question 15

A 25-year-old man sustains a low-velocity civilian gunshot wound to the anterior right elbow. Radiographs show a nondisplaced supracondylar humerus fracture. Neurological exam reveals an inability to flex the IP joint of the thumb and the DIP joint of the index finger, with complete loss of two-point discrimination over the volar tip of the index finger. What is the most appropriate management of the nerve injury?

Explanation

The patient has a median nerve palsy (involving AIN motor branches and proper sensory branches to the index finger). Neurological deficits associated with low-velocity gunshot wounds to the extremities are typically neurapraxias or axonotmesis resulting from the concussive shock wave of the bullet. The standard of care is non-operative observation initially. If there is no clinical recovery by 3 months, an EMG is obtained, and surgical exploration is considered if no reinnervation potentials are present. Immediate exploration is reserved for vascular injury, severe contamination, or if the deficit occurs after reduction.

Question 16

A 30-year-old skier presents with a painful, swollen thumb metacarpophalangeal (MCP) joint after a fall. Examination demonstrates 40 degrees of radial deviation laxity when the MCP joint is stressed in 30 degrees of flexion, with no palpable endpoint. Ultrasound confirms a Stener lesion. Which of the following accurately describes the anatomy of a Stener lesion?

Explanation

A Stener lesion occurs in complete ruptures of the ulnar collateral ligament (UCL) of the thumb (Skier's thumb). The ligament typically avulses from its distal insertion on the proximal phalanx. In a Stener lesion, the torn distal end retracts and displaces superficial to the adductor pollicis aponeurosis. Because the aponeurosis becomes interposed between the ligament and its insertion site, spontaneous healing is impossible, and operative repair is indicated.

Question 17

A 40-year-old man undergoes a single-incision anterior approach for repair of a complete acute distal biceps tendon rupture using a cortical button technique. Postoperatively, he complains of burning pain and numbness over the radial aspect of the mid-to-distal volar forearm. His motor function is completely intact. Which nerve was most likely injured during the surgical approach?

Explanation

The lateral antebrachial cutaneous nerve (LABC), the terminal sensory branch of the musculocutaneous nerve, exits the deep fascia lateral to the biceps tendon and runs near the cephalic vein. It provides sensation to the radial half of the volar forearm. It is highly susceptible to traction or transection injury during the anterior single-incision approach to the distal biceps. The posterior interosseous nerve (PIN) is at risk during a two-incision approach or with deep retractors, but it provides motor innervation (which is intact here).

Question 18

A 32-year-old dishwasher presents with a swollen, throbbing index finger 3 days after sustaining a puncture wound from a dirty wire brush. Examination reveals uniform fusiform swelling of the digit, a semi-flexed posture of the finger, severe pain on passive extension, and exquisite tenderness along the entire flexor tendon sheath. Which of the following organisms is the most common cause of this condition?

Explanation

The patient exhibits Kanavel's four cardinal signs of infectious flexor tenosynovitis: fusiform swelling, flexed posture, pain on passive extension, and tenderness along the flexor sheath. Staphylococcus aureus is by far the most common causative organism for this surgical emergency. Pasteurella is associated with cat bites, Eikenella with human bites, and Mycobacterium marinum with fish tank exposures.

Question 19

A 28-year-old male sustains a sharp complete transection of his radial nerve at the mid-humeral level. Within 24-48 hours post-injury, Wallerian degeneration begins. Which of the following best describes the pathophysiological process of Wallerian degeneration distal to the injury site?

Explanation

Wallerian degeneration occurs in the distal stump of a transected nerve. The axons and myelin sheath rapidly degrade, and macrophages migrate in to clear the debris. Crucially, the Schwann cells do not die; rather, they dedifferentiate, proliferate, and align to form longitudinal columns known as Bands of Büngner within the preserved endoneurial tubes. These bands secrete neurotrophic factors and provide a physical pathway to guide regenerating axonal sprouts from the proximal stump.

Question 20

A 24-year-old male presents to the emergency department following an arm wrestling match. Radiographs reveal a spiral fracture of the distal third of the humeral shaft. On examination, he is unable to actively extend his wrist or fingers, though he can forcefully extend his elbow. Sensation is decreased over the dorsal web space. Which of the following is the most appropriate initial management of this fracture and associated nerve injury?

Explanation

This is a Holstein-Lewis fracture (spiral fracture of the distal third of the humerus) with a primary radial nerve palsy. Despite the specific fracture pattern, the treatment of a primary radial nerve palsy associated with a closed humeral shaft fracture remains non-operative initially. Over 70-90% of these palsies represent neurapraxia or axonotmesis and will recover spontaneously. The standard of care is a coaptation splint or functional brace. Surgical exploration is indicated if the fracture is open, if there is an associated vascular injury, or if the nerve palsy develops secondarily after closed reduction.

Question 21

A 55-year-old woman is 6 months postoperative from an open reduction and internal fixation of a distal radius fracture with a volar locked plate. She now presents with a new inability to actively flex the interphalangeal joint of her thumb. Radiographs reveal the plate is positioned distal to the watershed line. Which of the following structures is most likely injured?

