Wrist, Hand Fractures/Dislocations

A 6-year-old boy presents with a supracondylar fracture sustained during a fall on an outstretched hand. A splint with the elbow flexed less than 90 degrees is placed. The patient is screaming in pain. Examination shows the affected hand has a 3-second capillary refill. Which of the following is the most appropriate next step in management? A) Closed reduction B) Continued observation and application of ice packs C) Elevation of the arm D) Exploration of the brachial artery E) Replacement of the current splint with an elbow extension splint

A Supracondylar fractures are one of the most common traumatic fractures seen in children. It occurs most commonly in children 5 to 7 years of age with similar male and female incidence. The mechanism is usually from a fall onto an outstretched hand. The fracture can lead to severe forearm edema, then ischemia leading to Volkmann's contracture. Immobilization would be long arm casting with the elbow flexed at less than 90 degrees. Arm elevation would decrease tissue perfusion and would therefore be contraindicated. Immediate bedside closed reduction by gentle traction and elbow flexion to 20 to 40 degrees would be indicated in this case as a next step. If the closed reduction is unsuccessful or ischemia persists after reduction or recurs, urgent operative closed reduction with percutaneous pinning is required. Pins are placed to prevent recurrence. Brachial artery exploration could be required if ischemia has not resolved even after successful reduction, but not initially.

A 25-year-old man presents to the office because of pain and swelling at the base of his dominant right thumb 3 days after a fall from his bicycle. X-ray study shows a Bennett fracture. The patient is scheduled for surgery. In addition to longitudinal traction and volarly directed pressure applied to the dorsal radial metacarpal base, which of the following best describes the appropriate reduction maneuver for this injury? A) Abduction and pronation of the thumb B) Abduction and supination of the thumb C) Adduction and flexion of the thumb D) Adduction and pronation of the thumb E) Adduction and supination of the thumb

A A Bennett fracture is an intra-articular fracture-dislocation of the carpometacarpal joint of the thumb that occurs following an axially loading force through a partially flexed metacarpal. A variable-sized volar ulnar fragment of the metacarpal base articular surface remains in position by attachment of the anterior oblique ligament to the trapezium. The larger fragment consisting of the remaining metacarpal base subluxates proximally, radially, and dorsally due to deforming forces from the abductor pollicis longus and the thumb extensors. Deforming forces from the adductor pollicis also cause metacarpal adduction and supination. To counteract the deforming forces of this unstable fracture-dislocation, reduction is attempted by applying axial traction to the extended thumb, palmar abduction, and pronation, while exerting pressure over the metacarpal base in preparation for insertion of Kirschner wires.

A 29-year-old right-hand-dominant man presents with a right distal radius fracture after falling on his outstretched hand. He reports increasing pain and a pins-and-needles feeling in the right hand and fingers. Distal capillary refill is less than 2 seconds, and radial and ulnar arteries are readily palpable, but the patient has severe pain on passive extension of the fingers. Early compartment syndrome is suspected. Which of the following compartments is most likely to have the most increased measured pressures in this case? A) Deep volar B) Dorsal C) Lateral D) Superficial volar

A Compartment syndrome is a devastating condition in which bleeding and/or edema within a muscle compartment surrounded and restricted by fascia can result in increased pressures leading to neurovascular compromise and muscle death. Sequelae of compartment syndrome include loss of function, Volkmann ischemic contracture, and even amputation. It typically presents with pain out of proportion to clinical examination, as well as increased pain with passive extension of the muscle bellies within the affected compartment. Signs of neurovascular compromise are often not seen until much later in the process. Compartment syndrome is most commonly associated with traumatic fractures.Distal radius fractures are the most common cause of compartment syndrome in the forearm. The forearm musculature is contained in four separate compartments: dorsal, lateral (or mobile wad), superficial volar, and deep volar. The deep volar compartment is the most likely to develop the highest interstitial pressures early in acute compartment syndrome after traumatic distal radius fracture. This compartment houses the flexor digitorum profundus and flexor pollicis longus muscles, which are the muscles most likely to be affected with untreated compartment syndrome and responsible for distal interphalangeal flexion of the phalanges and interphalangeal flexion of the thumb, respectively.

