Schluttenhofer, Adam T

Background: Anti-cyclic citrullinated peptide antibodies (ACPAs) are associated with more aggressive rheumatoid arthritis disease. We aimed to determine the effect of ACPA serostatus on survival free from revision, all-cause reoperation, and recurrence of coronal plane deformity in patients with rheumatoid arthritis (RA) undergoing silicone metacarpophalangeal (MCP) arthroplasty. Methods: We retrospectively identified silicone MCP arthroplasties performed in patients with RA with known ACPA serostatus from 2000 to 2022. Kaplan-Meier estimates were used to report survival free from revision, all-cause reoperation, and recurrence of coronal plane deviation >10° on postoperative radiographs. We analyzed ACPA serostatus as a risk factor for these endpoints using cluster-robust Cox proportional hazard models, adjusting for patient sex. Results: We included 133 joints in 39 ACPA seropositive patients (9.0 years mean follow-up) and 63 joints in 21 ACPA seronegative patients (5.7 years mean follow-up). Survival free from revision, all-cause reoperation, and recurrent coronal deformity was higher in seropositive patients than in seronegative patients. Anti-cyclic citrullinated peptide antibody seropositivity was significantly associated with lower risk for revision (hazard ratio [HR] = 0.16), all-cause reoperation (HR = 0.20), and recurrent coronal plane deviation >10° (HR = 0.28). Seropositive patients had longer average time to recurrent coronal deviation >10° (3.5 years vs 1.3 years) and less coronal deviation at final radiographic follow-up (15.9° vs 21.5°). Conclusions: Anti-cyclic citrullinated peptide antibody seropositivity is associated with improved silicone MCP implant survivorship and lower risk of recurrent coronal plane deformity in patients with rheumatoid arthritis. More work is needed to better understand the biologic basis of these findings.

Background: Use of pyrocarbon metacarpophalangeal (MCP) implants in rheumatoid arthritis (RA) patients has been associated with high rates of complications and reoperations. To date, few patient-specific prognostic factors have been identified. This study investigated body mass index (BMI) as a risk factor for RA patients undergoing pyrocarbon MCP arthroplasty. Methods: We included 148 joints (51 patients) that underwent pyrocarbon MCP implantation at our institution from 2000 to 2022. We analyzed survival free from revision, reoperation, and development of postoperative complications using cluster-robust Cox proportional hazard models with restricted cubic splines to plot non linear relationships. Secondarily, we compared survival above and below the World Health Organization cutoff for obesity of ≥ 30 kg/m 2 , adjusting for patient age and sex. Results: The relationship between BMI and risk for complications and revisions was J-shaped, with an increase in risk beyond 29 kg/m 2 . The relationship between BMI and late reoperations was U-shaped, with patients above 27.3 kg/m 2 and below 23.2 kg/m 2 at elevated risk. A BMI ≥ 30 kg/m 2 was associated with a 7.9-times increased risk for revision, 8.3-times increased risk for late reoperations, and 3.7-times increased risk for postoperative complications. Body mass index did not significantly influence risk for early reoperation. Conclusions: Body mass index was associated with pyrocarbon MCP implant failure in a non linear fashion, with overweight patients at risk for complications leading to revisions and late reoperations. Underweight patients may be at increased risk for late reoperations. These findings should inform patient and implant selection and help guide counseling for postoperative expectations.

Background: Pyrocarbon metacarpophalangeal (MCP) arthroplasty is associated with high rates of recurrent deformity and reoperation in patients with rheumatoid arthritis (RA). We sought to determine the impact of preoperative hand grip strength (HGS) on implant survivorship in these patients. Methods: We included primary pyrocarbon MCP arthroplasties in patients with RA at our single institution from 2000 to 2022. Cox proportional hazard models with restricted cubic splines were used to model the continuous relationship between HGS and hazard for revision, all-cause reoperation, and development of any complication, accounting for multiple joints per patient and adjusting for sex. Kaplan-Meier estimates were used to report survivorship at 2, 5, and 10 years. Results: We included 75 joints in 27 patients with an average preoperative HGS of 8.6 kg (11.1 years of follow-up). There were 16 (21%) total revisions, most commonly for recurrent deformity, along with 8 nonrevision reoperations, most commonly for tendon/ligamentous repair. There was a significant, J-shaped relationship between HGS and hazard for revision ( P = .001) and all-cause reoperation ( P < .001). Patients with HGS below 5.5 and 5.3 kg had an increased risk for revision (hazard ratio [HR]: 13.5) and all-cause reoperation (HR: 9.8) compared with patients with sufficiently high HGS. The 10-year revision survival was 93% in patients with HGS >5.5 kg and 63% in patients ≤5.5 kg. Hand grip strength did not significantly affect hazard for developing a first complication. Conclusion: Very low preoperative HGS is associated with worsened implant survivorship following pyrocarbon MCP arthroplasty in patients with RA.