Treatment Of Adult Spinal Deformity Research Articles

Prevalence and Prognosis of Coronal Malalignment Following Lateral Lumbar Interbody Fusion for Minimally Invasive Treatment of Adult Spinal Deformity.

Retrospective analysis of prospective multicenter adult spinal deformity (ASD) database. To determine the prevalence and prognosis of postoperative coronal malalignment following LLIF for ASD with Qiu type A coronal alignment. Qiu Type A coronal alignment is defined as coronal vertical axis (CVA) <30mm.1 There is concern that circumferential minimally invasive surgery (cMIS) with lateral lumbar interbody fusion (LLIF) is associated with postoperative coronal malalignment in ASD with preoperative Qiu type A patients. Qui type A patients undergoing cMIS with LLIF for ASD were included, with ASD defined with at least: maximum CC≥20°, SVA>5cm, PI-LL≥10°, or PT>20°. Two year (2Y) clinical outcomes were compared for type A with 2Y CVA≥30mm (MAL) versus <30mm (ALIGN) and were adjusted for factors reaching P<0.05 on univariate comparisons (age, BMI, and ODI). 43 patients met inclusion criteria, of which 12 (27.9%) developed coronal malalignment and 31 (72.1%) remained coronally aligned at 2Y. At baseline, MAL were older (73.0 vs. 69.0, P=0.045), had a lower BMI (26.09 vs. 29.45, P=0.047), and were less disabled (ODI 42.83 vs. 51.69, P=0.016). Otherwise, the groups were well-matched for baseline characteristics. At 2Y, MAL had a greater 2Y SVA (mean 54.08 vs 19.00mm, P=0.01). Clinically, MAL was associated with inferior 2Y SF-36 PCS (34.78 vs. 37.42, adj P=0.043) and 2Y SRS-22r function/activity domain (3.03 vs. 3.36, adj P=0.040), but otherwise similar in other patient-reported-outcome-metrics (adj P>0.05 for all). 2Y complications were similar between groups, including for reoperations and major and minor complications (adj P>0.05 for all). In Qui type A patients undergoing cMIS with LLIF for ASD, 27.9% develop coronal malalignment, which was associated with worse SF-36 PCS and SRS-22r function/activity. Despite radiographic malalignment, malalignment was not associated with higher 2-year complication rates including reoperations.

Early clinical outcomes and medical complications following long segment fusion for adult spinal deformity with and without three column osteotomy

BackgroundSurgical treatment of adult spinal deformity (ASD) commonly involves long-segment fusion with or without three column osteotomies (3CO) to provide satisfactory correction of sagittal and coronal balance. While some clinical studies have implicated 3CO as a driver of high surgical complication rates, these prior investigations are limited by small sample size. Herein, we compare early outcomes and adverse events in patients undergoing long segment posterior spinal fusion for ASD with and without 3CO. MethodsA multicenter administrative database was queried for patients undergoing elective posterior spinal fusion for ASD. Patients were stratified based upon long segment fusion with and without 3CO. Preoperative patient demographics, procedural characteristics, hospitalization events, and postoperative complication rates were evaluated. Student's t-test and Fisher's exact test were utilized where appropriate to compare differences between the two groups for continuous and categorical variables. Results340 cases met the inclusion criteria, of which 156 involved 3CO. Patients who required 3CO had a lower rate of preoperative diabetes (22.3 % vs 10.3 %, p = 0.003), higher rates of non-home discharge (26.2 % vs 57.1 %, p < 0.001), longer operation time (245.62 ± 9.45 vs. 434.40 ± 11.65, p < 0.001), and longer length of stay (4.17 ± 0.66 vs. 7.76 ± 0.83, p < 0.001). In terms of complications, 3CO patients had higher rates of deep surgical site infection (0 % vs 3.2 %, p = 0.02), reintubation (0 % vs 4.5 %, p = 0.004), inability to wean off ventilator (0 % vs 2.6 %, p = 0.04), and perioperative blood transfusion (20.1 % vs 76.3 %, p < 0.001). ConclusionsIn this retrospective analysis, posterior 3CO was frequently undertaken but associated with higher risk for postoperative adverse events following spinal deformity correction.

Explainable Machine Learning Approach to Prediction of Prolonged Intesive Care Unit Stay in Adult Spinal Deformity Patients: Machine Learning Outperforms Logistic Regression.