A 17-year-old boy comes to the office because of ongoing pain of the right hand after he punched a wall 5 days ago. Physical examination demonstrates tenderness of the fifth carpometacarpal joint. Posteroanterior, oblique, and lateral x-ray studies taken at an urgent care facility were read as negative by the radiologist. Which of the following additional radiographic views is most likely to help confirm this patient's diagnosis? A) Anteroposterior with 30 degrees of pronation from full supination B) Carpal tunnel view with wrist in full extension C) Clenched fist lateral in neutral forearm position D) Lateral with 15 degrees of supination from neutral forearm position E) Posteroanterior with 45 degrees of supination from full pronation

A Injuries to the fifth carpometacarpal joint, including subluxation, dislocation, and fracture-dislocation, are often missed with standard two-view and three-view hand images. Two views have been suggested to help detect this subtle injury: Anteroposterior view with forearm pronated 30 degrees from full supination. This view shows more clearly the profile of the articulation between the hamate and fifth metacarpal base. (This is similar to the "reverse oblique" view, which is typically done in 45 degrees of pronation and might also be useful.) Lateral with 30 degrees of pronation. This view is especially helpful for detecting subluxation of the metacarpal dorsally off of the hamate. In some cases, CT scan may be warranted if plain films are inconclusive.

A 32-year-old woman sustains a dorsal proximal interphalangeal (PIP) joint fracture-dislocation of the ring finger after a fall from standing. The fracture-dislocation is reduced, and the finger is splinted in the emergency department. Three days after injury, the patient presents to the office. An x-ray study demonstrates a volar lip fracture of the middle phalanx, which measures 40% of the joint. Live fluoroscopy demonstrates PIP joint congruency through an arc of motion of 20 to 100 degrees. Which of the following is the best treatment for this patient? A) Dorsal block splint B) Hemi-hamate resurfacing C) Open reduction and internal fixation D) PIP joint transarticular pinning E) Volar static splint

A Proximal interphalangeal (PIP) joint fracture-dislocations are generally stratified according to the percentage of middle phalanx articular surface disrupted: 30% or less, presumed stable; 30 to 50%, tenuous stability; and more than 50%, unstable. Stable fracture-dislocations (less that 30% of the middle phalanx palmar lip) are stable in full PIP joint extension. When 30 to 50% of the middle phalanx joint surface is fractured, stability is tenuous and can only be determined by clinical testing. Those fractures that require more than 30 degrees of flexion to maintain reduction are considered unstable and therefore require some form of surgical management for maintenance of reduction (dorsal block pinning, or open reduction and internal fixation).For all fracture-dislocations, treatment methods are grouped into five broad categories: static immobilization, articular reduction, dorsal extension block splinting, open reduction and internal fixation, and volar plate arthroplasty.Static immobilization is straightforward but generally avoided in cases of fractures involving the PIP joint, owing to the risk of overwhelming stiffness with prolonged immobilization.Articular reduction must be serially monitored by x-ray study, and immobilization for more than 3 weeks may result in significant PIP joint stiffness.Dorsal extension block dynamic splinting can be used for stable or tenuous fracture-dislocations. Dorsal block pinning uses the same concept as dorsal block splinting, but it requires the surgical insertion of a pin into the head of the proximal phalanx to prevent dorsal translocation of the middle phalanx with extension.Open reduction and internal fixation can be used to fix a noncomminuted fragment that is sufficiently large enough to stabilize with small lag screws or K-wires.Malerich and Eaton describe a procedure called volar plate advancement (advancement of the volar plate into the middle phalanx fracture defect), simultaneously restoring stability and resurfacing the damaged articular surface. Hastings and Kiefhaber describe hemi-hamate resurfacing arthroplasty (a technique used to resurface the volar lip of the middle phalanx with a hemi-hamate bone graft). Both of these resurfacing techniques (volar plate arthroplasty and hemi-hamate arthroplasty) are salvage procedures, better suited for chronic or subacute unstable fracture dislocations.The fracture in this scenario involves 40% of the joint and is thus considered tenuous, but it achieves stable reduction at 20 degrees of flexion, allowing for treatments such as dorsal block splinting or pinning. Given a choice, nonoperative management is preferred initially, and surgical correction (dorsal block pin or open reduction and internal fixation) is reserved for those that fail nonoperative management.

In patients with basilar joint arthritis of the thumb, treatment with trapeziectomy alone compared with trapeziectomy with ligament reconstruction and tendon interposition is most likely to result in which of the following? A) Decreased complication rate B) Increased risk for recurrent pain C) Longer recovery time D) Worse functional outcomes

A Simple trapeziectomy was first described in 1947 and though it is only utilized by a small minority of hand surgeons in the United States as solitary treatment for basilar thumb arthritis, its efficacy has not been demonstrated to be inferior to the more commonly employed trapeziectomy with ligament reconstruction and tendon interposition. Meta-analysis has demonstrated that simple trapeziectomy is equally beneficial in terms of pain relief and function as trapeziectomy with ligament reconstruction and tendon interposition, but results in fewer complications. A variety of reconstructive techniques have been employed in management of basilar thumb arthritis. Most commonly employed in the United States is the trapeziectomy with ligament reconstruction and tendon interposition utilizing the flexor carpi radialis tendon. Other described techniques include CMC joint implant arthroplasty, partial trapeziectomy with interposition arthroplasty, and thumb metacarpal extension osteotomy for early-stage arthritis. None of these techniques have demonstrated superiority over simple trapeziectomy, and synthetic implants have been associated with significant complications.

