Comprehensive Orthopedic Review: Elbow & Hand Trauma, Fractures, Tendon Injuries | Part 22138

Correct Answer: C

The patient's presentation of a radial head fracture followed by persistent wrist pain, DRUJ instability (positive shuck test), and radiographic evidence of proximal radial migration (positive ulnar variance) is pathognomonic for an Essex-Lopresti lesion. This complex injury involves a radial head fracture, disruption of the interosseous membrane, and injury to the distal radio-ulnar joint. The radial head is crucial for longitudinal forearm stability, and its injury, combined with interosseous membrane disruption, allows the radius to migrate proximally, leading to DRUJ dysfunction. Radial head non-union would primarily cause elbow pain and might not explain the DRUJ instability and proximal migration. Chronic lateral epicondylitis is an overuse condition of the elbow extensors. Heterotopic ossification causes stiffness but not typically DRUJ instability. Carpal tunnel syndrome is a median nerve compression neuropathy and would present with different symptoms.

Correct Answer: C

For a highly comminuted (Mason-Johnston Type III or IV) radial head fracture, especially in an active patient who desires a full return to function, radial head replacement is often the preferred surgical option. ORIF would be technically challenging or impossible with four fragments involving 60% of the articular surface, and stable fixation is unlikely. Radial head excision, while an option for low-demand patients, carries a significant risk of proximal radial migration and DRUJ instability, which would be detrimental to an active construction worker. Non-operative management is inappropriate for such a severely comminuted and displaced fracture. Primary elbow arthrodesis is a salvage procedure for end-stage arthritis or instability, not an acute fracture.

Correct Answer: C

The 'safe zone' for hardware placement in the radial head is a critical concept in ORIF to prevent impingement. This zone refers to the portion of the radial head that does not articulate with the capitellum of the humerus or the lesser sigmoid notch of the ulna through a full range of forearm pronation and supination. It is typically described as a 110-degree arc on the radial head, often corresponding to the posterolateral quadrant when the forearm is in neutral rotation. Placing hardware outside this zone can lead to pain, crepitus, and a mechanical block to motion, necessitating hardware removal. The other options describe articulating surfaces or specific quadrants that are not universally 'safe' throughout the entire range of motion.

Correct Answer: C

The 'terrible triad' of the elbow consists of a posterior elbow dislocation, a radial head fracture, and a coronoid process fracture. This injury pattern is characterized by significant instability. The most consistently injured and critical ligament for posterolateral rotatory stability of the elbow in this context is the lateral ulnar collateral ligament (LUCL). Injury to the LUCL, often avulsed from its humeral origin, allows for posterolateral subluxation or dislocation of the ulna relative to the humerus. While the MCL can also be injured, and the annular ligament is disrupted with the radial head fracture, the LUCL is the key structure whose integrity dictates posterolateral rotatory stability and often requires repair or reconstruction in conjunction with radial head replacement and coronoid fixation.

Correct Answer: B

A Mason-Johnston Type II radial head fracture with a mechanical block to forearm rotation, even with moderate displacement, is a strong indication for surgical intervention. The mechanical block signifies impingement of the displaced fragment, which will prevent full range of motion and lead to chronic dysfunction if not addressed. For a single, displaced fragment, open reduction and internal fixation (ORIF) is the preferred treatment to restore articular congruity and eliminate the mechanical block. Sling immobilization alone is insufficient. Radial head excision is generally reserved for severely comminuted fractures not amenable to ORIF or in low-demand patients, and carries risks of proximal radial migration. Radial head replacement is typically indicated for highly comminuted (Type III/IV) fractures or in cases of associated instability (e.g., Essex-Lopresti, terrible triad). Attempting closed reduction is unlikely to succeed with a palpable block from a displaced articular fragment.