Retrospective cohort study. Prolonged ICU stay is a driver of higher costs and inferior outcomes in Adult Spinal Deformity (ASD) patients. Machine learning (ML) models have recently been seen as a viable method of predicting pre-operative risk but are often 'black boxes' that do not fully explain the decision-making process. This study aims to demonstrate ML can achieve similar or greater predictive power as traditional statistical methods and follows traditional clinical decision-making processes. Five ML models (Decision Tree, Random Forest, Support Vector Classifier, GradBoost, and a CNN) were trained on data collected from a large urban academic center to predict whether prolonged ICU stay would be required post-operatively. 535 patients who underwent posterior fusion or combined fusion for treatment of ASD were included in each model with a 70-20-10 train-test-validation split. Further analysis was performed using Shapley Additive Explanation (SHAP) values to provide insight into each model's decision-making process. The model's Area Under the Receiver Operating Curve (AUROC) ranged from 0.67 to 0.83. The Random Forest model achieved the highest score. The model considered length of surgery, complications, and estimated blood loss to be the greatest predictors of prolonged ICU stay based on SHAP values. We developed a ML model that was able to predict whether prolonged ICU stay was required in ASD patients. Further SHAP analysis demonstrated our model aligned with traditional clinical thinking. Thus, ML models have strong potential to assist with risk stratification and more effective and cost-efficient care.

Instrumentation Failure in Adult Spinal Deformity Patients.

In recent years, advances in the surgical treatment of adult spinal deformity (ASD) have led to improved outcomes. Although these advances have helped drive the development of deformity surgery to meet the rising volume of patients seeking surgical treatment, many challenges have yet to be solved. Instrumentation failure remains one of the most common major complications following deformity surgery, associated with significant morbidity due to elevated re-operation rates among those experiencing mechanical complications. The two most frequently encountered subtypes of instrumentation failure are rod fracture (RF) and proximal junctional kyphosis/proximal junctional failure (PJK/PJF). While RF and PJK/PJF are both modes of instrumentation failure, they are two distinct entities with different clinical implications and treatment strategies. Considering that RF and PJK/PJF continue to represent a major challenge for patients with ASD and deformity surgeons alike, this review aims to discuss the incidence, risk factors, clinical impact, treatment strategies, preventive measures, and future research directions for each of these substantial complications.

Topping-Off a Long Thoracic Stabilization With Semi-Rigid Constructs May Have Favorable Biomechanical Effects to Prevent Proximal Junctional Kyphosis: A Biomechanical Comparison.

In-vitro cadaveric biomechanical study. Long posterior spinal fusion is a standard treatment for adult spinal deformity. However, these rigid constructs are known to alter motion and stress to the adjacent non-instrumented vertebrae, increasing the risk of proximal junctional kyphosis (PJK). This study aimed to biomechanically compare a standard rigid construct vs constructs "topped off" with a semi-rigid construct. By understanding semi-rigid constructs' effect on motion and overall construct stiffness, surgeons and researchers could better optimize fusion constructs to potentially decrease the risk of PJK and the need for revision surgery. Nine human cadaveric spines (T1-T12) underwent non-destructive biomechanical range of motion tests in pure bending or torsion and were instrumented with an all-pedicle-screw (APS) construct from T6-T9. The specimens were sequentially instrumented with semi-rigid constructs at T5: (i) APS plus sublaminar bands; (ii) APS plus supralaminar hooks; (iii) APS plus transverse process hooks; and (iv) APS plus short pedicle screws. APS plus transverse process hooks had a range of motion (ie, relative angle) for T4-T5 and T5-T6, as well as an overall mechanical stiffness for T1-T12, that was more favourable, as it reduced motion at adjacent levels without a stark increase in stiffness. Moreover, APS plus transverse process hooks had the most linear change for range of motion across the entire T3-T7 range. Present findings suggest that APS plus transverse process hooks has a favourable biomechanical effect that may reduce PJK for long spinal fusions compared to the other constructs examined.

