Trends in surgical management of spinal metastases in a Singaporean tertiary referral center: a 17-year retrospective review.

Introduction: Surgical treatment is increasingly the treatment of choice in cancer patients with epidural spinal cord compression and spinal instability. There has also been an evolution in surgical treatment with the advent of minimally invasive surgical (MIS) techniques and separation surgery. This paper aims to investigate the changes in epidemiology, surgical technique, outcomes and complications in the last 17 years in a tertiary referral center in Singapore. Methods: This is a retrospective study of 383 patients with surgically treated spinal metastases treated between January 2005 to January 2022. Patients were divided into 3 groups, patients treated between 2005 - 2010, 2011-2016, and 2017- 2021. Demographic, oncological, surgical, patient outcome and survival data were collected. Statistical analysis with univariate analysis was performed to compare the groups. Results: There was an increase in surgical treatment (87 vs 105 vs 191). Lung, Breast and prostate cancer were the most common tumor types respectively. There was a significant increase in MIS(p<0.001) and Separation surgery (p<0.001). There was also a significant decrease in mean blood loss (1061ml vs 664 ml vs 594ml) (p<0.001) and total transfusion (562ml vs 349ml vs 239ml) (p<0.001). Group 3 patients were more likely to have improved or normal neurology (p=<0.001) and independent ambulatory status(p=0.012). There was no significant change in overall survival. Conclusion: There has been a significant change in our surgical practice with decreased blood loss, transfusion and improved neurological and functional outcomes. Patients should be managed in a multidisciplinary manner and surgical treatment should be recommended when indicated.

A Risk Quantification Reference Table for Progressed Adolescent Idiopathic Scoliosis Surgery: An Exact Case Matched Outcomes Analysis.

STUDY DESIGN: Retrospective Exact Matched case-control study. OBJECTIVES: Surgical treatment delay in AIS due to family preferences is common. This study aims to quantify the increase in risks as the Cobb angle increases and provide a Quantifiable Risk Reference Table that can be utilized for counseling. METHODOLOGY: AIS patients were divided into 3 groups: Group A: Cobb angle 50-60°, Group 61-70°, and Group CFinal ≥80°. Each patient in Group CFinal who had curve progression were then traced-back-in-time (TBIT) to review the clinical data at earlier presentations at 50-60° (C1), and 61-70° (C2). Patient demographics, radiological, operative, and outcomes data were compared between Group A vs C1 and Group B vs Group C2. RESULTS: A total of 614 AIS surgeries were reviewed. Utilizing the EM technique, a total of 302 AIS patients were recruited. There were 147, 111, 31, and 32 patients matched in Groups A, B, C1, and C2, respectively. C2 Final patients had 34% curve pattern change, 23.2% higher incidence of requiring two surgeries, and 17.3% increase in complications. There was a statistically significant increase of 2.4 spinal levels fused, 12% increase in implant density, 35% increase in operative time, 97% increase in intra-operative blood loss, 10% loss of scoliosis correction, 40% longer hospitalization stay, and 36% increase in costs for patients who had curve progression. CONCLUSION: This study is the first to use a homogenously matched AIS cohort to provide a Quantifiable Risk Reference Table. The Risk Table provides essential knowledge for treating physicians when counseling AIS patients.

Selective Thoracic Fusion for Idiopathic Scoliosis: A Comparison of Three Surgical Techniques with Minimum 5-year Follow-up.

STUDY DESIGN: Single-center retrospective review of outcomes among three surgical techniques in the treatment of thoracic idiopathic scoliosis (T-AIS) with a follow-up of at least 5 years. OBJECTIVE: To investigate how outcomes compare in video-assisted anterior thoracic instrumentation (VATS), all hooks/hook-pedicle screw hybrid instrumentation (HHF), and all pedicle screw instrumentation (PSF) techniques for T-AIS. SUMMARY OF BACKGROUND DATA: Studies comparing outcomes for anterior versus posterior fusion for T-AIS are few and with short follow-up. METHODS: Three groups of patients with T-AIS who underwent thoracic fusion were included in this study: 98 patients with mean curve of 49.0°â€Š±â€Š9.5° underwent VATS (Group 1); 44 patients with mean curve of 51.1°â€Š±â€Š7.4° underwent HHF (Group 2); and 47 patients with mean curve of 47.6°â€Š±â€Š9.9° underwent PSF (Group 3). Radiological outcomes were compared at preoperative, and up to 5 years. Surgical outcomes were noted until latest follow-up. RESULTS: Group 1 had less blood loss, less fusion levels, longer surgical time, and longer hospital stay compared with the other groups (P < 0.01). Groups 1 and 3 were comparable in all time periods with 78.8% and 78.2% immediate curve correction, and 72.9% and 72.1% at 5 years, respectively. Group 2 had lower correction in all time periods (P < 0.0001). Thoracic kyphosis and lumbar lordosis decreased in Group 3, but improved in both Groups 1 and 2 (P < 0.0001). Group 1 had more respiratory complications. The posterior groups had more deep wound infections. Two patients in Group 1 and one patient in Group 2 required revision surgery for implant-related complications. Reoperations for deep wound infections were noted only in the posterior groups. CONCLUSION: This is the first report comparing 5 year outcomes between anterior and posterior surgery for T-AIS. All three surgical methods resulted in significant and durable scoliosis correction; however, curve correction using HHF was inferior to both VATS and PSF with the latter two groups achieving similar coronal correction. However, VATS involved fewer segments, kyphosis improvement, and no deep wound infection, whereas PSF has less surgical time, shorter hospital stays, and no revision surgery from implant-related complications.Level of Evidence: 3.

