To assess the profile of weight-bearing cartilage of hips with a cam deformity using T1ρ magnetic resonance imaging (MRI) and evaluate for a side-to-side difference in the T1ρ profile of patients with bilateral cam morphology but only unilateral hip pain.
19 patients with bilateral cam morphology undergoing osteochondroplasty for unilateral hip pain were prospectively recruited. Anterior and anterosuperior alpha angles were measured using computer tomography. All patients underwent bilateral 1.5T T1ρ MRI. The cartilage bilayer of the hip joint was evaluated and the mean T1ρ relaxation time calculated for each quadrant of the weight-bearing surface.
Mean T1ρ relaxation times were not significantly different when each quadrant was compared to the rest of the weight-bearing surface of the symptomatic (P = 0.068) and asymptomatic hips (P = 0.102). There was also no significant side-to-side difference between the same quadrants of symptomatic and asymptomatic hips. No correlation was detected between alpha angle and the mean T1ρ relaxation time in each quadrant. There was no significant difference in mean alpha angles between the symptomatic and asymptomatic sides at the anterior (54.2 vs 56.0°; P = 0.382) and anterosuperior positions (65.1 vs 65.2°; P = 0.971).
We conclude that previously observed regional variation in T1ρ values of normal hips is altered in hips with cam morphology. No difference in T1ρ values between symptomatic and asymptomatic cam hips was demonstrated. Therefore, regardless of the presence of hip pain, a cam deformity may predispose to hip joint cartilage degradation and increase the risk of hip osteoarthritis.