326 Factors Associated With the Maintenance of Cost-Effectiveness at 5 Years in Adult Spinal Deformity Corrective Surgery

INTRODUCTION: Substantial increase of costs in the surgical treatment of adult spinal deformity has given precedence to scrutinize the value it can provide hence cost-effectiveness (CE) is a vital analytical constituent. The analysis of factors associated with the durability of cost-effectiveness at 5 years has not been previously evaluated. METHODS: Adult spinal deformity (ASD) patients with baseline (BL) to 5-year (5Y) data were included. Cost calculation using PearlDiver database and CMS.gov definitions was used. Cost analysis was based on average DRG reimbursement rates. ODI was converted to SF-6D, with a 3% discount applied for residual decline in life expectancy. Cost per QALY gained at 2Y and 5Y was calculated. Threshold value for cost per QALY was $100,000. Patients that met 2Y (CE2+) were grouped based on meeting CE at 5Y(CE5+) or not(CE5-). Analysis based on meeting cost-effectiveness (CE) at 2Y and 5Y was conducted. Conditional-inference-tree (CIT) established cutoffs values for HRQLs. RESULTS: 299 patients with 5Y data were included. Major and minor complication rates were 11% and 47% respectively, while 26% underwent reoperation by 5Y. The mean cost of surgery was $91,095 ± $47,003, utility-gain of 0.091 ± 0.086, and QALY of 0.171 ± 0.183, CE of $118,976 ± $208,323. 85.5% of the cohort met CE at 2Y, 79.2% at 5Y, whereas 59.6% met both. Frailty was comparable at baseline but was worse in CE5- at 2Y. CIT depicted 2Y ODI &lt; 18 and SRS-22r &gt; 3.3 (both p &lt; 0.03) being associated with higher rates of C5+. Multivariable-regression depicted higher baseline CCI and pelvic tilt (PT) to be the strongest baseline predictors of not maintaining CE at 5Y (CCI OR: 1.821, p = 0.009) (PT OR: 1.079, p = .030). CONCLUSIONS: The majority that met cost-effectiveness at the 2 year went on to maintain it at 5 years. Lower baseline CCI and PT were strong predictive factors.

A guide to selecting upper thoracic versus lower thoracic uppermost instrumented vertebra in adult spinal deformity correction.

Operative treatment of adult spinal deformity (ASD) has been shown to improve patient health-related quality of life (HRQOL). Selection of the uppermost instrumented vertebra (UIV) in either the upper thoracic (UT) or lower thoracic (LT) spine is a pivotal decision with effects on operative and postoperative outcomes. This review overviews the multifaceted decision-making process for UIV selection in ASD correction. PubMed was queried for articles using the keywords "uppermost instrumented vertebra", "upper thoracic", "lower thoracic", and "adult spinal deformity". Optimization of UIV selection may lead to superior deformity correction, better patient-reported outcomes, and lower risk of proximal junctional kyphosis (PJK) and failure (PJF). Patient alignment characteristics, including preoperative thoracic kyphosis, coronal deformity, and the magnitude of sagittal correction influence surgical decision-making when selecting a UIV, while comorbidities such as poorbody mass index, osteoporosis, and neuromuscular pathology should also be taken in to account. Additionally, surgeon experience and resources available to the hospital may also play a role in this decision. Currently, it is incompletely understood whether postoperative HRQOLs, functional and radiographic outcomes, and complications after surgery differ between selection of the UIV in either the UT or LT spine. The correct selection of the UIV in surgical planning is a challenging task, which requires attention to preoperative alignment, patient comorbidities, clinical characteristics, available resources, andsurgeon-specific factors such as experience.

Factors Associated With the Maintenance of Cost-effectiveness at Five Years in Adult Spinal Deformity Corrective Surgery.

Retrospective cohort. To evaluate factors associated with the long-term durability of cost-effectiveness (CE) in ASD patients. A substantial increase in costs associated with the surgical treatment for adult spinal deformity (ASD) has given precedence to scrutinize the value and utility it provides. We included 327 operative ASD patients with five-year (5yr) follow-up. Published methods were used to determine costs based on CMS.gov definitions and were based on the average DRG reimbursement rates. The utility was calculated using quality-adjusted life-years (QALY) utilizing the Oswestry Disability Index (ODI) converted to Short-Form Six-Dimension (SF-6D), with a 3% discount applied for its decline in life expectancy. The CE threshold of $150,000 was used for primary analysis. Major and minor complication rates were 11% and 47%, respectively, with 26% undergoing reoperation by five years. The mean cost associated with surgery was $91,095±$47,003, with a utility gain of 0.091±0.086 at one years, QALY gained at 2 years of 0.171±0.183, and at five years of 0.42±0.43. The cost per QALY at two years was $414,885, which decreased to $142,058 at five years.With the threshold of $150,000 for CE, 19% met CE at two years and 56% at five years. In those in which revision was avoided, 87% met cumulative CE till life expectancy. Controlling analysis depicted higher baseline CCI and pelvic tilt (PT) to be the strongest predictors for not maintaining durable CE to five years [CCI OR: 1.821 (1.159-2.862), P =0.009] [PT OR: 1.079 (1.007-1.155), P =0.030]. Most patients achieved cost-effectiveness after four years postoperatively, with 56% meeting at five years postoperatively. When revision was avoided, 87% of patients met cumulative cost-effectiveness till life expectancy. Mechanical complications were predictive of failure to achieve cost-effectiveness at two years, while comorbidity burden and medical complications were at five years.

