Hip Instability in Adolescent/Young Adult Down Syndrome
The incidence of acetabular dysplasia in the skeletally mature Down syndrome patient population ranges from 8 to 25%, while hip subluxation or dislocation occurs in 1–7%. The morphology of the dysplastic acetabulum in a Down syndrome patient may be similar to idiopathic developmental dysplasia of the hip, with either global or anterior hypoplasia. A distinct subtype of acetabular dysplasia common in trisomy 21 is that of a deficient posterior wall with acetabular retroversion. The instability associated with a dysplastic hip in trisomy 21 is further compounded by generalized hypotonia, ligamentous laxity, and frequently cognitive delays. Untreated hip instability leads to early-onset osteoarthritis and hip pain in young adulthood. With increasing life expectancy in the Down syndrome patient population, the prevention of early osteoarthritis and associated hip pain with maintenance of functional hip range of motion is key to maximizing quality of life. Traditionally, hip instability in Down syndrome has been treated with multiple surgical interventions, including proximal femoral osteotomy, acetabular osteotomies (shelf, innominate, Sutherland, Chiari), and capsular plication with variable results. More recently, a Bernese periacetabular osteotomy (PAO) has demonstrated promising clinical outcomes in treating hip instability in the skeletally mature Down syndrome patient. The following case demonstrates unilateral hip instability in a Down syndrome patient who achieved good functional and radiographic outcomes after PAO.
KeywordsDown syndrome Trisomy 21 Hip instability Young adult Periacetabular osteotomy (PAO)
- Schrader T, Millis MB. Ganz periacetabular osteotomy. In: Morrissy RT, Weinstein SL, editors. Atlas of pediatric orthopaedic surgery. 4th ed. Philadelphia: Lippincott Williams and Wilkins; 2005. p. 319–27.Google Scholar