[Slipped proximal femoral epiphysis in adolescents. Risk factors]

The slipped capital femoral epiphysis (SCFE) is a fracture that occurs through the growth cartilage and causes slippage inside and under the proximal femoral epiphysis. The objective of this study was to determine whether the variables obesity, trauma and intense physical activity are associated with SCFE. A 32-item questionnaire was designed, in which weight, size and body mass index (BMI) were also reported.

Case and control study conducted from November 2009 to November 2010 at IMSS Trauma and Orthopedics Hospital #21. Inclusion criteria for cases were as follows: patients ages 9-16 years, with a diagnosis of SCFE made with anteroposterior (AP) and lateral hip X-rays, who answered a questionnaire and with weight and size measurements. Inclusion criteria for controls were as follows: students ages 10-16 years who answered the same questionnaire and had measurement of the same parameters.

Mean age, weight, and BMI in cases were 11.9 years, 69.16 and 27.5 kg, respectively, and 12.74 years, 55.53 and 21.49 kg in controls. A BMI above percentile 95 was a risk factor for SCFE, with an odds ratio of 17.8 and a confidence interval (CI) of 1.69 to 3.97. The same was observed for trauma as a risk factor for SCFE, with an odds ratio of 5.2 and a CI of 1.36-2.74. Male gender was another risk factor. A significant chi square was found in cases with a p = 0.05. Intense physical activity was not a risk factor for SCFE, with a 0.58 odds ratio. The difference in mean weight between cases and controls was significant in the t test with p = 0.05.

Obesity and trauma were associated with SCFE; physical activity was not. Given the increasing incidence of obesity, the orthopedic surgeon should be familiar with and have available percentile tables for early detection of obesity, and should educate the patients in whom this condition is detected to prevent SCFE and its complications.