Explanation

The flexor pollicis longus (FPL) tendon lies directly over the volar distal radius. Volar plates placed distal to the watershed line (the volar margin of the distal radius articular surface) prominent hardware can cause attrition and subsequent rupture of the FPL tendon. The EPL tendon is at risk from screws penetrating the dorsal cortex.

Question 22

A 35-year-old male falls from a height and sustains a 'terrible triad' injury of the elbow. According to standard biomechanical principles and accepted surgical protocols, what is the most appropriate sequence of surgical reconstruction?

Explanation

The standard surgical protocol for a terrible triad injury (elbow dislocation, radial head fracture, and coronoid fracture) involves a deep-to-superficial repair sequence. The most accepted sequence is to stabilize the coronoid first (restoring anterior stability), followed by the radial head (either ORIF or arthroplasty to restore the lateral column), and finally the lateral collateral ligament (LCL) complex. The MCL is typically only repaired if the elbow remains unstable after these three steps.

Question 23

A 28-year-old patient sustained a midshaft humerus fracture with an associated radial nerve palsy that shows no clinical or electromyographic signs of recovery at 6 months. For restoration of functional wrist extension, what is the most common and reliable tendon transfer?

Explanation

The standard set of tendon transfers for a high radial nerve palsy includes transferring the Pronator Teres (PT) (innervated by the median nerve) to the Extensor Carpi Radialis Brevis (ECRB) to restore wrist extension. The ECRB is preferred over the ECRL because its central location prevents radial deviation during active wrist extension.

Question 24

A 24-year-old male is evaluated for severe hand swelling, tense compartments, and pain out of proportion to the injury following an industrial crush injury. If a full hand fasciotomy is indicated, how many distinct fascial compartments in the hand must be released?

Explanation

There are 10 accepted fascial compartments in the hand that require release in the setting of compartment syndrome: 4 dorsal interosseous compartments, 3 volar interosseous compartments, the thenar compartment, the hypothenar compartment, and the adductor pollicis compartment.

Question 25

Avascular necrosis of the proximal pole of the scaphoid is a frequent complication following a scaphoid waist fracture. The primary blood supply to the proximal pole is derived from which of the following vessels?

Explanation

The scaphoid has a retrograde blood supply. The major blood supply to the scaphoid (and specifically the proximal pole) enters the dorsal ridge distal to the waist via the dorsal carpal branch of the radial artery. Fractures at the waist or proximally interrupt this retrograde flow, leading to avascular necrosis of the proximal pole.

Question 26

A 42-year-old woman sustains a shear fracture of the capitellum and lateral trochlea. CT imaging reveals significant posterior coronal comminution. According to the Dubberley classification, what is the significance of this posterior comminution?

Explanation

In the Dubberley classification of capitellum/trochlea fractures, Type A fractures lack posterior comminution, while Type B fractures have posterior condylar comminution. Type B fractures lack a posterior bony buttress, making them biomechanically unstable with isolated anterior-to-posterior screws. They typically require a posterior approach (or extensile lateral approach) with supplemental posterior plating to prevent fixation failure.

Question 27

A 22-year-old boxer sustains a Bennett fracture. The fracture pattern consists of a small volar-ulnar base fragment with proximal, dorsal, and radial subluxation of the metacarpal shaft. Which ligament securely anchors the small volar-ulnar fragment in its anatomical position?

Explanation

In a Bennett fracture, the shaft of the thumb metacarpal is pulled proximally, dorsally, and radially by the abductor pollicis longus (APL). However, the small volar-ulnar base fragment remains precisely in its anatomical location, securely tethered to the trapezium by the strong volar oblique ligament (also known as the anterior oblique ligament).

Question 28

A 40-year-old male sustains an APC-III pelvic ring injury. In the trauma bay, the decision is made to apply a non-invasive external pelvic binder to reduce pelvic volume. To maximize biomechanical efficacy, the binder should be centered over which of the following anatomic landmarks?

Explanation

For effective reduction of pelvic volume in anterior-posterior compression injuries, a pelvic binder must be applied directly over the greater trochanters. Placement higher over the iliac crests is incorrect and can paradoxically open the true pelvis further or be less effective in closing the symphyseal diastasis.

Question 29

A surgeon chooses to perform a distal biceps tendon repair using a two-incision technique rather than a single anterior incision. The two-incision technique historically carries a higher risk of which of the following complications compared to the single-incision technique?

Explanation

The two-incision technique for distal biceps repair exposes the patient to a higher risk of heterotopic ossification and proximal radioulnar synostosis because it dissects the interosseous membrane between the radius and ulna. In contrast, the single anterior incision approach carries a significantly higher risk of injury to the Lateral Antebrachial Cutaneous (LABC) nerve.

Question 30

A 32-year-old manual laborer presents with progressive dorsal wrist pain. Radiographs demonstrate sclerosis, cystic changes, and fragmentation of the lunate, with an ulnar variance of minus 3 mm. Which of the following is the most appropriate surgical treatment for this patient?

