Spinal Deformity Research Articles

Impact of Knee Osteoarthritis and Arthroplasty on Full Body Sagittal Alignment in Adult Spinal Deformity Patients.

Retrospective analysis of prospectively collected data. This study evaluates the impact of knee osteoarthritis (OA) and knee arthroplasty on alignments and patient-reported outcomes measures (PROMS) of patients undergoing adult spinal deformity (ASD) corrective surgery. The relationship between knee OA and spinal alignment in patients with ASD is incompletely understood. It is also unknown how patients with knee arthroplasty and ASD compare to ASD patients with native knees. Baseline full-body radiographs were used, and hip and knee OA were graded by two independent reviewers using the KL classification. Spinopelvic parameters and PROMs were compared across the different knee OA groups and compared between patients with knee replacement and native knees. 199 patients with bilateral non severe OA (G1), 31 patients with unilateral severe knee OA (G2), and 60 patients with bilateral severe knee OA (G3). Patients with severe knee OA presented with worse spinopelvic parameters. However, after multivariable regression analysis controlling for age, frailty, PI, T1PA, knee OA was an independent predictor of knee flexion (G1:-0.02±7.3, G2: 7.8±9.4, G3: 4.5±8.7, P<0.001), and ankle dorsiflexion (G1: 2.3±4.0, G2: 6.6±4.5, G3: 5.1±4.1, P<0.001). There was no difference in PROMs (P>0.05). Secondary analysis included 96 patients: 48 patients (50%) with non-severe knee OA, and 48 patients (50%) with knee replacement. There was no difference in radiographic parameters or PROMs between the groups. In this study of complex ASD patients, patients with worse spinal deformity were more likely to have concomitant knee OA. Knee OA was shown to be a predictor of knee flexion and ankle dorsiflexion angles, but was not associated with worse PROMs in this study population. Patients with knee arthroplasty, however, had comparable spinal alignment and PROMs relative to those with mild OA.

Composite Scaffold Materials of Nanocerium Oxide Doped with Allograft Bone: Dual Optimization Based on Anti-Inflammatory Properties and Promotion of Osteogenic Mineralization.

Spinal fusion technique is widely used in the treatment of lumbar degeneration, cervical instability, disc injury, and spinal deformity. However, it is usually accompanied by a high incidence of fusion failure and pseudoarthrosis, placing higher demands on bone implants. Therefore, materials with good biocompatibility, osteoconductivity, and even induce bone ingrowth, which can be used to improve spinal fusion rate and bone regeneration, have become a hot research topic. Here, ultra-small cerium oxide nanoparticles (CeO2 NPs) are prepared and loaded onto the surface of the homograft bone surface to prepare a composite scaffold AB@PLGA/CeO2. The composite scaffold shows the competitive ability to promote osteoblast differentiation in vitro. In vivo experiments show that AB@PLGA/CeO2 has a good bone enhancement effect. In particular, good biological effects of collagen fiber formation, osteogenic mineralization, and tissue repair are shown in intervertebral implant fusion. Further, transcriptome sequencing confirms that CeO2 NPs promote osteogenic differentiation and mineralization by regulating extracellular matrix (ECM) and collagen formation. Meanwhile, CeO2 NPs can regulate the function of the PI3K-Akt signaling pathway to exert its ability to promote osteogenic differentiation and mineralization and affect p53 and cell cycle signaling pathway to regulate osteogenic differentiation and mineralization. Hence, the proposed scaffold is a promising strategy for intervertebral fusion in the clinic.

A safe, novel and ingenious method for autogenous bone graft storage in spine surgery with constrained resources - operative site as the bone bank.

The aim of our study is to establish whether the bone graft harvested and stored in the surgical wound by our novel technique is safe, reproducible and preserves the viability of the graft. In doing so, it promises successful bony fusion in spine and orthopaedic surgeries. A prospective clinical case series was conducted for autogenous bone graft storage in complex spine surgeries requiring staged procedures, in resource constrained settings. The bone graft harvested was morselized, wrapped in moist sterile gauze and stored in the paraspinal gutter within the operative site. Thereafter, the surgical wound was easily closed without tension. During the second stage surgery, the stored bone was retrieved and mixed with more autologous/allogenic bone (if necessary) and appropriately laid at fusion sites. Bacterial samples were sent before implantation. 16 complex spinal deformity patients who underwent surgery in a resource constrained hospital over a period of 5 years were included. Duration between both stages was within 2 weeks. All patients showed successful fusion, with mean follow-up of 2.6 years. There were no cases of deep or systemic infection in our series. Surgeons found harvesting, storing and retrieval of graft to be straightforward. The operative site provides an ideal, safe and reproducible location for bone graft storage for staged surgeries conducted in resource constrained situations. The osteogenic potential of the autogenous bone graft is retained. This technique can be extrapolated to other orthopaedic surgeries conducted under resource limited environments like in surgical camps or combat medical facilities.

