置钉矫形治疗肌营养不良导致的颈椎侧前凸畸形一例报告

Pedicle screw placement treated cervical lateral lordosis deformity in muscular dystrophy: 1 case report

肌营养不良和脊柱畸形的诊治正成为脊柱外科医生的一项重大挑战。肌营养不良患者的脊柱畸形以胸段或腰段侧凸最常见。但是,颈椎的过伸或侧凸都很罕见。关于治疗颈椎过伸的文献报道很少。目前,已发表的相关病例报道为数不多。1988年,Giannini等[1]报道了第1例手术治疗颈椎过伸的病例。2005年至2006年,其又报告了7例共2个系列的病例[2-3]。

Objective To present one case of lateral cervical lordosis deformity treated by surgical correction using navigated pedicle screw placement. Methods A 19-year-old male patient with Emery-Dreyfus muscular dystrophy underwent surgical correction using navigated pedicle screw placement. The MRI scanning of the spine showed no abnormalities of the spinal cord. The MRI of extremities revealed a decrease in the muscle mass, and fatty infiltration in the biceps femoris and semimembranosus muscles bilaterally, consistent with the muscle dystrophy pattern. The cardiac function of the patient was evaluated by electrocardiography and echocardiography, and the results were normal. The respiratory function was evaluated by spirometry, which showed restrictive ventilatory defects, however, the arterial O2 saturation was normal. The laminas of vertebrae C2-T5 were bilaterally exposed. Traction or detachment of the interspinous ligament had not been applied. During the exposure, the neck hyperextension was gradually neutralized due to both the muscle release and gravity. Pedicle screws were bilaterally inserted at C2, C5, and T1-5 levels under navigation guidance. Lateral mass screws were bilaterally inserted at C3, C4, and C6. A special rod on the convex side was placed, then the rod was derotated. At the same time, an assistant pressed the head to bend the neck into a neutralized position. The screw nuts were then locked on the convex side. Meanwhile, the rod on the concave side was instrumented, and all the screw nuts were locked. Routine wound closure was performed and postoperative radiographs were taken. Results The surgery took 320 minutes. Blood loss was 600 ml. No surgical complications occurred. Both the cervical hyperextension and scoliosis were significantly corrected. After surgery, the patient＇s trunk had been well balanced on both frontal and sagittal view. And he was able to walk in an upright position with looking straight ahead on his own accord. The scoliotic curve was corrected from 35.0° to 6.2°, and the hyperextension was corrected from 56.6° to 24.5°. Conclusions Cervical deformity associated with muscular dystrophy is rare. Posterior cervical muscle release and instrumented fusion are effective for correcting such deformities. The selection of candidates for surgery depends mainly on the type of myopathy and cardiorespiratory function. Preoperative CT scans of patients should be thoroughly analyzed and close attention should be paid to the pedicle diameter.