2016, Number 2
Rev Mex Ortop Ped 2016; 18 (2)
Radiographic and MRI findings associated with early degenerative joint disease of the hip in patients with Legg-Calvé-Perthes disease
Castańeda P, Serrano-Ardila AM, Vidal RC, Mijares J
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ABSTRACTObjective: To identify a pattern of radiographic outcomes and Magnetic Resonance Imaging (MRI) findings in patients with the late sequelae of Legg-Calvé-Perthes disease (LCPD) leading to degenerative arthritis. Methods: 78 patients (88 hips) were classified into 3 groups according to the radiographic outcome at skeletal maturity: Group 1- Spherical congruency (n = 8), Group 2- Non-spherical congruency (n = 76) and Group 3- Incongruency (n = 4). MRI were obtained in 24 patients in Group 2, the presence of a labral injury was considered. We used the Tönnis scale to determine the presence of early degenerative arthritis at a minimum 10 year follow up. The Mann-Whitney U and Wilcoxon tests were used for statistical analysis. Results: Of the 8 hips in Group 1, 6 were considered Tönnis type 0 and 2 as type I (mean = 0.25). Of the 76 hips in Group 2, 4 were considered Tönnis type 0, 14 type I, 13 type II, 25 type III and 18 type IV (mean = 2.9). All 4 hips in Group 3 were considered Tönnis type IV. Of the 24 cases where an MRI was obtained in Group 2, 18 cases were found to have a labral tear, of these 18 hips, 6 were considered Tönnis type III and 12 as type IV. Univariate analysis demonstrated that joint incongruity and the presence of a labral tear were associated with signs of degenerative arthritis. Conclusion: The classification of hips in patients with LCPD into 3 Groups at skeletal maturity: 1. Spherical congruency, 2. Aspherical congruency and 3. Incongruency and the finding of a labral tear identifies patients at a higher risk of developing degenerative joint disease. Significance: The early radiographic and MRI patterns observed will allow surgeons to make better decisions in counselling their patients with LCPD.