Purpose To determine the risk factors of neurologic deficits during PVCR correction, so as to help improve safety during and after surgery. Methods A consecutive series of 76 patients with severe and rigid spinal deformities who were treated with PVCR at a single institution between October 2004 and July 2011 were included in our study. Of the 76 patients, 37 were male and 39 female, with an average age of 17.5 years (range 10-48 years). There were 52 adolescent patients (with an age \18 years) and 24 adult patients (with an age C18 years). Preoperatively, postoperatively and 6 months after surgery, we performed systemically neurologic function evaluations of each patients through meticulous physical examination. Any new abnormality or deterioration in evaluation of neurologic function than preoperative is reckoned postoperative neurologic deficits. Ten variables that might affect the safety of neurologic deficits during PVCR procedures, including imaging factors, clinical factors and operational factors, were analyzed using univariate analysis. Then the variables with statistical difference were analyzed by using multi-factor unconditional logistic regression analysis. Results No patient in this series had permanent paraplegia and nerve root injury due to operation. Change of neurologic status was found in six patients after surgery. Results of single-factor comparison demonstrated that the following seven variables were statistically different (P \ 0.05): location of apex at main curve (X 3 ), Cobb angle at the main curve at the coronal plane (X 4 ), scoliosis associated with thoracic hyperkyphosis (X 5 ), level of vertebral column resected (X 6 ), number of segmental vessels ligated (X 7 ), preexisting neurologic dysfunction (X 8 ), and associated with intraspinal and brain stem anomalies (X 9 ). The multi-factor unconditional logistic regression analysis revealed that X 8 (OR = 49.322), X 9 (OR = 18.423), X 5 (OR = 11.883), and X 6 (OR = 8.769) were independent and positively correlated with the neurologic deficit. Conclusions Preexisting neurologic dysfunction, associated with intraspinal and brain stem anomalies, scoliosis associated with thoracic hyperkyphosis and level of vertebral column resected are independent risk factors for neurologic deficits during PVCR procedure.

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The incidence of INAAs in SSDs was 42.6%. 65.1% of them present intact neurologic status. The most common neural anomaly was syrinx. Preoperative whole spine MRI must be beneficial for SSDs even in the absence of neurological findings. These slides can be retrieved under Electronic Supplementary Material.

Introduction Posterior vertebral column resection (PVCR) is an effective technique for treating severe rigid spinal deformities, and no other osteotomy is capable for such an excellent corrective effects. The purpose of this study was to discuss the correction mechanisms of PVCR. Materials and methods Forty-six patients with severe rigid spinal deformities undergoing PVCR were retrospectively analyzed. According to a routine posteroanterior supine entire spine radiograph performed before and after surgery, the major curve at coronal plane was divided into three segments factitiously: upper segment (from the superior endplate of the upper vertebra of the major curve to the inferior endplate of the upper vertebra adjacent to the resected vertebra), middle segment (from the inferior endplate of the upper vertebra adjacent to the resected vertebra to the superior endplate of the lower vertebra of the resected vertebra), and lower segment (from the superior endplate of the lower vertebra of the resected vertebra to the inferior endplate of the lower end vertebra of the major curve). Cobb method was used to measure the curvature of the major curve and each segment. We analyzed the changes of the Cobb angle in the major curve and each segment. We also analyzed the correlation between the placement of pedicle screws and deformity correction. Results The Cobb angle of the major curve decreased from 110.1 ± 18.1°to 51.0 ± 17.3°(p \ 0.05) after surgery (decreased by 59.1 ± 16.4°), the mean correction rate was 54.1 ± 12.2% (p \ 0.05). The Cobb angle of the middle segment decreased by 28.1 ± 14.7°(p \ 0.05), the contribution rate was 49.1 ± 27.3%. The upper and lower segments decreased by 15.7 ± 13.1°and 15.3 ± 12.4°, respectively (p \ 0.05). There were no significant differences in the contribution rate between upper and lower segments (25.2 ± 16.6% vs. 26.3 ± 22.6%) (p [ 0.05). 22 patients were instrumented with at least one pedicle screw in the adjacent upper and lower vertebras of the resected vertebra and gained a better corrective effect in comparison with the others (p \ 0.05). The data also indicated that deformity correction was closely related to the numbers of the pedicle screws (r = 0.82, p \ 0.05). Conclusion In conclusion, the middle segment offered the highest contribution rate to the deformity correction of the major curve, but at the same time the spinal cord was angulated in this segment. So, it is dangerous to gain too much deformity correction in the middle segment. Because spine would shorten and the tension in spinal cord would decrease after vertebral column resection, a better correction effect could be gained in upper and lower segments at a low risk of spinal cord injury. But it was actually too hard for such rigid spinal deformity. It could gain a better corrective effect and stability by placing more pedicle screws at major curve, especially at the upper and lower vertebras adjacent to the resected vertebra, but sometimes it was difficult to place enough pedicle screws in severe rigid spin...

