OBJECTIVE: The aim of this study was to assess the early and long term functional and radiographic outcomes of pedicle subtraction osteotomy (PSO) in patients with fixed sagittal deformities. METHODS: The medical records and radiographs performed during the pre- and post-operative period of nine patients with fixed sagittal deformities caused by ankylosing spondylitis (4 patients), flat back post-arthrodesis (3 patients), adult kyphoscoliosis (1 patient) and pseudohypoparathyroidism (1 patient), were retrospectively reviewed. All patients were submitted to lumbar osteotomy (three at level L3 and two at level L2). Clinical data such as durotomy, neurologic injury, infection of the surgical wound, implant failure and pseudarthrosis were also assessed. Pre- and post-operative radiographic assessment was performed by measuring angles of thoracic kyphosis, lumbar lordosis and sagittal axis. RESULTS: In patients with lumbar osteotomy, final follow up radiographs showed an increase in lumbar lordosis from 14.6° to 44.7° (increase of 30°), whereas thoracic kyphosis remained stable from 46° to 48°. Sagittal imbalance reduced from 13.7 to 5.4mm, and thoracic kyphosis remained stable (48°). The mean time of surgery was 8 hours 10 minutes and mean bleeding was 2,460mL. No neurologic complications were found, but one patient showed durotomy and two patients showed wound infection requiring posterior surgical approach. CONCLUSIONS: Although the pedicle subtraction osteotomy requires great surgical skills and experience, due to the blood loss, long operative time and severe implications, this procedure reaches a significant improvement in sagittal imbalance as observed in ankylosing spondylitis and implications of previous surgeries.
Osteotomy; Kyphosis; Ankylosing spondylitis; Spinal Curvatures; Spinal Diseases
