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PURPOSE: The purpose of this review was to evaluate the effectiveness of patient-specific rods for adult spinal deformity. METHODS: A systematic review of the literature was performed through an electronic search of the PubMed, Scopus, and Web of Science databases. Human studies between 2012 and 2023 were included. Sample size, sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), pelvic tilt (PT), operation time, blood loss, follow-up duration, and complications were recorded for each study when available. RESULTS: Seven studies with a total of 304 adult spinal deformity patients of various etiologies were included. All studies reported SVA, and PT; two studies did not report PI-LL. Four studies reported planned radiographic outcomes. Two found a significant association between preoperative plan and postoperative outcome in all three outcomes. One found a significant association for PI-LL alone. The fourth found no significant associations. SVA improved in six of seven studies, PI-LL improved in all five, and three of seven studies found improved postoperative PT. Significance of these results varied greatly by study. CONCLUSION: Preliminary evidence suggests potential benefits of PSRs in achieving optimal spino-pelvic parameters in ASD surgery. Nevertheless, conclusions regarding the superiority of PSRs over traditional rods must be judiciously drawn, given the heterogeneity of patients and study methodologies, potential confounding variables, and the absence of robust randomized controlled trials. Future investigations should concentrate on enhancing preoperative planning, standardizing surgical methodologies, isolating specific patient subgroups, and head-to-head comparisons with traditional rods to fully elucidate the impact of PSRs in ASD surgery.

PURPOSE: There is limited information on the clustering or co-occurrence of complications after spinal fusion surgery for neuromuscular disease in children. We aimed to identify the frequency and predictive factors of co-occurring perioperative complications in these children. METHODS: In this retrospective database cohort study, we identified children (ages 10-18 years) with neuromuscular scoliosis who underwent elective spinal fusion in 2012-2020 from the National Surgical Quality Improvement Program-Pediatric database. The rates of co-occurring complications within 30 days were calculated, and associated factors were identified by logistic regression analysis. Correlation between a number of complications and outcomes was assessed. RESULTS: Approximately 11% (709/6677 children with neuromuscular scoliosis undergoing spinal fusion had co-occurring complications: 7% experienced two complications and 4% experienced ≥ 3. The most common complication was bleeding/transfusion (80%), which most frequently co-occurred with pneumonia (24%) and reintubation (18%). Surgical time ≥ 400 min (odds ratio (OR) 1.49 [95% confidence interval (CI) 1.25-1.75]), fusion ≥ 13 levels (1.42 [1.13-1.79]), and pelvic fixation (OR 1.21 [1.01, 1.44]) were identified as procedural factors that independently predicted concurrent complications. Clinical risk factors for co-occurring complications included an American Society of Anesthesiologist physical status classification ≥ 3 (1.73 [1.27-2.37]), structural pulmonary/airway abnormalities (1.24 [1.01-1.52]), impaired cognitive status (1.80 [1.41-2.30]), seizure disorder (1.36 [1.12-1.67]), hematologic disorder (1.40 [1.03-1.91], preoperative nutritional support (1.34 [1.08-1.72]), and congenital malformations (1.20 [1.01-1.44]). Preoperative tracheostomy was protective against concurrent complications (0.62 [0.43-0.89]). Significant correlations were found between number of complications and length of stay, non-home discharge, r