Thoracolumbar Injury Classification and Severity Score Is Predictive of Perioperative Adverse Events in Operatively Treated Thoracic and Lumbar Fractures

Methods@#We performed a retrospective review of 199 patients with surgically treated thoracolumbar fractures operated between January 2007 and January 2018. The potential risk factors for the development of AEs as well as the development of common complications were evaluated by univariate analysis, and a multivariate logistic regression analysis was performed to identify independent risk factors predictive of the above. @*Results@#The overall rate of AEs was 46.7%; 83 patients (41.7%) had nonsurgical AEs, whereas 24 (12.1%) had surgical adverse events. The most common AEs were urinary tract infections in 43 patients (21.6%), and hospital-acquired pneumonia in 21 patients (10.6%). On multivariate logistic regression, a Thoracolumbar Injury Classification and Severity (TLICS) score of 8–10 (odds ratio [OR], 6.39; 95% confidence interval [CI], 2.33–17.51), the presence of polytrauma (OR, 2.64; 95% CI, 1.17–5.99), and undergoing open surgery (OR, 2.31; 95% CI, 1.09–4.88) were significant risk factors for AEs. The absence of neurological deficit was associated with a lower rate of AEs (OR, 0.47; 95% CI, 0.31–0.70). @*Conclusions@#This study suggests the presence of polytrauma, preoperative American Spinal Injury Association score, and TLICS score are predictive of AEs in patients with surgically treated thoracolumbar fractures. The results might also suggest a role for minimally invasive surgical methods in reducing AEs in these patients.

Risk factors for surgical complications in the management of ossification of the posterior longitudinal ligament.

BACKGROUND CONTEXT: Ossification of the posterior longitudinal ligament (OPLL) is a progressive, debilitating disease most commonly affecting the cervical spine. When compared to other degenerative pathologies, OPLL procedures carry a significantly higher risk of complications owing to increased case complexity and technical difficulties. Most previous studies have focused on functional outcomes and few have reported on risk factors for postoperative complications in OPLL patients. PURPOSE: To identify clinical and radiological risk factors of surgical complications following treatment for cervical OPLL STUDY DESIGN: Retrospective review PATIENT SAMPLE: One hundred thirty-one patients with cervical myelopathy secondary to OPLL who underwent surgical decompression with complete 2-year follow-up. OUTCOME MEASURES: Surgical and medical postoperative complications were analyzed. Revision surgery rates and mortality rates were recorded. METHODS: Clinical, surgical, and radiological characteristics were collected for each patient. Complications within 30 days were identified. Univariate and multivariate analysis were performed to identify risk factors for surgical complications. RESULTS: There were 39 (29.8%) surgical complications in the cohort, which included C5 palsy (7.6%), dural tear (3.1%), surgical site infection (3.1%), and epidural hematoma (1.5%). 2-year revision and mortality rates were 4.6% and 2.3%, respectively. Univariate analysis revealed that blood loss ≥750mL (OR 3.42, p=0.028), operative duration ≥5.5 hours (OR 3.16, p=0.008), hill-type OPLL (OR 3.08, p=0.011), K-line (-) OPLL (OR 5.39, p<0.001), and presence of a double-layer sign (OR 3.79, p=0.002) were significant risk factors. In multivariate analysis, only hill-type OPLL (OR 2.61, p=0.048) and K-line (-) OPLL (OR 2.98, p=0.031) were found to be significant. Patients with both hill-type and K-line (-) OPLL had a 3.5 times risk of developing surgical complications (p=0.009). CONCLUSIONS: Patients with OPLL have a higher risk of perioperative surgical complications if they had a hill-shaped OPLL and K-line (-) OPLL on preoperative imaging studies. To the best of the authors' knowledge, this study is the first to link hill-type and K-line (-) OPLL morphology as risk factors for perioperative surgical complications.

A novel hospital capacity versus clinical justification triage score (CCTS) for prioritization of spinal surgeries in the "new normal state" of the COVID-19 pandemic.

INTRODUCTION: During the Coronavirus disease 2019 outbreak, while healthcare systems and hospitals are diverting their resources to combat the pandemic, patients who require spinal surgeries continue to accumulate. The aim of this study is to describe a novel hospital capacity versus clinical justification triage score (CCTS) to prioritize patients who require surgery during the "new normal state" of the COVID-19 pandemic. METHODOLOGY: A consensus study using the Delphi technique was carried out among clinicians from the Orthopaedic Surgery, Neurosurgery, and Anaesthesia departments. Three rounds of consensus were carried out via survey and Webinar discussions. RESULTS: A 50-points score system consisting of 4 domains with 4 subdomains was formed. The CCTS were categorized into the hospital capacity, patient factors, disease severity, and surgery complexity domains. A score between 30 and 50 points indicated that the proposed operation should proceed without delay. A score of less than 20 indicates that the proposed operation should be postponed. A score between 20 and 29 indicates that the surgery falls within a grey area where further discussion should be undertaken to make a joint justification for approval of surgery. CONCLUSION: This study is a proof of concept for the novel CCTS scoring system to prioritize surgeries to meet the rapidly changing demands of the COVID-19 pandemic. It offers a simple and objective method to stratify patients who require surgery and allows these complex and difficult decisions to be unbiased and made transparently among surgeons and hospital administrators.