Blind Nasotracheal Intubation in a Patient With Ankylosing Spondylitis and Severe Cervical Spine Deformities: A Case Report on Challenges and Approaches to Difficult Airway Management

Blind Nasotracheal Intubation in a Patient With Ankylosing Spondylitis and Severe Cervical Spine Deformities: A Case Report on Challenges and Approaches to Difficult Airway Management

A team approach to improve outcomes in pediatric scoliosis surgery: a review of the current literature.

Review article. To review the literature on the effect of specialized pediatric spine teams on clinical outcomes. Thirty-eight studies were identified in the review. There were 11 studies discussing the efficacy of the dual-surgeon strategy, 5 studies discussing the benefits of adult dedicated spine teams, 3 studies discussing the benefits of dedicated pediatric spine teams, 8 studies discussing the healthcare professional composition of multidisciplinary spine teams, and 20 studies discussing various clinical markers evaluating the efficacy of new team- or protocol-based interventions. Pediatric spinal deformity surgery is a highly invasive procedure with room for intervention to minimize surgical complications and enhance patient outcomes. The use of standardized spine teams, comprising surgeons and various healthcare professionals from diverse disciplines, has proven to be an effective strategy for improving both quality and efficiency of care. Furthermore, implementing uniform protocols among these teams has led to reductions in surgical duration, hospitalization periods, and risks such as infections at the surgical site and excessive bleeding. Further studies are necessary to evaluate additional benefits that specialized pediatric spine teams can offer in terms of clinical outcomes.

Entry point and screw path study of second sacral alar-iliac screw trajectory in spinal pelvic fixation under O-arm navigation

Objective: To explore the feasibility of using the entry point and screw path parameters of sacroiliac (S2AI) screws inserted under O-arm 3D computer navigation as a reference for freehand screw insertion in patients with degenerative spinal deformities. Methods: A retrospective analysis was conducted on the clinical data of 66 patients with degenerative spinal deformities who received S2AI screw fixation assisted by the O-arm 3D computer navigation system at Nanjing Drum Tower Hospital Affiliated with Nanjing University Medical School from January 2017 to April 2022. The patients included 6 males and 60 females, with a mean age of (64.3±5.9) years. Preoperatively, the entry point was set as the intersection of 1 mm from the outer and lower edges of the S1 foramen, adjusted intraoperatively by navigation, and verified postoperatively by full spinal CT scans and 3D reconstructions. Using the S1 screw entry point as the origin, the position of the bilateral S2AI screw entry points, tailward angulation (SA), outward angulation (TA), and vertical distance from the entry point to the skin (SD) were measured on postoperative CT 3D images. The accuracy of S2AI screw placement and any intraoperative and postoperative complications were recorded. Differences in entry point coordinates and screw path parameters between the left and right sides were compared. The intraclass correlation coefficient (ICC) was used to assess intra-observer and inter-observer agreement. Results: The coordinates and screw path parameters for the S2AI screws placed using the O-arm navigation demonstrated good intra-observer and inter-observer consistency (ICC>0.75). The left entry point was located (8.08±1.39) mm laterally and (24.47±2.20) mm caudally from the S1 entry point, while the right entry point was (8.09±1.41) mm laterally and (24.40±2.54) mm caudally, with no significant difference between the left and right sides (both P>0.05). The left TA was 46.33°±3.44°, SA was 39.14°±6.12°, and SD was (60.38±13.37) mm; the right TA was 46.37°±3.41°, SA was 39.59°±5.89°, and SD was (60.30±12.24) mm, with no significant differences between the left and right parameters (all P>0.05). There was no significant neurovascular complications intraoperatively or two weeks postoperatively, with a screw insertion accuracy of 97.7% (129/132). Conclusions: In the fixation of the pelvis in degenerative spinal deformities, the use of O-arm navigation-assisted S2AI screw insertion has a high accuracy rate. It is recommended that for freehand screw insertion, the entry point should be located 24 mm caudally and 8 mm laterally from the outer and lower edges of the superior articular process of S1, with an TA of approximately 46° and a SA of approximately 39°.