Correct Answer: D

While all listed injuries can occur with radial head fractures, distal radio-ulnar joint (DRUJ) instability, often indicative of an Essex-Lopresti lesion, is frequently missed in the initial evaluation. It may not be immediately apparent on elbow radiographs and can present insidiously with wrist pain and instability days or weeks after the initial injury. A high index of suspicion and careful examination of the wrist, along with ipsilateral wrist radiographs (looking for proximal radial migration), are crucial. Coronoid and MCL injuries are typically associated with elbow dislocations (e.g., terrible triad) and are usually more obvious. Capitellum chondral injuries are less common and often require advanced imaging or arthroscopy. Olecranon fractures are usually clearly visible on initial X-rays.

Correct Answer: C

For elderly, sedentary patients with severely comminuted radial head fractures (Type III or IV) who are not candidates for ORIF (due to comminution or bone quality) or do not desire more extensive surgery like radial head replacement (due to comorbidities or complexity), radial head excision can be a reasonable option. While it carries the risk of proximal radial migration and DRUJ issues, in low-demand individuals, it can provide pain relief and improve motion with acceptable functional outcomes. ORIF is often not feasible due to comminution. Replacement is a good option but more involved surgery. Arthrodesis is a salvage procedure. Long arm casting would likely lead to severe stiffness in this age group and is generally avoided for radial head fractures.

Correct Answer: C

Early post-operative stiffness, pain, and crepitus following radial head fracture fixation are very commonly caused by hardware prominence and impingement. If screws or plates are not properly countersunk or are placed outside the 'safe zone' (the non-articulating portion of the radial head), they can impinge on the capitellum or the lesser sigmoid notch of the ulna during elbow flexion-extension or forearm rotation. This mechanical impingement causes pain and restricts range of motion. While infection, nerve injury, and non-union are possible complications, hardware impingement is a leading cause of early stiffness directly related to the fixation itself. Aseptic loosening is typically a later complication.

Correct Answer: C

Mason-Johnston Type I radial head fractures are characterized by a non-displaced crack or minimal displacement (less than 2mm) without a mechanical block to forearm rotation. For these injuries, non-operative management is the standard of care. This typically involves a brief period of immobilization (e.g., a few days to 1 week in a sling for comfort) followed by early active range of motion exercises. Prolonged immobilization, such as a long arm cast, should be avoided as it significantly increases the risk of elbow stiffness, a common and debilitating complication. Surgical interventions like ORIF, radial head replacement, or excision are not indicated for Type I fractures.

Correct Answer: C

The radial head plays two crucial roles in elbow and forearm stability. Firstly, it acts as a secondary stabilizer against valgus stress at the elbow, providing a bony buttress, especially when the primary valgus stabilizer (the anterior bundle of the medial collateral ligament) is compromised. Secondly, and critically, it provides longitudinal stability to the forearm, maintaining the length relationship between the radius and ulna. This longitudinal stability is essential for proper distal radio-ulnar joint (DRUJ) mechanics and overall forearm function. While it articulates to allow pronation/supination, its primary role in stability is as a secondary valgus stabilizer and longitudinal load bearer. The biceps attaches to the radial tuberosity, not the head itself. The coronoid process and olecranon prevent posterior dislocation of the ulna.

Correct Answer: D

For complex, comminuted intra-articular distal humerus fractures (AO 13-C3), a posterior approach with an olecranon osteotomy (e.g., Chevron osteotomy) provides the most extensive and direct visualization of the entire distal humeral articular surface and both columns. This allows for precise anatomical reduction of articular fragments and robust plate application, which is critical for restoring elbow function and minimizing post-traumatic arthritis. While triceps-sparing approaches are gaining popularity, they often provide less complete visualization for severely comminuted intra-articular fractures, making anatomical reduction more challenging. Anterior, medial, and lateral approaches are typically reserved for specific fracture patterns (e.g., isolated capitellar or trochlear fractures) or for less complex supracondylar fractures.

Correct Answer: C

Orthogonal plating, typically with a medial plate and a posterior or posterolateral plate, creates a more stable construct biomechanically than parallel plating. This configuration provides support against both valgus/varus and torsional forces, acting as a '90-90' system (relative to each other, not the bone's long axis). This multiplanar stability is crucial for complex, comminuted fractures to allow early range of motion. Parallel plating (two plates on the medial and lateral columns) is also a strong construct, particularly for stabilizing the columns, but biomechanical studies often show orthogonal plating to be superior in complex fractures due to better load distribution and resistance to displacement. Posterior plates alone or anterior plates are insufficient for complex intra-articular fractures.

