Use of Wheelchair Is a Risk Factor for Fracture in Muscular Dystrophy Patients

Results from a recent study published in the Journal of Pedriatric Orthopaedics showed full-time wheelchair use is a risk factor of first fracture among pediatric male patients with Duchenne or Becker muscular dystrophy. However, no correlation was found between fracture and corticosteroid use in these patient populations.

Muscular dystrophies (MDs) refer to a group of inherited diseases in which muscles are affected and muscle strength is weakened. Duchenne muscular dystrophy (Duchenne MD) is the most well-known form, whereas myotonic dystrophy is the most common. The age of onset varies between different MDs, whereby congenital MD is diagnosed early after birth, Duchenne and Becker MD during childhood and other types of MD, like myotonic dystrophy, regularly during adulthood. The diseases are caused by defects in several genes encoding for muscle function.

Fractures are a substantial problem for patients with Duchenne/Becker muscular dystrophy with 21% to 44% of males experiencing a fracture. To address this unmet issue, in the study titled “Risk Factors for First Fractures Among Males With Duchenne or Becker Muscular Dystrophy,” Katherine James, PhD and colleagues conducted retrospective research using the Muscular Dystrophy Surveillance, Tracking and Research Network cohort, a large, population-based sample to identify risk factors related with first fractures in patients with Duchenne or Becker muscular dystrophy. A total of 747 male patients with Duchenne or Becker muscular dystrophy who were born between 1982 and 2006 from Colorado, Iowa, Arizona, Georgia and western New York were identified.

To determine the risk factors associated with first fracture, the researchers used the multivariate Cox proportional hazard model. The risk factors included in the statistical analyses included race/ethnicity, surveillance site, status of ambulation, use and duration of calcium/vitamin D, use and duration of bisphosphonates, and use and duration of corticosteroids.

The results revealed that of the 747 cases, 249 patients had at least 1 fracture (33.3%). These patients had a mean age of 11.3 years at the time of fracture. There were 264 fractures overall, and 14 simultaneous incidences of fracture. The results also showed that full-time wheelchair use increased the risk of first fracture by 75% for every 3 months of use, but corticosteroid use, bisphosphonate use, and calcium/vitamin D use did not affect risk in the final statistical model.