Long-term outcomes of spinal fusion in adolescent idiopathic scoliosis: a literature review

Adolescent idiopathic scoliosis (AIS) is the most common form of spinal deformity in the younger population. The surgical management for these patients improved constantly over the last year and might not be comparable to modern treatment strategies. However, under this aspect the present investigation updates and discusses current evidence regarding the long-term outcome of the surgical management of AIS. All the clinical studies which evaluated the long-term outcomes of spinal fusion were considered. Level of evidence, clinical and radiological data, results of health-related questionnaires and surgery-associated complications during long-term follow-up, e.g., proximal and distal junctional kyphosis (PJK/DJK), and adjacent segment degeneration (ASD), are presented. Data concerning the following patient-reported outcomes measures were collected: Oswestry Disability Index (ODI), Scoliosis Research Society (SRS) Outcome Questionnaire, visual analogue scale (VAS), and short form-12 and 36 (SF-12/SF-36). Overall, data from 1115 patients were included. Of them, 324 underwent anterior and 791 posterior spinal fusion. One study focuses on a combined anterior/posterior fusions. The mean follow-up was 22.6 years (posterior fusion: 24.6 years, anterior fusion: 18.31 years). Seven studies focus on the thoracic segments, while 12 focus on the lumbar spine. Data on imaging was reported in 13 studies and those on PROMs in 15 investigations. In conclusion, there is low quality and paucity of long-term data on AIS. However, the long-term results of the implicated studies on AIS patients in this review appear to be satisfactory, although there are limitations in the outcome compared to healthy comparison cohorts. Adjacent degenerations appear to be the most common mechanical complication after long-segment fusions, despite their influence on the outcome remains unclear. With regard to pregnancies, there are slightly increased cesarean section rates, which could be explained by deviations in the sagittal profile.

TIA-UNet: Transformer-Enhanced Deep Learning for Adolescent Idiopathic Scoliosis Spinal X-Ray Image Segmentation

Abstract Adolescent Idiopathic Scoliosis (AIS) is a common spinal deformity where precise diagnosis is crucial for developing effective treatment strategies. Traditional manual X-ray image analysis is time-consuming and highly dependent on the operator’s expertise, thus constraining diagnostic efficiency and accuracy.This study aimed to develop an automated thoracolumbar spine segmentation method utilizing deep learning to enhance the efficiency and accuracy of AIS diagnosis. We introduced TIA-UNet, an innovative network architecture that combines Convolutional Neural Networks (CNN) with Transformer models.By integrating the IR Block and DA Block, TIA-UNet was optimized for feature extraction and multi-scale information fusion. The model underwent training and validation using our established Adolescent Scoliosis Medical Dataset (ASMD).TIA-UNet attained a Dice similarity coefficient of 90.02%, a Mean Intersection over Union (MIoU) of 81.96%, and a Hausdorff Distance (HD) of 4.09, significantly surpassing current state-of-the-art methods such as UNet and TransUNet. Moreover, TIA-UNet exhibited superior computational efficiency regarding parameter count, inference time, and floatingpoint operations (FLOPs).As an automated medical image segmentation algorithm, TIA-UNet enhanced segmentation accuracy while maintaining high computational efficiency, demonstrating significant potential for clinical diagnostic applications. This study provides compelling evidence supporting the utilization of deep learning&amp;#xD;techniques in medical image analysis.

What imaging does my AIS patient need? A multi-group survey of provider preferences.

Adolescent idiopathic scoliosis (AIS) is a common diagnosis managed by pediatric orthopedic surgeons with nonoperative radiographic monitoring representing a cornerstone of treatment. Differences in practices and techniques for obtaining radiographic studies contribute to variation, cost of care, and hamper data aggregation. We surveyed several large organizations dedicated to children's orthopedics or scoliosis care to obtain a consensus for radiographic evaluation of AIS. A REDCap-based survey was developed across four institutions and beta-tested by staff and fellows from a single institution. The finalized survey was distributed to members of POSNA, PSSG, and SOSORT, and shared on social media. Participants were asked to rank the importance of various datapoints in radiographic assessment of the spinal deformity, skeletal maturity, and study indications during initial, subsequent, preoperative, and final office visits for AIS. Response rate for the overall group was 26%. Cobb angle was considered the most important (> 94%) radiographic index across all time points. For positioning, 46% of respondents favored arms bent touching clavicles as the ideal positioning for X-rays, and another 24% favored arms down with palms forward (Table2). The majority of respondents obtain lateral X-rays at the first visit (99%) and at the preoperative visit (70%). At the preoperative visit, sagittal contour (86%), apex location (85%), and Lenke classification (73%) were considered important factors to record. Flexibility studies are primarily obtained at the preoperative visit (89%) and 81% of respondents prefer bending films as the flexibility technique of choice. Regarding measures of skeletal maturity, Sanders bone age was considered to be the most important by over 70% of respondents across initial, subsequent, preoperative and brace wean visits (Fig.2). MRIs were obtained routinely by 34% of respondents and only when the patient had a concerning symptom or finding for 67% of respondents. Despite large variations in radiographic examination of AIS, large areas of agreement were found. It is important to establish standards for positioning patients, evaluating skeletal maturity, and obtaining assessments including lateral views, flexibility studies, and advanced imaging. Establishing common practices for radiographic evaluation of AIS will allow for less variation in care and for critical questions to be answered through registry formation and large multicenter data collection. This study establishes current practitioner opinion on the radiographic evaluation of the AIS patient. Minimum data sets are useful for data aggregation and answering research questions in the face of data variability. Level V.

