Silent slipped capital femoral epiphysis in overweight and obese children and adolescents.

Abnormal loading of the hip in obese children may lead to anatomic alterations and an increased prevalence of slipped capital femoral epiphysis (SCFE). The aims of this study were to examine the hip motion in obese children and adolescents and to estimate the prevalence of SCFE in a subgroup of patients characterized by pathological clinical examination and/or pain in the knee or hip joint. A total of 411 individuals (196 males), mean age 14.5 ± 2.5 years (7.8-20.4), mean BMI of 32.9 ± 5.6 kg/m(2) (20.3-51.5, z score +2.65) who were consecutively admitted for an inpatient weight loss program were included in the study. Twenty-six percent of the patients had load-dependent and 11.7 % had load-independent pain in the knee joint. A total of 9.3 % had load-dependent and 4.7 % had load-independent pain in the hip joint. Two patients (0.5 %) underwent surgical treatment of SCFE prior to entry. A total of 18.2 % of the patients showed a reduced range of motion for hip flexion (<90°) and 18.5 % a pathological decreased internal rotation (<10°). Radiological evaluation of the hips in the clinically conspicuous subgroup (n = 54) revealed an abnormal head-neck ratio as a sign of prior silent slipped capital femoral epiphysis in 11 patients (20.4 % of the 54 patients, 2.7 % of total cohort). In conclusion, these data show a high prevalence of SCFE-like tilt deformities in a selected group of severely obese children. Mild deformation of the epiphysis at young age might be a major predisposing factor for the development of hip osteoarthritis in obese adults.