Lumbar Adding-on of the Thoracic Spine After Selective Fusion in Adolescent Idiopathic Scoliosis Lenke Types 1 and 2 Patients: A Critical Appraisal.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: This study aimed to identify risk factors that predict lumbar curve adding-on in patients who had selective thoracic fusion. SUMMARY OF BACKGROUND DATA: Selective thoracic fusion offers deformity correction of Lenke 1 and 2 thoracic curves and maintains lumbar range of movement. However, some patients may develop postoperative lumbar adding-on. METHODS: This study included patients 18 years or younger that underwent spinal instrumentation for Lenke 1 and 2 curves. RESULTS: A total of 161 patients were included (147 females, 14 males). The mean age was 14.0 ±â€Š2.1 years: 103 patients were Lenke 1, and 58 patients were Lenke 2 curves. Ninety-seven patients underwent posterior approach surgery, whereas 64 via anterior approach. In the posterior approach group, 79(81.4%) patients underwent selective fusion. Ten patients (6.2%) had lumbar curve adding-on, with nine females and one male. There were seven Lenke 1 and three Lenke 2 patients. All 10 patients were lumbar modifier (a), with 5 hypokyphotic patients. Selective fusion was done in nine patients. Lumbar adding-on was seen most commonly between 6 months to 1 year postoperative period (five patients). Two patients had adding-on because of incorrect distal fusion level, six were due to 1A-R curve, one due to the inadvertent fusion from the excessive long rod at the subjacent level. In multivariate analysis, hypokyphotic patients were at higher risk of lumbar adding-on (odds ratio = 9.2). Patients with Risser classification 0, 1, 2, 3 were also at higher risk of lumbar adding-on (odds ratio =6.1). CONCLUSION: The incidence of lumbar curve adding-on was 6.2%. Patients who were hypokyphotic and skeletally immature are nine times and six times more likely to have lumbar adding-on, respectively. This article examines adding-on in patients who had either anterior or posterior approach scoliosis surgeries, with follow-up stretching up to 10 years. This offers the rare opportunity to examine the natural history of the adding-on phenomenon.Level of Evidence: 3.

Symptomatic Construct Failure after Metastatic Spine Tumor Surgery.

STUDY DESIGN: Retrospective cohort study. PURPOSE: To evaluate the incidence and presentation of symptomatic failures (SFs) after metastatic spine tumor surgery (MSTS). To identify the associated risk factors. To categorize SFs based on the management in these patients. OVERVIEW OF LITERATURE: Few studies have reported on the incidence (1.9%-16%) and risk factors of SF after MSTS. It is unclear whether all SFs, occurring in MSTS-patients, result in revision surgery. METHODS: We conducted a retrospective analysis on 288 patients (246 for final analysis) who underwent MSTS between 2005-2015. Data collected were demographics and peri/postoperative clinical and radiological features. Early and late radiological SF were defined as presentation before and after 3 months from index surgery, respectively. Univariate and multivariate models of competing risk regression analysis were designed to determine the risk factors for SF with death as a competing event. RESULTS: We observed 14 SFs (5.7%) in 246 patients; 10 (4.1%) underwent revision surgery. Median survival was 13.4 months. The mean age was 58.8 years (range, 21-87 years); 48.4% were women. The median time to failure was 5 months (range, 1-60 months). Patients with SF were categorized into three groups: (1) SF when the primary implant was revised (n=5, 35.7%); (2) peri-construct progression of disease requiring extension (n=5, 35.7%); and (3) SFs that did not warrant revision (n=4, 28.5%). Four patients (28.5%) presented with early failure. SF commonly occurred at the implant-bone interface (9/14) and all patients had a spinal instability neoplastic score (SINS) >7. Thirteen patients (92.8%) who developed failure had fixation spanning junctional regions. Multivariate competing risk regression showed that preoperative Eastern Cooperative Oncology Group score was a significant risk factor for implant failure (adjusted sub-hazard ratio, 7.0; 95% confidence interval, 1.63-30.07; p<0.0009). CONCLUSIONS: The incidence of SF (5.7%) was low in patients undergoing MSTS although these patients did not undergo spinal fusion. Preoperative ambulators involved a 7 times higher risk of failure than non-ambulators. Preoperative SINS >7 and fixations spanning junctional regions were associated with SF. Majority of construct failures occurred at the implant-bone interface.

A 10-Year Radiographic Study Comparing Anterior Versus Posterior Instrumented Spinal Fusion in Patients With Lenke Type 5 Adolescent Idiopathic Scoliosis.

