Pedicle Subtraction Osteotomy for

STUDY DESIGN: A description of pedicle subtraction osteotomy for correction of kyphotic deformity of the cervical-thoracic spine and a prospective evaluation of the surgical outcomes. OBJECTIVES: To describe the surgical technique and the postoperative results of pedicle subtraction osteotomy in the upper thoracic spine and the cervical-thoracic junction. SUMMARY OF BACKGROUND DATA: Pedicle subtraction osteotomy (PSO) is used in reconstructive spine surgery to facilitate correction of spinal deformities in the sagittal plane. Interlaminar “SmithPeterson” osteotomies allow for correction over several spinal segments and have been utilized to correct sagittal plane deformities at spinal cord levels (i.e. cervical and thoracic levels). This technique requires an intact anterior motion segment or an anterior osteotomy if there is a preexisting anterior column fusion. PSO allows for significant correction through a single vertebral level and is a welldescribed technique for restoration of sagittal balance below cord level. PSO is a “shortening” osteotomy and may be safely used in the cervical-thoracic spine. METHODS: Three patients (2 male, 1 female; mean age 50 years) underwent pedicle subtraction osteotomy for kyphotic deformities of the upper thoracic spine or cervical-thoracic junction. Surgical indications included post laminectomy kyphosis, following spinal cord tumor resection, post-traumatic kyphosis and cervical-thoracic junctional kyphosis due to degenerative cervical spondylosis. Prospectively collected data was reviewed to document early postoperative results for this procedure. RESULTS: Mean follow up is 15.3 months (range 12 to 20 months). Average preoperative kyphosis was -55.6 degrees (range -38 to -70 degrees) at the cervical thoracic junction. Clinically satisfactory correction of deformity was accomplished in all patients. Mean correction was 23 degrees (range 15 to 30 degrees) after PSO. CONCLUSIONS: Kyphotic deformities of the cervical-thoracic junction, causing chin-on-chest deformity, are difficult problems to correct and require complex spinal reconstructive techniques to restore sagittal balance and allow forward gaze. PSO allows for significant correction through one spinal segment and may be used safely to achieve sagittal balance. PSO may be used alone or in combination with other