Correction of late traumatic thoracic and thoracolumbar kyphotic spinal deformities using posteriorly placed intervertebral distraction cages.

Abstract

To assess the safety and stability of thoracic or thoracolumbar deformity correction from a solely posterior approach with placement of modular anterior cages and posterior segmental fixation in one operation. Twenty-eight patients who failed brace trial for 6 months or longer were included in the series. All patients had progressive neurological deficit and/or deformity progression at time of operation. All patients underwent a single operation in the prone position. Segmental fixation was accompanied by anterior column reconstruction using modular cages avoiding nerve root sacrifice. Stackable cages were used for high thoracic deformity. Deformity, Cobb angle, visual analog pain score, and x-ray evaluation of fusion ensued for mean follow-up period of 31 months. Patients achieved a mean sagittal deformity correction of 13.3 degrees +/- 7.4 standard deviation. Improved or maintained American Spinal Injury Association scores were noted in all patients. The mean time of operation was 334 minutes +/- 85 standard deviation, or 6 to 7 hours. At a mean follow-up of 31 months (range, 12-36 mo), the following complications were noted: subsidence greater than 2.5 mm (n = 3), cage migration requiring revision (n = 1), brachial plexopathy from malpositioning (n = 1), and intraoperative cerebrospinal fluid leak managed via lumbar drain (n = 2). Plain and dynamic radiographic evidence of maintained deformity correction was noted in 27 patients. Delayed kyphotic deformity correction of the thoracolumbar spine is achieved via a posterior-only approach. At a mean follow-up period of 31 months, sagittal angles remained acceptable. Improved fusion criteria and patient numbers will be required to determine fusion and loss of correction rates over time.