Turner Syndrome (Orthopaedic Manifestations)

The combination of a short-statured girl with cubitus valgus, short fourth metacarpals and a Madelung deformity points to Turner syndrome, and the mechanism behind these skeletal features is haploinsufficiency of the SHOX, or short-stature homeobox, gene, which is located in the pseudoautosomal region of the X chromosome and is lost or reduced in the 45,X karyotype and its variants. The same SHOX deficiency causes the comparable skeletal features in Leri-Weill dyschondrosteosis. The classic skeletal signature also includes genu valgum, short fifth metacarpals, a high-arched palate, a short webbed neck and a shield chest. My orthopaedic priorities are, first, to recognise the pattern and ensure the diagnosis is confirmed and the multidisciplinary team is involved, because Turner syndrome is multisystem with cardiac, including aortic, renal and endocrine, involvement. Second, I would screen for and monitor spinal deformity, since scoliosis and kyphosis are more common, especially through growth. Third, I would attend to bone health, because bone mineral density is often reduced, related in part to the oestrogen deficiency of ovarian failure, with an increased fracture risk, so optimising oestrogen replacement, vitamin D and calcium and weight-bearing activity matters. The skeletal features interface with endocrine therapy - growth-hormone treatment is used to improve final height and oestrogen for puberty and bone - and I would treat significant deformities, such as a symptomatic Madelung deformity or genu valgum, on their merits within that context.