Introduction and importanceDegenerative lumbar scoliosis is a prominent cause of adult spinal deformity with an increasing prevalence as the population ages. This pathology is associated with debilitating symptoms, including radicular back pain and lower extremity claudication. Surgical realignment of the spine and restoration of sagittal imbalance can reduce low back pain. Chronic sacroiliac dysfunction commonly causes low back radicular pain. We present a complicated case where stereotactic navigation facilitated an extensive fusion and decompression procedure for adult spinal deformity in an obese patient with multiple prior surgeries for scoliosis and sacroiliac joint pathology.Case presentationA 69-year-old, obese female with scoliosis refractory to multiple interventions presented with severe, radicular lower back pain. On examination of the right lower extremity (RLE), she had mild weakness (3/5 strength) and reduced sensation to light touch over its anterolateral aspect (dermatome L4). She was unable to perform single leg stance or tandem walk. Imaging revealed moderate mid-lumbar levoscoliosis, severe degenerative disc disease and facet hypertrophy changes in the setting of prior multilevel lumbar fusion, and consecutive nerve root impingement between L1 and L5 (worst at L3-4). DEXA scan was consistent with osteoporosis. The patient underwent lumbar laminectomy with posterior fusion of T10-ilium, transforaminal lumbar interbody fusion, osteotomy, and decompression using stereotactic navigation. The presence of SI titanium dowels from her previous SI fusion procedure posed a challenge with respect to achieving pelvic fixation.Clinical discussionIliac screw placement is a critical adjunctive to lumbosacral fusion, notably for prevention of pseudoarthrosis; however, patients with prior SI fusion may present a biomechanical challenge to surgeons due to obstruction of the surgical site. The O-arm neuronavigation system was successfully used to bypass this obstru

Introduction and importanceDegenerative lumbar scoliosis is a prominent cause of adult spinal deformity with an increasing prevalence as the population ages. This pathology is associated with debilitating symptoms, including radicular back pain and lower extremity claudication. Surgical realignment of the spine and restoration of sagittal imbalance can reduce low back pain. Chronic sacroiliac dysfunction commonly causes low back radicular pain. We present a complicated case where stereotactic navigation facilitated an extensive fusion and decompression procedure for adult spinal deformity in an obese patient with multiple prior surgeries for scoliosis and sacroiliac joint pathology.Case presentationA 69-year-old, obese female with scoliosis refractory to multiple interventions presented with severe, radicular lower back pain. On examination of the right lower extremity (RLE), she had mild weakness (3/5 strength) and reduced sensation to light touch over its anterolateral aspect (dermatome L4). She was unable to perform single leg stance or tandem walk. Imaging revealed moderate mid-lumbar levoscoliosis, severe degenerative disc disease and facet hypertrophy changes in the setting of prior multilevel lumbar fusion, and consecutive nerve root impingement between L1 and L5 (worst at L3-4). DEXA scan was consistent with osteoporosis. The patient underwent lumbar laminectomy with posterior fusion of T10-ilium, transforaminal lumbar interbody fusion, osteotomy, and decompression using stereotactic navigation. The presence of SI titanium dowels from her previous SI fusion procedure posed a challenge with respect to achieving pelvic fixation.Clinical discussionIliac screw placement is a critical adjunctive to lumbosacral fusion, notably for prevention of pseudoarthrosis; however, patients with prior SI fusion may present a biomechanical challenge to surgeons due to obstruction of the surgical site. The O-arm neuronavigation system was successfully used to bypass this obstru

Adult spinal deformity (ASD) is a complex and heterogeneous disease that can severely impact patients' lives. While it is clear that surgical correction can achieve significant improvement of spinopelvic parameters and quality of life measures in adults with spinal deformity, there remains a high risk of complication associated with surgical approaches to adult deformity. Over the past decade, utilization of surgical correction for ASD has increased dramatically as deformity correction techniques have become more refined and widely adopted. Along with this increase in surgical utilization, there has been a massive undertaking by spine surgeons to develop more robust models to predict postoperative outcomes in an effort to mitigate the relatively high complication rates. A large part of this revolution within spine surgery has been the gradual adoption of predictive analytics harnessing artificial intelligence through the use of machine learning algorithms. The development of predictive models to accurately prognosticate patient outcomes following ASD surgery represents a dramatic improvement over prior statistical models which are better suited for finding associations between variables than for their predictive utility. Machine learning models, which offer the ability to make more accurate and reproducible predictions, provide surgeons with a wide array of practical applications from augmenting clinical decision making to more wide-spread public health implications. The inclusion of these advanced computational techniques in spine practices will be paramount for improving the care of patients, by empowering both patients and surgeons to more specifically tailor clinical decisions to address individual health profiles and needs.

