Lumbar Level Significantly Influences Postoperative Global Sagittal Balance Following Pedicle Subtraction Osteotomy

Study Design: Retrospective cohort study. Objectives: The current evidence regarding how level of lumbar pedicle subtraction osteotomy (PSO) influences correction of sagittal alignment is limited. This study sought to investigate the relationship of lumbar level and segmental angular change (SAC) of PSO with the magnitude of global sagittal alignment correction. Methods: This study retrospectively evaluated 53 consecutive patients with adult spinal deformity who underwent lumbar PSO at a single institution. Radiographs were evaluated to quantify the effect of PSO on lumbar lordosis (LL), thoracic kyphosis (TK), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), T1-spinopelvic inclination (T1SPI), T1-pelvic alignment (TPA), and sagittal vertical axis (SVA). Results: Significant correlations were found between PSO SAC and the postoperative increase in LL ( r = 0.316, P = .021) and PT ( r = 0.352, P = .010), and a decrease in TPA ( r = −0.324, P = .018). PSO level significantly correlated with change in T1SPI ( r = −0.305, P = .026) and SVA ( r = −0.406, P = .002), with more caudal PSO corresponding to a greater correction in sagittal balance. On multivariate analysis, more caudal PSO level independently predicted a greater reduction in T1SPI (β = −3.138, P = .009) and SVA (β = −29.030, P = .001), while larger PSO SAC (β = −0.375, P = .045) and a greater number of fusion levels (β = −1.427, P = .036) predicted a greater reduction in TPA. Conclusion: This study identified a gain of approximately 3 degrees and 3 cm of correction for each level of PSO more caudal to L1. Additionally, a larger PSO SAC predicted greater improvement in TPA. While further investigation of these relationships is warranted, these findings may help guide preoperative PSO level selection.

Download Full-text

Analysis of global spine sagittal parameters in cervical spondylotic patients and asymptomatic subjects

10.21203/rs.2.21726/v1 ◽

2020 ◽

Author(s):

Liang Zhu ◽

Xiaojun Ma ◽

Qiang Shen ◽

Bao Sun ◽

Qiang Fu

Keyword(s):

Cervical Spondylosis ◽

Lumbar Lordosis ◽

Sagittal Alignment ◽

Vertical Axis ◽

Normal Group ◽

Sacral Slope ◽

Sagittal Vertical Axis ◽

Thoracic Inlet ◽

Global Sagittal Alignment ◽

Sagittal Parameters

Abstract Background: Degenerative changes associated with cervical spondylotic can result in a change of normal sagittal alignment, and this may be the initial change of kyphosis and sagittal imbalance. Few studies have analyzed the correlations between the cervical spine lordosis and global spine balance in patients with cervical spondylotic. This study is applied to investigate the characteristics and relationships of cervical and global sagittal parameters in normal adults and cervical spondylotic patients. Methods: We reviewed 46 asymptomatic control subjects (normal group, NG) and 48 cervical spondylotic patients (cervical spondylotic group, CSG), who had both cervical MRI and global radiographs obtained together, between January 2016 and September 2018. Data includes C1-2 angle, C2–7 lordosis (CL), T1 slope (T1S), thoracic inlet angle (TIA), C2–7 sagittal vertical axis (CSVA), sagittal vertical axis(SVA), thoracic-kyphosis(TK), thoracic-lumbar lordosis(TL), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). The values were presented as the mean ± standard deviation. Student t-test and Pearson’s correlation coefﬁcient were used for statistical analysis. Probability values less than 0.05 were considered statistically signiﬁcant. Results: 1.Comparison of global sagittal parameters between the normal group and cervical spondylosis group. A total of 48 cervical spondylotic patients with an average age of 57.91±9.58 and 46 healthy people with an average age of 28.00±8.09 were recruited in our study. CL in the NG was significantly lower than CSG (P<0.05), while TK and TL were significantly lower than in the CSG(P< 0.01). However, a comparison of the NG and CSG yielded no significant differences in C1-2, TIA, TIS, LL, PT, PI, SS, CSVA, and SVA. 2.The relationship between cervical and global sagittal alignment. CL positively correlated with T1S (r=0.433) and TK (r=0.335) while negatively correlated with CSVA (r=-0.309) in cervical spondylosis group. TIA has positively correlated with T1S (r=0.376 in NG and r=0.416 in CSG) and no correlated with other parameters in both groups. Conclusions Cervical spondylosis causes changes in sagittal parameters of the cervical and thoracic spine but does not affect on lumbar and pelvic parameters. TIA is a relative constant parameter, not affected by cervical spondylotic.

