Is Synovectomy Necessary in Total Knee Arthroplasty with Rheumatoid Arthritis?

The risk of inflammation after a total knee arthroplasty in rheumatoid arthritis patients sometimes spurs surgeons to remove the synovium in hopes of preventing complications, such as the loosening of the arthroplasty. But a new study finds that synovectomy actually leads to more complications and inferior outcomes in patients with rheumatoid arthritis.

Philippe Hernigou of Hôpital Henri-Mondor in Créteil, France, presented long-term follow-up datafrom 65 bilateral total knee arthroplasties on March 1 at the 2016 annual meeting of the American Academy of Orthopaedic Surgeons in Orlando, Florida. Each patient had rheumatoid arthritis and underwent the replacement of both knees. The first knee underwent synovectomy as well as total knee arthroplasty. The second knee underwent total knee arthroplasty alone. The researchers then followed up with clinical and radiographic assessments between 15 and 22 years later (average 16 years).

Synovectomy was associated with a greater need for blood product transfusions than knee replacement without synovectomy (23.3 percent versus 16.6 percent, P<0.01), and synovectomy patients spent 9.6 days (95 percent C.I. =6.56; 13.63) recovering in the hospital versus 6.51 days (95 percent C.I. =5.50; 9.52) for patients without synovectomy (P<0.001).[[{"type":"media","view_mode":"media_crop","fid":"46382","attributes":{"alt":"©IrenaMisevic/Shutterstock.com","class":"media-image media-image-right","id":"media_crop_2921261442825","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"5377","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"font-size: 13.008px; line-height: 1.538em; float: right;","title":"©IrenaMisevic/Shutterstock.com","typeof":"foaf:Image"}}]]

Knee Society scores were better in knees without synovectomy (89.1) than those with (80.2, p=0.02), as was flexion range of motion (130 degrees without synovectomy; 102 degrees with, p=0.01). At 15 years post-surgery, the Kaplan-Meier survivorship for revision was lower after arthroplasty plus synovectomy than after arthroplasty alone, the researchers reported (84 percent (95 percent C.I., 78-95) versus 97 percent (95 percent C.I., 93-100).

Complications noted with synovectomy included patella baja (six patients) and severe hemotoma and deep infection (four patients). Knee stability and alignment were not different between groups.

"In our series, knees treated with complete synovectomy at the time of primary TKA had lower knee flexion and inferior pain scores, and more complications as compared with contralateral knees without synovectomy," the researchers concluded. "Absence of synovectomy in rheumatoid arthritis did not increase the risk of loosening."

References:

"Is Synovectomy Necessary in Total Knee Arthroplasty with Rheumatoid Arthritis?"

March 1, 2016 presentation at the annual meeting of the American Academy of Orthopaedic Surgeons. Philippe Hernigou, PhD, and Charles-Henri Flouzat Lachaniette, MD.