(A) Scapholunate ligament repair
(B) Radial styloidectomy
(C) Radial corrective osteotomy
(D) Ulnar shortening osteotomy
(E) Four-corner arthrodesis

The correct response is Option E.

This patient has scapholunate advanced collapse of the wrist, also known as SLAC wrist, with radioscaphoid arthrosis and a dorsiflexed intercalated segment instability deformity. This condition is caused by incompetency of the scapholunate ligament, which leads to rotatory subluxation of the scaphoid.

SLAC is the most common cause of degenerative arthritis of the wrist. This condition can be classified according to four stages, as shown in the table below.

Stage I Radioscaphoid
Stage II Radial midcarpal
Stage III Ulnar midcarpal
Stage IV Pancarpal

Surgical management is aimed at decreasing pain and optimizing wrist function, using two unaffected articular surfaces if possible. In this patient, goals of surgery include eliminating the radioscaphoid articulation and stabilizing carpal kinematics. Therefore, the most appropriate procedure is scaphoid excision and four-corner arthrodesis between the lunate, capitate, hamate, and triquetrum. None of the other procedures addresses all of the problems that are present in this patient’s wrist.

References
1. Blatt G, Tobias B, Lichtman DM. Scapholunate injuries. In: Lichtman DM, Alexander AH, eds. The Wrist and Its Disorders. Philadelphia, Pa: WB Saunders Co; 1997:268-306.
2. Weber ER, Hixson M, Frazier GT. Chronic wrist instability. In: Peimer CA, ed. Surgery of the Hand and Upper Extremity. New York, NY: McGraw Hill, Inc; 1996:727-758.

A 39-year-old assembly line worker has chronic disabling pain of the trapeziometacarpal joint of the dominant right hand that is exacerbated when he uses his tools. Radiographs show significant degenerative arthritis that is limited to the trapeziometacarpal joint.

Which of the following is the most appropriate operative management?

(A) Reconstruction of the palmar oblique (beak) ligament
(B) Trapeziectomy only
(C) Trapeziectomy with tendon interposition arthroplasty
(D) Trapeziectomy with Silastic interposition arthroplasty
(E) Trapeziometacarpal arthrodesis

The correct response is Option E.

In this 39-year-old assembly line worker who has significant degenerative arthritis of the trapeziometacarpal joint (ie, carpometacarpal joint of the thumb) of the dominant hand, the most appropriate management is trapeziometacarpal arthrodesis. Arthrodesis is recommended for younger patients who have arthritis that is limited to the trapeziometacarpal joint and who require strong grip and pinch. This procedure may increase stresses across the peritrapezial joints, leading to pain, laxity, and subsequent arthritis. In addition, some range of motion of the thumb is sacrificed, but this may improve over time. Other potential options include partial trapeziectomy and interposition of the palmaris longus, which is a new arthroscopic technique that has demonstrated promising results but is not yet used widely.

Trapeziectomy, with or without soft-tissue interposition arthroplasty, is most commonly used to treat trapeziometacarpal arthritis because it provides relief of pain and increased mobility. However, this technique results in a decrease of pinch and grip strength to approximately 75% of normal. Silastic arthroplasty is performed only in low-demand patients who have adequate bone stock.

Reconstruction of the palmar oblique (beak) ligament is indicated for treatment of prearthritic, painful instability of the trapeziometacarpal joint, and may prevent the development of arthritis. However, this procedure will not alleviate pain once significant arthritic changes have occurred.

References
1. Klimo GF, Verma RB, Baratz ME. The treatment of trapeziometacarpal arthritis with arthrodesis. Hand Clin. 2001;17:261-270.
2. Tomaino MM. Treatment of Eaton stage I trapeziometacarpal disease: ligament reconstruction or thumb metacarpal extension osteotomy? Hand Clin. 2001;17:197-205.

