Reduction and maintenance of scapholunate dissociation using the TwinFix screw

Abstract

Objective: Closed reduction and internal fixation of the scapholunate dissociation are currently performed using K-wires or a headless bone screw. We present an alternative for this fixation by means of a cannulated screw with dynamic adjustable interfragmentary compression and discuss the advantages of using this type of technique.

Methods: Closed reduction of the scapholunate interval was achieved using a K-wire centered through the scaphoid and lunate bones followed by delivery of a cannulated compression screw to maintain the scapholunate interval.

Results: Nine months after the surgery, the hand active range of motion was significantly improved. Only minimal pain was experienced with high loadings of the wrist and the patient achieved much improvement in his wrist strength.

Conclusions: The technique we present is simple to perform and represents an attractive alternative to the conventional procedures to achieve the reduction of the scapholunate diastasis and the maintenance of the scapholunate interval.

Figures

Figure 1

Fluoroscopic image of the carpal rows demonstrating markedly increased scapholunate interval (arrow) with mild palmar flexion of the scaphoid.

Figure 2

Cannulated double-threaded TwinFix screw.

Figure 3

Postoperative fluoroscopic image of the scapholunate interval of the right wrist depicting the reduced scapholunate interval and carpal malrotation.