The pathogenetic influence of I-parathyroid hormone on slipped capital femoral epiphysis. Towards a new etiologic approach?

The displacement of the femoral head along the upper femoral physis that occurs during adolescence or slipped capital femoral epiphysis (SCFE) is not a very common traumatic entity. Ever since Muller1 first described it in 1888, its symptoms, clinical manifestations, diagnosis, treatment and complications have been thoroughly described and studied. Nevertheless little progress has been accomplished as far as its etiology is concerned. In order to assess the potential pathologic influence of any parathyroid hormone (PTH) disturbances on the development of SCFE, we conducted a prospective clinical study with 14 patients, 7 boys and 7 girls (16 hips), suffering from SCFE (Group A). Another 5 patients who had been treated for SCFE a few years before the study, were used as a control group (Group B). We measured the level of I-PTH along with serum calcium (Ca) and phosphorus (P) levels. Furthermore, we checked all the necessary anthropometric characteristics of the patients (i.e., age, height, weight and sexual maturation). Each patient of Group A was categorized from grade I to grade V according to the progress of the slipping. The results showed an increased incidence of serum PTH level abnormalities (both decrease and increase) in Group A while Group B patients had normal results. The detected I-PTH serum level abnormalities were not in any pattern related to the Ca and P serum levels. We believe that a temporary parathyroid hormone disorder during the early years of adolescence may play a potentially significant role (along with other etiologic factors) in the development of SCFE.