A 65-year-old male laborer presents with worsening pain in the left thumb. An x-ray study is shown. Which of the following is the most important ligament to prevent radial subluxation of the first metacarpal at the carpometacarpal joint? A) Anterior oblique B) Dorsal central C) Posterior cruciate D) Transverse metacarpal E) Ulnar collateral

A This patient presents with severe osteoarthritis of the carpometacarpal (CMC) joint of the thumb. The thumb metacarpal is in adduction, and the proximal phalanx is in hyperextension. The complex range of motion of the thumb basal joint is achieved through stability from 16 ligaments. Of the choices given, only the anterior oblique ligament is in the thumb at the basal joint. It has been found to be the most important preventative measure against radial subluxation in cases of CMC arthritis in biomechanical studies. It originates on the volar tubercle of the trapezium and inserts on the thumb metacarpal volarly. In cases of severe thumb CMC arthritis, the progressive ligamentous incompetence of the anterior oblique ligament and dorsal radial ligament allow the thumb metacarpal to migrate dorsally and proximally. The dorsal radial ligament is also important for basal joint stabilization, while the other ligaments of the thumb basal joint are not as important. The ulnar collateral ligament is located at the metacarpophalangeal (MCP) joint of the thumb, and rupture leads to instability of that joint as seen with gamekeeper's thumb. The dorsal central ligament is not involved in CMC joint subluxation. The deep transverse metacarpal ligaments are located in the hand between the metacarpal heads and assist in supporting the metacarpal arch. The posterior cruciate ligament helps stabilize the knee by preventing the tibia from slipping posteriorly when flexed.

A 23-year-old man who works in an office undergoes evaluation of the left nondominant wrist after sustaining an injury from a fall 2 days ago. CT scan shows a nondisplaced distal scaphoid tubercle fracture. Examination reveals no other abnormalities. Which of the following is the most appropriate next step in management? A) Autologous bone grafting and internal fixation plus immobilization for 3 to 6 months B) Cast immobilization for 6 to 8 weeks C) Compression screw fixation plus immobilization for 6 to 12 weeks D) Physical therapy for 6 weeks E) Observation until the wrist is nontender

B Nondisplaced scaphoid fractures may not be apparent on plain radiographs and are better visualized on CT scan. Although the treatment options for nondisplaced scaphoid wrist fractures may include immobilization alone or surgical fixation, nondisplaced distal pole and tubercle fractures are felt to be more stable and can be treated with immobilization alone for 6 to 12 weeks. In addition, these fractures often have small fragments that are not as amenable to compression screw fixation. Observation and physical therapy allow mobilization of the wrist and are not recommended because of the potential for delayed healing or nonunion. Compression screw fixation is not generally necessary and is sometimes not possible for tubercle fractures, but it is a common treatment for scaphoid wrist fractures. Autologous bone grafting and internal fixation is generally reserved for scaphoid nonunions.

A 20-year-old woman comes to the office for evaluation of chronic pain of the right wrist, which is alleviated by nonsteroidal anti-inflammatory drugs (NSAIDs). Osteoid osteoma is suspected on x-ray. Which of the following imaging studies is most likely to confirm the suspected diagnosis? A) Bone scan B) CT scan C) Laser fluorescence angiography D) Magnetic resonance arthrography E) Ultrasonography

B Osteoid osteoma is a benign bone tumor that arises from osteoblasts; the principal symptom is focal pain at the site of the lesion. Multiple studies suggest that CT is the best imaging technique for detection of this tumor. Specifically, CT is best at depicting the nidus, the radiolucent area typical of this tumor type. Within the radiolucent nidus, a central area of high attenuation is often seen, representing mineralized osteoid. As ultrasound waves do not adequately penetrate bone, this intracortical lesion would not easily be detected by this technique. Although magnetic resonance (MR) has been used to detect these lesions, it is not as sensitive at detecting the nidus as CT scanning. This is because the nidus, especially if it is small, will have signal similar to cortical bone on MR. Although an arthrogram may detect an intra-articular osteoid osteoma, this is a more unusual entity. A bone scan may show the lesion, but it is nonspecific and will not confirm the diagnosis. Laser fluorescence angiography has gained popularity for assessing the perfusion of soft tissues (skin, flaps, etc.), but this technique will not help assess bone or tissues of significant depth, nor can it reliably distinguish tumor from other tissue.