MINI: This is a long-term prospective cohort study comparing the radiographic outcomes of anterior versus posterior instrumentation for Lenke 5 adolescent idiopathic scoliosis. Both approaches were comparable in terms of radiographic outcomes up to 10 years. The posterior approach is more prone to developing proximal junctional kyphosis. STUDY DESIGN: Prospective cohort study. OBJECTIVE: To compare the long-term, radiographic coronal and sagittal outcomes of these two approaches at 10-year follow-up. SUMMARY OF BACKGROUND DATA: Both anterior and posterior instrumented fusions have been found to be safe and effective treatments for Lenke 5 adolescent idiopathic scoliosis with up to 2 to 5 years of follow-up. Few studies follow patients beyond this duration. METHODS: 36 patients who underwent anterior (n = 25) or posterior instrumented spinal fusion (n = 11) for Lenke 5 adolescent idiopathic scoliosis over a 4-year period were recruited and followed for 10 years. Preoperative clinical data include patient's age and age of menarche. Operative data included instrumented levels, duration of surgery, and surgical blood loss. Postoperative data included duration of hospital stay, duration of intensive care unit stay, and complications. Pre- and postoperative radiographic data collected include coronal Cobb angles for structural thoracolumbar/lumbar curves, and sagittal angles-sagittal vertical axis, thoracic kyphosis, global lumbar angle, pelvic incidence, pelvic tilt, sacral slope, and upper and lower end vertebrae. RESULTS: Posterior surgery had a shorter operative time (P < 0.010) and hospital stay (P < 0.010). Coronal plane deformity improved by a mean of 74% in the anterior group and 71% in the posterior group. There was no significant change at 10 years in both groups (anterior P = 0.455 and posterior P = 0.325). Sagittal parameters remained unchanged. There was a higher incidence of proximal junctional kyphosis in the posterior (45%) compared to the anterior (16%) group (P < 0.010). CONCLUSION: Both anterior and posterior instrumentation and fusion are successful surgeries after 10 years of follow-up. They are comparable with regards to their ability to achieve and maintain good correction of scoliotic deformities and have a low rate of pseudoarthrosis and instrument failure. Ideal sagittal parameters are maintained up to 10 years of follow-up. LEVEL OF EVIDENCE: 3.

Prospective cohort study. To compare the long-term, radiographic coronal and sagittal outcomes of these two approaches at 10-year follow-up. Both anterior and posterior instrumented fusions have been found to be safe and effective treatments for Lenke 5 adolescent idiopathic scoliosis with up to 2 to 5 years of follow-up. Few studies follow patients beyond this duration. 36 patients who underwent anterior (n = 25) or posterior instrumented spinal fusion (n = 11) for Lenke 5 adolescent idiopathic scoliosis over a 4-year period were recruited and followed for 10 years. Preoperative clinical data include patient's age and age of menarche. Operative data included instrumented levels, duration of surgery, and surgical blood loss. Postoperative data included duration of hospital stay, duration of intensive care unit stay, and complications. Pre- and postoperative radiographic data collected include coronal Cobb angles for structural thoracolumbar/lumbar curves, and sagittal angles­sagittal vertical axis, thoracic kyphosis, global lumbar angle, pelvic incidence, pelvic tilt, sacral slope, and upper and lower end vertebrae. Posterior surgery had a shorter operative time (P < 0.010) and hospital stay (P < 0.010). Coronal plane deformity improved by a mean of 74% in the anterior group and 71% in the posterior group. There was no significant change at 10 years in both groups (anterior P = 0.455 and posterior P = 0.325). Sagittal parameters remained unchanged. There was a higher incidence of proximal junctional kyphosis in the posterior (45%) compared to the anterior (16%) group (P < 0.010). Both anterior and posterior instrumentation and fusion are successful surgeries after 10 years of follow-up. They are comparable with regards to their ability to achieve and maintain good correction of scoliotic deformities and have a low rate of pseudoarthrosis and instrument failure. Ideal sagittal parameters are maintained up to 10 years of follow-up. Level of Evidence: 3.

Intraoperative Neuromonitoring (IONM): Is There a Role in Metastatic Spine Tumor Surgery?

STUDY DESIGN: A retrospective design. OBJECTIVE: We aim to report our experience with multimodal intraoperative neuromonitoring (IONM) in metastatic spine tumor surgery (MSTS). SUMMARY OF BACKGROUND DATA: IONM is considered as standard of care in spinal deformity surgeries. However, limited data exist about its role in MSTS. METHODS: A total of 135 patients from 2010 to 2017, who underwent MSTS with IONM at our institute, were studied retrospectively. After excluding seven with no baseline signals, 128 patients were analyzed. The data collected comprised of demographics, pre and postoperative American Spinal Injury Association (ASIA) grades and neurological status, indications for surgery, type of surgical approach. Multimodal IONM included somatosensory-evoked potentials (SSEPs), transcranial electric motor-evoked potentials (tcMEP), and free running electromyography (EMG). RESULTS: The 128 patients included 61 males and 67 females with a mean age of 61 years. One hundred sixteen underwent posterior procedures; nine anterior and three both. The frequency of preoperative ASIA Grades were A = 0, B = 0, C = 10, D = 44, and E = 74 patients. In total, 54 underwent MSTS for neurological deficit, 66 for instability pain, and 8 for intractable pain.Of 128 patients, 13 (10.2%) had significant IONM alerts, representing true positives; 114 true negatives, one false negative, and no false positives. Among the 13 true positives, four (30%) underwent minimally invasive and nine (70%) open procedures. Eight (69.2%) patients had posterior approach. Seven (53.84%) true positive alerts were during decompression, which resolved to baseline upon completion of decompression, while five (38.46%) were during instrumentation, which recovered to baseline after adjusting/downsizing the instrumentation, and one (8.3%) during lateral approach, which reversed after changing the plane of dissection. Of the seven patients without baseline, five were ASIA-A and two were ASIA-C. The sensitivity, specificity, positive, and negative predictive values were 99.1%, 100%, 100%, and 92.9%, respectively. CONCLUSION: Multimodal IONM in MSTS helped in preventing postoperative neurological deficit in 9.4% of patients. Its high sensitivity and specificity to detect intraoperative neurological events envisage its use in ASIA-grade D/E patients requiring instrumented decompression. LEVEL OF EVIDENCE: 3.

