Surgical Outcomes of Post-Fusion Lumbar Flatback Deformity with Sagittal Imbalance

Kim, Jin Seong,Kim, Sung Min The Korean Neurosurgical Society 2016 Journal of Korean neurosurgical society Vol.59 No.6

Objectives : To review surgical results of post-fusion lumbar flatback treated with pedicle subtraction osteotomy (PSO) or Smith-Petersen osteotomies (SPOs). Methods : Twenty-eight patients underwent osteotomies. Radiological outcomes by sagittal vertical axis (SVA), and pelvic tilt (PT), T1 pelvic angle (T1PA), and pelvic incidence (PI)-lumbar lordosis (LL) at preoperative, postoperative 1 month, and final were evaluated. Oswestry Disability Index (ODI), visual analog scale (VAS) score of back pain/leg pain, and Scoliosis Research Society-22 score (SRS-22r) were analyzed and compared. Patients were divided into 2 groups (SVA ${\leq}5cm$ : normal, SVA >5 cm : positive) at final and compared outcomes. Results : Nineteen patients (68%) had PSO and the other 9 patients had SPOs with anterior lumbar interbody fusions (ALIFs) (Mean age : 65 years, follow-up : 31 months). The PT, PI-LL, SVA, T1PA were significantly improved at 1 month and at final (p<0.01). VAS score, ODI, and SRS-22r were also significantly improved at the final (p<0.01). 23 patients were restored with normal SVA and the rest 5 patients demonstrated to positive SVA. SVA and T1PA at 1 month and SVA, PI-LL, and T1PA at final were significantly different (p<0.05) while the ODI, VAS, and SRS-22r did not differ significantly between the groups (p>0.05). Common reoperations were early 4 proximal junctional failures (14%) and late four rod fractures. Conclusion : Our results demonstrate that PSO and SPOs with ALIFs at the lower lumbar are significantly improves sagittal balance. For maintenance of normal SVA, PI-LL might be made negative value and T1PA might be less than $11^{\circ}$ even though positive SVA group was also significantly improved clinical outcomes.

Three-Column Osteotomy for the Treatment of Rigid Cervical Deformity

Darryl Lau,Christopher P. Ames 대한척추신경외과학회 2020 Neurospine Vol.17 No.3

Adult cervical deformity (ACD) has been shown to have a substantial impact on quality of life and overall health, with moderate to severe deformities resulting in significant disability and dysfunction. Fortunately, surgical management and correction of cervical sagittal imbalance can offer significant benefits and improvement in pain and disability. ACD is a heterogenous disease and specific surgical correction strategies should reflect deformity type (driver of deformity) and patient-related factors. Spinal rigidity is one of the most important considerations as soft tissue releases and osteotomies play a crucial role in cervical deformity correction. For ankylosed, fixed, and severe deformity, 3-column osteotomy (3CO) is often warranted. A 3CO can be done through combined anteriorposterior (vertebral body resection) and posterior-only approaches (open or closed wedge pedicle subtraction osteotomies [PSOs]). This article reviews the literature for currently published studies that report results on the use of 3CO for ACD, with a special concentration on posterior based 3CO (open and closed wedge PSO). More specifically, this review discusses the indications, radiographic corrective ability, and associated complications.

Clinical Outcomes and Complications after Pedicle Subtraction Osteotomy for Fixed Sagittal Imbalance Patients : A Long-Term Follow-Up Data

Hyun, Seung-Jae,Rhim, Seung-Chul The Korean Neurosurgical Society 2010 Journal of Korean neurosurgical society Vol.47 No.2