A 32-year-old man presents following a motor vehicle collision in which he sustained a dorsal perilunate dislocation of the nondominant left hand. He was treated with open reduction and internal fixation including ligament repair with suture anchors and Kirschner-wires two days after the injury. Which of the following is the expected long-term outcome for this patient? A) Chronic pain and grip strength less than 50% of the normal side B) Evidence of moderate post-traumatic arthritis and 80% of grip strength compared to the opposite side C) Normal x-ray appearance with greater than 80% of motion compared with the opposite side D) Normal x-ray appearance with poor wrist motion and poor grip strength E) Severe post-traumatic arthritis requiring total wrist fusion

B Peri-lunate dislocations (PLD) and peri-lunate fracture dislocations (PLFD) are considered complex, high-energy injuries with potentially difficult recovery for many patients. In terms of outcomes research, long-term data are considered to be follow-up greater than 10 years. The long-term data are retrospective but consistent across many studies. The treatment of choice for PLD and PLFD is open reduction and internal fixation. Studies looking at closed reduction and casting or percutaneous pin fixation have shown inferior outcomes, and open treatment is recommend by most authors. All studies agree that there will be the presence of moderate or even severe post-traumatic arthritic changes on x-ray in most patients (50 to 100%), which can be various degrees of SLAC, SNAC, or avascular necrosis. However, the data also show that the presence of radiographic arthritis does not necessarily correlate with functional outcomes. On average, patients will achieve 65 to 70% of wrist flexion-extension arc and 80% grip strength compared with the unaffected side. Although some patients may develop severe complications of a PLD or PLFD such as advanced SLAC or SNAC or ulnar translation of the carpus, it is a rare finding. Most studies show outcomes in the good and fair range according to the Mayo wrist score and other outcome measures. Patients with the most severe arthritis usually do correspond to the worst symptoms and may require salvage procedures such as proximal row carpectomy or limited wrist fusion. Persistent, chronic pain is a rare finding with long-term outcomes of perilunate injuries. Pain with heavy activity only is the most commonly reported outcome, although many patients are largely pain free. Patients can have near normal looking x-rays after PLD or PLFD; however, this is rare. One would not expect >80% of wrist motion after an injury of this magnitude even with normal x-rays. Also, patients with minimal arthritic changes tend to show better functional outcomes.

A 24-year-old man is scheduled to undergo reconstruction for avascular necrosis of the proximal pole of the scaphoid with a free osteochondral bone flap. Which of the following arteries is the most commonly encountered vascular pedicle for the medial femoral condyle free bone flap? A) Anterior tibial recurrent B) Descending genicular C) Popliteal D) Saphenous E) Superficial femoral

B The medial femoral condyle free bone (corticocancellous) flap has been shown to be an excellent option for treatment of complicated degenerative bone pathology in the wrist, particularly scaphoid avascular necrosis. The Mayo group has also shown improved outcomes for scaphoid nonunion with humpback deformity compared with pedicled flaps from the distal radius. The same group has shown more consistent presence of supply from the medial superior genicular artery, which can be used in cases where the descending genicular artery is insufficient, although the pedicle length of the medial superior genicular artery is generally shorter. More recent anatomic analysis has shown this vessel can supply flaps up to 11 cm in length. The (superficial) femoral and popliteal arteries are larger, regional vessels, with the superficial femoral artery being the immediate source vessel for the descending genicular artery. The popliteal artery is the source vessel for the medial superior genicular artery. The anterior tibial recurrent artery is distal and lateral, lying over the lateral aspect of the tibial plateau, and does not supply the medial femoral condyle. The saphenous artery has been described as a branch of the superficial femoral supplying the skin paddle overlying the medial femoral condyle but does not supply the bone.

A 40-year-old man fell on his outstretched right wrist while snowboarding 12 months ago. His injury is displayed in the posteroanterior view of the right wrist on the x-ray study shown. Assuming a pattern of dorsal intercalated segment instability, a lateral view of the wrist is most likely to show the lunate bone in which of the following positions relative to the adjacent carpal bones? A) Lunate anatomic, scaphoid extended B) Lunate extended, scaphoid flexed C) Lunate flexed, scaphoid extended D) Lunate flexed, triquetrum anatomic E) Lunate flexed, triquetrum extended