Explanation

The clinical scenario describes Kienbock's disease (avascular necrosis of the lunate). In patients with negative ulnar variance (ulna minus) who do not yet have advanced radiocarpal arthritis or complete carpal collapse, joint-leveling procedures are indicated to unload the lunate. A radial shortening osteotomy is the standard joint-leveling procedure used in this scenario.

Question 31

During an anterior subcutaneous transposition of the ulnar nerve for cubital tunnel syndrome, the nerve must be completely mobilized. Failure to release which of the following structures located approximately 8 cm proximal to the medial epicondyle can lead to new iatrogenic compression of the ulnar nerve?

Explanation

The Arcade of Struthers is a fascial band extending from the medial head of the triceps to the medial intermuscular septum, located about 8 cm proximal to the medial epicondyle. If not divided during anterior transposition, it creates a new tethering point for the ulnar nerve. (Note: The Ligament of Struthers is associated with the median nerve and a supracondylar process, which is a classic distractor).

Question 32

According to the Mayfield classification of progressive perilunate instability, a Stage III injury is defined by the disruption of which of the following specific structures?

Explanation

Mayfield described four stages of progressive perilunate instability that occur in a sequential, C-shaped pattern around the lunate: Stage I (scapholunate ligament tear), Stage II (capitolunate disruption/space), Stage III (lunotriquetral ligament tear, resulting in a perilunate dislocation), and Stage IV (dorsal radiocarpal ligament tear with volar dislocation of the lunate into the carpal tunnel).

Question 33

A 45-year-old male sustains a bicondylar tibial plateau fracture with a displaced, large posteromedial coronal split fragment. A posteromedial surgical approach is chosen for optimal buttress plating. This approach develops an internervous plane between which of the following muscle groups?

Explanation

The posteromedial approach to the tibial plateau is critical for addressing posteromedial shear fragments, which cannot be adequately buttressed from an anteromedial approach. The correct anatomic interval is between the medial head of the gastrocnemius (retracted laterally/posteriorly) and the pes anserinus tendons (retracted medially/anteriorly).

Question 34

A 28-year-old sustains an untreated dorsal laceration over the proximal interphalangeal (PIP) joint, transecting the central slip. Over weeks, a Boutonniere deformity develops due to the volar subluxation of the lateral bands. In the normal finger anatomy, which structure primarily prevents this volar subluxation of the lateral bands?

Explanation

The triangular ligament is located dorsally over the middle phalanx and connects the two lateral bands. Its primary anatomical function is to prevent the lateral bands from subluxating volarly past the axis of rotation of the PIP joint. When the central slip ruptures, the triangular ligament eventually attenuates, allowing the lateral bands to slide volar and become flexors of the PIP, leading to a Boutonniere deformity.

Question 35

On a standard anteroposterior (AP) radiograph of the pelvis in a patient with a suspected acetabular fracture, the iliopectineal line serves as the radiographic landmark for which structural component of the acetabulum?

Explanation

In the radiographic evaluation of acetabular fractures (Judet-Letournel principles), the iliopectineal line represents the anterior column. The ilioischial line represents the posterior column. The anterior rim of the acetabulum represents the anterior wall, and the posterior rim represents the posterior wall.

Question 36

A 25-year-old carpenter sustains a volar oblique fingertip amputation of the index finger, resulting in a 1.5 cm soft tissue defect with exposed distal phalanx bone. The defect involves the pulp but spares the dorsal nail bed. Which of the following provides the most durable, robust coverage for this specific defect?

Explanation

A volar oblique fingertip amputation with exposed bone requires flap coverage. The cross-finger flap is the workhorse for volar oblique defects on the fingers, utilizing dorsal skin from an adjacent digit. The V-Y advancement (Atasoy) is best for transverse or dorsal oblique amputations. The Moberg advancement flap is indicated exclusively for the thumb due to its independent dual blood supply allowing the entire volar skin to be advanced.

Question 37

A 25-year-old male sustains a vertically oriented, displaced femoral neck fracture (Pauwels type III). Compared to a more horizontally oriented Pauwels type I fracture, what is the primary biomechanical disadvantage inherent to the Pauwels type III pattern?

Explanation

The Pauwels classification of femoral neck fractures is based on the angle of the fracture line relative to the horizontal plane. A Pauwels type III fracture is highly vertical (>50 degrees). Biomechanically, this steep angle translates axial loading forces into extremely high shear forces across the fracture site, predisposing the fracture to varus displacement and nonunion.

Question 38

A 22-year-old polytrauma patient presents with a midshaft humerus fracture and a documented inability to actively extend the wrist, thumb, and fingers. However, active extension of the elbow against resistance is perfectly preserved. There is sensory loss over the dorsal first web space. Anatomically, where is the most likely level of the nerve injury?

Explanation

The patient has a radial nerve palsy with preserved triceps function. The branches to the long head of the triceps arise very proximally in the axilla, and branches to the lateral and medial heads arise prior to or just as the nerve enters the spiral groove. An injury at the level of the spiral groove (common in midshaft humerus fractures) spares triceps extension but denervates the supinator, wrist extensors, and finger extensors, matching this presentation.

