Surgical management of severe scoliosis with high risk pulmonary dysfunction in Duchenne muscular dystrophy: patient function, quality of life and satisfaction

Abstract

In a previous study, the authors reported the clinical and radiological results of Duchenne muscular dystrophy (DMD) scoliosis surgery in 14 patients with a low FVC of <30%. The purpose of this study was to determine if surgery improved function and QOL in these patients. Furthermore, the authors assessed the patients' and parents' satisfaction. %FVC increased in all patients after preoperative inspiratory muscle training. Scoliosis surgery in this group of patients presented no increased risk of major complications. All-screw constructions and fusion offered the ability to correct spinal deformity in the coronal and pelvic obliquity initially, intermediate and long-term. All patients were encouraged to continue inspiratory muscle training after surgery. The mean rate of %FVC decline after surgery was 3.6% per year. Most patients and parents believed scoliosis surgery improved their function, sitting balance and quality of life even though patients were at high risk for major complications. Their satisfaction was also high.

Fig. 1

Pulmonary trainer (Threshold IMT, Philips Respironics, Inc., Murrysville, PA, USA) provides consistent and specific pressure for inspiratory muscle strength and endurance training, regardless of how quickly or slowly patients breathe. This device incorporates a flow-independent one-way valve to ensure consistent resistance and features an adjustable specific pressure setting (in cm H₂0) to be set by a healthcare professional. When patients inhale through Threshold IMT, a spring-loaded valve provides a resistance that exercises respiratory muscles through conditioning

Fig. 2

An 11-year-old boy being trained with inspiratory muscle training by a pulmonary trainer (Threshold IMT)

Fig. 3

a, b A 13-year-old boy with DMD. Anteroposterior radiograph shows severe scoliosis of 93° with significant pelvic obliquity of 20°. Thoracic hypokyphosis and lumbar hyperlordosis were present. c, d All-screw constructs and fusion to L5 were performed. Postoperative sitting views show significant coronal curve correction of 20° with normalization of sagittal plane. Pelvic obliquity improved to 5°

Fig. 4

Changes in %FVC are demonstrated. After preoperative respiratory muscle training for six weeks, %FVC increased in all patients. All 14 patients underwent surgical correction of scoliosis successfully without any complications. At six weeks after operation, %FVC remained stable or increased slightly. %FVC decreased in all patients at one year, two years after operation and at the last follow-up. The average rate of decline of %FVC was 3.6% per year at the last follow-up