Adult spinal deformity (ASD) is a complex and heterogeneous disease that can severely impact patients' lives. While it is clear that surgical correction can achieve significant improvement of spinopelvic parameters and quality of life measures in adults with spinal deformity, there remains a high risk of complication associated with surgical approaches to adult deformity. Over the past decade, utilization of surgical correction for ASD has increased dramatically as deformity correction techniques have become more refined and widely adopted. Along with this increase in surgical utilization, there has been a massive undertaking by spine surgeons to develop more robust models to predict postoperative outcomes in an effort to mitigate the relatively high complication rates. A large part of this revolution within spine surgery has been the gradual adoption of predictive analytics harnessing artificial intelligence through the use of machine learning algorithms. The development of predictive models to accurately prognosticate patient outcomes following ASD surgery represents a dramatic improvement over prior statistical models which are better suited for finding associations between variables than for their predictive utility. Machine learning models, which offer the ability to make more accurate and reproducible predictions, provide surgeons with a wide array of practical applications from augmenting clinical decision making to more wide-spread public health implications. The inclusion of these advanced computational techniques in spine practices will be paramount for improving the care of patients, by empowering both patients and surgeons to more specifically tailor clinical decisions to address individual health profiles and needs.

OBJECTIVE Complications after adult spinal deformity surgery are common, with implant-related complications occurring in up to 27.8% of cases. Sublaminar wire fixation strength is less affected by decreasing trabecular bone density in comparison to pedicle screw (PS) fixation due to the predominant cortical bone composition of the lamina. Sublaminar fixation may thus aid in decreasing implant-related complications. The goal of this study was to compare fixation characteristics of titanium sublaminar cables (SCs), ultra-high-molecular-weight polyethylene (UHMWPE) tape, PSs, and PSs augmented with UHMWPE tape in an ex vivo flexion-bending setup.METHODS Thirty-six human cadaver vertebrae were stratified into 4 different fixation groups: UHMWPE sublaminar tape (ST), PS, metal SC, and PS augmented with ST (PS + ST). Individual vertebrae were embedded in resin, and a flexion-bending moment was applied that closely resembles the in vivo loading pattern at transitional levels of spinal instrumentation.RESULTS The failure strength of PS + ST (4522 +/- 2314 N) was significantly higher compared to the SC (2931 +/- 751 N) and PS (2678 +/- 827 N) groups, which had p values of 0.028 and 0.015, respectively (all values expressed as the mean +/- SD). Construct stiffness was significantly higher for the PS groups compared to the stand-alone sublaminar wiring groups (p = 0.020). In contrast to SC, ST did not show any case of cortical breach.CONCLUSIONS The higher failure strength of PS + ST compared to PS indicates that PS augmentation with ST may be an effective measure to reduce the incidence of screw pullout, even in osteoporotic vertebrae. Moreover, the lower stiffness of sublaminar fixation techniques and the absence of damage to the cortices in the ST group suggest that ST as a stand-alone fixation technique in adult spinal deformity surgery may also be clinically feasible and offer clinical benefits.

Adult spinal deformity (ASD) is a complex and heterogeneous disease that can severely impact patients' lives. While it is clear that surgical correction can achieve significant improvement of spinopelvic parameters and quality of life measures in adults with spinal deformity, there remains a high risk of complication associated with surgical approaches to adult deformity. Over the past decade, utilization of surgical correction for ASD has increased dramatically as deformity correction techniques have become more refined and widely adopted. Along with this increase in surgical utilization, there has been a massive undertaking by spine surgeons to develop more robust models to predict postoperative outcomes in an effort to mitigate the relatively high complication rates. A large part of this revolution within spine surgery has been the gradual adoption of predictive analytics harnessing artificial intelligence through the use of machine learning algorithms. The development of predictive models to accurately prognosticate patient outcomes following ASD surgery represents a dramatic improvement over prior statistical models which are better suited for finding associations between variables than for their predictive utility. Machine learning models, which offer the ability to make more accurate and reproducible predictions, provide surgeons with a wide array of practical applications from augmenting clinical decision making to more wide-spread public health implications. The inclusion of these advanced computational techniques in spine practices will be paramount for improving the care of patients, by empowering both patients and surgeons to more specifically tailor clinical decisions to address individual health profiles and needs.

