Pyrocarbon interposition implant after lunate resection in Kienböck's disease: A case series

In advanced stages of Kienböck's disease, the lunate is no longer conservable. One of the surgical options is to resect the lunate and replace it with a prosthesis. The procedure consisted in lunate resection and interposition of a free APSI® or Pi2® pyrocarbon implant through a dorsal approach. Follow-up was clinical and radiological on QuickDASH and PRWE scores. At a median follow-up of 3 years, 12 patients were reviewed, with a median age of 56 years. Flexion significantly decreased from 42° to 28° (p < 0.01). Extension and pronation-supination were conserved. Strength was 94% compared to the opposite side, with no significant difference from the preoperative measurement. Median QuickDASH and PRWE scores were 15.9 and 23.5 respectively and had significantly improved. One patient underwent scaphocapitate fusion because she was still in pain; the other patients were pain-free. No patients had to change jobs because of their wrist. Radiographically, there was no carpal collapse and carpal height was conserved. Radioscaphoid angle and ulnar translation were stable. There was 1 case of asymptomatic implant dislocation. Interposition of a pyrocarbon implant after lunate resection in advanced Kienböck's disease is a motion-conserving procedure that provides pain relief and functional recovery in the short and medium term. LEVEL OF EVIDENCE: IV.