Can Microfracture Produce Repair Tissue in Acetabular Chondral Defects?

Purpose: The purpose of this study was to investigate percent fill and repair grade of microfractured lesions of the acetabulum. Methods: Nine patients underwent revision hip arthroscopy for a variety of procedures after undergoing microfracture for treatment of a full-thickness chondral defect of the acetabulum at primary arthroscopy. The size of the chondral defect was measured during primary arthroscopy, and the percent fill of the defect and repair grade were noted at revision hip arthroscopy. Results: Mean time from primary arthroscopy to revision was 20 months (range, 10 to 36 months). The average percent fill of the acetabular chondral lesions at second-look was 91% (range, 25% to 100%). Eight of the patients had grade 1 or 2 repair product at second-look. The 1 patient with 25% fill and grade 4 repair product had diffuse osteoarthritis on the femur and acetabulum at primary microfracture. One patient required total hip arthroplasty 66 months after the index microfracture. Conclusions: In this study, 8 of 9 patients had 95% to 100% coverage of an isolated acetabular chondral lesion or acetabular lesion associated with a femoral head lesion, with grade 1 or 2 appearance of the repair product at an average of 20 months follow-up. One patient who had diffuse osteoarthritis failed, with only 25% coverage with a grade IV appearance of the repair product 10 months after index arthroscopy. Level of Evidence: Level IV, therapeutic case series.