Correct Answer: D

The ulnar nerve is the most vulnerable neurological structure during posterior approaches to the distal humerus. It courses through the cubital tunnel posterior to the medial epicondyle and is often directly exposed, mobilized, and protected (often transposed anteriorly) during complex distal humerus fracture fixation to prevent iatrogenic injury or secondary compression. The radial nerve is at risk more proximally in the humeral shaft or during lateral approaches. The median nerve and brachial artery are anterior and generally protected by muscle bellies. The musculocutaneous nerve is even further anterior and lateral, making it less susceptible during a posterior approach.

Correct Answer: D

In osteoporotic patients, the primary concern for early complication after ORIF of a comminuted distal humerus fracture is hardware pull-out or failure. Poor bone quality provides inadequate purchase for screws, leading to loss of reduction and implant failure. This necessitates specific techniques like locking plates, longer screws, and sometimes bone augmentation (e.g., cement augmentation). Nonunion and heterotopic ossification are typically later complications. Infection is a risk but not specifically heightened by osteoporosis itself. Ulnar nerve palsy is a risk from the surgery but not directly related to implant mechanics in osteoporotic bone.

Correct Answer: C

While surgical fixation is likely indicated for a displaced intra-articular fracture, a CT scan with 3D reconstructions is crucial for operative planning. Plain radiographs often underestimate the degree of articular comminution and displacement, especially for complex intra-articular patterns. The CT scan provides detailed information about fragment size, location, and the extent of articular involvement, which guides the choice of surgical approach and fixation strategy. Immediate ORIF without CT is suboptimal. A cast is inappropriate for displaced intra-articular fractures in an active patient, and immediate ROM is contraindicated pre-operatively. Antibiotics are not indicated unless an open fracture is suspected.

Correct Answer: C

The primary advantage of an olecranon osteotomy is to provide a wide, direct, and panoramic surgical exposure of the entire distal humeral articular surface and both columns. This enables accurate anatomical reduction of often numerous small articular fragments under direct vision, which is paramount for restoring elbow function and minimizing post-traumatic arthritis. While an ulnar nerve decompression can be performed concomitantly, it's not the primary role of the osteotomy. The osteotomy itself is a separate fracture that requires fixation and has its own potential complications, and it doesn't directly prevent HO or shorten overall healing time.

Correct Answer: B

For elderly, osteoporotic patients with highly comminuted distal humerus fractures where stable ORIF is unlikely to be achieved, or if stable fixation will not allow early motion, Total Elbow Arthroplasty (TEA) is an increasingly accepted option, particularly in patients with low functional demands. It allows for immediate stability and early motion, which is critical in this population to prevent stiffness and achieve early functional recovery. Functional bracing is unlikely to yield a good result with a highly comminuted, unstable fracture. Elbow fusion would be highly disabling for a low-demand patient. Excision arthroplasty is rarely performed today due to poor outcomes. Hemiarthroplasty of the distal humerus is not a standard procedure for complex distal humerus fractures due to the articulation challenges with the native ulna and radius.

Correct Answer: B

Post-traumatic heterotopic ossification (HO) is a common cause of severe elbow stiffness after distal humerus fractures and their surgical treatment, even after successful fracture healing. It involves the formation of mature lamellar bone in soft tissues where bone does not normally exist, which can restrict motion significantly. While nonunion can cause pain and instability, it doesn't directly cause stiffness in the same way HO does. Ulnar nerve entrapment typically causes paresthesia and weakness, not direct mechanical stiffness. Chronic infection is possible but less common than HO. Radial head subluxation is not a typical complication leading to global stiffness after a distal humerus fracture.

