The Effect of Osteoporosis on Survival of Silicone and Pyrocarbon Metacarpophalangeal Implants in Rheumatoid Arthritis.

PURPOSE: To evaluate the impact of preoperative osteoporosis on rates of revision and reoperation for patients with rheumatoid arthritis (RA) who underwent primary metacarpophalangeal (MCP) arthroplasty with silicone or pyrocarbon implants.

METHODS

We retrospectively identified all primary silicone and pyrocarbon MCP arthroplasties performed in patients with RA at our institution over an 18-year period. Patient osteoporosis status was determined according to the National Bone Health Alliance criteria. We report survival free from revision (implant removal or replacement) and all-cause reoperation (including revisions) in these groups. We used cluster-robust, multivariable Cox proportional hazards models to analyze osteoporosis as a risk factor for revision and all-cause reoperation and report subgroup analysis for pyrocarbon and silicone implants.

RESULTS

The osteoporosis group included 200 joints (168 silicone, 32 pyrocarbon) in 56 patients with a mean follow-up of 7.9 years. The nonosteoporosis group included 129 joints (93 silicone, 36 pyrocarbon) in 42 patients with a mean follow-up of 10 years. With pyrocarbon implants, the osteoporosis group had lower 10-year survival free from revision (58% vs 100%) and all-cause reoperation (40% vs. 81%) than the nonosteoporosis group. In multivariable analysis of pyrocarbon implants, osteoporosis was associated with increased hazard for revision (HR, 11.0; 95% CI, 1.27-95.8) and all-cause reoperation (HR, 3.4; 95% CI, 1.2-10.3). With silicone implants, there was no difference in 10-year survival free from revision (88% in osteoporosis, 89% in nonosteoporosis) or all-cause reoperation (85% osteoporosis, 85% nonosteoporosis). Osteoporosis did not affect risk for silicone implant revision or reoperation.

CONCLUSIONS

Osteoporosis is associated with increased risk for pyrocarbon implant revision and all-cause reoperation in RA patients, though the precise effect size is unknown. Silicone MCP arthroplasty remains a durable option for patients with RA regardless of osteoporosis status.

TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.