Orthopaedic aspects of central core disease.

We studied the cases of fifteen patients who had central core disease, a non-progressive congenital myopathy that is usually inherited as an autosomal dominant trait. As infants, the patients had poor muscle tone and developmental delay, and as adolescents and adults, they had varying degrees of proximal muscle weakness and tended to use the Gower maneuver. The most common musculoskeletal problems were dislocation or subluxation of the hip, pes planus, and hypermobility of the joints. The most serious orthopaedic problems were in the hips: ten patients had a total of nine dislocations and six subluxations, nine being present at birth and six developing later. Only nine hips were stable after the initial treatment, and there was a propensity for hip-joint contractures. Scoliosis and patellar instability were also seen. Although patients who have central core disease have been reported to be at increased risk for malignant hyperthermia, this did not occur in our patients.