The aims of this study were: (1) to evaluate the mid-term results and survivorship of arthroscopic synovectomy (AS) of the knee in rheumatoid arthritis (RA) defined with the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) criteria; and (2) to identify prognostic factors.
Patients matching the 2010 ACR/EULAR criteria, with symptomatic knee synovitis for at least six months, treated with arthroscopic synovectomy of the knee at a minimum of three year followup were included. Pre-operative evaluation included Larsen, HAQ, DAS28, and Laurin scores. Post-operatively, Laurin, WOMAC, and patient satisfaction scores were evaluated. Different variables were investigated to find associations with the outcomes. Kaplan-Meier survival analysis was performed.
Sixty-four patients met the inclusion criteria. Seven patients (9.6%) were lost to followup, leaving 57 patients (66 knees) for the present study. The average followup was 96.3months (SD 41). The pre-operative Laurin score was 3.91 points (SD 1.3) and significantly (P<0.001) improved after surgery (mean 8.2, SD 2). The post-operative average WOMAC score was 73.9 points (SD 45.9). Eighteen knees (27.3%) underwent revision procedures at an average of 48.6 months (SD 39.8). Joint degeneration (Larsen grade III) and range of movement (ROM) reduction (>10%) were identified as negative prognostic factors. Kaplan-Meier survivorship with total knee replacement as endpoint was: 78% at one year, 28% at four years, and six percent at 10 years.
Although AS of the knee has still a role as a salvage procedure in the treatment of RA synovitis with initial joint degeneration (less than Larsen grade III) and good ROM, high revision rates and limited survivorship are reported.