Dropped head deformity due to cervical myopathy - Surgical treatment outcomes and complications spanning twenty years

Study Design. Case series. Objective. Report long-term outcomes, complications, and surgical technique of cervical myopathy (CM) patients treated with posterior instrumented, cervico-thoracic (C-T) fusions. Summary of Background Data. CM is a rare, progressive, debilitating condition where weakness of neck extensor muscles results in a dropped head deformity (DHD), or severe flexible, cervico-thoracic kyphosis. Treatment algorithms are currently based on small case reports and only 1 patient's short-term surgical outcome. Methods. Re-examination at follow-up, chart review, and radiographic analysis was carried out for all CM patients with DHD treated by the senior author. Additional outcome measures included Odom criteria, verbal rating scores for pain, and patient satisfaction ratings. Patients with less than 2-years follow-up, previous cervical spine surgery or intrinsic, structural spinal deformities were excluded. Results. Nine CM patients met the study inclusion criteria with average follow-up of 6 years (range, 2-17 years) and average age 67 years. Four primary and 5 secondary myopathies after radiotherapy underwent deformity correction and posterior arthrodesis with instrumentation from the second cervical level to the upper thoracic spine. Patient presentation, deformity correction, and surgical techniques are described. All pain ratings improved, satisfaction was excellent in 7 and fair in 2 patients, and Odom scores were good to excellent in 7 and fair in 2 patients. Shoulder weakness remained equivalent or improved after surgery and all ambulated independently, though 1 continued to use a walker. Eleven postoperative complications are described. Conclusion. Surgical correction with posterior, instrumented C-T spinal fusion is associated with high patient satisfaction rates in CM patients with DHD. Complications are frequent but do not diminish long-term outcomes. New rod and screw instrumentation with bone morphogenic protein may improve arthrodesis and correction.