A 25-year-old steelworker has significant posttraumatic trapeziometacarpal arthritis of the dominant thumb that interferes with job-related activities. Conservative management including joint protection and administration of anti-inflammatory drugs does not alleviate the pain.

Which of the following is the most appropriate operative management?

(A) Excision of the distal pole of the scaphoid
(B) Excision of the distal trapezium
(C) Excision of the proximal trapezium
(D) Scaphotrapezial arthrodesis
(E) Trapeziometacarpal arthrodesis

The correct response is Option E.

Patients with basilar joint arthritis of the thumb typically have involvement of the trapeziometacarpal joint; the scaphotrapeziotrapezoidal joint is involved less frequently. Conservative management including splinting, administration of anti-inflammatory agents, and joint protection should be attempted first. Recent studies have shown that administration of glucosamine and chondroitin sulfate may aid in alleviation of pain.

Both arthroplasty and arthrodesis are recommended in patients in whom conservative management has been unsuccessful. Either procedure will alleviate pain in the diseased trapeziometacarpal joint. Because arthroplasty has limited use in manual laborers who require durability, arthrodesis is more appropriate. Although trapeziometacarpal arthrodesis permits pain-free powerful grip and pinch, this procedure places greater motion demands on the metacarpophalangeal and scaphotrapezial joints. Another disadvantage of trapeziometacarpal arthrodesis is that the procedure results in a decrease in thumb metacarpal motion; as a result, hand span will be decreased, and the patient will be unable to flatten the palm completely.

The other procedures do not address the trapeziometacarpal joint of the thumb and thus are not indicated.

References
1. Doyle JR. Sliding bone graft technique for arthrodesis of the trapeziometacarpal joint of the thumb. J Hand Surg. 1991;16A:363.
2. Peng YP, Low CK, Looi KP. Comparison of first carpometacarpal joint arthrodesis with contralateral excision arthroplasty in a patient with bilateral saddle joint arthritis: a case report. Ann Acad Med Singapore. 1999;28:451-454.

PHOTO

The above radiograph is from a 30-year-old construction worker who injured his dominant right hand in a motor vehicle accident two months ago. These findings are most consistent with

(A) Kienbšck's disease
(B) midcarpal instability
(C) perilunate dislocation
(D) scapholunate dissociation
(E) scapholunate syndrome

The correct response is Option D.

This patient has findings consistent with scapholunate dissociation and longitudinal carpal instability. Scapholunate dissociation involves mechanical disruption of the ligament between the scaphoid and lunate bones. Anteroposterior radiographs will show an increased scapholunate gap; the scaphoid bone will appear foreshortened. Comparison radiographs with the opposite, unaffected wrist and anteroposterior radiographs with the fist clenched are also helpful in diagnosis. Early recognition and treatment are important to prevent the development of radiocarpal arthritis following injury, which can ultimately progress to scapholunate advanced collapse (SLAC wrist).

Interestingly, this patient's radiograph also shows diastasis of the capitatohamate joint and the third and fourth metacarpals. This is a rare finding that is only seen following high-energy injuries and should be treated as soon as possible.

Kienbšck's disease, or avascular necrosis of the lunate, is a progressive condition associated with an ulnar negative variance. Radiographs will show sclerosis or fragmentation of the lunate or loss of lunate height, depending on the stage of the disorder.

In patients with midcarpal instability, the proximal row is shifted into either dorsiflexed or volar-flexed intercalated segment instability. There is destabilization between the distal and proximal carpal rows on radial or ulnar deviation of the wrist. However, separation of the scaphoid and lunate bones would not be evident on radiographs.

Perilunate dislocations can be classified as either greater arc or lesser arc injuries depending the site of trauma and the extent of carpal bone injury. Anteroposterior radiographs will show overlap of the distal carpal row onto the proximal carpal row and a triangular-shaped lunate.

Scapholunate syndrome develops following fracture of both the scaphoid and capitate. The proximal pole of the capitate will typically be rotated either 90 degrees or 180 degrees.

References
1. Amadio PC, Talesnik J. Fractures of the carpal bones. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;1:809-864.
2. Garcia-Elias M. Carpal instabilities and dislocations. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;1:865-928.
3. Markiewitz AD, Ruby LK, O'Brien ET. Carpal fractures and dislocations. In: Lichtman DM, Alexander AH, eds. The Wrist and Its Disorders. Philadelphia, Pa: WB Saunders Co; 1997:206-211.