[Midcarpal partial arthrodesis with locking plate osteosynthesis].

OBJECTIVE: Preservation of residual mobility and pain reduction in the wrist in advanced carpal collapse (scapholunate advanced collapse, SLAC or scaphoid nonunion advanced collapse, SNAC).

INDICATIONS: Advanced osteoarthritis of the radiocarpal and intercarpal articulations, SLAC/SNAC stages 2-3.

CONTRAINDICATIONS: Arthrotic alterations to the proximal joint surface of the lunate bone or the corresponding joint surface of the radius (lunate fossa).

SURGICAL TECHNIQUE: Dorsal longitudinal incision and exposure of the wrist capsule using a radial pedunculated capsular flap. Resection of the scaphoid bone. Chondrolysis of the corresponding joint surface between the capitate bone and the lunate bone as well as between the hamate bone and the triquetral bone. Harvesting and insertion of radial cancellous bone. Repositioning of the lunate bone. Introduction of the plate and filling of the screwholes. Closure of the wrist capsule. Neutral placement of a lower arm plaster cast. Postoperative physiotherapy from out of the supporting cast to an extent of 20-0-20° extension-flexion. For protection the support cast should remain in place for 8 weeks.

RESULTS: Complete consolidation of the bone in the X‑ray control in all 11 patients 12 weeks postoperatively. No implant-based complications. In one case a postoperative carpal tunnel syndrome had to be surgically treated. The postoperative extent of mobility showed overall satisfactory results with extension-flexion of 53° ± 18° (47% of the healthy side) and radial-ulnar abduction 30 ± 5° (58% of the healthy side). The postoperative values on the visual analog pain scale (VAS) were 0.7 ± 1.2 at rest and 4.3 ± 2.8 under load bearing. The gripping power was 19 ± 14 kg (56% of the non-operated side) and the disabilities of the arm, shoulder, hand (DASH) value was 33 ± 24.