Four-Year Outcomes Following Arthroscopic Microfracture of the Hip in Patients with Advanced Chondral Lesions

This report examines 4-year patient reported outcomes and procedural survivorship in patients who underwent microfracture during hip arthroscopy compared to a matched group of non-microfracture patients as well as the risk factors for procedural failure following microfracture of articular lesions in the hip.

Data for 38 consecutive patients undergoing arthroscopic microfracture was retrospectively analyzed. Propensity score matching identified a matched group of hip arthroscopy patients who had Outerbridge grade 3 or grade 4 chondral lesions but did not undergo microfracture. Preoperative modified Harris Hip Scores (mHHS) and NonArthritic Hip Scores (NAHS) were compared to those at 2- and 4-year follow-up. Postoperative rates of ipsilateral revision arthroscopic surgery or hip arthroplasty were assessed.

Thirty-three (86.8%) of the 38 microfracture patients were available for 4-year follow-up. Forty-six patients were matched with the microfracture group. Scores including mHHS and NAHS increased postoperatively for both groups (p < 0.05), though there were no significant differences between groups (p > 0.05). Overall reoperations rates were 24.2% and 21.7% (p = 0.873) for the microfracture and non-microfracture groups, respectively. Hip arthroplasty rates were higher among microfracture patients (18.2% vs. 2.2%, p = 0.038), wherein Tonnis grade ≥ 2, cartilage lesions ≥ 400 mm2 , and femoral-sided lesions were associated with failure.

Patients who underwent microfracture treatment of chondral lesions fared no better than a matched group of patients who did not receive microfracture treatment. Risk of reoperation is high for both groups and microfracture patients are more likely to require conversion to total hip arthroplasty or hip resurfacing.