Satellite rod technique around rod-breaking area in revision surgery after three-column osteotomy

Abstract

Objective To evaluate the feasibility and clinical outcomes of satellite rod technique used around the rod-breaking area in the revision surgery due to rod fracture after three-column osteotomy. Methods 11 patients (7 males and 4 females) applying satellite rod technique from December 2012 to March 2015 were retrospectively reviewed. The average age of the cohort was 27.3 years and the average duration of follow-up after revision surgery was 19.0 months. The coronal parameters including Cobb angle and distance between C7 plumb line and center sacral vertical line (C7PL-CSVL), and the sagittal parameters including global kyphosis (GK) and sagittal vertical axis (SVA) were assessed at pre-revision, post-revision and last follow-up. The paired t test was used to analyze the difference among pre-operation, post-operation and last follow-up. Results The Cobb angles of pre-revision and post-revision were 38.4°±21.1° and 32.0°±19.9°. The average correction rate was 20.3%±14.4%. At last follow-up, the average Cobb angle was 31.4°±18.8°, no significant loss of correction. Post-revision C7PL-CSVL changed from (19.0±19.7) mm to (20.1±14.7) mm, of which the average value was (20.4±20.4) mm at last follow-up. The pre-revision and post-revision values of GK were 23.8°±24.8° and 19.0°±22.1° with the average correction rate being 23.7%±19.0%. At the last follow-up, the average GK was 19.8°±20.1° and the correction was well maintained. In terms of SVA, average (51.2±40.1) mm for pre-revision, (30.7± 16.7) mm for post-revision, and (29.7±19.6) mm for last follow-up. In addition, there was no complication of implant failure during follow-up. Conclusion The satellite rod technique used around the rod-breaking area in the revision surgery due to rod fracture in patients undergoing three-column osteotomy could reduce surgical trauma, get rigid fixation, and rebuild coronal and sagittal balance. With the utilization of satellite rod technique, the coronal and sagittal balance could be well maintained during follow-up. Key words: Scoliosis; Kyphosis; revision; Osteotomy; Reconstructive surgical procedures