Association of 5-Year Hip Arthroscopy Outcomes with Hip Morphology and Cartilage Status at Time of Surgery: A National Registry Study With HAGOS Outcomes in 281 Patients With Femoroacetabular Impingement Syndrome

Abstract

Background: The effects of specific bony hip morphologies, cam and dysplasia, and cartilage damage on mid- and long-term (≥5 years) patient-reported outcomes (PROs) are understudied. Purpose: To investigate if changes in PROs from preoperatively to 5 years after hip arthroscopy are associated with preoperative bony hip morphology and cartilage status in patients with femoroacetabular impingement syndrome. Study Design: Cohort study; Level of evidence, 3. Methods: Patients were identified in the Danish Hip Arthroscopy Registry. Hip and groin function was assessed from preoperatively to 5 years postoperatively with the Copenhagen Hip and Groin Outcome Score (HAGOS) Activities of Daily Living (ADL) and Sports and Recreation (Sport) subscales. Morphology was defined using the anterior alpha angle (AA) and lateral center-edge angle (LCEA) as follows: mild to moderate cam (55°≤ AA < 78°), severe cam (AA ≥ 78°), pincer (LCEA > 39°), and borderline dysplasia (20°≤ LCEA < 25°). Joint space width (JSW) was defined as slightly reduced (3.1 mm ≤ JSW ≤ 4 mm) or severely reduced (2.1 mm ≤ JSW ≤ 3 mm). Acetabular cartilage status was defined by modified Beck grades 0 to 4 and femoral head cartilage status by International Cartilage Regeneration & Joint Preservation Society grades 0 to 4. Acetabular and femoral cartilage injury areas were categorized as <1, 1 to 2, or >2 cm2. Multiple regression analyses assessed adjusted associations between hip morphology and cartilage injuries with improvement in HAGOS-ADL and HAGOS-Sport. Results: The study included 281 patients (age, 35 ± 10 years; 52.3% female). No cam and mild-to-moderate cam were associated with greater improvement in HAGOS-ADL (16 points [ P = .002] and 7 points [ P = .038], respectively) compared with severe cam. Normal JSW was associated with greater improvement in HAGOS-ADL (21 points; P = .026) compared with severely reduced JSW. Femoral head cartilage injury area <1 cm2 was associated with greater improvements in HAGOS-ADL (17 points; P = .03) and HAGOS-Sport (21 points; P = .035) compared with femoral cartilage injury area >2 cm2. Conclusion: Patients having no-to-moderate cam morphology, normal JSW, or femoral head cartilage injury area <1 cm2 had greater improvement in PROs 5 years after hip arthroscopy compared with patients having severe cam morphology, severely reduced JSW, or femoral cartilage injury area >2 cm2.