The Predictive Value of Preoperative Health-Related Quality-of-Life Scores on Postoperative Patient-Reported Outcome Scores in Lumbar Spine Surgery.

STUDY DESIGN: A single-center, retrospective cohort study. OBJECTIVE: To predict patient-reported outcomes (PROs) using preoperative health-related quality-of-life (HRQoL) scores by quantifying the correlation between them, so as to aid selection of surgical candidates and preoperative counselling. METHODS: All patients who underwent single-level elective lumbar spine surgery over a 2-year period were divided into 3 diagnosis groups: spondylolisthesis, spinal stenosis, and disc herniation. Patient characteristics and health scores (Oswestry Low Back Pain and Disability Index [ODI], EQ-5D, and Short Form-36 version 2 [SF-36v2]) were collected at 6 and 24 months and compared between the 3 diagnosis groups. Multivariate modelling was performed to investigate the predictive value of each parameter, particularly preoperative ODI and EQ-5D, on postoperative ODI and EQ-5D scores for all the patients. RESULTS: ODI and EQ-5D at 6 and 24 months improved significantly for all patients, especially in the disc herniation group, compared to the baseline. The magnitude of improvement in ODI and EQ-5D was predictable using preoperative ODI, EQ-5D, and SF-36v2 Mental Component Score. At 6 months, 1-point baseline ODI predicts for 0.7-point increase in changed ODI, and a 0.01-point increase in baseline EQ-5D predicts for 0.01-point decrease in changed EQ-5D score. At 24 months, 1-point baseline ODI predicts for 1-point increase in changed ODI, and a 0.01-point increase in baseline EQ-5D predicts for 0.009-point decrease in changed EQ-5D. A younger age is shown to be a positive predictor of ODI at 24 months. CONCLUSIONS: Poorer baseline health scores predict greater improvement in postoperative PROs at 6 and 24 months after the surgery. HRQoL scores can be used to decide on surgery and in preoperative counselling.

Normal variation in sagittal spinal alignment parameters in adult patients: an EOS study using serial imaging.

PURPOSE: To describe normal variations in sagittal spinal radiographic parameters over an interval period and establish physiological norms and guidelines for which these images should be interpreted. METHODS: Data were prospectively collected from a continuous series of adult patients with first-episode mild low back pain presenting to a single institution. The sagittal parameters of two serial radiographic images taken 6-months apart were obtained with the EOS® slot scanner. Measured parameters include CL, TK, TL, LL, PI, PT, SS, and end and apical vertebrae. Chi-squared test and Wilcoxon Signed Rank test were used to compare categorical and continuous variables, respectively. RESULTS: Sixty patients with a total of 120 whole-body sagittal X-rays were analysed. Mean age was 52.1 years (SD 21.2). Mean interval between the first and second X-rays was 126.2 days (SD 47.2). Small variations (< 1°) occur for all except PT (1.2°), CL (1.2°), and SVA (2.9 cm). Pelvic tilt showed significant difference between two images (p = 0.035). Subgroup analysis based on the time interval between X-rays, and between the first and second X-rays, did not show significant differences. Consistent findings were found for end and apical vertebrae of the thoracic and lumbar spine between the first and second X-rays for sagittal curve shapes. CONCLUSIONS: Radiographic sagittal parameters vary between serial images and reflect dynamism in spinal balancing. SVA and PT are predisposed to the widest variation. SVA has the largest variation between individuals of low pelvic tilt. Therefore, interpretation of these parameters should be patient specific and relies on trends rather than a one-time assessment.

Prevalence and Predictors of Pressure Injuries From Spine Surgery in the Prone Position: Do Body Morphological Changes During Deformity Correction Increase the Risks?