Which components of the global alignment proportionality score have the greatest impact on outcomes in adult spinal deformity corrective surgery?

To investigate the impact of the Global Alignment and Proportion (GAP) score components on patient outcomes in Adult Spine Deformity (ASD) surgery. Patients included underwent assessment via the GAP score and its individual components: pelvic version (GAP PV), lumbar lordosis (GAP LL), lumbar distribution index (GAP LDI) and spinopelvic component (GAP SP). Multivariable analyses assessed the association between alignment in these components and clinical outcomes in ASD patients. 762 ASD patients met inclusion criteria. Alignment in GAP SP independently predicted meeting MCID for SR-22S and ODI and was associated with a lower likelihood of developing mechanical complications. Patients aligned in GAP SP were less likely to develop proximal junctional kyphosis (OR 0.42, 0.26-0.73, p = 0.01) and PJF (OR 0.3, 0.13-0.74, p = 0.01). Proportioned alignment in GAP SP with disproportioned alignment in GAP LDI contributed to an increased risk of PJK and PJF (OR 2.67, 95% CI 1.95-6.82, p = 0.045). There was no significant association of GAP SP proportionality and GAP RPV (OR 1.1, 0.86-2.15, p = 0.253) or GAP LL (OR 1.34, 0.78-4.23, p = 0.673) disproportionality with outcomes. Disproportioned alignment in GAP SP but proportioned alignment in both GAP LL and GAP LDI was associated with decreased likelihood of PJK (OR 0.53, 95% CI 0.39-0.94, p = 0.02) and PJF (OR 0.31, 95% CI 0.19-0.67, p = 0.001). The spinopelvic component of the GAP score is the most significant independent predictor of clinical outcomes. Its interaction with the other components of the GAP score also aids assessment of the risk for mechanical complications.

Use of Artificial Intelligence in Cobb Angle Measurement for Scoliosis: Retrospective Reliability and Accuracy Study of a Mobile App.

Scoliosis is a spinal deformity in which one or more spinal segments bend to the side or show vertebral rotation. Some artificial intelligence (AI) apps have already been developed for measuring the Cobb angle in patients with scoliosis. These apps still require doctors to perform certain measurements, which can lead to interobserver variability. The AI app (cobbAngle pro) in this study will eliminate the need for doctor measurements, achieving complete automation. We aimed to evaluate the reliability and accuracy of our new AI app that is based on deep learning to automatically measure the Cobb angle in patients with scoliosis. A retrospective analysis was conducted on the clinical data of children with scoliosis who were treated at the Pediatric Orthopedics Department of the Children's Hospital affiliated with Fudan University from July 2019 to July 2022. Three measurers used the Picture Archiving and Communication System (PACS) to measure the coronal main curve Cobb angle in 802 full-length anteroposterior and lateral spine X-rays of 601 children with scoliosis, and recorded the results of each measurement. After an interval of 2 weeks, the mobile AI app was used to remeasure the Cobb angle once. The Cobb angle measurements from the PACS were used as the reference standard, and the accuracy of the Cobb angle measurements by the app was analyzed through the Bland-Altman test. The intraclass correlation coefficient (ICC) was used to compare the repeatability within measurers and the consistency between measurers. Among 601 children with scoliosis, 89 were male and 512 were female (age range: 10-17 years), and 802 full-length spinal X-rays were analyzed. Two functionalities of the app (photography and photo upload) were compared with the PACS for measuring the Cobb angle. The consistency was found to be excellent. The average absolute errors of the Cobb angle measured by the photography and upload methods were 2.00 and 2.08, respectively. Using a clinical allowance maximum error of 5°, the 95% limits of agreement (LoAs) for Cobb angle measurements by the photography and upload methods were -4.7° to 4.9° and -4.9° to 4.9°, respectively. For the photography and upload methods, the 95% LoAs for measuring Cobb angles were -4.3° to 4.6° and -4.4° to 4.7°, respectively, in mild scoliosis patients; -4.9° to 5.2° and -5.1° to 5.1°, respectively, in moderate scoliosis patients; and -5.2° to 5.0° and -6.0° to 4.8°, respectively, in severe scoliosis patients. The Cobb angle measured by the 3 observers twice before and after using the photography method had good repeatability (P<.001). The consistency between the observers was excellent (P<.001). The new AI platform is accurate and repeatable in the automatic measurement of the Cobb angle of the main curvature in patients with scoliosis.

