Two-stage posterior-only procedures for correction of severe spinal deformities.

PURPOSE: To review the outcomes of surgical treatment for severe spinal deformities via a two-stage posterior-only approach. METHODS: A total of 18 patients with large and rigid spinal deformities were studied based on clinical and radiographic data. All of them received a two-stage posterior-only approach: first on the concave side by internal distraction of pedicle screws and rods through intramuscular tunnels, followed by respiratory function exercise and improving nutritional status during the intervening period, and finally by posterior additional correction, ultimate instrumentation and spinal fusion in the second operation. RESULTS: The mean major coronal curve was corrected by 46% after the first operation and by 60.4% after the second operation. The mean thoracic kyphosis was corrected by 50.9% after the first operation and by 64.8% after the second operation. The loss of correction mean was 3.3° for the major coronal curve and 2.6° for the thoracic kyphosis at a mean of 31.5 months follow-up. The mean operation time for the first and second operation was 186.2 and 300.6 min, and the mean intraoperative blood loss was 211.1 and 1,597.2 mL, respectively. No severe complication was noticed in this series. CONCLUSIONS: The two-stage posterior-only procedures permitting stepwise correction for the treatment of severe spinal deformities provide safe and satisfactory outcomes in this patient population.