Abstract
Objective
Conventional correction techniques were challenging and of high risk of neurological complications for the correction of severe and rigid kyphoscoliosis. A new technical note we developed and named as sequential correction, was used to treat severe and rigid kyphoscoliosis. The present study was to compare the clinical outcomes of sequential correction versus conventional correction for the treatment of severe and rigid kyphoscoliosis.
Methods
This is a respectively case–control study. Between January 2014 and December 2019, 36 adults underwent the surgical correction of severe and rigid kyphoscoliosis and were included in the present study. Among them, 20 adults underwent conventional correction, 16 adults underwent sequential correction. Major curve Cobb angle, kyphotic angle, coronal imbalance, and sagittal vertical axis were compared between two groups. The patient‐reported health‐related quality of life outcomes, including the Oswestry disability index score, and SRS‐22 questionnaire, were recorded. Independent samples t‐test, Mann–Whitney U test, and Wilcoxon signed‐rank test, were used to compare the differences between two groups according to the results of normal distribution test.
Results
In conventional correction group, the mean major curve Cobb angle was 122.50° preoperatively, 40.35° immediately after surgery, and 43.95° at final follow‐up postoperatively; the mean kyphotic angle was 97.45° preoperatively, 34.45° immediately after surgery, and 38.30° at final follow‐up postoperatively. In the sequential correction group, the mean major angle was 134.44° preoperatively, 44.56° immediately after surgery, and 46.25° at final follow‐up postoperatively; the mean kyphotic angle was 112.31° preoperatively, 39.00° immediately after surgery, and 40.38° at final follow‐up postoperatively. The mean major curve Cobb angle and kyphotic angle of both groups were improved significantly, while there were no significant differences between two groups (p > 0.001). Improved self‐reported quality of life scores were achieved postoperatively and at final follow‐up postoperatively, and there were no significant differences between the two groups. The total complication rate of the patients underwent conventional correction was 55%, and the total complication rate of the patients underwent sequential correction was 43.75%. The complication rate of the two groups showed no significant difference.
Conclusions
Sequential correction is an excellent and safe treatment for severe and rigid kyphoscoliosis in adults, with similar clinical outcomes with conventional correction. The total complication rate of the patients who underwent sequential correction was slightly lower than conventional correction.
Keywords: Apical vertebrae, Conventional correction, Kyphoscoliosis, Scoliosis, Sequential correction
Sequential correction steps for severe and rigid kyphoscoliosis. (A) Screw placement, facetectomy, grade 4 spinal osteotomy or PVCR, and major curve correction at the apical vertebrae. (B, C) Correction maintained with short segmental instrumentation, and further correction via the rod cantilever technique. (D) Integration with appropriate application of long rods.
Introduction
Severe and rigid kyphoscoliosis in adults is a deformity with major curve Cobb angle ≥90° and flexibility ≤30%. 1 , 2 Correction of severe and rigid spinal deformity is difficult, with high risk of neurological complications. Conventional correction techniques combined with three‐column osteotomies, such as pedicle subtraction osteotomy (PSO), grade 4 spinal osteotomy (bone‐disc‐bone osteotomy, BDBO), vertebral column resection (VCR), and multilevel VCR, were commonly used in the treatment of severe and rigid kyphoscoliosis. 3 , 4 , 5 , 6 Circumferential VCR, and posterior VCR (PVCR) have been developed to correct severe and rigid spinal deformity. 7
Even though conventional correction techniques combined with three‐column osteotomies were proved to be of excellent clinical outcomes in previous studies, 3 , 4 , 5 , 6 , 7 only two long rods are used to correct the severe deformities during conventional correction procedures, maintaining the coronal and sagittal alignment. Therefore, conventional correction techniques were still challenging and had high risk of neurological complications. 3 , 4 , 5 , 6 , 7 In recent years, a new technical note we developed and named as sequential correction, was used to treat severe and rigid kyphoscoliosis. 8 The key correction procedures of the sequential correction were divided into several steps to better correct severe and rigid kyphoscoliosis, while the clinical outcomes of sequential correction were still uncertain.
The purpose of this study was to: (i) describe conventional correction and sequential correction for the correction of severe and rigid kyphoscoliosis; (ii) evaluate the efficacy and feasibility of conventional correction and sequential correction for the correction of severe and rigid kyphoscoliosis; and (iii) compare the clinical outcomes of sequential correction versus conventional correction for severe and rigid kyphoscoliosis.
Methods
Study Design and Inclusion and Exclusion Criteria
The inclusion criteria for this study were: (i) adult patients with severe and rigid kyphoscoliosis, with major curve Cobb angle ≥90° and flexibility ≤30%; and (ii) were treated by conventional correction or sequential correction. The exclusion criteria were: (i) accompanying infections, tumors, or other lesions; and (ii) history of spinal surgery.