Short-Segment Fusion vs. Isolated Decompression in Lumbar Spinal Canal Stenosis Patients with Cobb Angles Over 20 Degrees

Background ContextLumbar decompression and short-segment lumbar fusion are standard procedures for short-segment lumbar canal stenosis, even in patients with moderate Cobb angles. Adult degenerative scoliosis is diagnosed at a threshold of 10 degrees, and patients with coronal Cobb angles over 30 degrees are recommended for long fusion due to global spinal deformity. However, there is a lack of research on clinical outcomes in patients with moderate coronal deformity, such as Cobb angles between 20 and 30 degrees. PurposeThis study aims to investigate the radiographic and clinical outcome differences between isolated decompression and short-segment interbody fusion for lumbar spinal canal stenosis in patients with moderate coronal deformity. Study DesignA retrospective analysis of a prospectively collected registry Patient SamplePatients with Cobb angle exceeding 20 degrees who underwent 1- or 2- levels of lumbar surgery for lumbar canal stenosis. Patients diagnosed as spinal deformity were excluded. Outcome MeasuresPatient-reported outcomes included Oswestry Disability Index (ODI), VAS back, VAS leg, Short Form 12 Physical Component Score (SF-12 PCS) and Mental Component Score (SF-12 MCS), and Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF) at preoperative, 12-week postoperative, and 1-year postoperative timepoints. Preoperative and postoperative spinopelvic alignment was assessed using Cobb angle, pelvic tilt, sacral slope, pelvic incidence, lumbar lordosis and PI minus LL. MethodsA propensity score-matched analysis with the overlap weighting was utilized to investigate patient-reported outcomes at 12-week and 1-year postoperatively between the surgery groups. Spinopelvic alignments were compared between preoperative and 1-year postoperative timepoint using a linear mixed-effect model. ResultsBefore overlap weighting, the two surgery groups showed significant differences in age and diagnosis. No obvious sagittal malalignment was observed (decompression, 7.4° vs. fusion, 11.5°). After propensity score weighting, the fusion groups exhibited significantly better ODI and VAS back at the 1-year timepoint (ODI: fusion, 16.6 vs. decompression, 28.1, P=0.013; VAS back: fusion, 1.5 ± 2.1 vs. decompression, 3.7 ± 1.9, P<0.001). Radiographic assessment showed that the fusion group achieved better PI minus LL compared to decompression group (15° vs. 10°, P=0.008) ConclusionIn patients with degenerative scoliosis and a Cobb angle greater than 20 degrees, short-segment lumbar fusion surgery may result in enhanced improvement for short-segment lumbar pathology compared to isolated decompression.

Proximal lumbar anterior column realignment for iatrogenic sagittal plane adult spinal deformity correction: a retrospective case series

Anterior column realignment (ACR) is a powerful minimally invasive surgery (MIS) technique to restore sagittal alignment in adult spinal deformity (ASD). This can accomplish similar segmental lordosis restoration as 3-column osteotomy with less blood loss and comparable complication rates. ACR can be performed at adjacent disease segments in the proximal lumbar spine in revision cases. However, two-thirds of physiologic lordosis occurs between L4-S1, and concerns remain about altered lumbar morphology. We evaluated patients who underwent proximal lumbar ACR for iatrogenic flatback deformity. A total of 19 consecutive patients who underwent L1-2 or L2-3 ACR were retrospectively analyzed. All patients were treated with lateral MIS interbody technique, followed by posterior reconstruction with Smith-Peterson osteotomy (SPO). Pre- and post-operative radiographic and clinical outcomes were obtained. Mean follow-up was 19-months. All but one patient had a history of prior lumbar or lumbo-sacral fusion. SVA and PI-LL decreased from 11.9 cm to 6.1 cm (p<0.0001) and 34.2° to 12.8° (p<0.0001). Segmental lordosis increased from -2.7° to 21.9° (p<0.0001). Proximal lumbar lordosis (PLL) increased from -0.4° to 22.6° (p<0.0001), and lordosis distribution index (LDI) decreased from 79.5% to 48.9% (p<0.0001). Mean ODI and NPRS back pain decreased from 58.0 to 36.2 (p=0.0041) and 7.9 to 3.4 (p<0.0001). PROMIS-10 Physical and Mental Health T-scores increased from 34.1 to 43.3 (p=0.0049) and 40.4 to 45.0 (p=0.0993). Major complication rate was 15.8%. One patient required revision for mechanical failure. There were no permanent neurological or vascular injuries. Proximal lumbar ACR plus SPO can achieve sagittal correction with low major complication rates in patients with ASD and prior distal fusion. Differentially increasing PLL and lowering LDI did not have deleterious effects on radiographic or clinical outcomes. Further work is needed to understand the effect of proximal ACR in the surgical management of ASD.