MINI: Pressure injuries are prevalent in patients undergoing spine surgery while prone. Multiple risk factors exist and should be addressed. We found that patients undergoing spinal deformity correction surgery are at unique risk (odds ratio 3.31, P = 0.010) due to body morphological changes occurring secondary to intraoperative changes in spinal alignment. STUDY DESIGN: Review of data and prospective study. OBJECTIVE: To investigate the prevalence and predictive factors of pressure injuries in spine surgery performed in the prone position, and to determine whether morphological changes and truncal shifts occurring during deformity correction predispose to this complication. SUMMARY OF BACKGROUND DATA: Spine surgery performed in the prone position presents the risk of developing pressure injuries. This risk is potentially increased in deformity correction, because it tends to involve more extensive procedures, with associated longer operating times. METHODS: Cases of pressure injuries after spine surgery in the prone position were reviewed to ascertain prevalence and determine risk factors. Data including patient factors (age, sex, height, weight, body mass index, American Society of Anesthesiologists grade, comorbidities, Braden scale, neurological status, spinal pathology) and surgical factors (approach, procedure type, number of screws, operated levels, operative time) were collected. Independent risk factors were identified via multivariate analysis. A subsequent prospective analysis of all patients undergoing spinal deformity correction was conducted by performing intraoperative measurements of body morphological changes and shifts in truncal positions. Statistical correlation was performed to determine whether positional shifts cause pressure injuries. RESULTS: The prevalence of pressure injuries was 23.0%. Previous skin problems (P = 0.034), myelopathy (P = 0.013), operative time >300 minutes (P = 0.005), and more than four operated levels (P = 0.006) were independent predictors of pressure injuries. Being a spinal deformity patient was also an independent risk factor for developing pressure injuries (odds ratio 3.31, P = 0.010). Significant changes in body measurements during deformity correction were predictive of pressure injuries. CONCLUSION: Pressure injuries are prevalent in patients undergoing spine surgery while prone. Future studies should investigate strategies to prevent this complication based on the multiple risk factors identified in the present study. Patients undergoing spinal deformity correction surgery are particularly at risk due to intraoperative body morphological changes. Improved padding methods should be trialed in future studies. LEVEL OF EVIDENCE: 3.

Lumbar Spine Alignment in Six Common Postures: An ROM Analysis With Implications for Deformity Correction.

STUDY DESIGN: A cross-sectional study of prospectively collected data. OBJECTIVE: To compare lumbar spine alignment in six common postures, and estimate loss in range of motion (ROM) relative to standing. SUMMARY OF BACKGROUND DATA: Ideal position for fusion of lumbar spine remains unknown. Although surgical fusion is necessary for deformity correction and symptom relief, the final position in which the vertebrae are immobilized should provide maximum residual function. METHODS: Data were collected prospectively from 70 patients with low back pain recruited over a year. All subjects had x-rays performed in slump sitting, forward bending, supine, half squatting, standing, and backward bending postures. ROM quantified in terms of sagittal global and segmental Cobb angles was measured from L1 to S1. Loss of ROM relative to standing was calculated for each posture. Analysis of variance and unpaired t tests were used to identify differences in alignment between postures. RESULTS: Slump sitting gives the greatest lumbar flexion followed by forward bending, and supine postures (P < 0.001). Backward bending produces greater lumbar extension than standing (P = 0.035). Half-squatting and standing postures were not significantly different (P = 0.938). For all postures, L4-5 and L5-S1 segments remained in lordosis, with L4-5 having greater ROM than L5-S1. L1-2 turns kyphotic in lying supine, L2-3 at forward bending, and L3-4 at slump sitting in the form of a "kyphosing cascade." Should the entire lumbar spine be fused in standing position from L1-S1, there would likely be a mean loss of 47.6° of lumbar flexion and 5.9° of lumbar extension. CONCLUSION: The present study demonstrates the extent of flexibility required of the lumbar spine in assuming various postures. It also enables comparison of the differences in degree of motion occurring in the lumbar spine, both across postures and across segments. Significant loss in ROM, particularly flexion, is anticipated with fusion modeled after the lordotic standing lumbar spine. LEVEL OF EVIDENCE: 2.

Is Intraoperative Local Vancomycin Powder the Answer to Surgical Site Infections in Spine Surgery?

STUDY DESIGN: This is a retrospective cohort comparative study of all patients who underwent instrumented spine surgery at a single institution. OBJECTIVE: To compare the rate of surgical site infection (SSI) between the treatment (vancomycin) and the control group (no vancomycin) in patients undergoing instrumented spine surgery. SUMMARY OF BACKGROUND DATA: SSI after spine surgery is a dreaded complication associated with increased morbidity and mortality. Prophylactic intraoperative local vancomycin powder to the wound has been recently adopted as a strategy to reduce SSI but results have been variable. METHODS: In the present study, there were 117 (30%) patients in the treatment group and 272 (70%) patients in the comparison cohort. All patients received identical standard operative and postoperative care procedures based on protocolized department guidelines. The present study compared the rate of SSI with and without the use of prophylactic intraoperative local vancomycin powder in patients undergoing various instrumented spine surgery, adjusted for confounders. RESULTS: The overall rate of SSI was 4.7% with a decrease in infection rate found in the treatment group (0.9% vs. 6.3%). This was statistically significant (P = 0.049) with an odds ratio of 0.13 (95% confidence interval 0.02-0.99). The treatment group had a significantly shorter onset of infection (5 vs. 16.7 days; P < 0.001) and shorter duration of infection (8.5 vs. 26.8 days; P < 0.001). The most common causative organism was Pseudomonas aeruginosa (35.2%). Patient diagnosis, surgical approach, and intraoperative blood loss were significant risk factors for SSI after multivariable analysis. CONCLUSION: Prophylactic Intraoperative local vancomycin powder reduces the risk and morbidity of SSI in patients undergoing instrumented spine surgery. P. aeruginosa infection is common in the treatment arm. Future prospective randomized controlled trials in larger populations involving other spine surgeries with a long-term follow-up duration are recommended. LEVEL OF EVIDENCE: 3.

