Fractures in Hereditary Neuromuscular Disorders: Frequency, Risk Factors, and Implications

Hereditary neuromuscular disorders (NMD) are associated with compromised bone health and elevated fracture risk, though data are largely lacking.

This study aimed to assess the prevalence and risk factors of fractures in hereditary NMD.

We conducted a retrospective study in a cohort of adult patients with diverse hereditary NMD, using data from electronic medical records.

Among 469 patients, 505 fractures were recorded, with 5.5% of patients experiencing a fracture within the past year. In the 10 years preceding study inclusion, 31.1% of all patients sustained at least one fracture. The fracture rate was 47.3/1000 patient-years. Fracture incidence was highest in the second decade of life and the first five years after symptom onset. Fracture recurrence occurred in 25.6% over the next two years. Fractures were most prevalent in patients with Duchenne muscular dystrophy, myotonic dystrophy type 1/2, and spinal muscular atrophy. Patients with Vignos scale 5-6 had the highest fracture risk. Major osteoporotic fractures accounted for 28.6%, and 71.3% were caused by low-energy trauma. Long-term complications of a fracture were present in 44.2%, with 9.0% losing ambulation. Osteoporosis was confirmed in 47.5% of DXA scans. In patients with a normal DXA scan, 66.7% experienced a subsequent fracture. Hip T-scores declined with increasing Vignos scale (r = -0.27, p = 0.001). Fracture risk factors included glucocorticoid use, alcohol abuse, recent falls, and previous emergency visits for falls (all p < 0.05).

This cohort exhibited a high prevalence of fractures and osteoporosis, emphasizing the need for regular bone health assessment and fracture prevention in hereditary NMD patients.