Risk factors for postoperative ileus after corrective spinal surgery: association with reduction in the retrocrural space area.

The objective of this study was to determine whether a reduction in the retrocrural space (RCS) area is a risk factor for postoperative ileus (POI) in patients with adult spinal deformity (ASD) treated with spinal corrective surgery. In total, 100 patients (mean age 67.5 ± 8.3 years, 9 males and 91 females) with ASD treated with spinal corrective surgery were included in this study. Spinal parameters, including thoracolumbar kyphosis (TLK), and RCS area were measured pre- and postoperatively. The change (Δ) in spinal parameters was calculated. The percent change between pre- and postoperative RCS areas was calculated as ΔRCS. Patients were identified as having POI if they exhibited both gastrointestinal symptoms and radiographic findings. Each parameter was compared between patients with and without POI. Multivariable logistic regression analysis was performed with development of POI as the dependent variable. The incidence of POI was 11.0%. The RCS area was significantly smaller in the POI group than in the non-POI group (p < 0.001). Multivariable logistic regression analysis revealed that ΔTLK and ΔRCS were risk factors for POI (p = 0.029 and p = 0.033, respectively). A reduction in the RCS area is a risk factor for the development of POI after corrective spinal surgery in patients with ASD. Overcorrection of the thoracolumbar junction should be avoided to prevent POI.

Frailty and Malnutrition as Predictors of Major Complications Following Posterior Thoracolumbar Fusion in Elderly Patients: A Retrospective Cohort Study

Background ContextThe number of elderly patients with degenerative spinal deformity (DSD) is increasing, and posterior thoracolumbar fusion surgery is an effective treatment option, but there are often postoperative major complications, which may hinder the benefit for elderly patients. Currently, there is no consensus on the best risk assessment technique for predicting major complications in elderly patients undergoing long-segment fusion surgery. PurposeThis study constructs a risk assessment model using the Modified 5-Item Frailty Index (mFI-5) and serum albumin and evaluates its predictive value. Study DesignThis is a retrospective analysis of a prospectively established database of DSD. Patient SampleConsecutive patients (aged 65 and older) who underwent open posterior thoracolumbar fusion surgery for DSD between April 2018 and December 2023 were included. Outcome MeasuresOutcome measures included postoperative major complications, length of hospital stay [LOS], readmission and reoperation within 30 days, discharge disposition, physiological function recovery. MethodsThe study reviewed consecutive patients who underwent open posterior thoracolumbar fusion surgery for DSD. Patients were divided into three groups based on the presence or absence of frailty or frailty combined with malnutrition. Spearman ρ analysis was used to assess the correlation between mFI-5 and serum albumin levels. Univariate analyses and multivariate logistic regression were conducted to explore the relationship between frailty and malnutrition defined by mFI-5 and serum albumin and major postoperative complications. Finally, the Receiver Operating Characteristic (ROC) curve was used to evaluate the predictive value of this model for major complications. ResultsCompared to the Normal group (n = 59), both the Frailty group (n = 121) and the Frailty and Malnutrition group (n = 50) had higher rates of major complications (21.5% vs. 8.5%, p = .035; 28% vs. 8.5%, p = .002). Multivariate logistic regression showed that frailty and malnutrition status, higher ASA score, and more bleeding were independent predictors of major postoperative complications. The ROC curve demonstrated that frailty combined with malnutrition defined by mFI-5 and serum albumin had a larger area under the curve compared to mFI-5 or serum albumin alone (AUC: 0.676; 95% CI: 1.101-14.129; p < .001). ConclusionsCompared to considering frailty or malnutrition alone, the combined assessment of frailty and malnutrition using mFI-5 and serum albumin is valuable in predicting major complications in elderly patients undergoing posterior thoracolumbar fusion surgery. Level of evidenceIII

Frail patients require instrumentation of a more proximal vertebra for a successful outcome after surgery for adult spine deformity.