All procedures performed in the present study were in accordance with the ethical standards of the institutional research committee and the Declaration of Helsinki. Informed consent was obtained from the study participants. This retrospective case series was approved by the institutional review board of our hospital (No. S214). Between January 2014 and December 2019, 36 adults who underwent the correction of severe and rigid kyphoscoliosis and completed the 24‐month follow‐up, were included. Among them, 20 adults underwent conventional correction, 16 adults underwent sequential correction. Therefore, the case series were classified as two groups, conventional correction group and sequential correction group.
Surgical Technique
All surgical corrections were performed via a posterior approach. All procedures were performed under multimodality intraoperative neurophysiological monitoring, including motor evoked potential and somatosensory evoked potential.
Conventional Correction Technique
The pedicle screws were implanted, 9 facetectomy and costotransversectomy were carried out as planned, then the conventional correction or sequential correction was performed as follows. Grade 4 spinal osteotomy or PVCR were performed at the apical vertebrae, and the osteotomy sites were fixed with two short segmental rods to maintain the stability of the spine. 3 Then a long rod are inserted at the convex side from upper instrumented vertebra (UIV) to lower instrumented vertebra (LIV), and the rod cantilever technique was used directly to close the osteotomy sites, maintaining the coronal and sagittal alignment. 10 Then the short segmental rod was removed, and another long rod was inserted at the concave side from UIV to LIV to achieve global balance. (Figure 1).
Fig. 1.
Conventional correction steps for severe and rigid kyphoscoliosis. (A) Screw placement, facetectomy, grade 4 spinal osteotomy or PVCR were performed at the apical vertebrae, with the osteotomy sites maintained with short segmental instrumentation. (B) Correction performed via the rod cantilever technique with two long rods.
Sequential Correction Technique
The procedures of sequential correction technique were divided into six steps: screw placement and facetectomy, asymmetrical three‐column osteotomy at the apical vertebrae, major curve correction at the apical vertebrae, correction maintained with short segmental instrumentation, further correction via the rod cantilever technique, and integration with appropriate application of long rods. (Figure 2).
Fig. 2.
Sequential correction steps for severe and rigid kyphoscoliosis. (A) Screw placement, facetectomy, grade 4 spinal osteotomy or PVCR, and major curve correction at the apical vertebrae. (B, C) Correction maintained with short segmental instrumentation, and further correction via the rod cantilever technique. (D), Integration with appropriate application of long rods.
Grade 4 spinal osteotomy or PVCR were performed at the apical vertebrae, and the osteotomy sites were fixed with two short segmental rods to maintain the stability of the spine, preventing intraoperative vertebral subluxation. Then the gap between the osteotomy sites was closed step‐by‐step, partially correcting scoliosis and kyphosis. Afterward, a short segmental rod at the concave side was reserved to maintain the correction at the apical vertebrae, while the other short segmental rod at the convex side was removed. Then a long rod was inserted at the convex side from UIV to LIV, and the rod cantilever technique was used to further correct the scoliosis and kyphosis, maintaining coronal and sagittal alignment. 10 Another long rod was inserted at the concave side from UIV to LIV to achieve global balance.
Data Collection
Clinical examinations and radiographs were performed preoperatively, postoperatively and at each follow‐up after surgery. Demographic, surgical data and complications were recorded.
The major curve Cobb angles, kyphotic angles, coronal imbalance (CI) and C7 sagittal vertical axis (SVA) were measured preoperatively, postoperatively and at each follow‐up postoperatively. Fusion was evaluated in each patient at the final follow‐up postoperatively.
All the patients completed the self‐reported health‐related quality of life (HRQOL) assessments, including the Oswestry disability index (ODI) score and the Scoliosis Research Society‐22 (SRS‐22) questionnaire preoperatively, postoperatively and at final follow‐up postoperatively.
Statistical Analyses
SPSS 22.0 (IBM Corp., Armonk, NY, USA) statistical analysis software was used to perform the statistical analyses. Variables are presented as mean ± standard deviation. The Kolmogorov–Smirnov test was used to assess the normal distribution of the data. Independent samples t‐test was used to compare the differences between groups for normally distribution data. Nonparametric tests, including the Mann–Whitney U test, and the Wilcoxon signed‐rank test, were used to compare the differences between groups for non‐normally distributed data. A p‐value less than 0.05 was considered as statistically significant.
Results
Demographic data and baseline radiographic parameters of the included patients are summarized in Table 1.
TABLE 1.