Download Full-text

Sagittal profile modifications in hybrid versus all screw technique in adolescent idiopathic scoliosis

Scientific Reports ◽

10.1038/s41598-020-79523-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Laura Scaramuzzo ◽

Antonino Zagra ◽

Giuseppe Barone ◽

Stefano Muzzi ◽

Leone Minoia ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Thoracic Kyphosis ◽

Sagittal Alignment ◽

Vertical Axis ◽

Sagittal Profile ◽

Sacral Slope ◽

Sagittal Vertical Axis ◽

Lenke Classification

AbstractAim of the study was to evaluate sagittal parameters modifications, with particular interest in thoracic kyphosis, in patients affected by adolescent idiopathic scoliosis (AIS) comparing hybrid and all-screws technique. From June 2010 to September 2018, 145 patients were enrolled. Evaluation included: Lenke classification, Risser scale, coronal Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Patients were divided in two groups (1 all-screws and 2 hybrid); a further division, in both groups, was done considering preoperative TK values. Descriptive and inferential statistical analysis was conducted. 99 patients were in group 1, 46 in group 2 (mean follow-up 3.7 years). Patients with a normo-kyphotic profile developed a little variation in TK (Δ pre–post = 2.4° versus − 2.0° respectively). Hyper-kyphotic subgroups had a tendency of restoring a good sagittal alignment. Hypo-kyphotic subgroups, patients treated with all-screw implants developed a higher increase in TK mean Cobb angle (Δ pre–post = 10°) than the hybrid subgroup (Δ pre–post = 5.4°) (p = 0.01). All-screws group showed better results in restoring sagittal alignment in all subgroups compared to hybrid groups, especially in hypo-TK subgroup, with the important advantage to give better correction on coronal plane.

Download Full-text

Usefulness of anterior column release for segmental lordosis restoration in degenerative lumbar kyphosis

Journal of Neurosurgery Spine ◽

10.3171/2021.5.spine202196 ◽

2021 ◽

pp. 1-7

Author(s):

Jin-Sung Park ◽

Chong-Suh Lee ◽

Youn-Taek Choi ◽

Se-Jun Park

Keyword(s):

Sagittal Alignment ◽

Adult Spinal Deformity ◽

Anterior Column ◽

Sacral Slope ◽

High Morbidity ◽

Global Sagittal Alignment ◽

The Mean ◽

Lumbar Kyphosis ◽

Segmental Lordosis

OBJECTIVE Three-column osteotomies (3COs) for surgical correction of lumbar kyphosis show a strong correction capacity, but this procedure carries high morbidity rates. The anterior column release (ACR) technique was developed as a less invasive procedure. In this study the authors aimed to evaluate sagittal alignment restoration using ACR and to determine factors that affect the degree of correction. METHODS This study included 36 patients (68 cases) who underwent ACR of more than one level for adult spinal deformity. Parameters for regional sagittal alignment included segmental lordosis (SL). The parameters for global sagittal alignment included pelvic incidence, lumbar lordosis, sacral slope, pelvic tilt, and sagittal vertical axis (SVA). In addition, the interdiscal height (IDH) and difference of interdiscal angle (DIDA) were measured to evaluate the stiffness of the vertebra segment. The changes in SL were evaluated after ACR and the change of global sagittal alignment was also determined. Factors such as the location of the ACR level, IDH, DIDA, cage height, and additional posterior column osteotomy (PCO) were analyzed for correlation with the degree of SL correction. RESULTS Thirty-six patients were included in this study. A total of 68 levels were operated with the ACR (8 levels at L2–3, 27 levels at L3–4, and 33 levels at L4–5). ACR was performed for 1 level in 10 patients, 2 levels in 20, and 3 levels in 6 patients (mean 1.9 ± 0.7 levels per patient). Mean follow-up duration was 27.1 ± 4.2 months. The mean SL of the total segment was 0.4° ± 7.2° preoperatively and increased by 15.3° ± 5.5° at the last follow-up (p < 0.001); thus, the mean increase of SL was 14.9° ± 8.1° per one ACR. Global sagittal alignment was also improved following SL restoration with SVA from 101.9 mm to 31.4 mm. The degree of SL correction was correlated with the location of ACR level (p = 0.041) and was not correlated with IDH, DIDA, cage height and additional PCO. CONCLUSIONS This study demonstrated that the mean correction angle of SL was 14.9 per one ACR. The degree of disc space collapse and stiffness of segment did not affect the degree of correction by ACR.