A 45-year-old roofer has pain and swelling of the right wrist after falling off a roof and landing on his outstretched right hand. Radiographs are shown above. This patient most likely has which of the following types of fracture-dislocation?

(A) Carpometacarpal joint-hamate
(B) Radial styloid
(C) Scaphocapitate
(D) Scaphoid-perilunate
(E) Scaphotrapeziotrapezoid

The correct response is Option D.

This patient has a scaphoid-perilunate fracture-dislocation, also known as a scaphoid-dorsal perilunate fracture-dislocation. Wrist dislocations can range from simple injuries to extended fractures associated with dislocation of one or more carpal bones. This patient has sustained one of the most severe forms of wrist dislocation, as shown in the radiographs.

Fracture-dislocations of the wrist are identified according to the carpal bone(s) involved and the type of lunate dislocation (ie, incomplete or complete). Lunate dislocations are subdivided into midcarpal lunocapitate, complete lunate, and perilunate injuries. A complete lunate injury can be differentiated from a perilunate injury by the presence of a concomitant dislocation of the radiolunate joint. Greater arc injuries are typically caused by high-energy trauma. The radial styloid, scaphoid, capitate, hamate, triquetrum, and/or ulnar styloid may be fractured. Lesser arc dislocations involve injury to the scapholunate, lunocapitate, and/or lunotriquetral intervals; these injuries are rated as type I to type IV according to Mayfield’s classification.

The radiographs do not depict a carpometacarpal joint-hamate fracture-dislocation. A fracture-dislocation of the radial styloid would occur more proximally. The scaphocapitate and scaphotrapeziotrapezoid lie distal to the level of injury.
References
1. Szabo RM, Sutherland TB. Acute carpal fractures and dislocations. In: Peimer CA, ed. Surgery of the Hand and Upper Extremity. New York, NY: McGraw Hill, Inc; 1996:711-726.
2. Yaghoubian R, Goebel F, Musgrave DS, et al. Diagnosis and management of acute fracture-dislocations of the carpus. Ortho Clin North Am. 2001;32:295-305.

Which of the following scaphoid fracture patterns illustrated above has the highest incidence of avascular necrosis?

(A) A
(B) B
(C) C
(D) D
(E) E

The correct response is Option A.
Fractures of the scaphoid comprise as many as 60% of all carpal bone fractures; most of these fractures are caused by a fall onto a dorsally flexed wrist. Scaphoid fractures can be displaced or nondisplaced. In patients with nondisplaced fractures, application of a cast followed by mobilization results in a rate of union as high as 95%. A long arm thumb spica cast is typically applied first, then replaced with a short arm thumb spica cast.

In contrast, displaced fractures are often associated with an unacceptably high rate of nonunion if treated conservatively and a high incidence of avascular necrosis. This complication has been reported to occur in 13% to 40% of patients with scaphoid fractures; its incidence is dependent on the presence or absence of displacement and the anatomic location of the fracture. Because perforators to the scaphoid enter distally and proceed proximally, fractures that occur more proximally are more likely to interrupt the blood supply to the scaphoid.

The distal pole of the scaphoid has a good, protective blood supply; as a result, the risk for avascular necrosis is low. In contrast, fractures of the scaphoid waist are associated with an incidence of avascular necrosis of approximately 30%, and fractures of the proximal pole of the scaphoid have a rate of avascular necrosis that may be as high as 100%. Therefore, internal fixation is generally advocated for treatment of fractures of the proximal pole of the scaphoid. With rigid fixation of the bone, revascularization of the scaphoid occurs almost uniformly.

References
1. Gasser H. Delayed union and pseudoarthrosis of the carpal navicular: treatment by compression screw osteosynthesis: a preliminary report on 20 fractures. J Bone Joint Surg. 1965;47A:249.
2. Szabo RM, Sutherland TB. Acute carpal fractures and dislocations. In: Peimer CA, ed. Surgery of the Hand and Upper Extremity. New York, NY: McGraw-Hill, Inc; 1996.