Objective : Clinical, radiographic, and outcomes assessments, focusing on complications, were performed in patients who underwent pedicle subtraction osteotomy (PSO) to assess correction effectiveness, fusion stability, procedural safety, neurological outcomes, complication rates, and overall patient outcomes. Methods : We analyzed data obtained from 13 consecutive PSO-treated patients presenting with fixed sagittal imbalances from 1999 to 2006. A single spine surgeon performed all operations. The median follow-up period was 73 months (range 41-114 months). Events during peri operative course and complications were closely monitored and carefully reviewed. Radiographs were obtained and measurements were done before surgery, immediately after surgery, and at the most recent follow-up examinations. Clinical outcomes were assessed using the Oswestry Disability Index and subjective satisfaction evaluation. Results : Following surgery, lumbar lordosis increased from $-14.1^{\circ}{\pm}20.5^{\circ}$ to $-46.3^{\circ}{\pm}12.8^{\circ}$ (p<0.0001). and the C7 plumb line improved from $115{\pm}43\;mm$ to $32{\pm}38\;mm$ (p<0.0001). There were 16 surgery-related complications in 8 patients; 3 intraoperative, 3 perioperative, and 10 late-onset postoperative. The prevalence of proximal junctional kyphosis (PJK) was 23% (3 of 13 patients). However, clinical outcomes were not adversely affected by PJK. Intraoperative blood loss averaged 2,984 mL. The C7 plumb line values and postoperative complications were closely correlated with clinical results. Conclusion : Intraoperative or postoperative complications are relatively common following PSO. Most late-onset complications in PSO patients were related to PJK and instrumentation failure. Correcting the C7 plumb line value with minimal operative complications seemed to lead to better clinical results.

Multiple-Rod Constructs Do Not Reduce Pseudarthrosis and Rod Fracture After Pedicle Subtraction Osteotomy for Adult Spinal Deformity Correction but Improve Quality of Life

Anouar Bourghli,Louis Boissiere,David Kieser,Daniel Larrieu,Javier Pizones,Ahmet Alanay,Ferran PelIise,Franck Kleinstück,Ibrahim Obeid 대한척추신경외과학회 2021 Neurospine Vol.18 No.4

Objective: To compare the radiological and functional outcomes and complications of adult spinal deformity patients who underwent a pedicle subtraction osteotomy (PSO) below L2 but categorized according to their construct where either 2-rod or multiple-rod construct is applied. Methods: Sixty-seven patients met the inclusion criteria, and were categorized into 3 groups: 2 rods (2R), multiple rods around the PSO (MRP), multiple rods around the PSO and lumbosacral junction (MRL). Demographic data, operative parameters, spinopelvic parameters, functional outcomes, and complications were collected. Results: Health-related quality of life scores showed a better outcome at 6 months and last follow-up visits in the MRP and MRL groups which were noted on different domains of Scoliosis Research Society-22 questionnaire, 36-item Short Form Health Surve, and Oswestry Disability Index scores (p<0.05). The 3 groups showed similar rates of rod-related complications with no significant difference (p=0.95). And inside each group, distribution of complications between pseudarthrosis with revision and rod fracture without revision was also similar (p=0.99). Conclusion: The use of multiple rods across the PSO did not show a better outcome when compared to single rods in terms of incidence and types of mechanical complications. However, better postoperative coronal alignment and health-related quality of life scores in the multiple rods group could be seen demonstrating an improved functional outcome.

A Review of Complications and Outcomes following Vertebral Column Resection in Adults

Sravisht Iyer,Venu M. Nemani,Han Jo Kim 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.3

The correction of rigid spinal deformities in adult patients can require a three-column osteotomy (pedicle subtraction osteotomy [PSO] or vertebral column resection [VCR]) to obtain spinal balance. Unfortunately, the existing adult deformity literature frequently reports the outcomes and complications of these procedures together even though VCR is a more extensive procedure with potentially higher rates of complications. We sought to address this shortcoming and provide clinicians with an overview of the existing literature regarding VCR in adult patients. The goals of this review are: to determine the rate of overall and neurologic complications following VCR, the rate of complications with VCR compared to PSO, and the impact of VCR on clinical and radiographic outcomes. An electronic literature search was used to identify studies reporting outcomes or complications following VCR in adult patients. Raw data on patient demographics, case information, radiographic outcomes, complications and clinical outcomes were extracted. Data were pooled to report a rate of overall complications and neurologic complications. A pooled relative risk of complications following PSO vs. VCR was also calculated. Eleven retrospective studies (Level IV) met our inclusion criteria. The overall rate of complications was 69.2%. The reoperation rate was 9.6%. The rate of neurologic complications was 13.3% (range, 6.3% to 15.8%) with most cases being transient. The rate of permanent neurologic deficits was 2.0%. We found a significantly higher rate of all complications with VCR compared to PSO (relative risk, 1.36; 95% confidence interval, 1.24–1.49; p <0.001). All studies reporting clinical outcomes showed significant improvements in functional outcome postoperatively.