Question 39

In Scaphoid Nonunion Advanced Collapse (SNAC), degenerative changes progress through the wrist in a predictable anatomical sequence. Which of the following joints is typically the LAST to develop osteoarthritic changes and is specifically spared in early to middle stages?

Explanation

In both SNAC and SLAC (Scapholunate Advanced Collapse) patterns of wrist arthritis, the radiolunate joint is characteristically spared until the absolute latest stages of the disease. This is because the lunate maintains its congruency within the spherical lunate fossa of the distal radius, a concept central to the rationale for performing a four-corner fusion or proximal row carpectomy, both of which rely on a preserved radiolunate articulation.

Question 40

A 38-year-old male develops severe heterotopic ossification (HO) following a complex elbow fracture-dislocation, resulting in profound functional stiffness. Nonoperative management has failed. According to current evidence-based guidelines, what is the most reliable clinical and radiographic indicator that the HO is mature enough for safe surgical excision?

Explanation

Historically, surgeons waited 12 to 18 months or relied on alkaline phosphatase/bone scans before excising heterotopic ossification to prevent recurrence. Modern evidence demonstrates that HO can be safely excised much earlier (often at 6 months) as long as there is a clinical plateau in the recovery of range of motion and CT imaging confirms mature bone with sharp, distinct trabecular and cortical margins.

Question 41

A 45-year-old female presents with a closed elbow injury after a fall. Plain radiographs show a capitellum fracture. The lateral radiograph demonstrates a classic 'double arc sign.' Which of the following statements is true regarding this specific fracture pattern?

Explanation

The 'double arc sign' on a true lateral radiograph of the elbow is pathognomonic for a coronal shear fracture of the distal humerus that involves both the capitellum and the lateral trochlear ridge (McKee modification Type IV capitellum fracture). One arc represents the capitellum, and the second arc represents the trochlear ridge. These are highly unstable and typically require open reduction and internal fixation (ORIF), often via an extensile lateral or dual-incision approach, using headless compression screws.

Question 42

A 65-year-old man with a history of Dupuytren's disease undergoes surgery for a severe proximal interphalangeal (PIP) joint contracture of his ring finger. During dissection, the surgeon encounters the spiral cord. Which of the following normal anatomic structures is NOT a component of the spiral cord?

Explanation

The spiral cord in Dupuytren's disease causes PIP joint contracture and characteristically displaces the neurovascular bundle centrally, superficially, and proximally. It is formed by the pathological involvement of four normal structures: the pretendinous band, the spiral band, the lateral digital sheet, and Grayson's ligament. Cleland's ligament is located dorsal to the neurovascular bundle and is characteristically spared (not involved) in Dupuytren's disease.

Question 43

A 30-year-old construction worker sustained a high-pressure injection injury to his right index finger with an industrial paint thinner 2 hours ago. The entry wound is 2 mm at the distal palmar crease. He has mild swelling but no severe pain. What is the most appropriate next step in management?

Explanation

High-pressure injection injuries to the hand are surgical emergencies, especially when involving organic solvents like paint thinner, which cause severe chemical necrosis and possess a high amputation rate (often >50%). Despite benign initial appearances, the material dissects proximally along tendon sheaths. Emergent wide surgical debridement in the operating room is mandatory. Digital blocks are contraindicated due to the risk of exacerbating compartment pressures.

Question 44

A 28-year-old male is involved in a high-speed motorcycle accident and sustains a pelvic ring injury. Radiographs and CT demonstrate a symphysis pubis diastasis of 3.5 cm, with widening of the anterior sacroiliac joints. The posterior sacroiliac ligaments are intact. According to the Young and Burgess classification, what is the injury type and its primary plane of instability?

Explanation

An APC-2 injury is characterized by rupture of the symphysis pubis (>2.5 cm diastasis) and rupture of the anterior sacroiliac, sacrotuberous, and sacrospinous ligaments. The posterior sacroiliac ligaments remain intact. This results in rotational instability (an 'open book' pelvis) but preserves vertical stability. APC-3 involves complete disruption of both anterior and posterior SI ligaments, resulting in both rotational and vertical instability.

Question 45

Following a traumatic 'terrible triad' injury of the elbow, a 35-year-old patient undergoes ORIF of the coronoid and radial head with LCL repair. Which of the following is the most commonly reported complication after surgical management of this injury?

Explanation

While heterotopic ossification, ulnar neuropathy, and recurrent instability can occur, post-traumatic elbow stiffness is by far the most common complication following the surgical treatment of a terrible triad injury (elbow dislocation, radial head fracture, and coronoid fracture). Early postoperative mobilization is critical to mitigate this risk once a stable joint construct is achieved.

Question 46

A 40-year-old male sustains an isolated vertical femoral neck fracture (Pauwels Type III). He undergoes closed reduction and internal fixation. From a biomechanical perspective, which of the following fixation constructs offers the greatest resistance to vertical shear forces in this fracture pattern?