Download Full-text

Spinal sagittal alignment and head control in patients with cerebral palsy

Journal of Children s Orthopaedics ◽

10.1302/1863-2548.14.190160 ◽

2020 ◽

Vol 14 (1) ◽

pp. 17-23 ◽

Cited By ~ 1

Author(s):

Brice Ilharreborde ◽

Adrien de Saint Etienne ◽

Ana Presedo ◽

Anne-Laure Simon

Keyword(s):

Cerebral Palsy ◽

Sagittal Alignment ◽

Vertical Axis ◽

Sacral Slope ◽

Trunk Control ◽

Level Of Evidence ◽

Sagittal Vertical Axis ◽

Spinal Sagittal Alignment ◽

Trunk Posture ◽

Radiological Analysis

Purpose Spinal sagittal alignment restoration has been associated with improved functional outcomes and with reduced complications rates. Several limitations exist for radiological analysis in cerebral palsy (CP) patients. The goal of this study was to summarize the existing literature and report the important considerations to evaluate in a CP patient undergoing spinal surgery. Methods A retrospective radiological analysis was performed, including non-ambulant CP children with progressive scoliosis. Full-spine sitting radiographs performed pre-and postoperatively were required to measure spino-pelvic sagittal parameters. Result A total of 23 non-ambulating CP patients were included, mean age 16.0 years (standard error of the mean 0.5). Two distinct groups of patients were identified. Group 1 (61%) were patients with less trunk control (lumbar lordosis (LL) < 50°), retroverted and vertical pelvis (mean sacral slope (SS) 11.4° and pelvic tilt (PT) 38.1°) and anterior imbalance (mean sagittal vertical axis (SVA) 5.9 cm) and Group 2 (39%) were patients with better trunk control (LL > 60°, anteverted and horizontal pelvis (mean SS 49.3°, PT 9.7°) and posterior imbalance (mean SVA 5.8 cm). Postoperative measures showed significant impact of surgery with a PT reduction of 19° (p = 0.007), a mean SS increase of 15° (p = 0.04) and a LL gained of 10° (p = 0.2). Conclusion Sagittal spino-pelvic alignment in non-ambulating CP patients remains difficult to assess. The current literature is poor but our radiological study was able to define two distinct groups among Gross Motor Function Classification System (GMFCS) level V patients, based on the quality of their trunk control. All possible factors that may influence head and trunk posture should be systematically considered and optimized. Level of evidence Level IV

Download Full-text

Long-term effects of the Chêneau brace on coronal and sagittal alignment in adolescent idiopathic scoliosis

Journal of Neurosurgery Spine ◽

10.3171/2015.2.spine14970 ◽

2015 ◽

Vol 23 (4) ◽

pp. 505-509 ◽

Cited By ~ 18

Author(s):

Ming-Qiao Fang ◽

Chong Wang ◽

Guang-Heng Xiang ◽

Chao Lou ◽

Nai-Feng Tian ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Sagittal Alignment ◽

Vertical Axis ◽

Sacral Slope ◽

Long Term Effects ◽

Sagittal Vertical Axis ◽

Pelvic Parameters

OBJECT The aim of the present study was to retrospectively evaluate progressive correction of coronal and sagittal alignment and pelvic parameters in patients treated with a Chêneau brace. METHODS Thirty-two patients with adolescent idiopathic scoliosis (AIS) were assessed before initiation of bracing treatment and at the final follow-up. Each patient underwent radiological examinations, and coronal, sagittal, and pelvic parameters were measured. RESULTS No statistically significant modification of the Cobb angle was noted. The pelvic incidence remained unchanged in 59% of the cases and increased in 28% of the cases. The sacral slope decreased in 34% of the cases but remained unchanged in 50%. Thoracic kyphosis and lumbar lordosis were significantly decreased, whereas the sagittal vertical axis was significantly increased from a mean of -44.0 to -30.2 mm (p = 0.02). The mean pelvic tilt increased significantly from 4.5° to 8.3° (p = 0.002). CONCLUSIONS The Chêneau brace can be useful for preventing curvature progression in patients with AIS. However, the results of this study reveal high variability in the effect of brace treatment on sagittal and pelvic alignment. Treatment with the Chêneau brace may also influence sagittal global balance.