Biomechanical analysis of complications following T10-Pelvis spinal fusion: A population based computational study

Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are challenging complications of long fusion constructs for the treatment of adult spinal deformity. The objective of this study is to understand the biomechanical stresses proximal to the upper instrumentation of a T10-pelvis fusion in a large patient cohort. The pre-fusion models were subject-specific thoracolumbar spine models that incorporate the height, weight, spine curvature, and muscle morphology of 250 individuals from the Framingham Heart Study Multidetector CT Study. To create post-fusion models, the subject-specific models were further modified to eliminate motion between the intervertebral joints from T10 to the pelvis. OpenSim analysis tools were used to calculate the medial lateral shear force, anterior posterior shear force, and compressive force on the T9 vertebra during the static postures. Differences between pre-fusion and post-fusion T9 biomechanics were consistent between increased segmental mobility and unchanged segmental mobility conditions.For all static postures, compression decreased (p < 0. 0005). Anterior-posterior shear force significantly increased (p < 0. 0005) during axial twist and significantly increased (p < 0. 0005) during trunk flexion. Medial lateral shear force significantly increased (p < 0. 0005) during axial twist. This computational study provided the first use of subject-specific models to investigate the biomechanics of long spinal fusions. Patients undergoing T10-Pelvis fusion were predicted to have increased shear forces and decreased compressive force at the T9 vertebra, independent of change in segmental mobility. The computational model shows potential for the investigation of spinal fusion biomechanics to reduce the risk of PJK or PJF.

Pedicle Subtraction Osteotomy Versus Multilevel Anterior Lumbar Interbody Fusion and Lateral Lumbar Interbody Fusion in the Treatment of Adult Spinal Deformity: Trends, Outcomes, and Cost.

Retrospective cohort study. The aim of this study was to compare the outcomes of pedicle subtraction osteotomy (PSO) with multilevel anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF) in posterior long-segment fusion. PSO and ALIF/LLIF are 2 techniques used to restore lumbar lordosis and correct sagittal alignment, with each holding its unique advantages and disadvantages. As there are situations where both techniques can be employed, it is important to compare the risks and benefits of both. Patients aged 18 years or older who underwent PSO or multilevel ALIF/LLIF with posterior fusion of 7-12 levels and pelvic fixation were identified. 1:1 propensity score was used to match PSO and ALIF/LLIF cohorts for age, sex, and relevant comorbidities, including smoking status. Logistic regression was used to compare medical and surgical outcomes. Trends and costs were generated for both groups as well. ALIF/LLIF utilization in posterior long fusion has been steadily increasing since 2010, whereas PSO utilization has significantly dropped since 2017. PSO was associated with an increased risk of durotomy ( P < 0.001) and neurological injury ( P = 0.018). ALIF/LLIF was associated with increased rates of postoperative radiculopathy ( P = 0.005). Patients who underwent PSO had higher rates of pseudarthrosis within 1 and 2 years ( P = 0.015; P = 0.010), 1-year hardware failure ( P = 0.028), and 2-year reinsertion of instrumentation ( P = 0.009). Reoperation rates for both approaches were not statistically different at any time point throughout the 5-year period. In addition, there were no significant differences in both procedural and 90-day postoperative costs. PSO was associated with higher rates of surgical complications compared with anterior approaches. However, there was no significant difference in overall reoperation rates. Spine surgeons should select the optimal technique for a given patient and the type of lordotic correction required.

Analysis of Personalized Interbody Implants in the Surgical Treatment of Adult Spinal Deformity.