Explanation

Pauwels Type III (vertical) femoral neck fractures have a fracture angle greater than 50 degrees relative to the horizontal and are highly unstable due to significant vertical shear forces. Traditional multiple parallel cannulated screws have a high failure rate in this pattern because they do not adequately resist shear. A fixed-angle sliding hip screw (DHS) construct, often supplemented with a derotational screw, provides superior biomechanical resistance to shear forces and improved rates of union for vertical femoral neck fractures in young adults.

Question 47

During repair of a multiple-digit flexor tendon injury in Zone II, a surgical resident inadvertently advances the flexor digitorum profundus (FDP) tendon of the middle finger 1.5 cm distally before securing it. Postoperatively, the patient is unable to make a full composite fist with the adjacent, uninjured ring and small fingers. What is this phenomenon called?

Explanation

The Quadrigia effect occurs when the FDP tendon of one digit is overtensioned (advanced >1 cm) during repair or over-resected during amputation. Because the FDP tendons to the middle, ring, and small fingers share a common muscle belly, overtensioning one restricts the proximal excursion of the common muscle belly, leading to a flexion lag (incomplete active flexion) in the adjacent normal digits.

Question 48

A 22-year-old male sustains a Hawkins Type III talar neck fracture. Which of the following statements regarding the blood supply to the talar body and the risk of avascular necrosis (AVN) is most accurate?

Explanation

The primary blood supply to the talar body is the artery of the tarsal canal, which is a branch of the posterior tibial artery. A Hawkins Type III fracture is a talar neck fracture with both subtalar and tibiotalar dislocations. This severe injury disrupts the major blood supplies (tarsal canal, sinus tarsi, and superior neck vessels), leading to an AVN risk of nearly 90-100%.

Question 49

A 70-year-old female presents with advanced Scapholunate Advanced Collapse (SLAC) wrist osteoarthritis. Which joint space is characteristically PRESERVED (spared from arthritic change) even in the late stages of this disease?

Explanation

In both SLAC and SNAC (Scaphoid Nonunion Advanced Collapse) wrists, the radiolunate joint is characteristically spared from osteoarthritis. This is because the lunate has a spherical articulation with the lunate fossa of the radius, maintaining concentric loading without pathological shear forces, even when the scaphoid is destabilized. This preservation allows for salvage procedures like the four-corner fusion (capitate, hamate, lunate, triquetrum) combined with scaphoid excision.

Question 50

A 45-year-old male sustains a severe open tibia fracture (Gustilo-Anderson IIIB) to the middle third of his lower leg. After aggressive skeletal stabilization and serial debridement, a soft tissue defect remains that exposes bone devoid of periosteum. Which of the following soft tissue coverage options is most appropriate for a defect in the MIDDLE third of the tibia?

Explanation

For coverage of soft tissue defects of the lower extremity, rotational muscle flaps are chosen based on the level of the defect. The classic algorithm utilizes the medial gastrocnemius flap for the proximal third, the soleus flap for the middle third, and a free tissue transfer (e.g., anterolateral thigh or latissimus dorsi) for the distal third of the tibia.

Question 51

A 55-year-old female with long-standing rheumatoid arthritis presents with an acute inability to flex the interphalangeal (IP) joint of her thumb. She reports a sudden 'pop' at the wrist level while lifting a pan. Physical exam reveals lack of active IP flexion but full passive motion. What is the most likely location of the attritional bony spur causing this tendon rupture?

Explanation

This patient has a rupture of the flexor pollicis longus (FPL) tendon, a condition known as a Mannerfelt-Norman syndrome or lesion in rheumatoid arthritis. The attritional rupture is most commonly caused by a bony spur on the volar aspect of the scaphoid (volar beak) that erodes through the floor of the carpal tunnel. Ruptures at Lister's tubercle typically affect the extensor pollicis longus (EPL).

Question 52

A 40-year-old male sustained an elbow fracture-dislocation and is diagnosed with posteromedial rotatory instability (PMRI). Which of the following combinations of injury is the hallmark of PMRI?

Explanation

Posteromedial rotatory instability (PMRI) of the elbow occurs secondary to a varus and posteromedial rotatory force. The hallmark pathoanatomy includes an anteromedial facet fracture of the coronoid process combined with a tear of the lateral collateral ligament complex (specifically the LUCL). Failure to recognize and stabilize the anteromedial coronoid facet leads to rapid development of varus instability and early post-traumatic arthritis.

Question 53

A 32-year-old male sustains a high radial nerve palsy following a humerus shaft fracture. Six months later, there is no clinical or EMG evidence of recovery, and tendon transfers are planned. In a standard superficialis (Boyes) transfer, which donor tendon is used to restore wrist extension?

Explanation

In tendon transfers for radial nerve palsy, restoring wrist extension is almost universally accomplished by transferring the Pronator Teres (PT) to the Extensor Carpi Radialis Brevis (ECRB). This holds true for both the Boyes (superficialis) transfer and the standard FCR transfer. The Boyes transfer then uses FDS of the middle finger to EDC (finger extension) and FDS of the ring finger to EPL (thumb extension).

