Painful Knee is not Uncommon after total Knee Arthroplasty and can be Treated by Arthroscopic Debridement

After total knee arthroplasty (TKA), most patients have an improvement; however, a few continue to have residual pain. We reported a case series of painful knee after TKA with unreported reason.Forty-six arthroscopic surgeries were performed for painful knee after TKA. Of these, 16 were excluded due to infection, patellar clunk syndrome, patellofemoral synovial hyperplasia, aseptic loosening, or short follow up less than 6 months. Remaining 30 cases had marked tenderness at the medial and/or lateral tibiofemoral joint space, and they had pain during walking with pain or without pain at rest. The mean period from initial TKA to arthroscopy was 29 months, and the mean follow-up after arthroscopy was 36 months. All arthroscopic debridement was performed through 3 portals. Scar tissue impingements graded moderate or severe were found only in 30% of the cases in both the medial and lateral tibiofemoral joint spaces. The infrapatellar fat pad was covered with whitish scar tissue in all cases, and the tissue was connected with the scar tissue at the medial or lateral tibiofemoral joint spaces. All scar tissue was removed with a motorized shaver or punches.At the final follow-up, 63% were pain free, 3% had marked improvement, 20% had half improvement, 3% had slight improvement, and 11% had no change. We hypothesized that the lesser mobility of the scar tissue due to the continuity of the tissue between the infrapatellar fat pad and the tibiofemoral joint space could cause easy impingement at the tibiofemoral joint, even with the small volume of scar tissue.If infection and aseptic loosening could be ruled out in a painful knee after TKA, arthroscopic debridement appeared to be a good option to resolve the pain.