Three column osteotomy procedures through previous spinal fusion site for the revision surgical treatment in severe spi-nal deformity patients

Objective To investigate the safety and efficacy of three column osteotomy (3-CO) procedures through previ-ous spinal fusion site for the revision surgical treatment in severe spinal deformity patients. Methods From Oct. 2010 to May 2014 in our hospital, a total of 12 severe spinal deformity patients underwent 3-CO for the revision surgical treatment. There were 7 males and 5 females with the average age of (21.8±3.8) years, ranging from 18 to 30 years. The mean time from the initial opera-tion to the revision surgery was (10.2±4.8) years (ranging from 3 to 17 years). The reasons for revision were: curve progression in 7 patients, neurologic deficit in 2 cases, implant failure in 1 patient and pseudarthrosis in 2 patients. The coronal parameters includ-ing major Cobb angle and distance between C7 plumb line and center sacral vertical line (C7PL-CSVL), and the sagittal parameters including global kyphosis curve and sagittal vertical axis (SVA) were measured pre-operatively, post-operatively and at last follow-up, respectively. The operation time, intraoperative blood loss and complications were recorded. The paired t test was used to eval-uate the difference among pre-revision, post-revision and last follow-up. Results The average operation time was (451.7±83.1) min (range, 320-600 min) and the average blood loss was (4 016.7±1 080.0) ml (range, 2 700-6 000 ml). The average follow-up time after revision operation was (35.4±9.8) months (range, 24-49 months). The coronal Cobb angles of pre-revision and post-revi-sion were 83.8°±23.3°and 34.6°±13.7°. The average correction rate was 60.1% ±8.8%. At last follow-up, the average coronal Cobb angle was 34.9°±13.8°, there was no significant loss of correction. The pre-revision and post-revision values of global kypho-sis were 99.1°±13.3°and 38.7°±7.8° with a mean correction rate of 60.8% ±6.7%. At the last follow-up, the average global kypho-sis was 39.3°±7.5°and no loss of correction was found. For the C7PL-CSVL and SVA, pre-revision (30.3±17.1) mm and (40.1±31.1) mm were corrected to (14.3±7.6) mm and (19.1±12.3) mm immediately after revision operation, respectively. At final follow-up, the average C7PL-CSVL and SVA were(14.1±7.6) mm and (19.6±12.1) mm, the correction was well maintained. Obviously, two pa-tient's neurological status improved from Frankel C before revision surgery to Frankel E. Complications were encountered in five patients (41.7%), including SEP signal changed in 1 patient (8.3%), transient neurologic deficit after revision surgery in 1 patient (8.3%), cerebrospinal fluid leak in 1 patient (8.3%), and pleural effusion in 2 patients (16.7%). During the follow-up time, there was no patient experienced pseudarthrosis, implant failure, infection or significant loss of correction. Conclusion Based on re-sults of this study, it was concluded that 3-CO procedures through previous spinal fusion sites could obtain satisfactory and safety results in severe spinal deformity revision surgery. However, it is a technique-demanding procedure with more blood loss, longer operative time and higher risk of perioperative complications. Key words: Scoliosis; Kyphosis; Reoperation; Osteotomy; Spinal fusion