BackgroundThis cross sectional study describes a "Soft Landing" strategy utilizing hooks for minimizing proximal junctional kyphosis (PJK) and proximal junctional failure (PJF). The technique creates a gradual transition from a rigid segmental construct to unilateral hooks at the upper instrumented level and preservation of the soft tissue attachments on the contralateral side of the hooks. Authors devise a novel classification system for better grading of PJK severity.MethodsThirty-nine consecutive adult spinal deformity (ASD) patients at a single institution received the "Soft Landing" technique. The proximal junctional angle was measured preoperatively and at last follow-up using standing 36-inch spinal radiographs. Changes in proximal junctional angle and rates of PJK and PJF were measured and used to create a novel classification system for evaluating and categorizing ASD patients postoperatively.ResultsThe mean age of the cohort was 61.4 years, and 90% of patients were women. Average follow up was 2.2 years. The mean change in proximal junctional angle was 8° (SD 7.4°) with the majority of patients (53%) experiencing less than 10° and only 1 patients with proximal junctional angle over 20°. Four patients (10%) needed additional surgery for proximal extension of the uppermost instrumented vertebra (UIV) secondary to PJF.ConclusionsSoft Landing technique is a possibly effective treatment strategy to prevent PJK and PJF following ASD that requires further evaluation. The described classification system provides management framework for better grading of PJK. The "Soft Landing" technique warrants further comparison to other techniques currently used to prevent both PJK and failure.

OBJECTIVE Complications after adult spinal deformity surgery are common, with implant-related complications occurring in up to 27.8% of cases. Sublaminar wire fixation strength is less affected by decreasing trabecular bone density in comparison to pedicle screw (PS) fixation due to the predominant cortical bone composition of the lamina. Sublaminar fixation may thus aid in decreasing implant-related complications. The goal of this study was to compare fixation characteristics of titanium sublaminar cables (SCs), ultra-high-molecular-weight polyethylene (UHMWPE) tape, PSs, and PSs augmented with UHMWPE tape in an ex vivo flexion-bending setup.METHODS Thirty-six human cadaver vertebrae were stratified into 4 different fixation groups: UHMWPE sublaminar tape (ST), PS, metal SC, and PS augmented with ST (PS + ST). Individual vertebrae were embedded in resin, and a flexion-bending moment was applied that closely resembles the in vivo loading pattern at transitional levels of spinal instrumentation.RESULTS The failure strength of PS + ST (4522 +/- 2314 N) was significantly higher compared to the SC (2931 +/- 751 N) and PS (2678 +/- 827 N) groups, which had p values of 0.028 and 0.015, respectively (all values expressed as the mean +/- SD). Construct stiffness was significantly higher for the PS groups compared to the stand-alone sublaminar wiring groups (p = 0.020). In contrast to SC, ST did not show any case of cortical breach.CONCLUSIONS The higher failure strength of PS + ST compared to PS indicates that PS augmentation with ST may be an effective measure to reduce the incidence of screw pullout, even in osteoporotic vertebrae. Moreover, the lower stiffness of sublaminar fixation techniques and the absence of damage to the cortices in the ST group suggest that ST as a stand-alone fixation technique in adult spinal deformity surgery may also be clinically feasible and offer clinical benefits.