Multicenter cohort. A report from the International Spine Study Group (ISSG) noted that surgeons failed to achieve alignment goals in nearly two-thirds of 266 complex adult deformity surgery (CADS) cases. We assess whether personalized interbody spacers are associated with improved rates of achieving goal alignment following adult spinal deformity (ASD) surgery. ASD patients were included if their surgery utilized 3D-printed personalized interbody spacer(s) and they met ISSG CADS inclusion criteria. Planned alignment was personalized by the surgeon during interbody planning. Planned vs achieved alignment was assessed and compared with the ISSG CADS series that used stock interbodies. For 65 patients with personalized interbodies, 62% were women, mean age was 70.3 years (SD = 8.3), mean instrumented levels was 9.9 (SD = 4.1), and the mean number of personalized interbodies per patient was 2.2 (SD = .8). Segmental alignment was achieved close to plan for levels with personalized interbodies, with mean difference between goal and achieved as follows: intervertebral lordosis = .9° (SD = 5.2°), intervertebral coronal angle = .1° (SD = 4.7°), and posterior disc height = -0.1mm (SD = 2.3mm). Achieved pelvic incidence-to-lumbar lordosis mismatch (PI-LL) correlated significantly with goal PI-LL (r = .668, P < .001). Compared with the ISSG CADS cohort, utilization of personalized interbodies resulted in significant improvement in achieving PI-LL <5° of plan (P = .046) and showed a significant reduction in cases with PI-LL >15° of plan (P = .012). This study supports use of personalized interbodies as a means of better achieving goal segmental sagittal and coronal alignment and significantly improving achievement of goal PI-LL compared with stock devices.

Complications in adult spinal deformity: Current concepts

Surgical treatment for adult spinal deformity is associated with improved surgical alignment and improved outcome measures. Unfortunately, complications are a common consequence following surgery for adult spinal deformity. This article reviews the current concepts in complications including trends in complication profile over the past decade, classification of complications and risk calculators to help with complication stratification. The goal of this article is to identify the current best practices and to provide the reader with objective information to identify risk factors for complications and their prevention.

Three-Column Osteotomies: Past, Present, and Future

Three-Column Osteotomies (3CO's) refer to osteotomies that involve surgical removal of parts or all of the posterior, middle and anterior columns of the spine. The indications for using a 3CO in the surgical treatment of Adult Spinal Deformity (ASD) have slowly evolved over time but remains idiosyncratic for surgeons treating complex ASD patients. This manuscript will focus on the past and present use of 3CO's to highlight the changes over time in the indications, techniques, surgical results, complications and outcomes to place these procedures in the proper context to then discuss their probable use among ASD patients in the future.

Use of supplemental rod constructs in adult spinal deformity surgery

Operative treatment for adult spinal deformity (ASD) commonly involves long posterior instrumented fusions with primary rods spanning from the base of the construct to the upper instrumented vertebra. Over the past decade, additional supplemental rods have been increasingly utilized to bolster the primary instrumentation and mitigate risk of primary rod fracture/pseudarthrosis at areas of high biomechanical stress (e.g., 3-column osteotomy [3CO], multiple posterior column osteotomies [PCOs], lumbosacral junction). Supplemental rods for 3CO include satellite rods (4-rod technique with 2 deeply recessed short rods independently attached to pedicle screws across the 3CO), accessory rods (attached to primary rods via side-to-side connectors), and delta rods (accessory rods contoured only at the proximal and distal attachments to primary rods). Utilizing more than 4 rods across a 3CO may increase posterior construct stability; however, diminished load transfer to the anterior vertebral column may increase risk of nonunion and instrumentation failure. Similar supplemental rod constructs can be utilized to support multiple PCOs and/or the lumbosacral junction. We generally recommend using bilateral accessory rods for a total of 4 rods to support the lumbosacral junction (2 accessory rods and 2 primary rods). The novel “kickstand rod” can help facilitate coronal correction and/or function as an accessory rod distally anchored to an independent iliac screw; appropriate nomenclature is “iliac accessory rod” in cases without true kickstand distraction. In this narrative review, we aim to (1) provide a brief historical overview of supplemental rod constructs, (2) describe current indications for supplemental rods, and (3) report our results from a longitudinal analysis (2008–2020) of supplemental rod constructs used by International Spine Study Group (ISSG) surgeons.

Multiple-Rod Constructs in Adult Spinal Deformity Surgery: A Systematic Review and Meta-Analysis.