Posterior vertebral column resection (PVCR) was the most powerful technique for treating severe rigid spinal deformity, but it has been plagued with high neurologic deficits risk. The fluctuations of spinal cord blood flow (SCBF) play an important role in secondary spinal cord injury during deformity correction surgery. The objective of this study was to first provide the characteristic of SCBF during PVCR with spinal column shortening in severe rigid spinal deformity. Severe rigid scoliokyphosis patients received PVCR above L1 level were included in this prospective study. Patients with simple kyphosis, intraspinal pathology and any degree of neurologic deficits were excluded. The deformity correction was based on spinal column shortening over the resected gap during PVCR. Laser Doppler flowmetry was used to monitor the SCBF at different surgical stages. There were 12 severe rigid scoliokyphosis patients in the study. The baseline SCBF was 316 ± 86 perfusion unite (PU), and the SCBF decreased to 228 ± 68 PU after VCR ( P = .008). The SCBF increased to 296 ± 102 PU after the middle shortening and correction which has a 121% increased comparison to the SCBF after VCR ( P = .02). The SCBF will slightly decrease to 271 ± 65 PU at final fixation. The postoperative neural physical examination of all patients was negative, and the MEP and SSEP of all patients did not reach the alarm value during surgery. These results indicate that PVCR is accompanied by a change in SCBF, a proper spinal cord shortening can protect the SCBF and can prevent a secondary spinal cord injury during the surgery.

Preoperative skull-femoral traction effectively mitigates the neurological risks of PVCR for extremely severe rigid spinal deformity with sharp curve. During traction, scoliosis can be improved more significantly and easily than kyphosis.

Study design: A retrospective study. Objective: The aim was to evaluate the relationships of Cobb angle and pulmonary function tests (PFTs) changes in severe spinal deformity and underwent posterior vertebral column resection (PVCR). Summary of Background Data: No previous study focused on the correlation of deformity correction and PFTs changes in patients with cobb angle >90 degrees. Methods: PFTs values [forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and percent-predicted values FVC%, FEV1%] were evaluated preoperative and at 2 years after PVCR. FVC% <80% were defined as restrictive ventilation dysfunction (RVD), the severity of RVD were divided into mild (FEV1% ≥70%), moderate (70% > FEV1% ≥50%) and severe (FEV1% <50%). The relationships among PFTs values improvements and all possible impact factors (mainly correction cobb angle) collected in this study were analyzed. PFTs data were compared among the 3 RVD subgroups (mild vs. moderate vs. severe) and between residual >30 versus <30 degrees. Results: A total of 53 cases (28 male/25 female, mean ages 18.9 Y) underwent PVCR in one center from 2004 to 2016 were enrolled cobb angle. When 2 years after PVCR, average PFTs values showed significant improvements. PFTs values changes showed no correlation with correction rate and correction angle. The only significant impact factor in this study for FVC, FVC%, FEV1 improvements was preoperative FVC% and the only impact factor for FEV1% improvement was preoperative FEV1%, the relationships were negative. In accordance with the regression analysis, PFTs values improvements among the 3 RVD subgroups from high to low was severe>moderate>mild. However, patients with residual cobb angle <30 degrees had less PFTs values improvements than patients with residual cobb angle >30 degrees. Conclusions: Two years after PVCR, PFTs values were significantly improved. There is no linear correlation between cobb angle change and PFTs values improvements. Lower preoperative FVC% and FEV1% indicate more PFTs values improvements at 2 years post-PVCR. Level of Evidence: Level III.

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