Download Full-text

Multiple-rod constructs and use of bone morphogenetic protein–2 in relation to lower rod fracture rates in 141 patients with adult spinal deformity who underwent lumbar pedicle subtraction osteotomy

Journal of Neurosurgery Spine ◽

10.3171/2021.3.spine201968 ◽

2021 ◽

pp. 1-11

Author(s):

Qiunan Lyu ◽

Darryl Lau ◽

Alexander F. Haddad ◽

Vedat Deviren ◽

Christopher P. Ames

Keyword(s):

Bone Morphogenetic Protein ◽

Spinal Deformity ◽

Adult Spinal Deformity ◽

Vertical Axis ◽

Pedicle Subtraction Osteotomy ◽

Bone Morphogenetic Protein 2 ◽

Sagittal Vertical Axis ◽

Morphogenetic Protein ◽

Rod Fracture ◽

Lumbar Pedicle

OBJECTIVE The purpose of this study was to compare rod fracture (RF) rates among three types of rod constructs (RCs) following lumbar pedicle subtraction osteotomy (PSO) for adult spinal deformity (ASD). METHODS A retrospective review of consecutive patients with adult spinal deformity who were treated with lumbar PSO between 2007 and 2017 was performed. The minimum follow-up was 2 years. Three RCs were compared: standard (2 main rods), satellite (2 main rods with satellite rod), and nested (2 main rods and 2 short rods spanning osteotomy). Outcomes examined included RF rate, time to RF, pseudarthrosis, and reoperation. Multivariate analysis was used. RESULTS A total of 141 patients were included 55 with standard, 23 with satellite, and 63 with nested RCs. The mean age was 65.2 years and 34.8% of patients were male. Radiographic preoperative and postoperative results were as follows: sagittal vertical axis (11.0 vs 3.9 cm), lumbar lordosis (28.5° vs 57.1°), pelvic tilt (30.6° vs 21.0°), pelvic incidence (61.5° vs 60.0°), distance between central sacral vertical line and C7 plumb line (2.2 vs 1.5 cm), and scoliosis (18.9° vs 11.3°). The average time to RF was 12.4 months. Overall RF, bilateral RF, pseudarthrosis, and reoperation rates were 22.7%, 5.0%, 20.6%, and 17.7%, respectively. Standard RCs had a significantly higher RF (36.4% vs 13.0% vs 14.3%, p = 0.008), bilateral RF (35.0% vs 0.0% vs 0.0%, p = 0.021), pseudarthrosis (34.5% vs 8.7% vs 12.7%, p = 0.004), and reoperation (30.9% vs 4.3% vs 11.1%, p = 0.004) rates. Satellite RCs (OR 0.21, p = 0.015), nested RCs (OR 0.24, p = 0.003), and bone morphogenetic protein–2 (OR 0.28, p = 0.005) were independently associated with lower odds of RF. CONCLUSIONS Use of multiple rods in the satellite RC and nested RC groups was associated with lower rates of RF, pseudarthrosis, and reoperations following lumbar PSO. Bone morphogenetic protein–2 was associated with a reduction in RF rate as well.

Download Full-text

Sagittal alignment based on inflection point and its differences according to age groups

Journal of Orthopaedic Surgery ◽

10.1177/2309499020904615 ◽

2020 ◽

Vol 28 (1) ◽

pp. 230949902090461

Author(s):

Moon Soo Park ◽

Seong-Hwan Moon ◽

Tae-Hwan Kim ◽

Jae Keun Oh ◽

Seung Jin Lee ◽

...

Keyword(s):