Reproducibility of sagittal radiographic parameters in adolescent idiopathic scoliosis-a guide to reference values using serial imaging.

BACKGROUND CONTEXT: Knowledge of sagittal radiographic parameters in adolescent idiopathic scoliosis (AIS) patients has not yet caught up with our understanding of their roles in patients with adult spinal deformity. It is likely that more emphasis will be placed in restoring sagittal parameters for AIS patients in the future. Therefore, we need to understand how these parameters may vary in AIS to facilitate management plans. PURPOSE: This study aimed to determine the reproducibility of sagittal spinal parameters on lateral film radiographs in patients with AIS. STUDY DESIGN/SETTING: This was a retrospective, comparative study conducted in a tertiary health-care institution from January 2013 to February 2016 (3-year period). PATIENT SAMPLE: All AIS patients who underwent deformity correction surgery from January 2013 to February 2016 and had two preoperative serial lateral radiographs taken within the time period of a month were included in the study. OUTCOME MEASURES: Radiographic sagittal spinal parameters including sagittal vertical axis (SVA), cervical lordosis (CL), thoracic kyphosis (TK), thoracolumbar alignment (TL), lumbar lordosis (LL); standard spinopelvic measurements such as pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS); as well as end and apical vertebrae of cervical, thoracic, and lumbar curves were the outcome measures. METHODS: All patient data were pooled from electronic medical records, and X-ray images were retrieved from Centricity Enterprise Web. Averaged X-ray measurements by two independent assessors were analyzed by comparing two radiographs of the same patients performed within a 1-month time period. Chi-squared and Wilcoxon signed-rank tests were used for categorical and continuous variables. RESULTS: The study cohort comprised 138 patients, 28 men and 110 women, with a mean age of 15 years (range 11-20). Between the two lateral X-rays, there was a mean difference of 0.79 cm in SVA (p<.001), 0.70° in LL (p=.033), and 0.73° in PT (p=.010). In the combined Lenke 1 and 2 subgroup, there was a similar 0.77 cm (p=.002), 0.79° (p=.009), and 1.49° (p=.001) mean difference in SVA, LL, and PT, respectively. Additionally, there was also a 1.85° (p=.009) and 1.76° (p=.006) mean difference seen in TL and SS, respectively. The overall profile of the sagittal curves remained largely similar, with only the lumbar apex shifting from L3 to L4 during the first and the second X-rays, respectively (p<.001). This occurred for the combined Lenke 1 and 2 subgroup as well (p<.001). CONCLUSION: Most radiographic sagittal spinal parameters in AIS patients are generally reproducible with some variations up to a maximum of 4°. This natural variation should be taken into account when interpreting these radiographic sagittal parameters so as to achieve the most accurate results in surgical planning.

Spinal Implants Can Be Inserted in Patients With Deep Spine Infection: Results From a Large Cohort Study.

STUDY DESIGN: A retrospective, cohort study of 84 patients with deep spine infection managed at a major tertiary hospital over 14 years with a minimum follow up of 2 years. OBJECTIVE: To determine the role of instrumentation in spines with deep infection. SUMMARY OF BACKGROUND DATA: It is often believed that implants should not be inserted in patients with deep spine infection because of the risk of persistent or recurrent infection. However, there are often concerns about spinal stability and a paucity of evidence to guide clinical practice in this field. METHODS: We compared the mortality, reoperation, and reinfection rates in patients with spine infection treated with antibiotics alone, antibiotics with debridement, and antibiotics with debridement and instrumentation. Significant outcome predictors were determined using multivariable logistic regression model. RESULTS: Forty-nine males and 35 females with a mean age was 62.0 years had spine infection affecting the lumbar spine predominantly. The most common form of infection was osteomyelitis and spondylodiscitis (69.4%). Staphylococcus aureus was the most common causative organism (61.2%).There was no difference in terms of reoperation or relapse for patients treated with antibiotics alone, antibiotics with debridement, or antibiotics with debridement and instrumentation. However, compared with antibiotics alone, the crude inhospital mortality was lower for patients treated with instrumentation (odds ratio, OR, 0.82; P = 0.01), and antibiotics with debridement (OR 0.80; P = 0.02). CONCLUSION: Spinal instrumentation in an infected spine is safe and not associated with higher reoperation or relapse rates. Mortality is lower for patients treated with instrumentation. LEVEL OF EVIDENCE: 3.

Differences in erect sitting and natural sitting spinal alignment-insights into a new paradigm and implications in deformity correction.