시상면 불균형 환자에서 척추경을 통한 쐐기형 절골술[PSO]을 시행한 후 교정각 소실에 대한 원인 분석

김환정(Whoan Jeang Kim),강종원(Jong Won Kang),김규현(Kyou Hyeun Kim),박건영(Kun Young Park),정유훈(Yu Hun Jung),정학재(Hack Jae Jeong),최원식(Won Sik Choy) 대한정형외과학회 2004 대한정형외과학회지 Vol.39 No.6

목적: 시상면 불균형 환자에서 척추경을 통한 쐐기형 절골술을 시행한 후 교정각 소실의 원인을 방사선학적 측면에서 후 향적으로 분석하였다. 대상 및 방법: 척추경을 통한 쐐기형 절골술을 시행한 40예를 대상으로 하였다. 하요추부 가동 분절의 유무와 전방 지지 유무에 따른 교정각 소설의 원인을 방사선학적 측면에서 각각 조사하였다. 결과: 전체 전만곡도의 교정각 소설은 하요추부 가동 분절이 있는 군에서 통계학적으로 유의하게 증가하였으며(p=0.025), 절골 추체의 교정각 소실은 가동 분절의 유무에 관계없이 거의 없었다. 절골술 상부 고정 범위의 교정각 소실은 가동 분절의 유무에 따른 통계학적인 유의성은 없었으나(p=0.138), 하부 고정 범위에서는 하요추부 가통 분절이 있는 군에서 통계학적으로 유의하게 증가하였다(p=0.014). 가동 분절이 있는 경우 상부 고정 범위에 비해 하부 고정 범위에서 교정각 소실이 더 많이 발생하였으며, 전방 지지를 시행하지 않은 경우에서 하부 고정 범위의 교정각 소실이 유의하게 증가하였다 (p=0.012). 결론: 교정각 소설은 가동 분절이 있는 추간판에서 일어나고 특히, 절골술 상부 고정 범위에서보다 하부 고정 범위에서 유의하게 증가하므로 절골술 하부 고정 범위 모두를 전방지지 히는 것이 바람직할 것으로 사료된다. Purpose: To validate the surgical principles by analyzing the cause of a correction loss after pedicle subtraction osteotomy in patients with a sagittal imbalance in the radiological aspects, retrospectively. Materials and Methods: Forty cases were analyzed radiographycally according to the presence (Group A) or absence (Group B) of the lower mobile segment and anterior column support performed (Group A2) or not (Group A1), respectively. Results: The overall correction loss of the total fused part appeared to increase in group A (p=0.025) and the degree of lordosis of the osteotomy site showed an almost zero correction loss in group A and B. No statistic difference of the correction loss of the upper segment of the osteotomy site between the two groups was found (p=0.138). The correction loss of the lower segment of osteotomy site increased statistically more in goup A (p=0.014). The correction loss in group A occurred more in the lower segment than in the upper segment and the correction loss of the lower segment in group A1 appeared to have a better correlation than group A2 (p=0.012). Conclusion: Correction loss occurs at the intervertebral disc of the mobile segment. It is considered desirable to have anterior column support to all lower segment of the osteotomy site, because the correction loss increases more in the lower segment than in the upper segment.

Cervical Deformity Arising From Upper Thoracic Malalignment

Ibrahim Obeid,Louis Boissiere,Anouar Bourghli 대한척추신경외과학회 2020 Neurospine Vol.17 No.3

This study aims to describe the surgical management of cervical deformity arising from outside the cervical spine because of upper thoracic malalignment, using pedicle subtraction osteotomy (PSO). Cervical spine deformity is a complex topic and it can be generally divided into 2 categories, the first category is when the primary deformity is inside the cervical spine and the treatment will focus on the cervical spine itself, whereas the second category is when the primary deformity is outside the cervical spine usually in the adjacent upper thoracic area, the cervical deformity is a compensation for the adjacent malalignment, and thus in this situation, the management will occur in the upper thoracic area. Description of a single surgeon’s technique for performing PSO to treat rigid upper thoracic deformity. PSO in the upper thoracic spine is a safe and effective procedure and can result in satisfying clinical and radiological outcome with indirect correction of the compensatory cervical deformity. Cervical deformity arising from upper thoracic malalignment should be dealt with by treating the problem at its origin outside the cervical spine by performing a PSO in the upper thoracic spine.