Patient demographics parameters of patients underwent sequential correction or conventional correction.
| Characteristic | Conventional correction (n = 20) | Sequential correction (n = 16) | Statistic value | p value |
|---|---|---|---|---|
| Age (yrs) | 27.85 ± 10.28 | 30.50 ± 12.23 | 0.974 | 0.336 |
| Sex (Male: Female) | 7:13 | 5:11 | 0.234 | 0.863 |
| BMI (kg/m2) | 21.17 ± 4.73 | 20.44 ± 2.96 | 3.305 | 0.575 |
| Mean follow‐up (months) | 41.10 ± 11.72 | 37.88 ± 13.81 | 0.914 | 0.386 |
| Scoliosis classification | 0.125 | 0.912 | ||
| Idiopathic scoliosis | 10 | 9 | ||
| Congenital scoliosis | 9 | 5 | ||
| Neuromuscular scoliosis | 1 | 2 | ||
| Major curve type | 0.296 | 0.863 | ||
| Thoracic | 17 | 13 | ||
| Thoracolumbar/lumbar | 3 | 3 | ||
| Major curve flexibility (%) | 15.24 ± 4.39 | 11.78 ± 6.16 | 3.549 | 0.069 |
| Osteotomy Schwab's classification | 1.528 | 0.262 | ||
| Grade 4 (TWRO) | 17 | 10 | ||
| Grade 5 (PVCR) | 3 | 6 | ||
| Fused levels | 12.70 ± 1.30 | 13.56 ± 1.31 | 1.943 | 0.058 |
| Operation time (min) | 449.00 ± 108.91 | 501.88 ± 86.91 | 1.299 | 0.113 |
|
Estimated blood loss (mL) |
2605.00 ± 1198.45 | 2743.75 ± 581.91 | 0.948 | 0.352 |
Radiological Outcomes
The radiological outcomes of both conventional correction and sequential correction groups are summarized in Table 2. In the conventional correction group, the mean major curve Cobb angle was 122.50° preoperatively, 40.35° immediately after surgery, and 43.95° at final follow‐up postoperatively; the mean kyphotic angle was 97.45° preoperatively, 34.45° immediately after surgery, and 38.30° at final follow‐up postoperatively. In the sequential correction group, the mean major Cobb angle was 134.44° preoperatively, 44.56° immediately after surgery, and 46.25° at final follow‐up postoperatively; the mean kyphotic angle was 112.31° preoperatively, 39.00° immediately after surgery, and 40.38° at final follow‐up postoperatively The mean major curve Cobb angle and kyphotic angle of both groups were improved significantly, while there were no significant differences between the two groups (p >0.001). Bony fusion of the osteotomy was achieved by 6 or 12 months after surgery shown by radiographs or CT scans. A typical case of conventional correction group was shown in Figure 3, and a typical case of sequential correction group was shown in Figure 4.
TABLE 2.
Radiographic parameters comparison of the patients underwent sequential correction or conventional correction.
| Groups | Conventional correction (n = 20) | Sequential correction (n = 16) | Statistic value | p value | |
|---|---|---|---|---|---|
| Major curve Cobb angle (°) | Preop | 122.50 ± 19.59 | 134.44 ± 13.63 | 3.771 | 0.039 |
| Post‐op | 40.35 ± 14.82 | 44.56 ± 9.67 | 2.657 | 0.312 | |
| Statistic value | 2.850 | 1.809 | |||
| p | <0.001 | <0.001 | |||
| Final follow‐up | 43.95 ± 13.66 | 46.25 ± 9.43 | 2.530 | 0.555 | |
| Statistic value | 4.137 | 2.083 | |||
| p | <0.001 | <0.001 | |||
| Kyphosis angle (°) | Preop | 97.45 ± 28.34 | 112.31 ± 21.42 | 0.463 | 0.082 |
| Post‐op | 34.45 ± 13.15 | 39.00 ± 15.11 | 0.391 | 0.349 | |
| Statistic value | 6.652 | 3.470 | |||
| p | <0.001 | <0.001 | |||
| Final follow‐up | 38.30 ± 11.93 | 40.38 ± 15.12 | 0.982 | 0.657 | |
| Statistic value | 8.099 | 3.538 | |||
| p | <0.001 | <0.001 | |||
| CI (mm) | Preop | 37.95 ± 23.38 | 33.75 ± 22.02 | 0.621 | 0.539 |
| Post‐op | 24.40 ± 17.27 | 28.56 ± 20.73 | 0.848 | 0.525 | |
| Statistic value | 4.529 | 0.584 | |||
| p | 0.044 | 0.564 | |||
| Final follow‐up | 20.20 ± 13.48 | 31.69 ± 26.81 | 4.481 | 0.133 | |
| Statistic value | 10.934 | 0.226 | |||
| p | 0.006 | 0.838 | |||
| C7SVA (mm) | Preop | 40.10 ± 32.12 | 39.19 ± 47.39 | 0.446 | 0.671 |
| Post‐op | 22.40 ± 14.51 | 25.00 ± 14.56 | 0.269 | 0.598 | |
| Statistic value | 6.387 | 0.019 | |||
| p | 0.033 | 0.985 | |||
| Final follow‐up | 17.40 ± 14.05 | 23.38 ± 17.54 | 1.568 | 0.277 | |
| Statistic value | 7.484 | 0.453 | |||
| p | 0.008 | 0.669 | |||
Note: Bold indicates statistically significance (p < 0.05)
Abbreviations: CI, coronal imbalance; C7SVA, C7 sagittal vertical axis.
