Microfracture in the Hip: Results of a Matched-Cohort Controlled Study With 2-Year Follow-up
Background: Microfracture in hip preservation surgery has demonstrated favorable outcomes, but studies with a higher level of evidence assessing microfracture are warranted.
Purpose: To assess 2-year outcomes of patients who underwent hip arthroscopy with full-thickness chondral damage treated with microfracture and compare these outcomes with those of a control group from a similar cohort of patients who did not have full-thickness chondral damage and who were not treated with microfracture.
Study design: Cohort study; Level of evidence, 3.
Methods: Between February 2008 and May 2012, prospectively gathered data for patients undergoing microfracture during hip arthroscopy with a 2-year follow-up were reviewed. All patients were assessed pre- and postoperatively at 3 months, 1 year, and 2 years with 4 patient-reported outcome (PRO) instruments. A matched cohort of patients who did not have full-thickness chondral damage and hence did not receive microfracture was selected on a 1:2 ratio. Matching criteria were sex, age within 6 years, workers' compensation status, concomitant labral treatment, and radiographic parameters. Statistical analyses were performed to compare the change in PROs in both groups.
Results: A total of 79 hips were included in the microfracture group and 158 in the control group. There was no significant difference in PRO scores preoperatively between the groups. Both groups demonstrated significant improvement in all postoperative PRO scores at all time points. There was no statistically significant difference in postoperative PRO scores between the microfracture and control groups, except for the visual analog scale (VAS) score at 2 years, which was higher (P = .02) in the microfracture group (mean ± SD, 3.63 ± 2.50) than in the control group (2.82 ± 2.76). Patient satisfaction was 7.2 for the microfracture group and 8.04 for the control group, which was statistically different (P < .05). The mean change in all PRO scores was similar between groups at 3 months and 1 year postoperatively but significantly lower in the microfracture group at 2 years postoperatively. The greatest improvement in both groups was noted at 3 months postoperatively.
Conclusion: This study showed that patients undergoing microfracture during hip arthroscopy had equivalent PRO scores compared with the control group at 2 years postoperatively. The change in PRO scores from preoperatively to 2 years postoperatively was significantly lower in the microfracture group compared with the control group. The VAS scores and satisfaction were inferior by 0.81 and 0.84 units, respectively, in the microfracture group compared with the control group, likely due to lack of full-thickness chondral defects in the latter. However, both groups showed significant improvement in all PRO scores after surgery, with no significant difference in final PRO scores.