B The posteroanterior x-ray study of the right wrist demonstrates static scapholunate (SL) dissociation with more than 3 mm of widening between the scaphoid and lunate bones. In a normal wrist, with radial to ulnar deviation of the wrist, the proximal carpal bones go into flexion then extension. With ulnar deviation, the hamate bone pushes the triquetrum into relative extension, while the scaphotrapezium-trapezoid (STT) ligament pulls the scaphoid into extension. The lunate follows the direction of its counterparts. With radial deviation, loading across the STT joint pulls the scaphoid into flexion; the lunate and triquetrum follow while translating dorsally and pronating.When there is complete dissociation between the scaphoid and lunate, the dorsal SL ligament and secondary stabilizers (such as the dorsal intercarpal ligament) have failed. Dorsal intercalated segment instability (DISI) describes the abnormal position of the lunate relative to the long axis of the radius. Secondary to the loss of the SL and associated stabilizers, the scaphoid falls into a position of flexion and pronation, while the triquetrum pulls the lunate into the triquetrum's preferred position of extension given the intact lunotriquetral ligament. Additionally, the lunate's configuration with a narrower dorsum and volarly inclined radial joint surface plays a role. Volar intercalated segment instability (VISI) describes the pattern of lunate flexion with disruption of the lunotriquetral ligament; the lunate is pulled into flexion with the scaphoid while the triquetrum falls into its normal tendency to extend. The dorsal radiocarpal ligament has been implicated as well in VISI pattern deformity.

A 19-year-old college baseball player sustained an injury to his left hand when hitting the ball with a bat 6 weeks ago. The patient reports immediate pain in his palm, weakness of grip, and within hours developed tingling into his small and ring fingers, which persisted for 6 weeks despite rest. He reports continued tingling in the ulnar fingers. Standard x-ray studies of the hand show no abnormalities. A CT scan of this patient's hand is likely to show a fracture of which carpal bone? A) Capitate B) Hamate C) Lunate D) Pisiform E) Scaphoid

B This college student has sustained a hook of hamate fracture that was missed on standard hand x-ray studies. Impact from the bat or from catching a pitched ball are common mechanisms of injury for a hook of hamate fracture in a baseball player. While fractures of other carpal bones may occur in baseball players, they would not produce the symptom spectrum described in the scenario.An x-ray study from the carpal tunnel view and a CT scan will likely show the correct diagnosis. At 6 weeks, this patient is unlikely to improve with casting alone. Surgically, he may be offered open reduction and internal fixation versus resection of the bony fragment. During surgery, the flexor tendons to the small finger should be evaluated as they can sustain attritional injury next to the fracture fragment. Nerve irritation to the ulnar nerve (sensory and motor) usually resolves spontaneously after surgery, but the nerve should be examined during surgery.

A 27-year-old man is evaluated because of chronic right wrist pain after a motor vehicle collision. X-ray studies show no fractures and normal carpal bone alignment. Watson's scaphoid shift test is positive. Which of the following modalities offers the highest sensitivity and specificity for the diagnosis of this injury? A) Anteroposterior x-ray study B) Arthroscopy C) Clenched fist x-ray study D) CT scan E) MR arthrogram

B scapholunate and other intercarpal ligament injuries as the injury is directly visualized. The scapholunate ligament is generally best visualized through the 3,4 portal, and midcarpal joint arthroscopy is also recommended to make the diagnosis. Arthroscopy is the standard that all other modalities are compared against.Standard x-ray studies should be performed for any patient with suspected wrist pathology. In addition to posteroanterior, lateral, and oblique films, both scaphoid and clenched fist views should be obtained. Dynamic scapholunate instability will have normal x-ray studies, and it can take 3 months or longer to see any evidence of scapholunate instability, such as scapholunate diastasis greater than 3 mm or an increased scapholunate angle greater than 70 degrees.Noncontrast MRI is a common method of evaluation for intercarpal ligament tears. The accuracy of MRI is improved with a 1.5-T or greater magnet, thin slices, use of a wrist coil, and reading by a fellowship-trained musculoskeletal radiologist. Studies show that MRI is only about 70% sensitive but highly specific (close to 100%) for scapholunate ligament tears.Arthrography, both conventional CT and MR, can improve the accuracy of imaging. Contrast extravasation to the midcarpal joint is diagnostic of a complete tear but does not examine the extent of the lesion. Arthrography sensitivity and specificity is approximately 95% and 85%, respectively.

A 23-year-old man presents 1 week after an altercation, during which he sustained a spiral fracture of the metacarpal bone of the ring finger with malrotation. No reduction was performed at the time of injury. Which of the following forms of osteosynthesis is most likely to provide sufficient stability to allow early motion in this patient? A) External fixation B) Internal plate fixation with monocortical screws C) Lag screw technique D) Noncompressive intramedullary nail E) Percutaneous Kirschner wire fixation

C Absolute stability is achieved with constructs that heal by primary (Haversian) healing. These constructs do not allow micromotion, are low strain at the fracture site, and have high fixation stiffness. This form of bone healing occurs with absolute fracture stability, direct osteonal remodeling, and no callus formation. Relative stability allows for indirect healing, which goes through the phases of inflammation, soft callus formation, hard callus formation, and then remodeling. Of the choices, lag screw technique is the only one that will achieve primary healing of a fracture.