Fig. 3.
A 21‐year‐old woman with severe and rigid kyphoscoliosis treated by conventional correction combined with grade 4 spinal osteotomy at the apical vertebrae. (A, B) The coronal major curve angle and the kyphotic angle were 130° and 81° respectively on preoperative anteroposterior and lateral radiographs. (C, D) Preoperative appearance. (E, F) The coronal major curve angle and the kyphotic angle were 47° and 16° respectively on postoperative anteroposterior and lateral radiographs. (G, H) The coronal major curve angle and the kyphotic angle were 48° and 18° respectively on anteroposterior and lateral radiographs at 12‐month follow‐up. (I, J) The coronal major curve angle and the kyphotic angle were 50° and 19° respectively on postoperative anteroposterior and lateral radiographs at 24‐month follow‐up. (K, L) Postoperative appearance.
Fig. 4.
A 21‐year‐old woman with severe and rigid kyphoscoliosis treated by sequential correction combined with grade 4 spinal osteotomy at the apical vertebrae. (A, B) The coronal major curve angle and the kyphotic angle were 141° and 98° respectively on preoperative anteroposterior and lateral radiographs. (C, D) Preoperative appearance. (E, F) The coronal major curve angle and the kyphotic angle were 31° and 29° respectively on postoperative anteroposterior and lateral radiographs. (G, H) The coronal major curve angle and the kyphotic angle were 32° and 30° respectively on anteroposterior and lateral radiographs at 6‐month follow‐up. (I, J) The coronal major curve angle and the kyphotic angle were 32° and 30° respectively on postoperative anteroposterior and lateral radiographs at 24‐month follow‐up. (K, L) Postoperative appearance.
Clinical Outcomes
The mean ODI score and SRS‐22 questionnaire scores of both conventional correction and sequential correction groups were summarized in Table 3. The mean ODI score of conventional correction group was improved from 33.20 ± 15.89 preoperatively to 17.40 ± 10.40 at final follow‐up postoperatively. The mean ODI score of sequential correction group was improved from 40.25 ± 11.73 preoperatively to 17.75 ± 7.44 at final follow‐up postoperatively. For the SRS‐22 questionnaire, scores on activity, pain, appearance, mental health, satisfaction and total score of both sequential correction and conventional correction groups were improved significantly at final follow‐up, compared with preoperative data. The mean ODI score and SRS‐22 questionnaire scores of the two groups showed no significant difference.
TABLE 3.
Variance in health‐related quality of life (HRQOL) of the patients underwent conventional correction or sequential correction.
| Groups | Conventional correction (n = 20) | Sequential correction (n = 16) | Statistic value | p value | |
|---|---|---|---|---|---|
| ODI | Preop | 33.20 ± 15.89 | 40.25 ± 11.73 | 1.293 | 0.200 |
| Final follow‐up | 17.40 ± 10.40* | 17.75 ± 7.44* | 0.706 | 0.498 | |
| Statistic value | 3.230 | 4.427 | |||
| P | 0.001 | <0.001 | |||
| SRS‐22 | |||||
| Activity | Preop | 2.71 ± 0.35 | 2.66 ± 0.36 | 0.388 | 0.718 |
| Final follow‐up | 3.92 ± 0.33* | 3.89 ± 0.33* | 0.422 | 0.694 | |
| Statistic value | 5.287 | 4.733 | |||
| p | <0.001 | <0.001 | |||
| Pain | Preop | 2.67 ± 0.40 | 2.64 ± 0.51 | 0.048 | 0.962 |
| Final follow‐up | 3.96 ± 0.33* | 4.04 ± 0.37* | 0.633 | 0.539 | |
| Statistic value | 5.360 | 4.769 | |||
| p | <0.001 | <0.001 | |||
| Appearance | Preop | 2.55 ± 0.50 | 2.25 ± 0.54 | 1.673 | 0.102 |
| Final follow‐up | 3.62 ± 0.40* | 3.40 ± 0.44* | 1.506 | 0.140 | |
| Statistic value | 4.849 | 4.192 | |||
| p | <0.001 | <0.001 | |||
| Mental health | Preop | 3.21 ± 0.41 | 3.19 ± 0.50 | 0.113 | 0.912 |
| Final follow‐up | 3.94 ± 0.30* | 3.92 ± 0.33* | 0.066 | 0.962 | |
| Statistic value | 4.662 | 3.768 | |||
| p | <0.001 | <0.001 | |||
| Satisfaction | Preop | 2.32 ± 0.57 | 2.34 ± 0.65 | 0.034 | 0.987 |
| Final follow‐up | 3.80 ± 0.52* | 3.91 ± 0.42* | 0.511 | 0.671 | |
| Statistic value | 5.081 | 4.679 | |||
| p | <0.001 | <0.001 | |||
| Total | Preop | 2.69 ± 0.19 | 2.62 ± 0.18 | 0.801 | 0.440 |
| Final follow‐up | 3.86 ± 0.16* | 3.83 ± 0.16* | 0.738 | 0.479 | |
| Statistic value | 5.444 | 4.826 | |||
| p | <0.001 | <0.001 | |||
Note: ODI: 0, no pain, 100, worst conceivable pain; SRS‐22 scale: 5, best; 1, worst. Bold indicates statistically significance (p < 0.05)
Abbreviations: ODI, Oswestry disability index; Preop, preoperation; postop, postoperation; SRS‐22, Scoliosis Research Society 22‐item questionnaire.
