Using satellite rod around the osteotomy area in patients with severe spinal deformity undergoing three-column osteotomy

Objective To evaluate the feasibility and clinical outcomes of satellite rod technique utilized in severe spinal deformity undergoing three-column osteotomy. Methods Thirteen patients (6 males and 7 females) with an average age of 30.9±19.1 years from July 2012 to January 2014 were retrospectively reviewed. The coronal parameters including Cobb angle and distance between C7 plumb line and center sacral vertical line (C7PL-CSVL), as well as the sagittal parameters including global kyphosis (GK) and sagittal vertical axis (SVA) were measured pre-operatively, post-operatively and at last follow-up. The Short Form-36 Health Survey (SF-36) was fulfilled at pre-operation and each follow-up. The paired t test was used to analyze the differences among pre-operation, post-operation and last follow-up. Results The average follow-up period was 15.8±3.8 months. The pre-operative and post-operative Cobb angles were 86.3°±22.6° and 45.2°±19.7°. The correction rate of Cobb angle was 47.7%±19.1%. At the last follow-up, the average Cobb angle was 39.9°±19.8° with no significant loss of correction. The pre-operative, post-operative and last follow-up C7PL-CSVL were 43.7±36.8 mm, 18.8±5.6 mm and 19.2±8.3 mm, respectively. Significant post-operative improvement was observed while there was no change at last follow-up. Post-operative GK significantly improved from 80.9°±18.7° to 35.1°±14.5° with the correction rate of 57.8%±13.8%. SVA decreased significantly from 55.0±51.5 mm to 29.3±19.5 mm. The average GK and SVA at last follow-up were 36.3°±10.0° and 34.2±17.5 mm, and no loss of correction was found. In addition, no change or loss of motor or somatosensory evoked potential occurred during surgery. In spite of two malposition screws, no other complications of implant failure were found during follow-up. Conclusion The satellite rod used in patients with severe spinal deformity undergoing three-column osteotomy could disperse stress of each rod and get satisfied clinical outcomes. With the utilization of satellite rod technique, the coronal and sagittal balance could be well maintained during follow-up. Key words: Scoliosis; Kyphosis; Osteotomy; Postoperative complications