Arthrodesis of the thumb metacarpophalangeal joint: Conventional open technique with a locking plate or compression pins versus minimally invasive technique with compression pins or screws.

Arthrodesis of the thumb metacarpophalangeal (MCP) joint usually leads to satisfying results when performed with an open technique. The main complication is adhesion of the extensor tendons that sometimes requires hardware removal associated with tenolysis. The goal of this study was to assess whether a minimally invasive technique could reduce the risk of this complication. Arthrodesis of the thumb MCP was performed using an open technique with a locking plate or compression pins in 12 cases (group I) and using a minimally invasive technique with compression pins or screws in 12 cases, for a total of 24 patients aged 48.9 years on average, among which 15 were women. At the last follow-up, the average pain level was rated at 2/10 in group I and 2.3/10 in group II. The QuickDASH was 40.70/100 in group I and 36.24 in group II, grip strength was 79% of the contralateral side in group I and 51% in group II. Pinch strength was 81% of the contralateral side in group I and 45% in group II. Fusion was achieved in all cases in group I and in 7 of 12 cases in group II. Surgical revision for non-union was needed in 5 cases in group II, with hardware removal and tenolysis performed in 2 cases. The non-unions were observed in non-rheumatoid cases. While the two groups were not identical, arthrodesis of the thumb MCP using a minimally invasive technique with compression pins or screws seems to give satisfying results for rheumatoid cases in which no cartilage remains.