Question 54

An 82-year-old woman with severe osteoporosis presents with a comminuted, intra-articular distal humerus fracture (AO Type 13-C3). The surgeon decides to proceed with a Total Elbow Arthroplasty (TEA) rather than ORIF. According to the literature, which of the following is an expected comparative outcome of TEA versus ORIF for this specific patient population at 1 to 2 years postoperatively?

Explanation

In elderly patients with severe osteoporotic comminuted distal humerus fractures, TEA is often favored over ORIF because it allows immediate postoperative mobilization and provides better, more predictable functional scores and range of motion at 1-2 years. However, TEA is associated with a permanent lifting restriction (typically <5-10 lbs) and higher lifetime complication and reoperation rates (e.g., aseptic loosening, bushing wear, periprosthetic fracture).

Question 55

A 25-year-old male sustains an Essex-Lopresti injury characterized by a comminuted radial head fracture, DRUJ dislocation, and interosseous membrane disruption. The radial head is deemed unsalvageable. Radial head excision without replacement is contraindicated in this setting due to the risk of which of the following?

Explanation

An Essex-Lopresti injury disrupts the longitudinal radioulnar axis. The radial head is a crucial secondary stabilizer against proximal translation of the radius. If the radial head is excised without prosthetic replacement when the interosseous membrane is torn, the radius will migrate proximally, leading to severe DRUJ incongruity, distal ulna abutment against the carpus (ulnocarpal impaction), and profound wrist pain/dysfunction. A radial head arthroplasty is mandatory.

Question 56

A patient with carpal tunnel syndrome undergoes electrodiagnostic testing (EMG/NCS), which confirms median neuropathy at the wrist but also demonstrates anomalous innervation where motor fibers cross from the median nerve to the ulnar nerve in the forearm. This anomaly is known as:

Explanation

The Martin-Gruber anastomosis is an anomalous connection between the median and ulnar nerves in the forearm, present in roughly 15-20% of the population. It typically carries motor fibers from the median nerve to the ulnar nerve, often innervating intrinsic hand muscles (like the first dorsal interosseous) that are normally ulnar-innervated. Riche-Cannieu is a median-ulnar connection in the palm. Marinacci is an ulnar-to-median connection in the forearm. Berrettini is a sensory connection between the common digital nerves in the palm.

Question 57

During a single-incision anterior approach for a distal biceps tendon repair, excessive lateral retraction is applied to expose the radial tuberosity. Postoperatively, the patient complains of numbness and paresthesias along the lateral aspect of their volar forearm. Which nerve was most likely injured?

Explanation

The Lateral Antebrachial Cutaneous Nerve (LABCN), a continuation of the musculocutaneous nerve, exits between the biceps and brachialis and runs laterally in the distal arm and proximal forearm. It is highly susceptible to stretch or transection during the anterior single-incision approach to the distal biceps, particularly with overzealous lateral retraction. It provides sensation to the lateral aspect of the volar forearm.

Question 58

A 25-year-old male sustains an acute tibia fracture and subsequently develops compartment syndrome. The surgeon performs a standard two-incision, four-compartment fasciotomy. The medial incision is placed too anteriorly, just behind the medial tibial crest, and fails to adequately release a specific compartment. Which structures are at highest risk of ischemic contracture?

Explanation

The deep posterior compartment is the most frequently missed or inadequately released compartment during a fasciotomy for leg compartment syndrome, especially if the medial incision is not placed far enough posteriorly (it should be 2 cm posterior to the posteromedial border of the tibia). Failure to release it jeopardizes its contents: the tibialis posterior, flexor hallucis longus, and flexor digitorum longus muscles, leading to claw toe and equinovarus contractures.

Question 59

A trauma patient is evaluated for an acetabular fracture. The obturator oblique radiographic view reveals a classic 'spur sign.' This radiographic finding is pathognomonic for which type of acetabular fracture according to the Letournel and Judet classification?

Explanation

The 'spur sign' on an obturator oblique radiograph represents the lowest limit of the intact portion of the ilium (the strut of bone above the acetabular roof) that remains attached to the axial skeleton while the entire articular surface (both anterior and posterior columns) is detached and medially displaced. It is pathognomonic for an associated both-column fracture.

Question 60

A patient with an isolated, complete high ulnar nerve injury at the mid-arm level is evaluated. During physical examination, when asked to pinch a piece of paper between the thumb and index finger, the thumb IP joint hyperflexes while the MCP joint hyperextends. This finding (Froment's sign) occurs due to weakness of which muscle, and what muscle compensates to create the IP flexion?

Explanation

Froment's sign tests for ulnar nerve palsy. The primary thumb adductor is the adductor pollicis (ulnar nerve). When it is weak or paralyzed, the patient cannot execute a strong key pinch. They compensate by using the flexor pollicis longus (FPL), innervated by the anterior interosseous nerve (branch of median nerve), which causes hyperflexion at the thumb IP joint. The simultaneous MCP hyperextension is termed Jeanne's sign.

Question 61

A patient presents with a coronal shear fracture of the distal humerus involving the capitellum and the lateral ridge of the trochlea. According to the Dubberley classification, what specific radiographic feature defines the suffix 'B' in this injury?