A 47-year-old woman comes to the office after sustaining an injury to the left wrist after falling on her outstretched hand. Examination shows pain of the radial aspect of the left wrist and anatomical snuffbox. Scaphoid fracture is suspected. When obtaining posterior-anterior x-ray studies, which of the following is the optimal positioning of the wrist for evaluation of the entire scaphoid? A) Wrist in 20 degrees of radial deviation, 20 degrees of wrist extension B) Wrist in 20 degrees of radial deviation, 20 degrees of wrist flexion C) Wrist in 20 degrees of ulnar deviation, 20 degrees of wrist extension D) Wrist in 20 degrees of ulnar deviation, 20 degrees of wrist flexion E) Wrist in neutral radial/ulnar position, neutral flexion/extension

C Scaphoid fractures are the most common carpal fracture and frequently occur after a fall onto an extended and radially deviated wrist. Initial workup often involves plain x-ray studies, which have a sensitivity of approximately 85%. The optimal position of the wrist when imaging scaphoid fractures includes ulnar deviation and wrist extension, which allows for evaluation of the long axis of the scaphoid. CT scan or MRI may be used as additional imaging if plain x-ray studies do not demonstrate a fracture, yet there is high clinical suspicion.

A 19-year-old man comes to the office because of persistent left wrist pain after an ATV accident 4 months ago. Medical history includes cast treatment of a wrist fracture. X-ray study shows a proximal pole scaphoid fracture without arthritic changes or collapse. Which of the following is the most appropriate imaging for assessing the vascularity of the bone fragment in this patient? A) Angiography B) CT scan C) MRI D) Triple phase bone scan E) Ultrasonography

C The most appropriate imaging modality is MRI. This patient has presented with a delayed proximal pole scaphoid fracture/nonunion, which was previously untreated. The primary blood supply to the scaphoid enters distally and travels proximally. As a result, perfusion to the proximal portion of the scaphoid occurs in a retrograde fashion. Fractures of the proximal pole of the scaphoid are located at the furthest distance from the blood supply, and these fragments are at risk for nonunion and avascular necrosis. MRI (particularly with gadolinium enhancement) would be the best imaging study for evaluating the blood supply to the scaphoid fragment and looking for the presence of avascular necrosis. MRI can also provide anatomical information regarding the fracture. Direct intraoperative visualization of bleeding of the fragment has also been advocated in assessing vascularity. Angiography can show blood flow patterns, but would not provide anatomic information. CT scan is useful for detailed anatomic analysis of fractures and assessment of healing, but would be less helpful than MRI in determining avascular necrosis. Bone scan shows the presence of inflammatory activity and can be used in identifying the presence of occult fractures (high sensitivity, albeit with low specificity), but has low resolution and would not be helpful in determining avascular necrosis. Ultrasonography has been used in the diagnosis of acute fractures, but would not determine vascularity.

A 53-year-old man comes to the office because of a 2-year history of increasing pain of the radial aspect of the right wrist. X-ray studies show scapholunate disruption and arthritis. Which of the following joints is most likely to be affected first by the arthritic degeneration in this patient? A) Capitolunate B) Radiolunate C) Radioscaphoid D) Radioulnar E) Scaphotrapezio

C This patient has early-stage scapholunate advanced collapse (SLAC) wrist. SLAC wrist is generally categorized by the Watson classification, which is a descriptive classification but also helps determine management options. The Watson classification is as follows: Stage I: Arthritis between scaphoid and radial styloidStage II: Arthritis between scaphoid and entire scaphoid facet of the radiusStage III: Arthritis between capitate and lunate While original Watson classification describes preservation of radiolunate joint in all stages of SLAC wrist, subsequent description by other surgeons of pancarpal arthritis (stage IV) observed rare cases in which the radiolunate joint is affected. The radioulnar joint is not affected by SLAC wrist.

