Arthroscopic Treatment of Patellar Clunk Syndrome After Total Knee Arthroplasty.

BACKGROUND: Patellar clunk syndrome is a complication of total knee arthroplasty. Surgical treatment with arthroscopic irrigation and debridement and lysis of adhesions is often required when conservative treatment fails. This study examines patient improvement following arthroscopic treatment of patellar clunk.

METHODS: This single-surgeon case series uses a posterior-stabilized implant design. We performed a retrospective review of all patients from September 2013 to November 2020 treated for patellar clunk syndrome with arthroscopic debridement. Patient variables analyzed included knee flexion/extension angle and symptoms, including pain and mechanical symptoms. Analysis used paired t-tests with an alpha level of 0.05.

RESULTS: Fifty procedures were examined. Mean patient age was 61.4 years (standard deviation [SD] = 8.57 years), and 64% were female. Before arthroscopy, the mean maximum knee extension (KE) of the affected side was 0.85° (SD = 3°), and the mean maximum knee flexion (KF) was 120.5° (SD = 9.4°). At the last follow-up, the mean maximum KE was 0.36° (SD = 1.3°), and the mean maximum KF was 123.1° (SD = 9.4°). Paired t-tests comparing preoperative and postoperative KF and KE were P = .138 and P = .487, respectively. All patients reported less pain, and 90% (45/50) reported mechanical symptom improvement.

CONCLUSIONS: Arthroscopic treatment of symptomatic patellar clunk syndrome is safe and effective: almost all included patients experienced symptom relief, with a slight improvement in KF. This was a retrospective cohort study with a level of evidence of III.