Progression of spinal deformity in wheelchair-dependent patients with Duchenne muscular dystrophy who are not treated with steroids

Abstract

We determined the frequency, rate and extent of development of scoliosis (coronal plane deformity) in wheelchair-dependent patients with Duchenne muscular dystrophy (DMD) who were not receiving steroid treatment. We also assessed kyphosis and lordosis (sagittal plane deformity). The extent of scoliosis was assessed on sitting anteroposterior (AP) spinal radiographs in 88 consecutive non-ambulatory patients with DMD. Radiographs were studied from the time the patients became wheelchair-dependent until the time of spinal fusion, or the latest assessment if surgery was not undertaken. Progression was estimated using a longitudinal mixed-model regression analysis to handle repeated measurements. Scoliosis ≥ 10° occurred in 85 of 88 patients (97%), ≥ 20° in 78 of 88 (89%) and ≥ 30° in 66 of 88 patients (75%). The fitted longitudinal model revealed that time in a wheelchair was a highly significant predictor of the magnitude of the curve, independent of the age of the patient (p < 0.001). Scoliosis developed in virtually all DMD patients not receiving steroids once they became wheelchair-dependent, and the degree of deformity deteriorated over time. In general, scoliosis increased at a constant rate, beginning at the time of wheelchair-dependency (p < 0.001). In some there was no scoliosis for as long as three years after dependency, but scoliosis then developed and increased at a constant rate. Some patients showed a rapid increase in the rate of progression of the curve after a few years - the clinical phenomenon of a rapidly collapsing curve over a few months. A sagittal plane kyphotic deformity was seen in 37 of 60 patients (62%) with appropriate radiographs, with 23 (38%) showing lumbar lordosis (16 (27%) abnormal and seven (11%) normal). This study provides a baseline to assess the effects of steroids and other forms of treatment on the natural history of scoliosis in patients with DMD, and an approach to assessing spinal deformity in the coronal and sagittal planes in wheelchair-dependent patients with other neuromuscular disorders.

European Cross-Sectional Survey of Current Care Practices for Duchenne Muscular Dystrophy Reveals Regional and Age-Dependent Differences

“…The current life expectancy of≥30 years [16, 17] and a mean “late-ambulatory II” age of 19 years from our data indicate patients spend >10 years with impaired hand function, emphasising the importance of preventive and therapeutic measures to maintain hand function [14, 18]. Sitting ability facilitates mobility, social participation, eating, and eye-level communication, but becomes impaired by scoliosis, a frequent complication in non-ambulatory DMD patients [19, 20]. Standards recommend regular monitoring and surgical correction for scoliosis in non-ambulatory patients [4].…”

Duchenne muscular dystrophy: the management of scoliosis

“…In those at high risk of a rapid deterioration, it is suggested that surgery should be performed once the curve progresses beyond 20° (34). In some patients, surgery may not be required if at skeletal maturity, the rate of scoliosis progression plateaus (24).…”

Growth Hormone Increases Bone Toughness and Decreases Muscle Inflammation in Glucocorticoid-Treated Mdx Mice, Model of Duchenne Muscular Dystrophy

“…(5) More commonly, changes in bone health result in the development of kyphosis and scoliosis that compromise posture, often resulting in a cascade of vertebral fractures and exacerbation of respiration difficulties in DMD patients. (6) Poor bone health is thought to result partly from a lack of proper mechanical loading on bone, (3) as well as chronic inflammation in dystrophic muscle that can stimulate osteoclastogenesis and bone resorption (4) and may also contribute to delayed bone fracture healing. (7) There is also persistent vitamin D insufficiency in most DMD patients (8) that may affect bone health.…”