Explanation

In the Dubberley classification of capitellar fractures, Type 1 involves the capitellum, Type 2 involves the capitellum and trochlea, and Type 3 is comminuted. The suffix 'A' indicates an intact posterior condyle, while 'B' indicates posterior condylar comminution, which often necessitates posterior supplemental fixation.

Question 62

A 55-year-old female sustains a distal radius fracture treated with a volar locking plate. Radiographs show the plate positioned distal to the watershed line (Soong Grade 2). Which of the following complications is she at highest risk for developing?

Explanation

Placement of a volar plate distal to the watershed line of the distal radius places the hardware in direct contact with the flexor tendons. The flexor pollicis longus (FPL) tendon is the most commonly irritated and ruptured tendon in this specific scenario.

Question 63

A 32-year-old male sustains a closed, transverse midshaft humerus fracture. His initial neurologic exam in the emergency department is intact. Following closed reduction and application of a coaptation splint, he is unable to actively extend his wrist or fingers. What is the most appropriate next step in management?

Explanation

A secondary (iatrogenic) radial nerve palsy that develops after closed reduction or manipulation of a humeral shaft fracture is an absolute indication for surgical exploration. This is required to ensure the nerve is not entrapped or lacerated within the fracture site.

Question 64

A 24-year-old male presents with a symptomatic proximal pole scaphoid nonunion. MRI demonstrates avascular necrosis (AVN) of the proximal pole fragment. Which of the following is the most appropriate surgical management to maximize the chance of union?

Explanation

Proximal pole scaphoid nonunions complicated by avascular necrosis require a vascularized bone graft for optimal healing. The free vascularized medial femoral condyle (MFC) graft provides robust structural support and reliable blood supply, demonstrating significantly higher union rates than pedicled grafts for AVN.

Question 65

A patient undergoes open reduction and internal fixation of a Galeazzi fracture. Intraoperatively, after rigid anatomic fixation of the radius, the distal radioulnar joint (DRUJ) remains highly unstable in supination. What is the most appropriate intraoperative management of the DRUJ?

Explanation

In a Galeazzi fracture, if the DRUJ remains grossly unstable after anatomic fixation of the radius, it should be pinned in the position of maximum stability to allow the ligaments to heal. This is typically achieved by transfixing the DRUJ with K-wires in supination for 4 to 6 weeks.

Question 66

In the predictable progression of Scapholunate Advanced Collapse (SLAC) wrist arthritis, which specific carpal articulation is characteristically spared from degenerative changes?

Explanation

In a SLAC wrist, the radiolunate joint is characteristically spared from early osteoarthritis. This occurs because the spherical proximal articular surface of the lunate remains congruent with the lunate fossa, whereas the misaligned elliptical scaphoid causes progressive radioscaphoid wear.

Question 67

Which muscles are located in the deep volar compartment of the forearm and are considered the most susceptible to irreversible ischemic necrosis in an unrecognized compartment syndrome?

Explanation

The deep volar compartment of the forearm contains the flexor digitorum profundus (FDP), flexor pollicis longus (FPL), and pronator quadratus. Due to their deep location adjacent to the interosseous membrane, these muscles are most severely affected by elevated compartment pressures.

Question 68

A 55-year-old woman presents with the inability to flex her thumb interphalangeal joint 8 months after undergoing volar locking plate fixation for a distal radius fracture. Radiographs show a healed fracture but the plate is positioned anterior to the watershed line. Which of the following is the most likely cause of her current presentation?

Explanation

Volar plates placed distal to the watershed line of the distal radius can irritate and eventually cause attritional rupture of the flexor pollicis longus (FPL) tendon. This requires surgical intervention, often with tendon transfer or grafting.

Question 69

A 35-year-old female sustains a highly comminuted capitellum and trochlea fracture extending into the posterior column (Dubberley Type 3B). Which surgical approach provides the most optimal exposure for bicolumnar fixation of this specific injury pattern?

Explanation

While an extended lateral approach is common for isolated capitellar fractures, Dubberley Type 3 fractures involving both the capitellum and trochlea with posterior comminution often require a posterior approach with an olecranon osteotomy for adequate visualization and stable bicolumnar fixation.

Question 70

A 25-year-old male sustains a vertically oriented (Pauwels type III) femoral neck fracture. To maximize biomechanical stability and minimize shear forces across the fracture site, which fixation strategy is most appropriate?

Explanation

Pauwels type III fractures experience high vertical shear forces. A fixed-angle device, such as a sliding hip screw with an anti-rotation screw, provides superior biomechanical stability compared to parallel cancellous screws in vertically oriented fractures.

Question 71

A 22-year-old athlete presents with a proximal pole scaphoid nonunion. MRI demonstrates avascular necrosis of the proximal pole. Which surgical approach and graft choice is most appropriate for this specific injury?

Explanation

Proximal pole scaphoid fractures are best accessed via a dorsal approach. In the setting of avascular necrosis, a vascularized bone graft (such as the pedicled 1,2-ICSRA graft or a free medial femoral condyle graft) is indicated to promote healing.

