The use of three rods in correcting severe scoliosis

Purpose: The three-rod technique, utilising a short apical concavity rod is an option to achieve controlled correction in severe scoliosis. We describe this technique, the complications encountered, and the long-term outcomes. Method: All paediatric patients who had at least 2 years follow-up after undergoing corrective surgery for scoliosis ≥ 100° using 3 parallel rods were included. Radiographs were assessed to evaluate the correction and clinical records examined for any loss of correction, complications, revision procedures or neuromonitoring events. Results: Twenty-five patients met the inclusion criteria. Four underwent prior anterior fusion to prevent crankshaft phenomenon. The mean angle of the deformity was 112.0° (range 100.3–137.1). Mean maximal kyphosis was 48.8° (range 11.4–78.8°) and mean curve flexibility 4.4% (range 0–37.0%). Intraoperative traction achieved an average of 70.4% (95% CI 56.6–84.1%). Nine patients (39%) showed a reduction in MEPs during definitive surgery. All returned to within 75% of baseline by the end of surgery. All patients had normal postoperative neurology. One patient underwent removal of hardware for late infection. The mean overall Cobb correction was 55.7° (95% CI 50.2–61.2°), equating to 50.2% (95% CI 44.9–55.4%) of the mean initial deformity. Thoracic kyphosis reduced by a mean of 18.2° (95% CI 12.8–23.6°). Conclusion: Our series suggests that three-rod constructs are able to safely and effectively achieve 50% correction of severe scoliosis.