Arthrodesis of the thumb metacarpophalangeal joint using a cannulated screw and threaded washer.

We describe a technique of arthrodesis of the thumb metacarpophalangeal joint that we performed in 26 patients. Indications for surgery were instability (6 patients), chronic instability with secondary degenerative joint disease (6), osteoarthritis (6), inflammatory arthritis (7), and paralytic boutonniere (1). The technique uses the cup-and-cone method of decortication and positioning with the internal fixation using a 3.0-mm partially threaded cannulated screw and threaded washer (Synthes, Paoli, PA). Twenty-five of 26 joints had clinical and radiographic fusion. Average time to radiographic fusion for 24 patients (1 nonunion, 1 patient without x-rays until 4 months) was 10 weeks. Long-term follow-up evaluation was available for 20 patients and averaged 32 months (range, 21-44 months). All 20 had stable radiographic fusion with maintenance of the fusion angle. There were no infections and no need for hardware removal. Our results indicate that this technique for arthrodesis of the thumb metacarpophalangeal joint is effective and reliable, is accomplished easily, and has a low incidence of complications.