Complications
The complications of the patients who underwent conventional correction or sequential correction are summarized in Table 4. In the conventional correction group, three patients had intro‐operative neuromonitoring changes. One of them was found with transient neurological complication, and he underwent revision surgery. In the sequential correction group, one patient had intro‐operative neuromonitoring changes and transient neurological complication, and his neurological function recovered after a revision surgery. Another patient in the sequential correction group underwent revision surgery for better coronal imbalance correction. The total complication rate of the patients underwent conventional correction was 55%, and the total complication rate of the patients underwent sequential correction was 43.75%. The total complication rate of the sequential correction group was slightly lower than the conventional correction group. However, the complication rates of the two groups showed no significant difference.
TABLE 4.
Complications of the patients underwent conventional correction or sequential correction.
| Complications | Conventional correction (n = 20) | Sequential correction (n = 16) | Statistic value | p value |
|---|---|---|---|---|
| Pleural tear | 8 | 5 | 0.536 | 0.671 |
| Intro‐operative neuromonitoring changes | 3 | 1 | 0.818 | 0.671 |
| Transient neurological complications | 1 | 1 | 0.160 | 0.962 |
| Permanent neurological complications | 0 | 0 | 0.000 | 1.000 |
| Deep infection | 0 | 0 | 0.000 | 1.000 |
| Revision surgery | 1 | 2 | 0.798 | 0.718 |
| Total | 11 | 7 | 0.661 | 0.582 |
Discussion
A new technical note we developed and named as sequential correction, was used to treat the severe and rigid kyphoscoliosis. 8 The present study described both conventional correction and sequential correction for the correction of severe and rigid kyphoscoliosis. It was found that the clinical outcomes of sequential correction versus conventional correction for severe and rigid kyphoscoliosis had no significant differences.
Choices of Surgical Treatment for Severe and Rigid Kyphoscoliosis
For patients with severe and rigid kyphoscoliosis, surgical treatment is recommended to improve pulmonary function and increase life expectancy. 11 , 12 Surgical correction of severe and rigid kyphoscoliosis is challenging and associated with a high risk of neurological injury. 13 , 14 Different techniques with anterior, posterior or combined approaches were used to treat severe and rigid kyphoscoliosis. Anterior and posterior VCR is a choice for the treatment of severe and rigid kyphoscoliosis. Zhou et al. 2 treated 16 patients with severe and rigid idiopathic scoliosis using circumferential approach VCR, the average major curve Cobb angle improved from 99.3° to 32.9° at the immediate postoperative assessment, with a correction of 66.4° (66.9%). Zhou et al. 15 reported that 16 patients of severe and rigid adult idiopathic scoliosis by two‐stage VCR, with the mean major curve Cobb angle corrected from 101.7° to 30.1° immediately after surgery, with a correction of 71.6° (70.4%), and the mean major curve was corrected to 31.9° at final follow‐up, with a correction of 69.8° (68.6%). Kandwal et al. 16 treated 21 patients with severe and rigid scoliosis using staged anterior release and posterior instrumentation, the average major curve Cobb angle was corrected from 116.6° to 26.5°, with a correction of 90.1° (77.3%).
Even though excellent correction could be achieved via anterior or combined approaches, posterior‐only approach is preferable with the advancement of pedicle screw systems. Grade 4 spinal osteotomy, PVCR may be necessary for the correction in patients with severe and rigid kyphoscoliosis. In the present study, grade 4 spinal osteotomy or PVCR were used to treat severe and rigid kyphoscoliosis. Moreover, both conventional correction and sequential correction were used to treat severe and rigid kyphoscoliosis, the clinical outcomes of two different techniques were discussed, respectively.
