Summary

Coblation chondroplasty had no adverse findings on MR imaging or patient reported outcomes at one year

Abstract

Introduction

The impact of Coblation? radiofrequency (RF)- based chondroplasty compared to mechanical chondroplasty (MC) on magnetic resonance (MR) imaging over time has not been evaluated. There has been concern based on animal studies that RF chondroplasty may be detrimental to the cartilage and patient outcomes. Our hypothesis was that Coblation? RF chondroplasty would be as safe as MC, with no adverse outcomes on MR imaging or patient reported outcomes.

Methods

A prospective, randomized clinical trial was conducted in 57 subjects requiring arthroscopic treatment of a single medial femoral chondral lesion (Grade 3A) plus partial medial meniscectomy procedure. Subjects were randomized to undergo (RF)-based chondroplasty or mechanical chondroplasty (MC). Patient reported outcomes (Knee Injury and Osteoarthritis Outcome Score (KOOS)) and MR images were obtained and analysis conducted on patients undergoing mechanical chondroplasty (MC) compared to radiofrequency (RF)-based chondroplasty using the Quantum? 2 Controller plus Paragon T2? ICW Wand (RF). Twenty-eight patients underwent RF debridement and twenty-nine patients underwent mechanical debridement with their partial medial meniscectomy. All subjects were assessed post-debridement with MR imaging at Day 10 (PostOp-baseline), and then at Week 52 and Week 104. These MR images were used to calculate the percent lesion fill (PLF) and the change of PLF over time. The KOOS was administered pre-operatively, at Week 6, Week 12, Week 24, Week 36, Week 52 and Week 104. Device related adverse events were collected as well as adverse MR findings (defined as MOAKS abnormal cartilage signal and morphology, subarticular bone marrow abnormality, cysts, bone attrition, marginal osteophytes, synovial thickening and joint effusion and loose bodies).

Results

There were no device related adverse events in either group. There were no adverse MR findings in either group at any time point. At Day 10, the results of the imaging analysis showed no significant differences in the PLF between the treatment groups (52.9±16.6 (RF group), 53.5±16.8 (MC group), p=0.83). The overall differences in change of PLF at any visit were not significant (P>0.05) between the treatment groups. The mean KOOS scores in both treatment groups improved from the pre-operative status to each study. This improvement in KOOS scores was greater in subjects randomized to RF-based debridement for pain only at Weeks 12 and 24. There was no evidence of a significant difference between the groups for overall KOOS score at any visit. Although not significant (P=0.07), there was a trend of improvement in the KOOS Sports/Recreation subscale with an increase in PLF between the postoperative-baseline and Week 52 visits.

Conclusions

Coblation? Radiofrequency (RF)-based chondroplasty was not found to cause any adverse events on MR imaging for up to two years post operatively. MR imaging and patient reported outcomes were similar between groups, suggesting equivalence of the two chondroplasty procedures. The sample size for comparisons was small, not allowing for correlations between the imaging and clinical data. The trend of improvement of certain KOOS subscales and increase in PLF at Week 52 suggests a correlation between the structural properties of the repair cartilage and functional outcomes.