Brugada Syndrome (BrS) is a genetic condition associated with ventricular fibrillation and sudden cardiac death. In BrS, several pharmacological agents may increase the risk for arrhythmia and total intravenous anesthesia with propofol (TIVA) may be contraindicated due to the increased risk of perioperative cardiac arrest. Anesthesia with halogenated volatile agents has to be used instead, making monitoring of sensory and motor evoked potentials in spine surgery problematic. Furthermore, hyperthermia may induce ventricular arrhythmia in BrS, thus making temperature control of paramount importance. The purpose of this paper is to describe the particular challenges of anesthesia and intraoperative neuromonitoring associated with corrective spinal surgery in an adolescent girl with BrS. We present an analysis of a multidisciplinary approach to performing corrective spine surgery in an otherwise healthy 14-year-old girl with scoliosis. Before surgery, multidisciplinary meetings were conducted, including anesthesia and intensive care, pediatric cardiology as well as the spine team. The surgery was performed with inhalation anesthesia using sevoflurane and cardiac monitoring. Continuous somatosensory potentials were monitored as well as motor evoked potentials. The patient underwent corrective surgery from Th3 to L2. With a multidisciplinary team approach involving anesthesia and cardiology outlining the appropriate precautions, scoliosis correction with intraoperative neuromonitoring, can be safely performed in patients with BrS using inhalation anesthesia.

This thesis is a study assessing the three-dimensional growth at the apical vertebral body in adolescent idiopathic scoliosis (AIS). It utilized a novel reconstruction and alignment technique utilizing non-harmful magnetic resonance imaging scans to quantitively demonstrate growth asymmetry in AIS patients with progressive deformity, with aims to further understanding of the progressive deformity in this condition.

Correction of severe spinal deformity is a significant challenge for spinal surgeons. Although halo-gravity traction (HGT) has been shown to be well-tolerated and safe, we report here a case of neurologic decline during treatment. A 24-year-old male presents with severe thoracic kyphoscoliosis with > 180° of 3-dimensional deformity. Magnetic resonance imaging showed his thoracic spinal cord draped across his T7-9 apex. His neurologic exam showed lower extremity myelopathy. During week 7 at a goal traction weight of 18.1 kg, his distal lower extremity exam declined from 4+/5 to 2/5. His traction weight was lowered to 11.3 kg. He subsequently sustained a ground-level fall and became paraparetic with a motor exam of 1-2/5. He subsequently underwent a T1-L4 posterior spinal instrumentation and fusion with a T7-9 vertebral column resection. Postoperatively, he was noted to have a complete return to his baseline neurologic exam. At his 4-month postoperative visit, he was now full strength in his lower extremities with complete resolution of his myelopathy. We present here a case of neurologic decline in a patient with severe kyphoscoliosis who underwent HGT and discuss the management decisions associated with this challenging scenario.

Purpose: There is controversy regarding age-related deterioration of spinal sagittal alignment in cross-sectional study. Although we reported that deterioration in spinal alignment originated at the cervical spine in males and the pelvis in females, others studies have indicated that the lumbar spine is initially implicated in both sexes. The purpose of this study was to clarify these differences in a longitudinal cohort study.Methods: Our analysis was based on 237 individuals aged 60-89 years who participated in our health screening study in 2014 and 2018. They were classified into 6 groups by birth-year and sex: 60-69 years (26 males, 49 females); 70-79 years (35 males, 88 females); and 80-89 years (19 males, 20 females). The following parameters were measured from standing radiographs: pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), T1 slope (TS), cervical lordosis (CL), C7 sagittal vertical axis (C7 SVA), and C2-7 SVA.Results: In males, the first significant change was an increase in the PT angle (19°, in 2014, to 21°, in 2018) in the 80-89 years age group (P<0.05), with no significant deterioration in cervical parameters. In females, spinal deterioration included a change in the SS (32° to 30°), PT (18° to 20°), and SVA (-8 mm to 6 mm) in the 60-69 years age group (P<0.05), with no change in the LL.Conclusions: Contrary to prior studies, our longitudinal data indicated that deterioration in spinal alignment originate in the pelvis for both sex but develop earlier in females than males.