Sequential Correction versus Conventional Correction for the Treatment of Severe and Rigid Kyphoscoliosis
Conventional correction with both grade 4 spinal osteotomy and PVCR was of excellent outcomes for severe and rigid kyphoscoliosis. Surgical correction via grade 4 spinal osteotomy or BDBO, has excellent outcomes for severe and rigid kyphoscoliosis. Fan et al. 4 treated 60 patients with severe and stiff thoracic kyphoscoliosis via three‐column osteotomy, among them 14 patients underwent grade 4 spinal osteotomy. The major curve Cobb angle was corrected from 133.9° to 58.2° immediately after surgery, with a correction of 75.7° (56.5%), and the major curve Cobb angle was corrected to 60.6° at final follow‐up, with a correction of 73.3° (54.7%). 4 The kyphosis was corrected from 119.1° to 48.6° immediately after surgery, with a correction of 70.5°, and the kyphosis angle was corrected to 51.5° at final follow‐up, with a correction of 67.6°. 4 In our previous study, grade 4 spinal osteotomy at the apical vertebrae was found to be an excellent treatment for severe and rigid kyphoscoliosis. The mean major curve Cobb angle was corrected from 107.6° to 37.5° with a correction of 70.1° (65.1%) immediately after surgery, and the mean kyphotic angle was corrected from 90.6° to 30.5° with a correction of 60.1° immediately after surgery. 3
Surgical correction via PVCR at the apical vertebrae may be a preferred technique for the treatment of severe and rigid spinal deformity. 13 , 17 , 18 , 19 , 20 , 21 , 22 Suk et al. 21 reported 16 patients of severe and rigid scoliosis by PVCR, and the mean major curve Cobb angle was corrected from 109.0° to 43.1° immediately after surgery, with a correction of 65.9° (60.4%), and the mean major curve Cobb angle was corrected to 45.6° at final follow‐up, with a correction of 63.4° (58.2%). Lenke et al. 18 treated 43 patients with severe spinal deformity by PVCR, and the average major curve Cobb angle correction was 57° (69%) for the scoliosis cases, 45° (54%) for the global kyphosis cases, 49° (63%) for the angular kyphosis cases. Fan et al. 4 treated 60 patients with severe and stiff thoracic kyphoscoliosis via three‐column osteotomy, among them 27 patients underwent PVCR. The major curve Cobb angle was corrected from 124.7° to 52.1° immediately after surgery, with a correction of 72.6° (58.1%), and the major curve Cobb angle was corrected to 55.6° at final follow‐up, with a correction of 69.1° (55.4%). 4 The kyphosis was corrected from 119.8° to 56.1° immediately after surgery, with a correction of 63.7°, and the kyphosis was corrected to 62.1° at final follow‐up, with a correction of 57.7°. 4 Xie et al. 23 reported 14 patients with rigid kyphoscoliosis via PVCR, the major curve Cobb angle was corrected from 116.6° to 44.9° immediately after surgery, with a correction of 71.7° (61.5%), and the mean major curve Cobb angle was corrected to 48.6° at final follow‐up, with a correction of 68.0° (58.3%). The mean kyphotic angle was corrected from 77.7° to 24.5° immediately after surgery, and 25.1° at final follow‐up. 23 Zhang et al. 6 reported that 12 patients of severe and rigid adult idiopathic scoliosis by PVCR, with the mean major curve Cobb angle corrected from 108.9° to 56.5°, immediately after surgery, with a correction of 52.4° (48.1%), and the mean major curve Cobb angle was corrected to 57.0° at final follow‐up, with a correction of 51.9° (47.6%).
In the present study, 20 patients were included in the conventional correction group. Among them, 17 patients underwent grade 4 spinal osteotomy, and three patients underwent PVCR. The mean major curve Cobb angle was corrected from 122.50° preoperatively, to 40.35° immediately after surgery, with a correction of 67.06%, and 43.95° at final follow‐up postoperatively, with a correction of 64.12%. The mean kyphotic angle was corrected from 97.45° preoperatively, to 34.45° immediately after surgery, and 38.30° at final follow‐up postoperatively. Similar correction was achieved with previous studies.
Sixteen patients were included in the sequential correction group, among them 10 patients underwent grade 4 spinal osteotomy, and six patients underwent PVCR. The mean major Cobb angle was corrected from 134.44° preoperatively, to 44.56° immediately after surgery, with a correction of 66.86%, and 46.25° at final follow‐up postoperatively, with a correction of 65.60%. The mean kyphotic angle was corrected from 112.31° preoperatively, to 39.00° immediately after surgery, and 40.38° at final follow‐up postoperatively. It was found that similar outcomes were achieved via both conventional correction and sequential correction, maintaining similar global coronal balance and sagittal alignment. The total complication rate of sequential correction is slightly lower than conventional correction, therefore sequential correction may be safer than conventional correction.
