Treatment of grade III femoral chondral lesions: mechanical chondroplasty versus monopolar radiofrequency probe

Abstract

Purpose: Articular cartilage defects are commonly found on the femoral condyle, and their treatment with thermal energy is thought to provide a smoother surface, sealing the damaged articular cartilage and possibly decreasing the progression of these lesions. Reports of femoral avascular necrosis (AVN) developing after bipolar thermal chondroplasty are worrisome. The purpose of this study was to compare the effects on subchondral bone and the early clinical effectiveness of mechanical shaving versus mechanical shaving plus monopolar radiofrequency (MRF) on grade III femoral chondromalacia.

Type of study: Randomized, prospective, controlled trial.

Methods: In this trial 60 subjects were treated by either mechanical shaving alone (n = 30) or mechanical shaving plus MRF (n = 30). Preoperative and 12-month postoperative magnetic resonance imaging (MRI) evaluations and Tegner, Lysholm, Cincinnati, International Knee Documentation Committee, and visual analog scale assessments at 12 and 24 months were obtained.

Results: Of the subjects, 56 were available for the final analysis (28 treated by shaver and 28 treated by shaver plus MRF). Baseline demographics were similar between treatment groups. Postoperative MRI findings were similar between groups, including no incidents of AVN. At a mean of 19 months postoperatively, Tegner, Lysholm, Cincinnati, International Knee Documentation Committee, and visual analog scale assessments improved significantly from pretreatment levels in both groups. No difference in mean improvement was observed between groups.

Conclusions: The primary endpoint was to look for AVN. No subchondral bone effects attributable to either mechanical shaving or radiofrequency energy were noted. The secondary endpoint was a clinical evaluation. Both groups showed significant improvements in pain and function outcomes with no discernible differences between groups. The use of monopolar radiofrequency as an adjuvant to mechanical chondroplasty with a shaver for the treatment of grade III chondral lesions did not affect MRI findings or pain and function outcomes when compared with mechanical chondroplasty by use of a shaver only.

Level of evidence: Level II, randomized controlled trial with confidence intervals not reported.