Intraoperative acoustic evaluation of living human cartilage of the elbow and knee during mosaicplasty for osteochondritis dissecans of the elbow: an in vivo study.

Background: Autologous osteochondral mosaicplasty for osteochondritis dissecans of the capitellum is being used increasingly in adolescent patients. Little research has been published on the material properties of living human cartilage of the elbow and knee.

Hypothesis: The cartilage of the osteochondritis dissecans lesion is detected as degenerated by ultrasound. The material properties of the cartilage of the intact part of the elbow are not different from those of the intact knee except in thickness.

Study Design: Descriptive laboratory study.

Methods: The authors studied 10 young male athletes with osteochondritis dissecans of the capitellum who underwent mosaicplasty. An acoustic probe was used for measurement, and the wavelet transform method was used. Three parameters were used: signal intensity (index of cartilage stiffness), signal duration (index of roughness), and signal interval (index of thickness).

Results: The cartilage of the osteochondritis dissecans lesion had lower signal intensity than did the intact part of the capitellum. The cartilage of the radial head opposite the capitellum had significantly lower signal intensity and higher signal duration than did other sites. The signal intensity of the radial head was significantly higher in early-stage patients than in late-stage patients, although the macroscopic view was almost all intact. The signal intensity of the plug was decreased significantly after grafting.

Conclusion: The osteochondritis dissecans lesion had lower signal intensity than did the intact part of the capitellum. Although the macroscopic view looked intact, the radial head cartilage was degenerated as measured acoustically.

Clinical Relevance: Not only the cartilage of the capitellum but the cartilage of the radial head are acoustically degenerated in osteochondritis dissecans patients. Plugs might be damaged in the transplanting procedure, and further follow-up is necessary.