Comparison of Clinical Outcomes and Complications of Primary and Revision Surgery Using a Combined Anterior and Posterior Approach in Patients with Adult Spinal Deformity and Sagittal Imbalance

Whoan Jeang Kim,Hyun Min Shin,Dae Geon Song,Jae Won Lee,Kun Young Park,Shann Haw Chang,Jin Hyun Bae,Won Sik Choy 대한정형외과학회 2021 Clinics in Orthopedic Surgery Vol.13 No.2

Background: The purpose of this study was to compare clinical outcomes and complications of primary and revision surgery in patients with adult spinal deformity (ASD) accompanied by sagittal imbalance. Revision surgery has been associated with poor clinical outcomes and increased risk of complications. Previous studies comparing primary versus revision surgery included data for a wide variety of diseases and ages, but few investigated patients with ASD with sagittal imbalance undergoing anterior and posterior combined surgery. Methods: Retrospective cohort analysis of prospectively collected data. We identified 60 consecutive patients with ASD combined with sagittal imbalance who underwent primary or revision surgery; of these, 6 patients were excluded for lack of a minimal 2-year follow-up. Patients’ surgical and radiological data, clinical outcomes, and complications were reviewed. Results: There were 30 patients in the primary group and 24 patients in the revision group. Patient characteristics, including the prevalence of sarcopenia, were similar between the two groups. Pedicle subtraction osteotomy was performed more frequently in the revision group although there was no statistically significant difference between groups. The primary group had more proximal junctional problems, whereas the revision group had more rod breakage (p < 0.05). There were significant improvements in clinical outcomes in both groups when the preoperative and 2-year postoperative values were compared. The Oswestry disability index and visual analog scale score were similar in both groups 2 years postoperatively. Conclusions: Considering the greater pain and disability at the time of the revision procedure, revision patients benefited more from surgery at the 2-year follow-up than the primary surgery patients. Complication rates were similar between the groups except for proximal junctional problems and rod breakage. Therefore, revision surgery should not be avoided in the treatment of ASD patients with sagittal imbalance.

A Comparative Biomechanical Analysis of Various Rod Configurations Following Anterior Column Realignment and Pedicle Subtraction Osteotomy

Muzammil Mumtaz,Justin Mendoza,Ardalan Seyed Vosoughi,Anthony S. Unger,Vijay K. Goel 대한척추신경외과학회 2021 Neurospine Vol.18 No.3

Objective: The objective of this study was to compare the biomechanical differences of different rod configurations following anterior column realignment (ACR) and pedicle subtraction osteotomy (PSO) for an optimal correction technique and rod configuration that would minimize the risk of rod failure. Methods: A validated spinopelvic (L1-pelvis) finite element model was used to simulate ACR at the L3–4 level. The ACR procedure was followed by dual-rod fixation, and for 4-rod constructs, either medial/lateral accessory rods (connected to primary rods) or satellite rods (directly connected to ACR level screws). The range of motion (ROM), maximum von Mises stress on the rods, and factor of safety (FOS) were calculated for the ACR models and compared to the existing literature of different PSO rod configurations. Results: All of the 4-rod ACR constructs showed a reduction in ROM and maximum von Mises stress compared to the dual-rod ACR construct. Additionally, all of the 4-rod ACR constructs showed greater percentage reduction in ROM and maximum von Mises stress compared to the PSO 4-rod configurations. The ACR satellite rod construct had the maximum stress reduction i.e., 47.3% compared to dual-rod construct and showed the highest FOS (4.76). These findings are consistent with existing literature that supports the use of satellite rods to reduce the occurrence of rod fracture. Conclusion: Our findings suggest that the ACR satellite rod construct may be the most beneficial in reducing the risk of rod failure compared to all other PSO and ACR constructs.