The aim of this study was to investigate the impact of the level of upper instrumented vertebra (UIV) in frail patients undergoing surgery for adult spine deformity (ASD). Patients with adult spinal deformity who had undergone T9-to-pelvis fusion were stratified using the ASD-Modified Frailty Index into not frail, frail, and severely frail categories. ASD was defined as at least one of: scoliosis ≥ 20°, sagittal vertical axis (SVA) ≥ 5 cm, or pelvic tilt ≥ 25°. Means comparisons tests were used to assess differences between both groups. Logistic regression analyses were used to analyze associations between frailty categories, UIV, and outcomes. A total of 477 patients were included (mean age 60.3 years (SD 14.9), mean BMI 27.5 kg/m2 (SD 5.8), mean Charlson Comorbidity Index (CCI) 1.67 (SD 1.66)). Overall, 74% of patients were female (n = 353), and 49.6% of patients were not frail (237), 35.4% frail (n = 169), and 15% severely frail (n = 71). At baseline, differences in age, BMI, CCI, and deformity were significant (all p = 0.001). Overall, 15.5% of patients (n = 74) had experienced mechanical complications by two years (8.1% not frail (n = 36), 15.1% frail (n = 26), and 16.3% severely frail (n = 12); p = 0.013). Reoperations also differed between groups (20.2% (n = 48) vs 23.3% (n = 39) vs 32.6% (n = 23); p = 0.011). Controlling for osteoporosis, baseline deformity, and degree of correction (by sagittal age-adjusted score (SAAS) matching), frail and severely frail patients were more likely to experience mechanical complications if they had heart failure (odds ratio (OR) 6.6 (95% CI 1.6 to 26.7); p = 0.008), depression (OR 5.1 (95% CI 1.1 to 25.7); p = 0.048), or cancer (OR 1.5 (95% CI 1.1 to 1.4); p = 0.004). Frail and severely frail patients experienced higher rates of mechanical complication than 'not frail' patients at two years (19% (n = 45) vs 11.9% (n = 29); p = 0.003). When controlling for baseline deformity and degree of correction in severely frail and frail patients, severely frail patients were less likely to experience clinically relevant proximal junctional kyphosis or failure or mechanical complications by two years, if they had a more proximal UIV. Frail patients are at risk of a poor outcome after surgery for adult spinal deformity due to their comorbidities. Although a definitively prescriptive upper instrumented vertebra remains elusive, these patients appear to be at greater risk for a poor outcome if the upper instrumented vertebra is sited more distally.

Glycemic Laboratory Values Are Associated With Increased Length of Stay and 90-Day Revision Risk Following Surgical Management of Adult Spinal Deformity

Diabetes mellitus (DM) is a common comorbidity among patients undergoing spinal fusion for adult spinal deformity (ASD) surgery. An elevated Hemoglobin A1c (HbA1c) and elevated postoperative glucose have been shown to increase the risk of complications following spine and other orthopaedic surgeries; however, data is limited for ASD. To investigate glycemic control and ASD surgery to inform surgical decision making, medical optimization, and patient education. Retrospective cohort. Total of 106 adult patients undergoing surgical correction for ASD with an HbA1c drawn within six months preoperatively or two weeks postoperatively and valid plasma glucose levels throughout postoperative hospital stay. Length of stay, 90-day wound complication, 90-day readmission, 90-day revision. All patients undergoing spinal fusion of seven or more levels between 2021 and 2023 at two large academic medical centers were identified using institutional data acquisition software. Medical charts were then manually reviewed to obtain and confirm demographic, laboratory, and surgical characteristics and outcomes. Laboratory characteristics included preoperative HbA1c, mean postoperative glucose (PG), and maximum PG. Surgical characteristics and outcomes included procedure time, estimated blood loss (EBL), length of inpatient stay (LOS), transfusion requirement, 90-day complications, 90-day revision, and 90-day readmission. Bivariate analysis was performed followed by simple and multiple regression analysis. Odds ratios were established relative to the laboratory threshold values informed by receiver operating characteristics. Of 872 original procedures identified, 106 patients (12.2%) were adults with preoperative HbA1c and postoperative plasma glucose measurements who underwent surgery for a diagnosis of ASD. Median patient age was 67 years (IQR 59-72 years), 59 (55.7%) were female, and 96 (90.6%) were of Caucasian race. Median LOS was 7 days (IQR 5-10 years) and median HbA1c was 5.9% (IQR 5.3%-6.5%). Higher preoperative HbA1c was correlated with increased LOS (R=0.22, P=0.023). The odds ratio for patients requiring extended LOS was 2.49 (95% CI 1.06-5.86, P=0.034) for those with HbA1c ≥6.3%. Multiple regression analysis of LOS identified HbA1c [B= 1.51 (95% CI 0.32-2.70), P=0.013] as a positive predictor of LOS and mean PG [B= -0.05 (95% CI -0.10-(-0.01), P=0.019] as a weakly negative predictor of LOS. Upon simple logistic regression, the odds ratio for 90-day revision was 1.81 (95% CI 1.02-3.19, P=0.042) for every unit increase in HbA1c. Patients with mean PG ≥165 mg/dL [OR=5.76 (95% CI 1.28-26.01), P=0.024] were at increased risk for 90-day revision. Glycemic laboratory values do not seem to predict 90-day wound complications or 90-day readmission following surgery for ASD. Elevated preoperative HbA1c is associated with increased LOS and risk for revision within 90 days of ASD surgery. Postoperative hyperglycemia is also associated with increased 90-day revision risk. To our knowledge, this study is the first to evaluate HbA1c and outcomes following ASD surgery. These findings can be leveraged to inform preoperative medical optimization and highlight the importance of glycemic control in ASD patients undergoing corrective surgical intervention.

