Instability of the hip after anatomical re-alignment in patients with a slipped capital femoral epiphysis

Abstract

Aims: Several studies have reported the safety and efficacy of subcapital re-alignment for patients with slipped capital femoral epiphysis (SCFE) using surgical dislocation of the hip and an extended retinacular flap. Instability of the hip and dislocation as a consequence of this surgery has only recently gained attention. We discuss this problem with some illustrative cases.

Materials and methods: We explored the literature on the possible pathophysiological causes and surgical steps associated with the risk of post-operative instability and articular damage. In addition, we describe supplementary steps that could be used to avoid these problems.

Results: The causes of instability may be divided into three main groups: the first includes causes directly related to SCFE (acetabular labral damage, severe abrasion of the acetabular cartilage, flattening of the acetabular roof and a bell-shaped deformity of the epiphysis); the second, causes not related to the SCFE (acetabular orientation and poor quality of the soft tissues); the third, causes directly related to the surgery (capsulotomy, division of the ligamentum teres, shortening of the femoral neck, pelvi-trochanteric impingement, previous proximal femoral osteotomy and post-operative positioning of the leg).

Conclusion: We present examples drawn from our clinical practice, as well as possible ways of reducing the risks of these complications, and of correcting them if they happen. Cite this article: Bone Joint J 2017;99-B:16-21.

Keywords: Hip dislocation; Joint instability; Slipped capital femoral epiphysis; Subcapital re-alignment.