Matched patients with smaller chondral defects or larger chondral defects undergoing arthroscopic acetabular microfracture with treatment for labral tears and FAI demonstrated similar outcomes at >=2 years.
Chondral defects are of paramount consideration in hip preservation. However, the literature evaluating the effect of defect size on microfracture outcomes is limited.
Patients with larger chondral defects (LCDs; >= 200mm²) have inferior outcomes after microfracture compared to those with smaller chondral defects (SCDs; <=150 mm²).
The study period was between 2/2008 and 11/2014. Data were prospectively collected on patients that underwent hip arthroscopy. The inclusion criteria were acetabular microfracture; concomitant treatment for labral tears and femoro-acetabular impingement (FAI); and preoperative modified Harris Hip Score, Non-Arthritic Hip Score, Hip Outcome Score – Sports Specific Subscale, and Visual Analogue Scale. Exclusion criteria were Worker’s Compensation, preoperative Tonnis grade >1, or previous hip conditions. Patients were grouped based on SCDs or LCDs, then matched 1:1 by age at surgery ±10 years, sex, BMI ±5, labral treatment, capsular treatment, acetabuloplasty, and femoroplasty.
Of 131 eligible cases, 107 (81.7%) had minimum two-year follow-up. Thirty-five patients were matched for each group. Mean follow-up time was 47.9 months (range: 24.0, 84.1) for the matched LCD group and 46.1 months (range: 24.0, 88.1) for the matched SCD group. Ligamentum teres debridement (p=0.03) was performed more frequently in the LCD group. No other differences were found regarding demographics, intraoperative findings, procedures, preoperative scores, or follow-up scores. Both groups demonstrated significant improvements in all scores. Rates of revision or conversion to arthroplasty were similar between groups. The relative risk for conversion to arthroplasty was 2.33 for patients with LCDs >= 300mm² compared to patients with defects <= 250mm² (p=0.13). Deep-vein thrombosis occurred in 3 (5.3%) patients with LCDs.
Matched patients with smaller chondral defects or larger chondral defects undergoing arthroscopic acetabular microfracture with treatment for labral tears and FAI demonstrated similar outcomes at >= 2 years. Patients with chondral defects approaching 300 mm² or greater may have a higher propensity towards requiring arthroplasty.