A 30-year-old man is evaluated for a hand injury after punching a wall. X-ray study shows a fracture of the fifth metacarpal neck. Which of the following findings is most likely to require surgical intervention? A) Angulation B) Callus formation C) Impaction D) Malrotation E) Shortening

D Malrotation causes scissoring of the affected digit, which will adversely affect neighboring digits. This will affect activities of daily living and is an indication for operative intervention. Other indications for operative intervention include displaced intra-articular fractures, severe soft-tissue injury, unstable open fractures, segmental bone loss, and multiple fractures. Angulation is usually dorsal tip-oriented because of intrinsic and extrinsic muscle pull. A good rule of thumb is the 10, 20, 30, 40 for digits two, three, four, and five. The fourth and fifth digits have carpometacarpal joint mobility and can tolerate larger angulation. The fifth digit metacarpal may even tolerate up to 70 degrees of angulation as long as there is no extensor lag. Impaction can lead to shortening and/or angulation, which is tolerated more than rotational deformities. Similarly, shortening is well tolerated as long as there is no extensor lag. Nonoperative complications include aesthetic with loss of knuckle and possible pain in the palm from the metacarpal head. Callus formation is indicative of an old, healed fracture.

A 28-year-old man sustains acute wrist extension during a fall on an outstretched arm. Examination shows snuffbox tenderness. A scaphoid fracture is suspected. Which of the following imaging studies should be performed first to identify this patient's injury? A) Bone scan B) CT scan C) MRI D) Plain x-ray studies E) Ultrasonography

D The correct answer is plain x-rays. Negative x-rays in scaphoid fractures are up to 30%. Cost effectiveness of obtaining x-rays first is shown by the positive finding in 70%. The predictive value of clinical examination is 13-69% with an average of 21%. Depending on clinical suspicion and whether the patient needs to avoid immobilization if the absence of fracture can be confirmed, additional imaging studies may be obtained. For MRI, the estimated sensitivity is 97.7% and the specificity is 99.8% with 96% accuracy. For a CT scan, estimated sensitivity is 85.2 to 94% and the specificity is 96 to 99.5% with 98% accuracy. Bone scintigraphy is 96 to 97.8% and 89 to 93.5%, respectively, with 93% accuracy. For follow-up x-ray studies, 91.1 and 99.8%, respectively. MRI is therefore the best test for ruling in scaphoid fractures where the other tests are better at ruling out scaphoid fractures. Cost effectiveness of MRI for patients with suspicion for scaphoid fracture with negative x-rays is shown by getting patients out of unnecessary splints sooner.

A 25-year-old man has an acute fracture of the third metacarpal on his dominant hand. An x-ray study shows a displaced oblique fracture with shortening and rotation. During open reduction, which of the following muscles is most likely attached to the fracture fragments? A) Abductor digiti minimi B) Extensor digiti minimi C) Extensor indicis proprius D) Interosseous E) Lumbrical

D The correct answer is the second dorsal interossei radially and third dorsal interossei ulnarly. There is little variation in atomic origins of the interosseous muscles. All interossei originate from the corresponding metacarpal shafts. The extensor indicis proprius and extensor digiti minimi muscle bellies are located in the forearm. The abductor digiti minimi muscle is attached to the 5th metacarpal.The lumbrical originates on the flexor digitorum profundus tendon and not on the bone.

A 36-year-old man comes to the office because of a 2-week history of pain of the right wrist after a fall on his outstretched hand. X-ray studies are shown. If this injury is left untreated, which of the following joint surfaces is most likely to develop arthritis first? A) Capitolunate B) Lunotriquetral C) Radiolunate D) Radioscaphoid E) Scaphocapitate

D The most likely joint surface to develop arthritis is the radioscaphoid joint. This patient shows evidence of scapholunate ligament tear. There is evidence of widening of the scapholunate interval and increase in the scapholunate angle. The scapholunate angle is calculated by measuring the angle between a line drawn perpendicular to the distal surface of the lunate and along the axis of the scaphoid on the lateral view. The normal scapholunate angle varies from 30 to 60 degrees. A tear in the scapholunate ligament results in volar flexion of the scaphoid bone and dorsiflexion of the lunate, with a resultant increase in the angle. If a scapholunate ligament tear is left untreated, a degenerative pattern of changes result. This is known as scapholunate advanced collapse (SLAC) wrist. Over time there is separation of the scaphoid and lunate bones and descent of the capitate into the intervening space. With scapholunate ligament tears, arthritis occurs in a predictable sequence. This initially begins in the radioscaphoid joint, followed by the scaphocapitate joint and the capitolunate joint. The radiolunate joint is typically spared until advanced stages. The lunotriquetral ligament is intact and arthritis does not occur in this area with SLAC wrist.

