Page 12 - Slipped Capital Femoral Epiphysis Pathogenetic and Clinical aspects

Chapter 1
Slipped capital femoral epiphysis (SCFE) is the most common non-traumatic hip disorder in adolescents, although its occurrence is rare. Sometimes it can be misdiagnosed as a traumatic femoral head fracture.
In SCFE, the physis is not strong enough to withstand the shear forces acting on the femoral head. This results in a displacement of the epiphysis relative to the metaphysis. The metaphysis shifts in an anterolateral and cranial direction and rotates externally. The epiphysis hereby remains in the acetabulum.
This disorder can lead to a restriction in movement and pain in the short term, and early symptomatic hip joint arthritis in the long term. It is also one of the few adolescent disorders that always needs surgical treatment to prevent an increase in slip of the femoral head, which can worsen the functional outcome. If left untreated, a deformity of the femoral head may gradually develop.
SCFE can compromise blood supply to the femoral head. The medial circumflex artery runs posteriorly of the femoral neck. A posteromedial displaced slipped femoral head may damage this artery which supplies the vascularity of the metaphysis and epiphysis. If the blood supply is impaired, avascular necrosis of the femoral head and neck can occur, leading to further deformity of the femoral head.
This thesis addresses different aspects of SCFE. The first question asked was whether the incidence of SCFE is increasing in the Netherlands? In the literature, results from other western countries (USA and Sweden) suggest an incidence of 10 to 80 cases per 100,000 population, compared to a much lower (but currently increasing) incidence of 1 to 2 per 100,000 in Singapore and Japan. In the Netherlands, all patients who are admitted to hospital are registered in the National hospitalization registration system (LMR). Two international classifications of disease codes, traumatic and the non-traumatic SCFE, were analyzed.
The second question of this thesis concerns the potential causes of a slip of the physes of the femoral head. The literature attributes slips to both biochemical and biomechanical causes. The slip occurs mostly in puberty, when the hormonal balance is changing in the body. Hypothetically, such hormonal imbalance could be the underlying cause of the slip. Although there is some histological research of the physis in SCFE, we are not aware of any published research about hormonal receptors in the physes in SCFE. To understand more about the hormonal imbalance, we reviewed the literature about which hormones could be involved
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