Characteristics of sagittal spinopelvic alignment in Thai population: a cross-sectional study.

The prevalence of spinal deformity is a significant health concern often associated with the aging process. It is primarily attributed to the thickening of spinal joints, ligament pathologies, or the narrowing of the spinal canal, leading to compression of the spinal cord and nerve roots, and subsequently causing musculoskeletal problems. When considering corrective surgery for adult spinal deformities, it is crucial for spine surgeons to take into account the standard values of sagittal spinopelvic alignment. Notably, there is currently a lack of specific data on this aspect within the Thai population. Therefore, our study was focused on evaluating the alignment in the Thai population. To analyze sagittal spinopelvic alignment parameters in the asymptomatic Thai population and compare them with other populations. This study was designed as a cross-sectional analysis involving 194 participants, wherein the sagittal spinopelvic parameters were evaluated utilizing radiographic images. The measurements of the sagittal vertical axis (SVA), pelvic incidence (PI), lumbar lordosis (LL), sacral slope (SS), and pelvic tilt (PT) were determined by averaging the assessments conducted by two orthopedic residents and a spine surgeon. In addition, participants' demographic information was obtained through questionnaires, and further analysis was performed on age, gender, and body mass index data. The study also encompassed the determination of correlations between various parameters and the comparison of these parameters with other populations. The body mass index (BMI) of the study participants demonstrated significant associations with several spinal parameters. Specifically, BMI showed significant correlations with sagittal vertical axis (SVA) (r = 0.2, p = 0.09), pelvic incidence (PI) (r = 0.4, p < 0.01), lumbar lordosis (LL) (r = 0.2, p = 0.02), sacral slope (SS) (r = -0.2, p = 0.02), and pelvic tilt (PT) (r = 0.2, p = 0.02). The SS exhibited a statistically significant decline with increasing age (p = 0.04). Furthermore, the mean SVA, PI, LL, SS, and PT differed significantly between the study participants and the Indian population. In addition, the SS was notably lower when compared to the European population. The study revealed the spinopelvic parameters in a cohort of healthy Thai population and observed a correlation between their body mass index (BMI) and pelvic incidence (PI), lumbar lordosis (LL), sacral slope (SS), and pelvic tilt (PT). Notably, the average SS among Thai adults was found to be statistically lower than that of individuals from Indian, European Caucasian, Asian, and Mexican populations. These insights hold potential value as a reference when strategizing surgical interventions for Thai patients with spinal deformities.

Letter to the Editor: "Do different pathologies of adult spinal deformity (idiopathic lumbar scoliosis against de novo lumbar scoliosis) affect preoperative and postoperative selfimage?

Letter to the Editor: "Do different pathologies of adult spinal deformity (idiopathic lumbar scoliosis against de novo lumbar scoliosis) affect preoperative and postoperative selfimage?

A Biomechanical Analysis of Instrumentation Constructs During Vertebral Column Resection: Stability When You Need It!

Biomechanical Testing. Investigate the optimal construct for stabilization of the spine during vertebral column resection (VCR). VCR is a powerful technique for achieving correction in severe cases of spinal deformity. However, this also creates an unstable spine which requires stable fixation to prevent iatrogenic neurologic injury. It is common practice to place a temporary unilateral rod configuration to achieve this stability during surgery but no study to date has investigated the optimal construct configuration. A unilateral VCR model representing an acute 50° kyphotic deformity with a standardized 30mm resection was created. Three conditions underwent testing: 1) Rod material and diameter, 2) rod configuration, and 3) number of fixation points. Six unique samples were tested in each group in both flexion-extension. Prior to testing a 10N preload and underwent cyclical testing in flexion/extension. System stiffness was calculated and compared across groups. Assessment of rod size and composition using a single screw construct (2 total screws) demonstrated that for Titanium (Ti) rods, increasing rod size significantly increased the construct stiffness (P=0.001). Although Cobalt-chromium (Co-Cr) rods where significantly stiffer than the corresponding sized Ti rods, there was no significant difference between rod diameters for Co-Cr (P=0.98). However, when tested using a dual screw (4 total screws) construct, these constructs were significantly stiffer than the corresponding single screw constructs (P<0.0001). Of the various rod configurations, the dual rod demonstrated the greatest stiffness (34.8±2.1N/mm; P<0.0001). Surgical construct stiffness during a VCR is multifactorial. Larger rod diameter, increased number of fixation points, stiffer rod material, and increased number of rods across the resection site increase the construct stiffness. With minimal points of fixation using Co-Cr rods, increasing rod diameter does not impart greater construct stiffness unless additional fixation points are included.