Major Superiority of Sequential Correction for the Treatment of Severe and Rigid Kyphoscoliosis
The major superiority of sequential correction is to make the complex deformity correction as step‐by‐step procedures, which could be performed more safely. In conventional correction techniques, only two long rods are used to correct the deformity and maintain global coronal balance and sagittal alignment. During the sequential correction, the major curve was partially corrected via the apical vertebrae osteotomy and fixed with one segmental rod. The short segmental rod is helpful to prevent the displacement of the osteotomy site, maintain the correction at the apical vertebrae, and disperse the stretching force on the apical vertebrae area. One long rod on the convex side was used to correct the major curve via the rod cantilever technique. Then, another long rod was used only responsible for controlling global alignment. The spine can be stabilized after each surgical step and the final biomechanical property is also superior compared to traditional two‐rod instrumentations.
Limitations
There are also some shortcomings for the present study. The procedure remains technically demanding and exhausting, with a potential risk for complications. The present study is limited by its small sample size and short follow‐up. All these surgical procedures were performed by the same senior author. Perhaps, further multicenter randomized controlled study should be conducted, comparing the clinical outcomes of sequential correction versus conventional correction in treating severe and rigid kyphoscoliosis in adults.
Conclusions
In this study, we described a new technique of sequential correction for severe and rigid kyphoscoliosis in adult patients. Sequential correction is an excellent and safe treatment for severe and rigid kyphoscoliosis in adults, with similar clinical outcomes with conventional correction. The total complication rate of the patients underwent sequential correction was slightly lower than conventional correction.
Author Contributions
Wenbin Hua and Wencan Ke participated in the design of this study, performed the statistical analysis, and drafted the manuscript. Shuai Li, Xiaobo Feng, Kun Wang, Huipeng Yin, Xinghuo Wu, Yukun Zhang, and Yong Gao collected the clinical data and follow‐up details of this study. Li Ling and Cao Yang participated in the study design and helped to revise the manuscript. All authors read and approved the final manuscript.
Funding Information
This work was supported by the National Natural Science Foundation of China (Grant no. 81904020 and 81772401), Higher Education Teaching Research Project of Hubei Province (No. 2021063), and Science Foundation of Union Hospital (2022‐F016010032200311006).
Conflict of Interest
The authors declare that they have no competing interests.
Ethics Statement
This study was conducted in accordance with the Declaration of Helsinki and with approval from the Ethics Committee of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. Informed consent was obtained from all individual participants included in the study.
Wenbin Hua and Wencan Ke contributed equally to this study.
Contributor Information
Li Ling, Email: 1580209179@qq.com.
Cao Yang, Email: caoyangunion@hust.edu.cn.
References
- 1. Shen J, Qiu G, Wang Y, Zhang Z, Zhao Y. Comparison of 1‐stage versus 2‐stage anterior and posterior spinal fusion for severe and rigid idiopathic scoliosis–a randomized prospective study. Spine (Phila Pa 1976). 2006;31(22):2525–2528. [DOI] [PubMed] [Google Scholar]
- 2. Zhou C, Liu L, Song Y, Liu H, Li T, Gong Q, et al. Anterior and posterior vertebral column resection for severe and rigid idiopathic scoliosis. Eur Spine J. 2011;20(10):1728–1734. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Hua W, Zhang Y, Wu X, Gao Y, Li S, Wang K, et al. Transpedicular wedge resection osteotomy of the apical vertebrae for the treatment of severe and rigid thoracic kyphoscoliosis: a retrospective study of 26 cases. Spine Deform. 2019;7(2):338–345. [DOI] [PubMed] [Google Scholar]
- 4. Fan H, Li X, Huang Z, Sui W, Yang J, Deng Y, et al. Radiologic parameters can affect the preoperative decision making of three‐column spinal osteotomies in the treatment of severe and stiff kyphoscoliosis. Spine (Phila Pa 1976). 2017;42(23):E1371–E1379. [DOI] [PubMed] [Google Scholar]