Pelvic Incidence ◽

Sagittal Plane ◽

Sagittal Alignment ◽

Age Groups ◽

Vertical Axis ◽

Sacral Slope ◽

Sagittal Vertical Axis ◽

Inflection Points ◽

Lumbar Segment ◽

Cervical Segment

Purpose: We have always used the standard anatomical landmark vertebrae to measure the sagittal alignment. Instead, scoliosis has been evaluated by the end vertebrae in the coronal plane. There have been clinical studies to investigate sagittal alignment on the end vertebrae of inflection points (IPs). The purpose is to determine sagittal alignment based on IPs and to elucidate the changes while considering age groups. Methods: We identified the most titled vertebrae in the sagittal plane to define the end vertebrae of S1, thoracolumbar and cervicothoracic IPs and to measure the Cobb angles of sacral slope, functional lumbar, thoracic, cervical segment between them, and the McGregor’s line, and the IP distances from the C2 plumb line to the point bisecting the upper end plate of the IPs, in addition to S1. Results: The most common thoracolumbar and cervicothoracic IPs were L2 and T1, respectively. However, the next most common cervicothoracic IP changed from T2 in the youngest to C7 in the oldest age group. The sagittal angles decreased at the sacral slope and functional lumbar segment but not the functional thoracic segment and functional cervical segment. Similarly, the distance increased at the C2 sagittal vertical axis (SVA) distance to S1 and thoracolumbar IP distance but not at the cervicothoracic IP distance. There was no difference in the pelvic incidence among age groups. Conclusion: The sagittal Cobb angles based on the IPs decreased at the sacral slope and functional lumbar segment in the older adults. Consequently, the C2 SVA distance to S1 and thoracolumbar IP distance increased.

Download Full-text

Beyond Pelvic Incidence–Lumbar Lordosis Mismatch: The Importance of Assessing the Entire Spine to Achieve Global Sagittal Alignment

Global Spine Journal ◽

10.1177/2192568217699405 ◽

2017 ◽

Vol 7 (6) ◽

pp. 536-542 ◽

Cited By ~ 8

Author(s):

Robert K. Merrill ◽

Jun S. Kim ◽

Dante M. Leven ◽

Joung Heon Kim ◽

Samuel K. Cho

Keyword(s):

Lumbar Lordosis ◽

Pelvic Incidence ◽

Adult Spinal Deformity ◽

Case Series ◽

Vertical Axis ◽

Retrospective Case ◽

Sagittal Vertical Axis ◽

Global Sagittal Alignment ◽

Sagittal Parameters ◽

Combined Parameters

Study Design: Retrospective case series. Objective: To investigate which sagittal parameters contribute to a normal sagittal vertical axis (SVA) when there is a pelvic incidence-lumbar lordosis (PI-LL) mismatch >10° following adult spinal deformity (ASD) correction. Methods: We performed a retrospective review of ASD patients with >5 levels fused. Sagittal measurements between cohorts of postoperative PI-LL >10° and PI-LL<10° were compared. We correlated SVA to pelvic tilt (PT), thoracic kyphosis (TK), PI-LL, cervical lordosis (CL), and correlated the pre- to postoperative change in SVA to change in PT, change in TK, change in PI-LL, and change in CL. We also correlated SVA and the change in SVA to combined parameters of ((PI-LL) − PT + TK). Results: We analyzed 52 patients with a mean age of 59 ± 16 years. In patients with a postoperative SVA <5cm, a smaller TK was seen when PI-LL >10° than when PI-LL<10° (15.45° vs 33.04°, P = .0004). Additionally, PT was larger when PI-LL >10° than when PI-LL <10° (25.73° vs 19.07°, P = .006). SVA correlated better with ((PI-LL) − PT + TK) ( R2 = 0.51) than with PI-LL alone ( R2 = 0.33). Lastly, there was no significant correlation between change in pre- to postoperative SVA with change in TK for all cases ( P = .73), but in cases where change in PI-LL was <10°, there was a significant correlation between change in TK and change in SVA ( P = .009). Conclusion: Our results demonstrate that PT and TK, and not just PI-LL, play an important role in maintaining sagittal balance when there is a PI-LL mismatch >10°.

Download Full-text

Analysis of the Sagittal Balance in Patients with Adult Spinal Deformity: Modified Sagittal Vertical Axis

10.21203/rs.3.rs-599654/v1 ◽

2021 ◽

Author(s):

Yang Yu ◽

Bing Wu ◽

Zhaohan Wang ◽

Junyao Cheng ◽

Bo Li ◽

...

Keyword(s):

