• ABSTRACT
    • This study investigates the management of metacarpophalangeal joint (MCP) hyperextension in patients undergoing trapeziectomy for thumb base osteoarthritis. A total of 297 thumbs with painful trapeziometacarpal osteoarthritis were assessed on pain and thumb key and tip pinch preoperatively and at 1 year. Before surgery 101 had no MCP hyperextension, 168 had hyperextension ≤ 30° and 28 had hyperextension ≥ 35°. Of these 157 hyperextension deformities ≤ 30° and eight ≥ 35° were not treated. The others were treated by temporary insertion of a Kirschner wire (n = 9), MCP fusion (n = 6), sesamoid bone tethering to the MC head (n = 5) and palmar capsulodesis using a bone anchor (n = 11). Untreated MCP hyperextension deformities < 30° did not influence the outcome of trapeziectomy. MCP hyperextension deformities ≥ 35° can be improved by capsulodesis or MCP fusion but this may not improve the clinical outcome.