Silicone Metacarpophalangeal Arthroplasty: A Matched Cohort of Osteoarthritis and Rheumatoid Arthritis Patients

Little is known about how silicone metacarpophalangeal (MCP) arthroplasty outcomes compare between rheumatoid arthritis (RA) and osteoarthritis (OA) patients.

Using our single institutional data from 2000 to 2022, we propensity matched 46 primary silicone MCP arthroplasties in 33 OA patients 1:2 to 92 arthroplasties in 54 RA patients based on age, sex, body mass index, operative digit, and if the surgery was on the dominant hand. We used Kaplan-Meier estimates and cluster-robust Cox proportional hazard models to compare survival free from revision, all-cause reoperation, and development of coronal plane deviation >10°.

There was comparable 10-year survival free of revision (94% OA, 91% RA) and all-cause reoperation (91% OA, 87% RA), with no difference in risk for each outcome between groups. Revision in OA patients occurred early (mean 0.6 years) for recurrent deformity (n = 2) and periprosthetic joint infection (n = 1). Revision in the RA cohort occurred later (mean 6.3 years postoperatively) for recurrent deformity (n = 3) and dislocation (n = 1). Osteoarthritis patients had less coronal plane deviation at the final radiographic follow-up (6.5° vs 16.2°, P < .001), higher 10-year survival free from coronal deviation > 10° (79% vs 17%), and lower risk of progressive coronal deformity (hazard ratio 0.15, P < .001).

Silicone MCP arthroplasty remains a durable option with low reoperation rates for RA and OA. Osteoarthritis patients experience less coronal deviation and late reoperation for deformity than RA patients, likely due to their more robust soft-tissue stabilizers and noninflammatory disease process.