BACKGROUND CONTEXT: Sitting spinal alignment is increasingly recognized as a factor influencing strategy for deformity correction. Considering that most individuals sit for longer hours in a "slumped" rather than in an erect posture, greater understanding of the natural sitting posture is warranted. PURPOSE: This study aimed to investigate the differences in sagittal spinal alignment between two common sitting postures: a natural, patient-preferred posture; and an erect, investigator-controlled posture that is commonly used in alignment studies. DESIGN/SETTING: This is a randomized, prospective study of 28 young, healthy patients seen in a tertiary hospital over a 6-month period. PATIENT SAMPLE: Twenty-eight patients (24 men, 4 women), with a mean age of 24 years (range 19-38), were recruited for this study. All patients with first episode of lower back pain of less than 3 months' duration were included. The exclusion criteria consisted of previous spinal surgery, radicular symptoms, red flag symptoms, previous spinal trauma, obvious spinal deformity on forward bending test, significant personal or family history of malignancy, and current pregnancy. OUTCOME MEASURES: Radiographic measurements included sagittal vertical axis (SVA), lumbar lordosis (LL), thoracolumbar angle (TL), thoracic kyphosis (TK), and cervical lordosis (CL). Standard spinopelvic parameters (pelvic incidence, pelvic tilt [PT], and sacral slope) and sagittal apex and end vertebrae were also measured. METHODS: Basic patient demographics (age, gender, ethnicity) were recorded. Lateral sitting whole spine radiographs were obtained using a slot scanner in the imposed erect and the natural sitting posture. Statistical analyses of the radiographical parameters were performed comparing the two sitting postures using chi-squared tests for categorical variables and paired t tests for continuous variables. RESULTS: There was forward SVA shift between the two sitting postures by a mean of 2.9 cm (p<.001). There was a significant increase in CL by a mean of 11.62° (p<.001), and TL kyphosis by a mean of 11.48° (p<.001), as well as a loss of LL by a mean of 21.26° (p<.001). The mean PT increased by 17.68° (p<.001). The entire thoracic and lumbar spine has the tendency to form a single C-shaped curve with the apex moving to L1 (p=.002) vertebra in the majority of patients. CONCLUSIONS: In a natural sitting posture, the lumbar spine becomes kyphotic and contributes to a single C-shaped sagittal profile comprising the thoracic and the lumbar spine. This is associated with an increase in CL and PT, as well as a constant SVA. These findings lend insight into the body's natural way of energy conservation using the posterior ligamentous tension band while achieving sitting spinal sagittal balance. It also provides information on one of the possible causes of proximal junctional kyphosis or proximal junctional failure.

T9 versus T10 as the upper instrumented vertebra for correction of adult deformity-rationale and recommendations.

BACKGROUND CONTEXT: Adult spinal deformity correction sometimes involves long posterior pedicle screw constructs extending from the lumbosacral spine to the thoracic vertebra. As fusion obliterates motion and places supraphysiological stress on adjacent spinal segments, it is crucial to ascertain the ideal upper instrumented vertebra (UIV) to minimize risk of proximal junctional failure (PJF). The T10 vertebra is often chosen to allow bridging of the thoracolumbar junction into the immobile thoracic vertebrae on the basis that it is the lowest immobile thoracic vertebra strut by the rib cage. PURPOSE: This study aimed to characterize the range of motion (ROM) of each vertebral segment from T7 to S1 to determine if T10 is truly the lowest immobile thoracic vertebra. STUDY DESIGN/SETTING: This is a prospective, comparative study. PATIENT SAMPLE: Seventy-nine adults (mean age of 45.4 years) presenting with low back pain or lower limb radiculopathy or both, without previous spinal intervention, metastases, fractures, infection, or congenital deformities of the spine, were included in the study. OUTCOME MEASURES: A ROM >5° across two vertebral segments as determined by the Cobb method from radiographs. METHODS: Lumbar flexion-extension and neutral erect radiographs were obtained in randomized order using a slot scanner. Segmental ROM was measured from T7-T8 to L5-S1 and analyzed for significant differences using t tests. Age, gender, radiographical indices such as standard spinopelvic parameters, sagittal vertical axis (SVA), C7-T12 SVA, T1 slope, thoracic kyphosis (TK), and lumbar lordosis (LL) were studied via multivariate analysis to identify predictive factors for >5° change in ROM at the various segmental levels. There were no sources of funding and no conflicts of interest associated with this study. RESULTS: In the thoracolumbar spine, significant decreases in ROM when compared with the adjacent caudad segment occurs up to T9-T10, with mean total ROM of 1.98±1.47° (p<.001) seen in T9-T10, 2.19±1.67° (p<.001) in T10-T11, and 3.92±3.21°(p<.001) in T11-T12. The total ROM of T8-T9 (2.53±1.79°) was not significantly different from that of T9-T10 (p=.261). At the thoracolumbar junction, absence of scoliosis (OR 11.37, p=.020), high pelvic incidence (OR 1.14, p=.046), and low T1 slope (OR 1.45, p=.030) were predictive of ROM >5°. CONCLUSIONS: Lumbar spine flexion-extension ROM decreases as it approaches the thoracolumbar junction. T10 is indeed the lowest immobile thoracic vertebra strut by the rib cage, and the last significant decrease in ROM is observed at T9-T10, in relation to T10-T11. However, because this also implies that a UIV of T10 would mean there is only one level of fixation above the relatively mobile segment, while respecting other factors that influence UIV selection, we propose the T9 vertebra as a more ideal UIV to fulfill the biomechanical concept of bridge fixation. However, this decision should still be taken on a case-by-case basis.