Correct Answer: A

An open fracture is an absolute indication for emergent surgical débridement and fixation due to the high risk of infection and subsequent devastating complications. Neurovascular deficits, especially an acute deficit following injury, often warrant emergent exploration but can sometimes be observed if a neuropraxia is suspected without overt vascular compromise. Intra-articular displacement > 2mm is a strong indication for ORIF but is generally considered a relative indication (compared to an open fracture). Age > 65 years is a patient factor, not a fracture characteristic dictating surgery. An associated olecranon fracture is a complex injury but not an absolute indication in itself compared to an open fracture.

Correct Answer: B

Severe pain, swelling, and bullae post-operatively, especially pain out of proportion to the injury, are highly concerning for evolving compartment syndrome, particularly in the forearm. Immediate release of all constrictive dressings (splints, casts, bandages) is paramount. If suspicion remains high or objective signs (e.g., pain with passive stretch of digits, paresthesia, tense compartments) are present, emergent fasciotomy is indicated to prevent irreversible ischemic damage to muscles and nerves. While elevation is good, and antibiotics might be considered later if infection is suspected, the immediate life-altering threat is compartment syndrome. Ultrasound for DVT is not relevant to acute swelling and pain in this context, and hot packs would worsen swelling.

Correct Answer: C

The most reliable maneuver to confirm an FDP rupture is to isolate the action of the FDP tendon. This is done by stabilizing the PIP joint in full extension and asking the patient to actively flex the DIP joint. If the FDP is ruptured, active DIP flexion will be absent. Assessing passive range of motion will typically be full, as the FDP rupture is an active deficit. Palpating a tender gap can be indicative but is not always reliable, especially with swelling. Grip strength is a global measure and not specific enough. Finkelstein's test is for De Quervain's tenosynovitis and is irrelevant in this context.

Correct Answer: C

This scenario describes a classic Type I Jersey finger. A Type I injury involves rupture of the FDP tendon without a bony avulsion, and the tendon typically retracts into the palm, losing its vincula blood supply. The primary concern driving the urgency for repair (ideally within 7-10 days, but sooner if possible) is the preservation of the tendon's intrinsic vascularity to prevent necrosis and facilitate healing. Type II also lacks a bony avulsion but the tendon is retained at the A3 pulley level, often with intact vincula, making it less urgent than Type I. Type III involves a bony avulsion fragment, which prevents further retraction and maintains tendon blood supply, making it less urgent. Type IV involves an avulsed bone fragment with the tendon avulsed from the fragment, and Type V involves an intra-articular fracture with tendon avulsion; these are also distinct from the given scenario.

Correct Answer: C

The vincula tendinum are mesotendinous structures that connect the flexor tendons to the phalanges and provide the primary blood supply to the tendons within the flexor sheath. In a Type I Jersey finger, the FDP tendon avulses distal to the vincula longa and retracts into the palm, often stripping it of its vincula and thus its blood supply, leading to a high risk of tendon necrosis. The A2 pulley is a critical mechanical structure but not primarily a source of blood supply to the tendon itself. The flexor sheath provides an environment, not the primary blood supply. Annular ligaments are the pulleys. Lumbrical muscles have their own blood supply but do not supply the FDP tendon directly.

Correct Answer: D

The gold standard for flexor tendon repair involves a strong core suture technique that provides robust mechanical strength against gapping and pull-out. The Modified Kessler (or similar variations like Lim-Tsai, Modified Becker, Pennington) is a common and effective core suture. An epitendinous suture is typically used in addition to a core suture to create a smooth gliding surface and add some strength, but it is not sufficient on its own for primary repair strength. Simple interrupted, horizontal mattress, and running locking sutures are not typically used as primary core sutures in flexor tendon repair due to lower strength and potential for gapping or strangulation.

Correct Answer: A

The quadriga effect is a well-known complication of FDP repair, particularly when the tendon is shortened (e.g., through advancement or overtightening during repair). Because the FDP tendons of the medial four fingers share a common muscle belly (or are closely intertwined proximally), overtensioning of one FDP tendon will restrict full flexion of the adjacent, healthy FDP tendons. This results in the inability of the adjacent digits to fully flex. The other options describe different complications or aspects of tendon repair.

