Spinal deformity is a 3-dimensional deformity. Decompensation both in the coronal and the sagittal plane leads to specific clinical complaints, pain, neurologic deficit, progression of deformity, trunk imbalance, cardiopulmonary compromise, or interference with activities of daily living. In severe or rigid spinal deformities, conventional correction methods, such as posterior instrumentation or combined anterior release and posterior instrumentation, are usually unsatisfactory.
Vertebral resection removing three columns of vertebra makes a space, which is closed to correct deformity. Vertebral resection has been used for severe and/or rigid deformities with various etiologies, showing better deformity correction and balance than conventional correction methods. It is a technically demanding and exhausting procedure with high complication rates.
There are two kinds of vertebral resection, decancellation osteotomy (egg-shell procedure, pedicle subtraction osteotomy) and VCR.
Several authors have reported overall complications rate of decancellation osteotomy ranging from 15% to 60%. Murrey et al. [12
] reported on 59 patients who underwent decancellation osteotomy. Ten patients had complications, such as pulmonary complication, instrument failure and infection, for a complication rate of 16.9%. They had no postoperative neurologic complication. Willems et al. [17
] presented complications of lumbar decancellation osteotomy for 62 patients with ankylosing spondylitis. Complications included 14.5% infections, 9.6% permanent neurologic deficit, 16% instrument failures, and 13% major general complications. The analysis of these data calculated the overall complication rate to be 53%. Boachie-Adjei et al. [13
] demonstrated the results of lumbar decancellation osteotomy for 24 patients with fixed sagittal deformity. They found 17 complications in 14 patients (58%), which included 4 dural tears, 1 nerve root injury, 5 instrument-related problems, 1 hematoma, 1 infection, and others. Bridwell [16
] reported an 8% incidence of neurologic deficit with decancellation.
In this series, the complication rate of decancellation osteotomy was 42%. There were transient neurologic deficit in 6 patients (7.4%), permanent neurologic deficit in 1 (1.2%), instrument failure or progressing curve in 13 (16%), wound infection in 4 (4.9%), dura tear in 6 (7.4%), and others in 2 (2.5%). Our results were comparable to other studies.
There were few papers reporting on the complications of VCR. Bradford and Tribus [15
] reported on 24 patients with rigid coronal decompensation who underwent combined anterior and posterior VCR. They had 31complicatios in 14 patients (58%). The most common complication was dural tear, which occurred in 8 patients. Other complications included wound infection in 3 patients, neurologic complication in 3, and pseudarthrosis in 3. In the previous report, the authors of this paper presented the results of PVCR for 70 spinal deformity patients. Twenty-four patients (34%) had complications, which consisted of 2 complete cord injuries, 6 hematomas, 4 root injuries, 5 instrument failures, 2 infections, and 5 hemopneumothoraxes [2
In this study, the complication rate of PVCR was 39.5%. There were transient neurologic deficit in 21 patients (13.8%), permanent neurologic deficit in 5 (3.3%), instrument failure or progressing curve in 12 (7.9%), wound infection in 10 (6.6%), dura tear in 17 (11.2%), and others in 9 (5.9%).
Several authors categorized complications into major and minor in adult spinal deformity surgery [18-21
]. In those studies, major complication usually included nerve injury, neurologic deficit, deep infection, fatal cardiopulmonary problem, and instrumentation failure. Minor complication included CSF leakage, superficial infection, and minor cardiopulmonary problem. Auerbach et al. [20
] reported that major complications occurred in 35% of all 3-column osteotomies, including 38% of pedicle subtraction osteotomy (decancellation osteotomy) and 22% of Vertebral column resection. Daubs et al. [18
] reported the overall complication rate of 37%, with the major complication rate of 20% in patients over 60 years of age, who underwent major spinal deformity surgery requiring a minimum 5-level arthrodesis procedure. In this study, the major complication rate of PVCR was 32% (49/152); the minor complication rate of PVCR was 14% (21/152); and those of decancellation and osteotomy were 30% (24/81) and 15% (12/81), respectively.
For the first time, this study made a comparison of complications between decancellation osteotomy and PVCR and analyzed the data to find risk factors of complication for PVR, using many cases (n = 233). There was no significant difference in incidence of complication between decancellation osteotomy and PVCR.
Eight Risk factors of overall complications and postoperative neurologic deficit were found in this study. The most important risk factor of overall complication was the preoperative neurologic deficit, and preoperative kyphosis, followed by the fusion extent of more than 5 segments. Patients with preoperative neurologic deficit and kyphosis had 22 times higher complication rate compared to patients without both factors in the PVR surgery. Two important risk factors of postoperative neurologic deficit were the preoperative neurologic deficit and resection of 2 or more vertebrae. Patients with two risk factors had 29 times higher neurologic complication rate compared to patients without these factors in the PVR operation.
The authors confirm that the results obtained from this study will provide important information to patients and families with the indication of PVR operation. Furthermore, the identification of the risk factors of complications may play a major role in reducing the incidence of complications in PVR.