Is synovectomy still of benefit today in total knee arthroplasty with rheumatoid arthritis?

Purpose: There is a lack of long-term data evaluating the impact of synovectomy versus no synovectomy during total knee arthroplasty (TKA) in patients with rheumatoid arthritis (RA). This study aimed to assess and compare bilateral TKA outcomes with and without synovectomy in the same patients over a similar follow-up period.

Methods: A retrospective review was conducted on 65 bilateral staged posterior-stabilized (PS) fixed-bearing TKAs (28 men, 37 women) performed by a single surgeon on RA-affected knees, with an average follow-up of 17 years (range: 15-24 years). In the first knee, synovectomy was performed during TKA, while no synovectomy for the contralateral TKA. Outcomes assessed included Knee Society scores for knee and function, radiographic findings, complications, and patellar position using the Insall-Salvati ratio.

Results: The synovectomy group had a higher rate of blood transfusion (23.3% vs. 16.6%; P < 0.01) and longer hospital stays (mean 9.60 days [95% CI: 6.56-13.63] vs. 6.51 days [95% CI: 5.50-9.52]; P < 0.001). The group without synovectomy demonstrated significantly better Knee Society Scores (89.1 vs. 80.2 points; P = 0.02) and greater range of motion (ROM) for flexion (130° vs. 102°; P = 0.01). Both groups had similar knee alignment, stability, and femoral and tibial component alignment. Patella baja was observed in six patients in the synovectomy group. Severe haematoma (n = 6) and deep infections (n = 4) were noted exclusively in the synovectomy group. Kaplan-Meier survivorship at 15 years was 81% (95% CI: 78-95) for TKA with synovectomy and 95% (95% CI: 90-100) for TKA without synovectomy.

Conclusion: Knees undergoing synovectomy during primary TKA exhibited reduced knee flexion, inferior Knee Society pain scores, and higher complication rates compared to contralateral knees without synovectomy. Omitting synovectomy in RA patients did not increase the risk of implant loosening.