Correct Answer: B

The 'lumbrical plus' phenomenon occurs when the FDP tendon is advanced and overtensioned, or the repair site is too stiff, causing the lumbrical muscle to be pulled proximally. When the patient attempts to flex the finger (activating the FDP), the lumbrical is put under tension before the FDP can flex the DIP joint. Since the lumbrical inserts into the extensor mechanism, its contraction paradoxically extends the DIP joint instead of allowing FDP flexion. This results in the DIP joint extending or remaining extended when the patient attempts to make a full fist. Option E describes the quadriga effect.

Correct Answer: C

For chronic FDP ruptures where direct primary repair is not feasible due to significant tendon retraction and shortening, staged tendon reconstruction using a silicone rod (Hunter rod) is often the preferred strategy. The silicone rod creates a pseudosheath, which then facilitates the passage of an autogenous tendon graft (commonly palmaris longus or plantaris) in a second stage. FDP advancement is only feasible for gaps typically less than 1 cm. Delayed primary repair with an interpositional graft is a possibility, but less predictable than staged reconstruction for significant gaps. Amputation is overly aggressive, and observation alone will not restore function in a chronic rupture.

Correct Answer: D

The primary rationale for early active motion protocols after flexor tendon repair is to promote tendon gliding and prevent the formation of restrictive adhesions within the flexor sheath. Controlled motion helps to maintain the gliding surface between the tendon and the surrounding tissues, which is crucial for achieving a good functional outcome and full range of motion. While it may indirectly help with swelling and muscle atrophy, its main goal is to optimize tendon healing and prevent adhesions, which is a major cause of post-operative stiffness.

Correct Answer: B

The A2 and A4 pulleys are considered the most critical annular pulleys for maintaining the mechanical efficiency of the flexor tendons and preventing bowstringing. The A2 pulley is located over the proximal phalanx, and the A4 pulley is over the middle of the distal phalanx. Their integrity is paramount for normal finger flexion biomechanics. Damage to these pulleys significantly compromises the tendon's leverage and function.

Correct Answer: D

At 6 weeks, a Type I Jersey finger is considered a chronic injury. Significant tendon retraction and shortening would have occurred, making direct primary repair or FDP advancement (which is typically for gaps <1cm) impossible without excessive tension leading to quadriga or re-rupture. Therefore, staged tendon reconstruction using a silicone rod followed by a tendon graft is the most appropriate option to reconstruct the flexor mechanism and restore function. Non-operative management will not restore active DIP flexion. Amputation is a last resort.

The standard surgical sequence for a terrible triad injury involves addressing the structures from deep to superficial: fixing the coronoid, fixing or replacing the radial head, and finally repairing the lateral collateral ligament (LCL). If instability persists after these steps, the MCL or a hinged external fixator may be considered.

The biomechanical strength and resistance to gap formation in a flexor tendon repair are most directly correlated with the number of core suture strands crossing the repair site and adequate core purchase length. Epitendinous sutures further increase repair strength and smooth the gliding surface.

The scaphoid receives its primary blood supply from the dorsal carpal branch of the radial artery, which enters the dorsal ridge distally and supplies the proximal pole in a retrograde fashion. This vulnerable vascular anatomy highly predisposes proximal pole fractures to nonunion and avascular necrosis.

In a Bennett fracture, the abductor pollicis longus (APL) pulls the metacarpal shaft proximally, dorsally, and radially. The adductor pollicis exerts a supinating and ulnar-directed force on the distal metacarpal, while the volar ulnar beak fragment remains tethered by the anterior oblique ligament.

This describes a Leddy and Packer Type I FDP avulsion (Jersey finger), where the tendon retracts into the palm, disrupting both the long and short vincula. It requires surgical repair within 7-10 days before the tendon undergoes contracture and ischemic necrosis.

The standard surgical algorithm for a terrible triad injury works from deep to superficial and medial to lateral: fix the coronoid first, address the radial head (fixation or arthroplasty), and finally repair the LCL complex to restore posterolateral stability. The MCL is rarely repaired unless instability persists after addressing the other three components.