The purpose of this research was to compare the therapeutic efficacy of multiple-rod constructs vis-a-vis 2-rod constructs in the treatment of adult spinal deformity. A systematic review and meta-analysis were performed to determine whether the multiple-rod construct outperformed the 2-rod construct. We initially retrieved 357 papers, but only 12 were chosen for further meta-analysis. The rod breakage rates in the multiple-rod and the 2-rod groups were 10.66% and 29.87%, respectively. The multiple-rod construct inhibited rod breakage (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.19-0.41; p<0.001), pseudarthrosis (OR, 0.30; 95% CI, 0.18-0.50; p<0.001) and rod fracture at the osteotomy site (OR, 0.34; 95% CI, 0.13-0.89; p=0.03). Furthermore, the multiple-rod construct reduces the risk of revision surgery (OR, 0.38; 95% CI, 0.20-0.73; p=0.04) as well as the revision risk of pseudarthrosis/rod fracture in the multiple- rod group (OR, 0.31; 95% CI, 0.18-0.52; p<0.001), but increases the risk of caudal screw loosening (OR, 4.99; 95% CI, 1.87-13.30; p=0.001). There was no statistically significant difference in proximal junctional kyphosis (PJK) parameters (p=0.85), cerebrospinal fluid leakage (p=0.09), wound infection (p =0.71), age at surgery (p=0.62), gender distribution (p=0.93), body mass index (p =0.86), smoking status (p=0.05), hospital stay (p=0.09), osteoporosis (p=0.95), CoCr rod material (p=0.15), bone morphogenetic protein-2 (p=0.58), L5/S1 interbody fusion (p=0.07), high-grade osteotomies (p=0.07), the number of fusion levels (p=0.11), operation time (p=0.30), and blood loss volume (p=0.34). Regarding radiographic parameters, only preoperative sagittal vertical axis was found to be higher (weight means difference [WMD], 25.60; 95% CI, 15.43-35.77; p<0.001) in the multiple-rod group. There was no difference in preoperative Oswestry Disability Index (ODI) (WMD, -3.32; 95% CI, -7.38 to 0.73; p=0.11), but the multiple-rod group had a lower ODI at follow-up (WMD, -7.71; 95% CI, -11.62 to -3.86; p<0.001). Multiple-rod constructs could prevent rod breakage and pseudarthrosis while also lowering the revision rate, resulting in a better clinical outcome than the 2-rod construct. Nonetheless, due consideration should be given to PJK and screw loosening in multiple-rod constructs, possibly due to the increased stiffness caused by the multiple-rod structure.

Risk factors for radiographic progression of proximal junctional fracture in patients undergoing surgical treatment for adult spinal deformity.

Proximal junctional fracture (PJFx) at the uppermost instrumented vertebra (UIV) or UIV+1 is the most common mechanism of proximal junctional failure (PJF). Few studies have assessed radiographic progression after PJFx development. Therefore, this study sought to identify the risk factors for radiographic progression of PJFx in the surgical treatment for adult spinal deformity. In this retrospective study, among 317 patients aged > 60 years who underwent ≥ 5-level fusion from the sacrum, 76 with PJFx development were included. On the basis of the change in the proximal junctional angle (PJA), 2 groups were created: progression group (group P) (change ≥ 10°) and nonprogression group (group NP) (change < 10°). Patient, surgical, and radiographic variables were compared between the groups with univariate and multivariate analyses to demonstrate the risk factors for PJFx progression. The receiver operating characteristic (ROC) curve was used to calculate cutoff values. Clinical outcomes, such as visual analog scale (VAS) scores for back and leg pain, Oswestry Disability Index (ODI) score, the Scoliosis Research Society (SRS)-22 score, and the revision rate were compared between the 2 groups. The mean age at index surgery was 71.1 years, and 67 women were enrolled in the study (88.2%). There were 45 patients in group P and 31 in group NP. The mean increase in PJA was 15.6° (from 23.2° to 38.8°) in group P and 3.7° (from 17.2° to 20.9°) in group NP. Clinical outcomes were significantly better in group NP than group P, including VAS-back score, ODI score, and SRS-22 scores for all items. The revision rate was significantly greater in group P than in group NP (53.3% vs 25.8%, p = 0.001). Multivariate analysis revealed that overcorrection relative to the age-adjusted ideal pelvic incidence (PI)-lumbar lordosis (LL) target at index surgery (OR 4.484, p = 0.030), PJA at the time of PJFx identification (OR 1.097, p = 0.009), and fracture at UIV (vs UIV+1) (OR 3.410, p = 0.027) were significant risk factors for PJFx progression. The cutoff value of PJA for PJFx progression was calculated as 21° by using the ROC curve. The risk factors for further progression of PJFx were overcorrection relative to the age-adjusted PI-LL target at index surgery, PJA > 21° at initial presentation, and fracture at the UIV level. Close monitoring is warranted for such patients in order to not miss timely revision surgery.

