BackgroundFemoroacetabular impingement (FAI) can lead to labral and articular cartilage injuries as well as early osteoarthritis of the hip. Currently, the association of patient symptoms with the progression of labral and articular cartilage injuries due to FAI is poorly understood.
PurposeTo evaluate the correlation between patient-reported outcome (PRO) scores and cartilage compositional changes seen on quantitative magnetic resonance imaging (MRI) as well as cartilage and labral damage seen during arthroscopic surgery in patients with FAI.
Study designCohort study; Level of evidence, 3.
MethodsPatients were prospectively enrolled before hip arthroscopic surgery for symptomatic FAI. Patients were included if they had cam-type FAI without radiographic arthritis. All patients completed PRO scores, including the Hip disability and Osteoarthritis Outcome Score (HOOS) and a visual analog scale for pain. MRI with mapping sequences (T1ρ and T2) on both the acetabular and femoral regions was performed before surgery to quantitatively assess the cartilage composition. During arthroscopic surgery, cartilage and labral injury grades were recorded using the Beck classification. Pearson and Spearman correlation coefficients were then obtained to evaluate the association between chondrolabral changes and PRO scores.
ResultsA total of 46 patients (46 hips) were included for analysis (mean age, 35.5 years; mean body mass index [BMI], 23.9 kg/m2; 59% male). Increasing BMI was correlated with a more severe acetabular cartilage grade (ρ = 0.37; 95% CI, 0.08-0.65). A greater alpha angle was correlated with an increased labral tear grade (ρ = 0.59; 95% CI, 0.37-0.82) and acetabular cartilage injuries (ρ = 0.61; 95% CI, 0.42-0.80). With respect to PRO scores, increasing femoral cartilage damage in the anterosuperior femoral head region, as measured on quantitative MRI using T1ρ and T2 mapping, correlated with lower (worse) scores on the HOOS Activities of Daily Living (r = 0.35; 95% CI, 0.06-0.64), Symptoms (r = 0.32; 95% CI, 0.06-0.57), and Pain (r = 0.31; 95% CI, 0.06-0.55) subscales. There was no correlation between PRO scores and acetabular cartilage damage or labral tearing found on quantitative MRI or during arthroscopic surgery.
ConclusionFemoral cartilage damage, as measured on T1ρ and T2 mapping, appears to have a greater correlation with clinical symptoms than acetabular cartilage damage or labral tears in patients with symptomatic FAI.