An extreme case of transcaphoid-transcapitate perilunate dislocation in an adolescent

Treatment of acute perilunate dislocation or fracture dislocation using dorsal approach and diamond-shaped Kirschner-wire fixation

Objectives

This study aims to evaluate the clinical and radiological outcomes of diamond-shaped Kirschner (K)-wire fixation for the treatment of acute perilunate dislocation (PLD) or trans-scaphoid perilunate fracture dislocation (PLFD).

Patients and methods

We performed a retrospective review of 18 patients (18 wrists; 17 males, 1 female; mean age 31.5±2.6 years; range, 18 to 47 years) treated for PLD/PLFD using a dorsal approach with the diamond-shaped K-wire fixation between November 2001 and September 2017. The mean follow-up of cohort was 27 (range, 13 to 74) months. Using a dorsal approach, open ligament repair and bone fixations were performed. Perilunate dislocation was reduced and the carpal bones and midcarpal joint were held in anatomical position using four K-wires transfixing the scapholunate (SL), lunotriquetral, scaphocapitate, and triquetrohamate joints in such a shape that each bone received two K-wires.

Results

The mean range of motion and grip strength measured using a Jamar® dynamometer of the injured wrist compared to the uninjured extremity were 84.3% and 78.8%, respectively. The mean Mayo wrist score was 78.3 (range, 70 to 90). The mean Visual Analog Scale score was 1.2 (range, 0 to 4). The average SL gap at the final follow-up evaluation was 1.62 (range, 1 to 2.3) mm. The mean SL and capitolunate angles were 49.3° (range, 40 to 75°) and 4.2° (range, 2 to 12°), respectively.

Conclusion

Because every bone is fixed with two K-wires using this configuration, a closed ring is created; hence no motion is possible between the scaphoid, capitate, hamate, triquetrum, lunate and the midcarpal joint. We believe that diamond-shaped fixation may provide reliable fixation and satisfactory clinical outcomes in patients with PLD and PLFD.