Delayed gadolinium-enhanced magnetic resonance imaging of cartilage in the long-term follow-up after Perthes disease.

BACKGROUND

Aim of this study was to assess the glycosaminoglycan content in hip joint cartilage in mature hips with a history of Legg-Calvé-Perthes (LCPD) disease using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC).

METHODS

Thirty one hips in 27 adults (mean age: 30.5+/-10.9 y) with LCPD in childhood were included. Mean follow-up after diagnosis was 24.5+/-11.4 years. Clinical symptoms and standard radiographic parameters were evaluated. dGEMRIC indices were calculated as T1(Gd) mean values in four coronal MRI slices medially, centrally, and laterally. For comparison, the morphologically normal appearing contra-lateral hips (21 hips) were assessed.

RESULTS

The following T1(Gd) values for the LCPD group were noted: medial (507+/-100 ms), central (543+/-104 ms), and lateral (553+/-105 ms). The total T1(Gd) mean value was 534+/-104 ms. The difference between LCPD and normal hips was statistically significant only for the medial compartment (P=0.018).

CONCLUSIONS

Hip joint cartilage after LCPD shows a significant glycosaminoglycan loss in the medial compartment while this decrease is less apparent centrally and laterally. dGEMRIC allows direct assessment of cartilage matrix biochemistry and may depict the complex damage pattern of hip joint cartilage after LCPD spatially and qualitatively better than other radiographic methods.

LEVEL OF EVIDENCE

Prognostic study, Level II-1 (retrospective study).