Introduction: The debridement of deep cartilage defects is one of the most frequently used Methods: in arthroscopic surgery.

This randomized study was undertaken to compare the effectiveness of simple mechanical debridement and the 52°C-controlled bipolar chondroplasty.

Materials and Methods: A total of 60 patients (28 male, 32 female, average age 43.3 years, range 20 to 50 years) who were suffering from a grade III cartilage defect of the medial femoral condyle were included. Exclusion criteria were revision arthroscopy, injury or osteoarthritis (grade II or higher).

After randomization, 30 patients underwent simple debridement of the cartilage defects, which was performed with a mechanical shaver (MSD = mechanical shaver debridement). The remaining patients underwent thermal chondroplasty, which was performed with a temperature-controlled bipolar device with a constant thermo-application of 51°C (RFC = Radio-Frequency-based Chondroplasty).

The patients were evaluated by the Knee-injury and Osteoarthritis Outcome Score (KOSS) preoperatively and at time of follow-up. Activity levels were measured by the Tegner score (activity level before onset of the symptoms and at time of follow-up). Follow-up was undertaken 4 years after the arthroscopy.

Results: No significant differences between the preoperative findings for the two groups were observed.

One patient from the MSD group had died, and one female patient in the RFC group was lost to follow-up. A total of 18 patients had undergone revision operations due to persistent knee problems: in the MSD group, there were 8 endoprostheses, 4 osteotomies, and 2 revision arthroscopies; in the RFC group there was 1 one replacement, 2 osteotomies, and 1 revision arthroscopy with subtotal medial meniscectomy. The proportion of revisions was significantly higher in the MSD group (p=0.006). These patients were excluded from the evaluation.

The remaining 40 patients from both groups benefited from the operation. The preoperative KOOS was 11.3 points in the MSD group and 15.5 points in the RFC group (p=0.279). Patients from the MSD group had a KOOS of 53.2 at the time of follow-up. In the RFC group the KOOS (71.8) was significantly higher (p< 0.001).

Patients from both groups had to accept a decrease in their level of physical activity. However, patients from the RFC group had a significantly improved (p=0.005) Tegner activity score in comparison to the patients from the MSP group.

The radiographic and MRI findings in the MSD group were also worse than in RFC patients.

Conclusion: RFC is a potential method for the treatment of deep cartilage defects. The 4-year outcome is better than after MSD. Long-term results are still lacking.