Reverse Microfracture for Acetabular Wave Signs: Clinical and MRI Outcomes at Minimum 2-Year Follow-up

Background: Acetabular wave signs represent a form of cartilage delamination and may progress to more extensive chondral damage in patients with femoroacetabular impingement (FAI). The current lack of high-quality evidence supporting an optimal surgical strategy underscores the need to investigate reverse microfracture as a viable, safe, cost-effective, and cartilage-preserving treatment option. Purpose/Hypothesis: The purpose of this study is to evaluate the clinical and imaging outcomes of arthroscopic treatment of acetabular wave signs using a reverse drilling technique performed from the supralabral region of the acetabulum without damaging the articular cartilage. It was hypothesized that this technique would provide clinical improvement without additional cartilage damage. Study Design: Case series; Level of evidence, 4. Methods: A total of 40 patients (mean age, 40.2 ± 9.2 years; 24 women and 16 men) underwent hip arthroscopy with concomitant FAI treatment and reverse microfracture, with a minimum follow-up of 2 years. Outcomes included Harris Hip Score (HHS), visual analog scale (VAS), lateral center-edge angle (LCEA), alpha angle, and magnetic resonance imaging (MRI). Results: The HHS increased from 68.88 ± 10.81 to 97.90 ± 2.22 ( P < .001), and the VAS score decreased from 7.40 ± 1.03 to 1.35 ± 1.08 ( P < .001). The alpha angle decreased from 61.88°± 2.50° to 50.05°± 1.75° ( P < .001), and the LCEA decreased from 36.75°± 4.66° to 32.43°± 1.92° ( P < .001). MRI demonstrated no deterioration in cartilage quality or additional lesions after the procedure, with cartilage appearance similar to adjacent noninjured areas and no evidence of delamination. Conclusion: Reverse microfracture may represent a potential treatment option for acetabular wave signs. In this retrospective series, the procedure was associated with improvement in pain and functional scores, and no evidence of additional cartilage deterioration was observed on postoperative MRI during a minimum 2-year follow-up. However, given the absence of a control group, the specific contribution of the drilling technique to the observed clinical improvements cannot be determined. Clinical improvement likely reflects the combined effect of comprehensive arthroscopic management of FAI rather than the isolated effect of reverse drilling.