Question 72

A 40-year-old male falls from a height and sustains a comminuted, unsalvageable radial head fracture. During examination, he reports severe pain at the ipsilateral wrist, and the distal radioulnar joint (DRUJ) is grossly unstable. What is the most appropriate management?

Explanation

This patient has an Essex-Lopresti injury, consisting of a radial head fracture, interosseous membrane tear, and DRUJ disruption. Radial head excision is contraindicated as it leads to proximal radial migration; treatment requires rigid radial head arthroplasty and DRUJ stabilization.

Question 73

Following a Zone II flexor tendon repair of the middle finger, a patient is started on an early active motion protocol. What is the primary biomechanical advantage of early active motion compared to passive motion protocols?

Explanation

Early active motion protocols aim to increase tendon excursion. This minimizes the formation of restrictive peritendinous adhesions and improves functional outcomes, though careful adherence is required to prevent tendon rupture.

Question 74

A 30-year-old male is brought to the trauma bay following a motorcycle crash. His pelvis is mechanically unstable (APC III pattern), his blood pressure is 70/40 mmHg, and his heart rate is 130 bpm. A pelvic binder is applied, and he remains hypotensive despite 2 liters of crystalloid and 2 units of PRBCs. FAST exam is negative. What is the most appropriate next step?

Explanation

In a hemodynamically unstable patient with a pelvic ring injury and a negative FAST scan, the source of bleeding is retroperitoneal. Pre-peritoneal pelvic packing or angiography with embolization is the critical next step to achieve hemostasis.

Question 75

A surgeon is planning a distal biceps tendon repair using a two-incision technique (modified Boyd-Anderson). Which complication is specifically increased with the two-incision technique compared to a single anterior incision approach?

Explanation

The two-incision technique was historically associated with a higher risk of radioulnar synostosis, especially if the interosseous membrane is violated or muscle planes are not respected. The single-incision technique carries a higher risk of lateral antebrachial cutaneous nerve (LABC) injury.

Question 76

A 60-year-old woman undergoes a ligament reconstruction and tendon interposition (LRTI) for advanced thumb carpometacarpal arthritis. Postoperatively, radiographs show 3 mm of proximal subsidence of the thumb metacarpal. What is the most likely clinical consequence of this radiographic finding?

Explanation

Radiographic subsidence of the thumb metacarpal following LRTI is a very common finding. Multiple studies have demonstrated that subsidence does not correlate with poor clinical outcomes, and patients typically have excellent pain relief and function.

Question 77

A 45-year-old male sustains a bicondylar tibial plateau fracture. CT imaging reveals a large, displaced posteromedial shear fragment. Which surgical approach and fixation strategy is most appropriate for addressing this specific fragment?

Explanation

A displaced posteromedial shear fragment in a tibial plateau fracture cannot be adequately reduced and stabilized from an anterolateral approach. A posteromedial approach with an anti-glide or buttress plate provides biomechanically superior fixation against vertical shear forces.

Question 78

A 6-year-old boy presents with a Gartland Type III supracondylar humerus fracture. On examination, the hand is pink and well-perfused, but the radial pulse is absent. Following closed reduction and percutaneous pinning, the hand remains pink, but the pulse is still absent. What is the next best step in management?

Explanation

In the setting of a pink, pulseless hand following successful reduction and pinning of a pediatric supracondylar fracture, the standard of care is close clinical observation. Open exploration is only indicated if the hand becomes pale and poorly perfused (ischemic).

Question 79

According to the Mayfield classification of progressive perilunate instability, which structure or joint is disrupted in Stage III, ultimately leading to a midcarpal dislocation?

Explanation

Mayfield Stage I involves the scapholunate ligament, Stage II involves the capitulolunate articulation, and Stage III involves the lunotriquetral ligament (resulting in a perilunate dislocation). Stage IV results in lunate enucleation into the carpal tunnel.

Question 80

A 28-year-old male with a closed tibial shaft fracture complains of severe leg pain out of proportion to the injury. His diastolic blood pressure is 80 mmHg. Intracompartmental pressure monitoring is performed. At what threshold is fasciotomy definitively indicated based on the delta pressure concept?

Explanation

The delta pressure is calculated as Diastolic Blood Pressure minus Compartment Pressure. A delta pressure of less than 30 mmHg is the most reliable threshold indicating inadequate tissue perfusion and the need for emergent fasciotomy.

Question 81

A 45-year-old mechanic complains of volar forearm pain and numbness in the radial three-and-a-half digits. He has a negative Phalen's test but experiences pain with resisted forearm pronation. Sensation over the thenar eminence is decreased. What is the most likely diagnosis?

Explanation

Pronator syndrome is a proximal median nerve compression. It is differentiated from carpal tunnel syndrome by volar forearm aching, pain with resisted pronation, and decreased sensation over the thenar eminence, which is supplied by the palmar cutaneous branch that spares the carpal tunnel.

Orthopedic Surgery Board Review MCQs: Arthroplasty, Trauma & Spine Part 255

Orthopedic Board Review MCQs: Trauma, Hand & Elbow | Part 24

Key Takeaway

Orthopedic Board Review MCQs: Trauma, Hand & Elbow | Part 24

Chapter Index