Five-year radiographic and clinical outcomes after arthroscopic synovectomy of the ankle in rheumatoid arthritis: A clinical trial.

Background: Rheumatoid arthritis (RA) affects ankle joints in up to one half of patients with established disease, causing inflammation and damage. Arthroscopic synovectomy removes inflamed tissue to improve joint function, but long-term outcomes and the potential role of adjunctive therapies are limited.

Materials and methods: A total of 176 patients who had a preoperative diagnosis of RA according to the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria, radiographic Larsen grade ≤ 3, and who underwent arthroscopic synovectomy from May 2013 to May 2019 were prospectively enrolled. Weight-bearing anteroposterior and lateral plain radiographs of the ankle were performed annually after initial surgery. The Larsen grade was used to evaluate the progression of ankle joint damage in RA, and patient-reported outcomes (American Orthopaedic Foot and Ankle Society [AOFAS] Ankle-Hindfoot Scale and the Foot and Ankle Outcome Score [FAOS]) were collected annually. The primary outcome measure was 5-year AOFAS score. Baseline characteristics, including age, body mass index (BMI), duration of symptoms before surgery, Larsen grade before surgery, and other potentially related factors, including number of platelet-rich plasma (PRP) injections and change in BMI from baseline, were recorded.

Results: There were 138 patients included, all with minimum 5-year follow-up data. The overall reoperation rate was 13% (95% confidence interval [CI] 6.8-18.9%; 18 of 138). According to multivariable analysis, 5-year AOFAS scores were associated with number of PRP injections (correlation coefficient = 2.09 [95% CI 1.47-2.71]; P < 0.001), duration of symptoms before surgery (correlation coefficient = 0.42 [95% CI 0.14-0.70]; P = 0.01), Larsen grade before surgery (correlation coefficient = 0.28 [95% CI 0.06-0.49]; P = 0.034), and mean BMI change from baseline (correlation coefficient = -1.23 [95% CI -1.57 to -0.89]; P < 0.001). When comparing the number of PRP injections (0, 1-2, or ≥ 3), patients who had serial PRP injections (≥ 3) had diminished functional and radiographic deterioration over time.

Conclusions: Arthroscopic synovectomy improves symptoms for ankle RA and appears to slow-but not halt-radiographic deterioration over 5 years. Serial PRP injections and reduction in BMI from baseline could be associated with better clinical outcomes and slower joint degeneration, which needs to be verified by randomized controlled trials.

Level of evidence: Level II, prospective cohort study. Trial registration Research Registry, researchregistry10878. Registered 24 November 2024-retrospectively registered, http://researchregistry.knack.com/researchregistry10878.