Microfracture for acetabular chondral defects in patients with femoroacetabular impingement : results at second-look arthroscopic surgery

Background: Microfracture is a proven technique to treat articular cartilage defects in the knee. However, there is little evidence in the literature to confirm the ability of microfracture to produce repair tissue in the hip joint. Purpose: The purpose of this study was to report the macroscopic and microscopic appearances of repair tissue after microfracture performed at hip arthroscopic surgery for isolated full-thickness acetabular cartilage defects in patients with femoroacetabular impingement (FAI). Study Design: Case series; Level of evidence, 4. Methods: Twenty patients who underwent arthroscopic surgery for FAI had a localized full-thickness acetabular chondral defect treated by microfracture and then underwent a later second-look hip arthroscopic procedure. The size of the full-thickness defect was measured at the primary arthroscopic procedure. A visual assessment of the extent and quality of repair tissue was performed at second-look arthroscopic surgery. Two patients also had a biopsy of the repair tissue, which was studied histologically. Results: At an average follow-up of 17 months, 19 of the 20 patients had a mean fill of 96% ± 7% with macroscopically good quality repair tissue. One patient had only a 25% fill with poor quality repair tissue. Histologically, the tissue was found to be primarily fibrocartilage with some staining for type II collagen in the region closest to the bone. Conclusion: Microfracture in the hip appears to be an effective technique that produces excellent coverage of the defect with good quality repair tissue on visual inspection and microscopic examination at an average follow-up of 17 months