A 26-year-old man sustained a crush injury to the tip of the left middle finger with an associated fracture at the dorsal base of the distal phalanx with nail bed injury 6 months ago. No treatment was provided. Examination shows non-union of the distal phalanx. Which of the following is the most likely secondary deformity in this patient? A) Boutonniere deformity B) Jersey finger C) Quadriga D) Swan neck deformity E) Trigger finger

D The scenario described involves a bony mallet deformity in which a distal phalanx fracture is associated with disruption of terminal extension at the distal interphalangeal joint. If untreated, the DIP extension loss due to a non-union of a bony mallet injury may progress to a swan neck deformity through compensatory proximal phalangeal hyperextension in the setting of continued and persistent flexion at the distal interphalangeal joint (from unopposed pull of the flexor digitorum profundus tendon). A secondary swan neck deformity may occur because of dorsal subluxation of the lateral bands and attenuation of the volar plate and transverse retinacular ligament at the PIP joint level. A jersey finger is caused by rupture of the terminal flexor digitorum profundus. A boutonniere deformity can be caused by an injury to the central slip (but not the terminal extensor tendon). Quadriga is due to loss of length of a repaired FDP tendon, causing the finger with the repaired tendon to reach terminal flexion sooner than the other fingers whose FDP tendons are of normal length. A trigger finger does not involve a fracture of the DIP joint.

A 50-year-old woman with type 2 diabetes mellitus is scheduled to undergo ligament reconstruction tendon interposition (LRTI) surgery for trapeziometacarpal joint arthritis. The procedure is expected to last 90 minutes. Which of the following is the most appropriate antibiotic prophylaxis for this patient? A) Oral antibiotics for 3 days following surgery B) Single dose intravenous antibiotic within 1 hour of surgery C) Single dose intravenous antibiotic within 1 hour of surgery and oral antibiotics for 24 hours following surgery D) Single dose intravenous antibiotic within 1 hour of surgery and oral antibiotics for 3 days following surgery E) No antibiotic prophylaxis is indicated

E Multidrug resistant bacterial infections continue to rise and antimicrobial overuse is the leading cause for antibiotic resistance. There is growing evidence that prophylactic antibiotic use is not necessary for clean plastic surgery cases, aside from breast surgery cases. Despite consensus guidelines, the use of prophylactic antibiotics for elective Hand Surgery cases continues to increase. Level I evidence exists that demonstrates prophylactic antibiotics are not necessary for clean Hand Surgery cases lasting less than 2 hours. Although there has been concern regarding diabetes and surgical infection risk, this has not been demonstrated in larger studies with multivariate analyses.

A 71-year-old woman elects to undergo surgery for basal thumb osteoarthritis. In addition to carpal tunnel syndrome and presence of pathology at the scaphotrapeziotrapezoid (STT) joint, assessment for which of the following additional concomitant conditions is most appropriate during the operative planning for this patient? A) Lunotriquetral dissociation B) Radioscaphoid arthritis C) Scapholunate dissociation D) Thumb interphalangeal arthritis E) Thumb metacarpophalangeal hyperextension

E Operative planning for surgical treatment of basal thumb osteoarthritis requires not only careful history, physical examination, and radiographic examination of the basal thumb joint, but also the scaphotrapeziotrapezoid (STT) joint, the carpal tunnel, and the thumb metacarpophalangeal (MP) joint. Persistent arthritic symptoms following treatment of the basal thumb joint are often due to unrecognized STT arthritis, and many patients will have carpal tunnel syndrome concomitant with basal thumb arthritis; thus, it is important to evaluate for these pathologies to avoid persistent symptoms following surgery. The MP joint must be evaluated for collapse, or hyperextension, particularly with pinch prior to operative treatment. Failure to correct MP hyperextension, particularly that beyond 30 degrees, may lead to persistent pain and progressive collapse of the thumb. The scapholunate, lunotriquetral, thumb interphalangeal, and radioscaphoid joints are not associated with basal thumb arthritis or its treatment.

A 29-year-old man undergoes evaluation for nonunion of a scaphoid fracture. Reconstruction with a vascularized osseous flap is planned, and a medial femoral condyle flap is chosen. During harvest, the vascular pedicle for this flap runs between which of the following structures? A) Anterior to the tensor fascia lata and posterior to the vastus lateralis B) Anterior to the vastus medialis and anterior to the adductor tendon C) Anterior to the vastus medialis and posterior to the rectus femoris D) Posterior to the rectus femoris and anterior to the vastus lateralis E) Posterior to the vastus medialis and anterior to the adductor tendon

E The medial femoral condyle osseous free flap has become a useful option for reconstruction of bony defects in the extremities, particularly of the scaphoid waist and proximal pole. The vascular supply to this flap is from the descending geniculate artery in the distal medial aspect of the thigh. To explore and identify the pedicle for this flap, the vastus medialis is reflected anteriorly, and the adductor tendon is found posterior to the vessels. The rectus femoris is located anterior to the dissection for this flap.