Femoral Notch Stenosis Caused by Soft Tissue Impingement in Semi or Open-Box Posterior-Stabilized Total Knee Arthroplasty

The goal of this study was to evaluate the treatment of femoral notch stenosis caused by soft tissue hypertrophy. Nineteen patients (19 knees) were evaluated arthroscopically for late-onset clinical findings of progressive loss of extension, pain, and/or crepitus after posterior-stabilized total knee arthroplasty. The patients had similar pathology that included marked hypertrophic soft tissue in the posterior-stabilized box impinging against the polyethylene post. Patients underwent arthroscopic débridement, with a mean increase in Knee Society pain scores of 39 points (range, 6-76 points), a mean increase of Knee Society function scores of 37 points (range, 10-72 points), and a mean increase in range of motion of 12° (range, −15° to 61°). One patient had a recurrence of symptoms at final follow-up, which was treated with reoperation. In patients with normal radiographs and clinically stable knees, the findings of progressive loss of extension with pain and crepitus may merit further evaluation. If notch stenosis is identified, arthroscopic débridement usually leads to a satisfactory result, at least at short-term follow-up.