Economic burden of nonoperative treatment of adult spinal deformity.

The purpose of this study was to investigate the cost utility of nonoperative treatment for adult spinal deformity (ASD). Nonoperatively and operatively treated patients who met database criteria for ASD and in whom complete radiographic and health-related quality of life data at baseline and at 2 years were available were included. A cost analysis was completed on the PearlDiver database assessing the average cost of nonoperative treatment prior to surgical intervention based on previously published treatments (NSAIDs, narcotics, muscle relaxants, epidural steroid injections, physical therapy, and chiropractor). Utility data were calculated using the Oswestry Disability Index (ODI) converted to SF-6D with published conversion methods. Quality-adjusted life years (QALYs) used a 3% discount rate to account for residual decline in life expectancy (78.7 years). Minor and major comorbidities and complications were assessed according to the CMS.gov manual's definitions. Successful nonoperative treatment was defined as a gain in the minimum clinically importance difference (MCID) in both ODI and Scoliosis Research Society (SRS)-pain scores, and failure was defined as a loss in MCID or conversion to operative treatment. Patients with baseline ODI ≤ 20 and continued ODI of ≤ 20 at 2 years were considered nonoperative successful maintenance. The average utilization of nonoperative treatment and cost were applied to the ASD cohort. A total of 824 patients were included (mean age 58.24 years, 81% female, mean body mass index 27.2 kg/m2). Overall, 75.5% of patients were in the operative and 24.5% were in the nonoperative cohort. At baseline patients in the operative cohort were significantly older, had a greater body mass index, increased pelvic tilt, and increased pelvic incidence-lumbar lordosis mismatch (all p < 0.05). With respect to deformity, patients in the operative group had higher rates of severe (i.e., ++) sagittal deformity according to SRS-Schwab modifiers for pelvic tilt, sagittal vertical axis, and pelvic incidence-lumbar lordosis mismatch (p < 0.05). At 2 years, patients in the operative cohort showed significantly increased rates of a gain in MCID for physical component summary of SF-36, ODI, and SRS-activity, SRS-pain, SRS-appearance, and SRS-mental scores. Cost analysis showed the average cost of nonoperative treatment 2 years prior to surgical intervention to be $2041. Overall, at 2 years patients in the nonoperative cohort had again in ODI of 0.36, did not show a gain in QALYs, and nonoperative treatment was determined to be cost-ineffective. However, a subset of patients in this cohort underwent successful maintenance treatment and had a decrease in ODI of 1.1 and a gain in utility of 0.006 at 2 years. If utility gained for this cohort was sustained to full life expectancy, patients' cost per QALY was $18,934 compared to a cost per QALY gained of $70,690.79 for posterior-only and $48,273.49 for combined approach in patients in the operative cohort. Patients with ASD undergoing operative treatment at baseline had greater sagittal deformity and greater improvement in health-related quality of life postoperatively compared to patients treated nonoperatively. Additionally, patients in the nonoperative cohort overall had an increase in ODI and did not show improvement in utility gained. Patients in the nonoperative cohort who had low disability and sagittal deformity underwent successful maintenance and cost-effective treatment.

Trans-sacral interbody fixation in long fusions to the sacrum for adult spinal deformity: complications and fusion rates at minimum two years follow-up.

This study aims to investigate the fusion rate and complications associated with trans-sacral interbody fusion (TSIF) in long fusions to the sacrum for adult spinal deformity (ASD) over a twoyear follow-up period. Potential predictor variables associated with pseudarthrosis were also examined. A retrospective clinical review was conducted on a consecutive series of ASD patients who underwent long fusions to the sacrum, with TSIF performed as a same-day or staged procedure. Patient demographics, bone mineral density, operative details, perioperative and late complications, and fusion rates were reviewed. Univariate analysis was used to identify the risk factors associated with pseudarthrosis. The study included 43 patients with an average age of 55.3 ± 8.9years. The perioperative complication rate was 28%, with 12% of the complications directly related to TSIF. The late complication rate was 33%, with 16% related to TSIF. The most common complications were pseudarthrosis (14%) and postoperative ileus (7%). The overall radiographic fusion rate at twoyears was 86%. Univariate analysis revealed that revision surgery was significantly associated with pseudarthrosis (p = 0.027). Over the follow-up period, patients who underwent TSIF during long posterior fusions to the sacrum showed improvement in overall SRS scores, ODI scores, and SF-36 physical health and mental health (p < 0.05). TSIF is a relatively safe and minimally invasive method for achieving interbody fusion at the lumbosacral junction in the treatment of ASD, with acceptable fusion rates and a low complication rate. However, TSIF is not recommended for revision reconstruction in ASD.

