Adaptive Proximal Scaphoid Implant (APSI): 10-year outcomes in patients with SNAC wrists

Radioscaphoid arthroplasty with the Adaptive Proximal Scaphoid Implant (APSI^®) is an attractive treatment alternative in the short and medium term for patients with early scaphoid non-union advanced collapse (SNAC) wrist. The purpose of our study was to determine the long-term outcomes of this implant in SNAC wrists. All patients who received the implant from October 2002 to October 2010 were included. A clinical and radiographic study was performed. Our case series included 39 patients, of which 33 were contacted, with a mean follow-up of 10 years (5.8-13.4). Most of the patients had stage-1 SNAC wrist (95%). There were nine complications (27%), seven of which required reoperation: implant dislocation (44%) or progression of the carpal degeneration (33%). Ninety-six percent of patients contacted were satisfied or very satisfied with their surgery (although 21% needed a second surgery) with a Mayo Wrist Score of 80/100 and a Patient-Rated Wrist Evaluation of 17.5/100. Wrist strength was 86% of the contralateral side. Flexion-extension range was 101° and pain assessed using a visual analog scale was at 1.2 (0-6). We report satisfactory and lasting results with the APSI^®, similar to those of scaphoid excision with four-corner fusion and proximal row carpectomy. Hence, the APSI^® is a reliable alternative for treating osteoarthritis in SNAC wrists.