Biomechanical studies have consistently demonstrated that a 4-strand core suture technique provides the minimum tensile strength required to safely withstand the forces of early active motion protocols. A 2-strand repair is generally considered too weak and carries a higher risk of rupture with active flexion.

The McKee modification (Type IV) describes a coronal shear fracture extending medially to involve the capitellum and most of the trochlea. To adequately visualize and fix both the capitellum and trochlear fragments, an extensile lateral approach or a posterior approach with an olecranon osteotomy is required.

Stage III SNAC wrists involve arthritis at both the radioscaphoid and capitolunate joints, while the radiolunate joint remains preserved. Four-corner fusion with scaphoid excision relies on the preserved radiolunate joint, whereas PRC is contraindicated because the capitate head (which would articulate with the lunate fossa) is already arthritic.

A central slip rupture allows the lateral bands to subluxate volarly to the axis of rotation of the PIP joint, converting them into PIP flexors. Their continued pull on the distal phalanx simultaneously causes hyperextension of the DIP joint, creating the classic Boutonniere deformity.

Leddy and Packer Type I injuries involve an FDP tendon that retracts into the palm, rupturing both the vincula brevis and longus, severely compromising its blood supply. These injuries require urgent repair (typically within 7-10 days) before the tendon undergoes permanent ischemic contracture.

Bridge plating with a pre-contoured locking plate provides superior stability for comminuted olecranon fractures, preventing the shortening and collapse that often occur with compression techniques. Tension band wiring is contraindicated in comminuted fractures because it relies on anterior cortical contact to convert tensile forces into compressive forces.

An irreducible DRUJ following anatomic fixation of the radius in a Galeazzi fracture is most often caused by soft tissue interposition. The extensor carpi ulnaris (ECU) tendon is the most common offending structure, frequently becoming entrapped in the ulnar notch.

Bado Type I describes a proximal ulna fracture with anterior dislocation of the radial head, the most common type. In adults, the standard of care is anatomic ORIF of the ulna, which typically results in spontaneous, stable closed reduction of the radial head.

While all four Kanavel signs indicate purulent flexor tenosynovitis, pain with passive extension is recognized as the earliest and most sensitive sign. The inflammation of the sheath causes exquisite pain when the tendon is stretched by passive finger extension.

SLAC staging follows a predictable pattern of arthritic progression. Stage I involves the radial styloid; Stage II involves the entire radioscaphoid fossa; and Stage III progresses to involve the capitolunate joint. The midcarpal joint is preserved here, placing it in Stage II.

The modified Henry approach utilizes the internervous plane between the median nerve (supplying FCR) and the radial nerve (supplying brachioradialis). Superficially, the surgeon develops the interval between the FCR tendon and the radial artery to safely retract the neurovascular structures.

In a Bennett fracture, the volar-ulnar beak fragment remains attached to the anterior oblique ligament. The main metacarpal shaft fragment is displaced proximally, dorsally, and radially by the strong pull of the abductor pollicis longus (APL) tendon.

This is a Dubberley Type 3B fracture (involving capitellum and trochlea with posterior comminution). Posterior comminution dictates the need for posterior buttress plating to prevent displacement, typically requiring an extensile lateral or posterior approach.

Increasing the number of core suture strands increases the ultimate tensile strength of the repair, which is beneficial for early active motion. However, it also increases the bulk of the repair, significantly increasing gliding resistance and the work of flexion.

For unstable dorsal PIP fracture-dislocations involving greater than 40% of the volar articular surface, joint reconstruction via volar plate arthroplasty, hemihamate autograft, or dynamic external fixation is indicated to restore stability and congruity.

The standard deep-to-superficial approach to the terrible triad involves fixing structures from inside out: first the coronoid, then the radial head (fixation or arthroplasty), and finally repairing the lateral collateral ligament (LCL) complex.

This is a Type 1 Jersey finger (FDP retracted into the palm), compromising its vascular supply from the vincula. It requires early surgical repair within 7-10 days to prevent permanent myostatic contracture and tendon necrosis.