Diagnosis and treatment of adult spinal deformity

Background: The diagnosis rate of adult spinal deformity (ASD) is increasing with increased life expectancy and the prevalence of degenerative spinal diseases. The prevalence of ASD in adults aged &gt;60 years has been reported to be up to 68%. ASD has significant impact on the pain, disability, and mental health. Therefore, it is necessary to establish an effective surgical plan by accumulating modern knowledge on ASD, developing surgical techniques, and improving pre- and post-operative care so as to achieve optimal surgical outcomes.Current Concepts: ASD results from coronal and sagittal malalignments caused by degenerative diseases or iatrogenic factors. Recently, the significance of sagittal alignment correction has been emphasized, and the SRSSchwab classification of ASD is generally accepted. Individualized correction goals can be set through sufficient preoperative evaluations and imaging studies, and appropriate coronal and sagittal alignment correction can be achieved through intraoperative positioning of patient, anterior and posterior approach spine surgery, screw fixation, and osteotomies.Discussion and Conclusion: It is necessary to establish an optimal correction target and select the appropriate surgical approach for each patient with ASD, so as to improve patients’ quality of life. Surgical interventions for ASD can be safely completed by adequately comprehending and anticipating perioperative complications.

Comparison of complications, revisions, spinopelvic parameters, and health-related quality of life after posterior spinal fusion using multiple-rod constructs or two-rod constructs for adult spinal deformity: a systematic review and meta-analysis.

The incidence of mechanical complications is high in patients undergoing posterior spinal fusion (PSF) for adult spinal deformity (ASD), especially for cases with severe sagittal malalignment or a prior spinal fusion requiring three-column osteotomy (3-CO) or spinopelvic fixation (SPF). The purpose of this systematic review and meta-analysis was to compare the complications, revisions, radiographic spinopelvic parameters, health-related quality of life (HRQoL), and surgical data of PSF using multiple-rod constructs to those of two-rod constructs for the treatment of ASD. A comprehensive literature search was performed for relevant studies in PubMed, EMBASE, Web of Science, and the Cochrane Library. Complications, revisions, spinopelvic parameters, HRQoL, and surgical date were compared between patients with ASD who underwent PSF using multiple-rod constructs (multi-rod group) and two-rod constructs (two-rod group). Ten studies, comprising 797 patients with ASD (399 in the multi-rod group and 398 in the two-rod group), were included. All these studies were retrospective cohort studies. There were no significant differences in the surgical, wound-related, and systemic complications between the groups. In the multi-rod group, we noted a significantly lower incidence of rod fracture (RR, 0.43; 95% CI 0.33 to 0.57, P < 0.01), pseudoarthrosis (RR, 0.38; 95% CI 0.28 to 0.53, P < 0.01), and revisions (RR, 0.44; 95% CI 0.33 to 0.58, P < 0.01); a superior restoration of PI-LL (WMD, 3.96; 95% CI 1.03 to 6.88, P < 0.01) and SVA (WMD, 31.53; 95% CI 21.16 to 41.90, P < 0.01); a better improvement of ODI score (WMD, 6.82; 95% CI 2.33 to 11.31, P < 0.01), SRS-22 total score (WMD, 0.44; 95% CI 0.06 to 0.83, P = 0.02), and VAS-BP score (WMD, 1.02; 95% CI 0.31 to 1.73, P < 0.01). Compared with the two-rod constructs, PSF using multiple-rod constructs was associated with a lower incidence of mechanical complications, a lower revision rate, a superior restoration of sagittal alignment, and a better improvement of HRQoL, without increasing surgical invasiveness. Multiple-rod constructs should be routinely considered to for ASD patients, especially for cases with severe sagittal malalignment or a prior spinal fusion requiring 3-CO or SPF.