BACKGROUND:There have been no reports describing how cervical reconstruction surgery affects global spinal alignment (GSA). OBJECTIVE:To elucidate the effects of cervical reconstruction for GSA through a retrospective multicenter study. METHODS:Seventy-eight patients who underwent cervical reconstruction surgery for cervical kyphosis were divided into a Head-balanced group (n = 42) and a Trunk-balanced group (n = 36) according to the values of the C7 plumb line (PL). We also divided the patients into a cervical sagittal balanced group (CSB group, n = 18) and a cervical sagittal imbalanced group (CSI group, n = 60) based on the C2 PL-C7 PL distance. Various sagittal Cobb angles and the sagittal vertical axes were measured before and after surgery. RESULTS:Cervical alignment was improved to achieve occiput-trunk concordance (the distance between the center of gravity [COG] PL, which is considered the virtual gravity line of the entire body, and C7 PL < 30 mm) despite the location of COG PL and C7PL. A subsequent significant change in thoracolumbar alignment was observed in Head-balanced and CSI groups. However, no such significant change was observed in Trunk-balanced and CSB groups. We observed 1 case of transient and 1 case of residual neurological worsening. CONCLUSION:The primary goal of cervical reconstruction surgery is to achieve occiput-trunk concordance. Once it is achieved, subsequent thoracolumbar alignment changes occur as needed to harmonize GSA. Cervical reconstruction can restore both cervical deformity and GSA. However, surgeons must consider the risks and benefits in such challenging cases.

Adult spinal deformity (ASD) is a complex disease that significantly affects the lives of many patients. Surgical correction has proven to be effective in achieving improvement of spinopelvic parameters as well as improving quality of life (QoL) for these patients. However, given the relatively high complication risk associated with ASD correction, it is of paramount importance to develop robust prognostic tools for predicting risk profile and outcomes. Historically, statistical models such as linear and logistic regression models were used to identify preoperative factors associated with postoperative outcomes. While these tools were useful for looking at simple associations, they represent generalizations across large populations, with little applicability to individual patients. More recently, predictive analytics utilizing artificial intelligence (AI) through machine learning for comprehensive processing of large amounts of data have become available for surgeons to implement. The use of these computational techniques has given surgeons the ability to leverage far more accurate and individualized predictive tools to better inform individual patients regarding predicted outcomes after ASD correction surgery. Applications range from predicting QoL measures to predicting the risk of major complications, hospital readmission, and reoperation rates. In addition, AI has been used to create a novel classification system for ASD patients, which will help surgeons identify distinct patient subpopulations with unique risk-benefit profiles. Overall, these tools will help surgeons tailor their clinical practice to address patients' individual needs and create an opportunity for personalized medicine within spine surgery.

BACKGROUND:There have been no reports describing how cervical reconstruction surgery affects global spinal alignment (GSA). OBJECTIVE:To elucidate the effects of cervical reconstruction for GSA through a retrospective multicenter study. METHODS:Seventy-eight patients who underwent cervical reconstruction surgery for cervical kyphosis were divided into a Head-balanced group (n = 42) and a Trunk-balanced group (n = 36) according to the values of the C7 plumb line (PL). We also divided the patients into a cervical sagittal balanced group (CSB group, n = 18) and a cervical sagittal imbalanced group (CSI group, n = 60) based on the C2 PL-C7 PL distance. Various sagittal Cobb angles and the sagittal vertical axes were measured before and after surgery. RESULTS:Cervical alignment was improved to achieve occiput-trunk concordance (the distance between the center of gravity [COG] PL, which is considered the virtual gravity line of the entire body, and C7 PL < 30 mm) despite the location of COG PL and C7PL. A subsequent significant change in thoracolumbar alignment was observed in Head-balanced and CSI groups. However, no such significant change was observed in Trunk-balanced and CSB groups. We observed 1 case of transient and 1 case of residual neurological worsening. CONCLUSION:The primary goal of cervical reconstruction surgery is to achieve occiput-trunk concordance. Once it is achieved, subsequent thoracolumbar alignment changes occur as needed to harmonize GSA. Cervical reconstruction can restore both cervical deformity and GSA. However, surgeons must consider the risks and benefits in such challenging cases.

