Metacarpophalangeal Surface Replacement Arthroplasty Improves Pain in RA, Despite Frequent Complications

Metacarpophalangeal (MCP) surface replacement arthroplasty demonstrated improvements in hand range of motion and reductions in pain associated with rheumatoid arthritis (RA), but the procedure was associated with frequent complications and reoperations, according to study results in published in HAND.

The study was a retrospective analysis of electronic medical records and an institutional joint registry that included charts of patients with RA who underwent surface replacement arthroplasty of the MCP joint at the Mayo Clinic in Rochester, Minnesota. A total of 80 MCP surface replacement arthroplasties that were performed over a 12-year period (December 1993 to December 2005) in 27 patients with RA were included in the review. The investigators collected demographic data as well as information on procedure revisions, reoperations, complications, pain, and MCP arc of motion.

Medical management of RA in the retrospective cohort included nonsteroidal anti-inflammatory drugs/hydroxychloroquine (n=5), methotrexate (n=28), or other disease-modifying antirheumatic drugs (n=29). The mean postoperative follow-up period was 9.5 years (range, 2.1-20.5 years). All surface replacement arthroplasties included in the review had ≥2 years of follow up. The mean age of the patients was 52.8 years, and the majority (92.5%) were women.

Approximately 16% (n=13) of procedures underwent revision arthroplasty and 36% (n=29) of arthroplasties required reoperation. The 5-year rate of revision-free survival was 95% vs 85% at 10 years, 80% at 15 years, and 69% at 20 years. In addition, the respective 5-, 10-, 15-, and 20-year rates of survival from reoperation were 80%, 65%, 55%, and 46%. A significant increase in the percentage of joints producing no or mild pain was observed from preoperation to postoperation (43% vs 87%, respectively; P <.0001), and no pain was reported by approximately 73% of patients who underwent arthroplasties after operation.

A significant improvement was also found for the mean MCP arc of motion from preoperation to postoperation (29.4° vs 49.3°, respectively; P <.0001). The investigators also observed a significant improvement in the mean extension lag from 56.7° to 23.3° after operation (P <.0001). In addition, there was a significant postprocedural improvement in grip strength (P =.04).

Overall, 64% (n=51) of arthroplasties were associated with ≥1 complication. A total of 25 fingers had 1 complication, 12 fingers had 2 complications, 7 fingers had 3 complications, 6 fingers had 4 complications, and 1 had 7 complications. Soft-tissue contracture was the most common complication (38%).

Limitations of the study included its retrospective nature, lack of preoperative and postoperative patient-reported outcome measures, and a limited number of end points, which precluded the researchers’ ability to conduct a multivariate analysis.

With regard to the 16% revision rate at follow-up in these patients, the investigators suggested “the clinical results of [surface replacement arthroplasty] implants deteriorated with time” and wrote that these findings highlight “the inherent deficiencies at stabilizing an inherently soft-tissue-deficient joint in patients with RA.”

Reference

Claxton MR, Wagner ER, Rizzo M. Long-term outcomes of MCP surface replacement arthroplasty in patients with rheumatoid arthritis [published online June 2, 2020]. HAND. doi: 10.1177/1558944720926631