Following rigid fixation of the radius in a Galeazzi fracture, the DRUJ must be assessed. Gross instability in neutral or all forearm positions dictates the need for DRUJ stabilization, typically via radioulnar pinning in supination or open TFCC repair.

The fifth metacarpal neck (Boxer's fracture) can tolerate up to 70 degrees of volar angulation due to the compensatory mobility of the 5th carpometacarpal (CMC) joint. Greater angulation, or any significant malrotation, requires reduction.

In a Bennett fracture, the abductor pollicis longus (APL) pulls the metacarpal shaft proximally, dorsally, and radially. The small volar ulnar fragment remains held in its anatomic position by the anterior oblique ligament.

Displacement of greater than 1 mm in an acute scaphoid fracture is an absolute indication for surgical fixation due to the high risk of nonunion and subsequent Scaphoid Nonunion Advanced Collapse (SNAC). Proximal pole fractures are a strong relative indication.

A Boutonniere deformity is characterized by PIP flexion and DIP extension. It is caused by rupture or attenuation of the central slip, allowing the lateral bands to subluxate volarly to the PIP joint axis of rotation, acting as PIP flexors and DIP extensors.

A nonunion of a hook of the hamate fracture can lead to chronic friction and subsequent spontaneous rupture of the adjacent flexor tendons, most commonly the flexor digitorum profundus (FDP) to the small finger.

The most common complication of tension band wiring for olecranon fractures is symptomatic prominent hardware, reported in up to 40-80% of patients. This frequently necessitates a secondary procedure for hardware removal.

The standard surgical algorithm for a terrible triad injury progresses from deep to superficial and typically from lateral to medial. The sequence is coronoid fixation, radial head repair or replacement, LCL complex repair, and finally MCL repair or hinged external fixation if the elbow remains unstable.

Radioulnar synostosis is a known complication of the two-incision (Boyd) approach for distal biceps repair. It is most commonly caused by subperiosteal elevation of the supinator and stripping of the proximal ulna, which triggers heterotopic ossification bridging the radius and ulna.

This patient has Stage III SNAC wrist, characterized by arthritis extending to the capitolunate joint while sparing the radiolunate joint. Scaphoid excision and four-corner fusion is the treatment of choice, whereas proximal row carpectomy is contraindicated due to capitate articular wear.

The tensile strength of a flexor tendon repair is directly proportional to the number of core suture strands crossing the repair site. A 4-strand or 6-strand repair provides significantly more strength than a 2-strand repair, making it robust enough to withstand the forces of early active motion protocols.

A Stener lesion occurs when the distal end of the completely torn UCL flips superficial to the adductor pollicis aponeurosis. This interposition prevents the ligament from healing to its anatomic footprint on the proximal phalanx, necessitating surgical repair.

In Monteggia fracture-dislocations, if the radial head remains irreducible after restoring ulnar length and alignment, the most common block to reduction is soft tissue interposition, specifically the annular ligament or joint capsule.

Extensor pollicis longus (EPL) ruptures following non-displaced distal radius fractures are primarily ischemic in nature. The intact extensor retinaculum of the third dorsal compartment restricts swelling, leading to increased pressure, decreased synovial perfusion, and subsequent tendon necrosis and rupture.

In a Galeazzi fracture with persistent DRUJ instability after anatomic radius fixation, the joint should be reduced in its most stable position (usually supination) and secured with transverse radioulnar K-wires for 4-6 weeks to allow the TFCC to heal.

While most mallet fractures are treated non-operatively, surgical fixation (such as extension block pinning) is indicated for 'bony mallet' injuries involving greater than 30-40% of the articular surface or when there is volar subluxation of the distal phalanx.

The deep volar compartment contains the flexor digitorum profundus (FDP) and flexor pollicis longus (FPL). Because they rest directly against the interosseous membrane and bone, they are subjected to the highest pressures during compartment syndrome, making them the most susceptible to profound ischemia and subsequent Volkmann's ischemic contracture.