Patellar clunk syndrome after total knee arthroplasty; risk factors and functional outcomes of arthroscopic treatment.

Abstract

This study reports the incidence, risk factors, and functional outcomes of the largest reported series of patients treated arthroscopically for patella clunk syndrome (PCS). All patients treated arthroscopically for PCS were identified. Patients were matched with controls by sex and date of surgery. Follow-up was conducted using SF-12 and WOMAC questionnaires. Operative notes and preoperative and postoperative radiographs were reviewed. Seventy-five knees in 68 patients were treated arthroscopically for PCS. Average follow-up was 4.2 years. Functional scores demonstrated no statistical difference. PCS patients had a significantly more valgus preoperative alignment, greater change in posterior femoral offset and smaller patellar component size. PCS is a relatively common complication following TKA. Arthroscopy yields functional results comparable to controls. Radiographic and technical factors are associated with PCS.