Quality Of Life ◽

Orthopedic Surgery ◽

Sagittal Balance ◽

Adult Spinal Deformity ◽

Pearson Correlation ◽

Vertical Axis ◽

Sagittal Vertical Axis ◽

Life Score ◽

Pearson Correlation Analysis

Abstract Objective: The overall sagittal balance of patient with adult spinal deformity (ASD) is crucial for satisfactory postoperative outcome. SVA is the parameter often used to assess the sagittal balance. However, pelvis often rotates backward to compensate for sagittal imbalance in patients with ASD. In the case, SVA cannot reflect the real sagittal balance. Modified sagittal vertical axis (MSVA) is the parameter we found to better assess the real sagittal balance in patients with ASD. And we want to explore the relationship between MSVA and the quality of life. Methods: We used sample of 60 patients with ASD who underwent long-segment orthopedic surgery (≥4 vertebrae) between the period of 2015 and 2018. The paired-sample t test and Pearson correlation analysis were used for statistical analysis. P value <0.05 was considered significant. Results: SVA, TK, TLK, LL, SS, PT, PI-LL and MSVA were significantly changed in 60 patients preoperatively and postoperatively (p<0.05). The ODI, SRS22, VAS scores were significantly improved postoperatively (p<0.05). Pearson correlation analysis was used to conclude that postoperative SVA, postoperative MSVA and postoperative quality of life score were related. Postoperative MSVA has the strongest correlation with the quality-of-life score. Conclusions: Through spinal orthopedic surgery, the postoperative spinal parameters and quality of life of patients with ASD were significantly improved. MSVA is of great significance for evaluating postoperative sagittal balance and quality of life of patients with ASD.

Download Full-text

Improvement in cervical lordosis and sagittal alignment after vertebral body sliding osteotomy in patients with cervical spondylotic myelopathy and kyphosis

Journal of Neurosurgery Spine ◽

10.3171/2020.3.spine2089 ◽

2020 ◽

Vol 33 (3) ◽

pp. 307-315 ◽

Cited By ~ 1

Author(s):

Dong-Ho Lee ◽

Choon Sung Lee ◽

Chang Ju Hwang ◽

Jae Hwan Cho ◽

Jae-Woo Park ◽

...

Keyword(s):

Vertebral Body ◽

Cervical Spondylotic Myelopathy ◽

Sagittal Alignment ◽

Japanese Orthopaedic Association ◽

Vertical Axis ◽

Sacral Slope ◽

Cervical Lordosis ◽

Sagittal Vertical Axis ◽

Segmental Lordosis

OBJECTIVEVertebral body sliding osteotomy (VBSO) is a safe, novel technique for anterior decompression in patients with multilevel cervical spondylotic myelopathy. Another advantage of VBSO may be the restoration of cervical lordosis through multilevel anterior cervical discectomy and fusion (ACDF) above and below the osteotomy level. This study aimed to evaluate the improvement and maintenance of cervical lordosis and sagittal alignment after VBSO.METHODSA total of 65 patients were included; 34 patients had undergone VBSO, and 31 had undergone anterior cervical corpectomy and fusion (ACCF). Preoperative, postoperative, and final follow-up radiographs were used to evaluate the improvements in cervical lordosis and sagittal alignment after VBSO. C0–2 lordosis, C2–7 lordosis, segmental lordosis, C2–7 sagittal vertical axis (SVA), T1 slope, thoracic kyphosis, lumbar lordosis, sacral slope, pelvic tilt, and Japanese Orthopaedic Association scores were measured. Subgroup analysis was performed between 15 patients with 1-level VBSO and 19 patients with 2-level VBSO. Patients with 1-level VBSO were compared to patients who had undergone 1-level ACCF.RESULTSC0–2 lordosis (41.3° ± 7.1°), C2–7 lordosis (7.1° ± 12.8°), segmental lordosis (3.1° ± 9.2°), and C2–7 SVA (21.5 ± 11.7 mm) showed significant improvements at the final follow-up (39.3° ± 7.2°, 13° ± 9.9°, 15.2° ± 8.5°, and 18.4 ± 7.9 mm, respectively) after VBSO (p = 0.049, p < 0.001, p < 0.001, and p = 0.038, respectively). The postoperative segmental lordosis was significantly larger in 2-level VBSO (18.8° ± 11.6°) than 1-level VBSO (10.3° ± 5.5°, p = 0.014). The final segmental lordosis was larger in the 1-level VBSO (12.5° ± 6.2°) than the 1-level ACCF (7.2° ± 7.6°, p = 0.023). Segmental lordosis increased postoperatively (p < 0.001) and was maintained until the final follow-up (p = 0.062) after VBSO. However, the postoperatively improved segmental lordosis (p < 0.001) decreased at the final follow-up (p = 0.045) after ACCF.CONCLUSIONSNot only C2–7 lordosis and segmental lordosis, but also C0–2 lordosis and C2–7 SVA improved at the final follow-up after VBSO. VBSO improves segmental cervical lordosis markedly through multiple ACDFs above and below the VBSO level, and a preserved vertebral body may provide more structural support.

Download Full-text