- 5. Suh SW, Modi HN, Yang J, Song HR, Jang KM. Posterior multilevel vertebral osteotomy for correction of severe and rigid neuromuscular scoliosis: a preliminary study. Spine (Phila Pa 1976). 2009;34(12):1315–1320. [DOI] [PubMed] [Google Scholar]
- 6. Zhang Y, Tao L, Hai Y, Yang J, Zhou L, Yin P, et al. One‐stage posterior multiple‐level asymmetrical ponte osteotomies versus single‐level posterior vertebral column resection for severe and rigid adult idiopathic scoliosis: a minimum 2‐year follow‐up comparative study. Spine (Phila Pa 1976). 2019;44(20):E1196–E1205. [DOI] [PubMed] [Google Scholar]
- 7. Bekmez S, Ozhan M, Olgun ZD, Suzer A, Ayvaz M, Demirkiran HG, et al. Pedicle subtraction osteotomy versus multiple posterior column osteotomies in severe and rigid neuromuscular scoliosis. Spine (Phila Pa 1976). 2018;43(15):E905–E910. [DOI] [PubMed] [Google Scholar]
- 8. Yin H, Wang K, Li S, Song Y, Feng X, Hua W, et al. Sequential correction using satellite rod for the treatment of severe rigid spinal deformity: a retrospective study of 19 cases. Eur J Med Res. 2022;27(1):316. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9. Kim YJ, Lenke LG, Bridwell KH, Cho YS, Riew KD. Free hand pedicle screw placement in the thoracic spine: is it safe? Spine (Phila Pa 1976). 2004;29(3):333–342. [DOI] [PubMed] [Google Scholar]
- 10. Rajpal S, Resnick DK. Rod cantilever techniques. Neurosurgery. 2008;63(3 Suppl):157–162. [DOI] [PubMed] [Google Scholar]
- 11. Koller H, Zenner J, Gajic V, Meier O, Ferraris L, Hitzl W. The impact of halo‐gravity traction on curve rigidity and pulmonary function in the treatment of severe and rigid scoliosis and kyphoscoliosis: a clinical study and narrative review of the literature. Eur Spine J. 2012;21(3):514–529. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12. Sucato DJ. Management of severe spinal deformity: scoliosis and kyphosis. Spine (Phila Pa 1976). 2010;35(25):2186–2192. [DOI] [PubMed] [Google Scholar]
- 13. Lenke LG, O'Leary PT, Bridwell KH, Sides BA, Koester LA, Blanke KM. Posterior vertebral column resection for severe pediatric deformity: minimum two‐year follow‐up of thirty‐five consecutive patients. Spine (Phila Pa 1976). 2009;34(20):2213–2221. [DOI] [PubMed] [Google Scholar]
- 14. Kelly MP, Lenke LG, Shaffrey CI, Ames CP, Carreon LY, Lafage V, et al. Evaluation of complications and neurological deficits with three‐column spine reconstructions for complex spinal deformity: a retrospective scoli‐risk‐1 study. Neurosurg Focus. 2014;36(5):E17. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15. Zhou C, Liu L, Song Y, Liu H, Li T, Gong Q. Two‐stage vertebral column resection for severe and rigid scoliosis in patients with low body weight. Spine J. 2013;13(5):481–486. [DOI] [PubMed] [Google Scholar]
- 16. Kandwal P, Goswami A, Vijayaraghavan G, Subhash KR, Jaryal A, Upendra BN, et al. Staged anterior release and posterior instrumentation in correction of severe rigid scoliosis (cobb angle >100 degrees). Spine Deform. 2016;4(4):296–303. [DOI] [PubMed] [Google Scholar]
- 17. Bridwell KH. Decision making regarding smith‐petersen vs. pedicle subtraction osteotomy vs. vertebral column resection for spinal deformity. Spine (Phila Pa 1976). 2006;31(19 Suppl):S171–S178. [DOI] [PubMed] [Google Scholar]
- 18. Lenke LG, Sides BA, Koester LA, Hensley M, Blanke KM. Vertebral column resection for the treatment of severe spinal deformity. Clin Orthop Relat Res. 2010;468(3):687–699. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19. Smith JS, Wang VY, Ames CP. Vertebral column resection for rigid spinal deformity. Neurosurgery. 2008;63(3 Suppl):177–182. [DOI] [PubMed] [Google Scholar]
- 20. Suk SI, Kim JH, Kim WJ, Lee SM, Chung ER, Nah KH. Posterior vertebral column resection for severe spinal deformities. Spine (Phila Pa 1976). 2002;27(21):2374–2382. [DOI] [PubMed] [Google Scholar]
- 21. Suk SI, Chung ER, Kim JH, Kim SS, Lee JS, Choi WK. Posterior vertebral column resection for severe rigid scoliosis. Spine (Phila Pa 1976). 2005;30(14):1682–1687. [DOI] [PubMed] [Google Scholar]
- 22. Hamzaoglu A, Alanay A, Ozturk C, Sarier M, Karadereler S, Ganiyusufoglu K. Posterior vertebral column resection in severe spinal deformities: a total of 102 cases. Spine (Phila Pa 1976). 2011;36(5):E340–E344. [DOI] [PubMed] [Google Scholar]
- 23. Xie J, Wang Y, Zhao Z, Zhang Y, Si Y, Li T, et al. Posterior vertebral column resection for correction of rigid spinal deformity curves greater than 100 degrees. J Neurosurg Spine. 2012;17(6):540–551. [DOI] [PubMed] [Google Scholar]