RF can have many uses in orthopedic surgery. The applications in foot and ankle arthroscopy include synovectomy, chondroplasty, resection of impingement lesions, debridement, fusion, and ankle stabilization procedures (Fig. 18-2).

RF treatment of cartilage defects and chondromalacia in all joints has been controversial. Initially, Turner et al. and then Kaplan et al. found favorable results treating chondral pathology with RF.⁸, ⁹ Lu et al. studied monopolar RF in 36 adult female sheep with partial-thickness articular cartilage defects. They found that the monopolar RF caused death of almost all chondrocytes in the defect.¹⁰ Lu et al. continued to study monopolar and bipolar RF and found significant depth of chondrocyte death up to 1,000 µm.¹¹, ¹², ¹³, ¹⁴ These findings were noted to be controversial, and further studies found the depth of penetration much less with chondrocyte viability noted just below the treatment area.¹⁵ Amiel et al. stated that the difference in findings was likely multifactorial including only reporting chondrocyte viability with confocal microscopy and previously not studying chondrocyte metabolism with glycosaminoglycan synthesis looking at ³⁵SO₄ uptake. Furthermore, and probably most importantly, using an actual surgeon rather than a preset jig, Amiel et al. showed a consistently well-defined zone of ablation with a consistent margin of chondrocyte death 100 to 200 µm.¹⁵ Similar depths of chondrocyte injury likely occur with mechanical devices. More recently, it has been shown in animal models that certain RF devices are safe for treating partial chondral defects and/or chondromalacia, but each device has unique effects on the chondral surfaces with different levels of penetration.¹⁴, ¹⁵