Adult spinal deformity (ASD) is a complex disease that significantly affects the lives of many patients. Surgical correction has proven to be effective in achieving improvement of spinopelvic parameters as well as improving quality of life (QoL) for these patients. However, given the relatively high complication risk associated with ASD correction, it is of paramount importance to develop robust prognostic tools for predicting risk profile and outcomes. Historically, statistical models such as linear and logistic regression models were used to identify preoperative factors associated with postoperative outcomes. While these tools were useful for looking at simple associations, they represent generalizations across large populations, with little applicability to individual patients. More recently, predictive analytics utilizing artificial intelligence (AI) through machine learning for comprehensive processing of large amounts of data have become available for surgeons to implement. The use of these computational techniques has given surgeons the ability to leverage far more accurate and individualized predictive tools to better inform individual patients regarding predicted outcomes after ASD correction surgery. Applications range from predicting QoL measures to predicting the risk of major complications, hospital readmission, and reoperation rates. In addition, AI has been used to create a novel classification system for ASD patients, which will help surgeons identify distinct patient subpopulations with unique risk-benefit profiles. Overall, these tools will help surgeons tailor their clinical practice to address patients' individual needs and create an opportunity for personalized medicine within spine surgery.

Polymeric sublaminar cables have a number of advantages over metal cables in the field of spinal deformity surgery, with decreased risk of neurological injury and potential for higher correction forces as the two most predominant. However, currently available polymer cables are radiolucent, precluding postoperative radiological assessment of instrumentation stability and integrity. This study provides a preclinical assessment of a woven UHMWPE cable made with radiopaque UHMWPE fibers. Our primary goal was to determine if the addition of a radiopacifier negatively affects the mechanical properties of UHMWPE woven cables. Tensile mechanical properties were determined and compared to suitable controls. Radiopacity was evaluated and radiopacifier leaching was assessed in vitro and in vivo. Finally, in vivo bismuth organ content was quantified after a 24-week implantation period in sheep. Results show that the mechanical properties of woven UHMWPE cables were not deleteriously affected by the addition of homogenously dispersed bismuth oxide particles within each fiber. Limited amounts of bismuth oxide were released in vitro, well below the toxicological threshold. Tissue concentrations lower than generally accepted therapeutic dosages for use against gastrointestinal disorders, well below toxic levels, were discovered in vivo. These results substantiate controlled clinical introduction of these radiopaque UHMWPE cables. (c) 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 771-779, 2018.

BackgroundCurrent health-related quality of life (HRQL) metrics used to assess patient outcomes following surgical correction of cervical deformity (CD) are not deformity-specific and thus cannot capture all aspects of a patient's deformity and outcomes. The purpose of this study is to evaluate the sensitivity of different HRQL outcome measures in assessing CD patients' outcomes 1-year post-operatively.MethodsRetrospective review of prospective multi-center database. Inclusion criteria: CD patients ≥18 yrs with pre- and 1-year post-operative radiographs and HRQLs [modified Japanese Orthopaedic Association (mJOA), EuroQol five-dimensions (EQ-5D), neck disability index (NDI)]. Associations between changes in EQ5D and NDI with improvement at 1-year in mJOA scores were assessed by whether or not the patient met the minimum clinically important difference (MCID) as well as whether or not they improved by one or more categories (i.e., change from moderate to mild). Odds ratios reported with 95% confidence intervals.ResultsSixty-three CD patients were included (mean 62 y, 55.6% F). Average baseline NDI scores were 46.75, mJOA was 13.68, and EQ-5D 0.74. Overall baseline myelopathy breakdown: none-9.5%, mild-30.2%, moderate-42.9%, high-17.5%. At 1-year, 46% of patients improved in mJOA, 71.4% NDI, and 65.1% EQ-5D. 19% of patients met mJOA MCID, 44.4% NDI MCID, 19% EQ-5D MCID. One-point improvement in NDI increased the odds of mJOA improvement and reaching mJOA MCID (improvement: OR, 1.06, CI: 1.01-1.10, P=0.01; MCID: OR, 1.06, CI: 1.02-1.11, P=0.006). Improvement in EQ-5D by 0.1 increased the odds of improving in mJOA and reaching mJOA MCID at 1-year (improvement: OR, 3.85, CI: 1.51-9.76, P=0.005; MCID: OR, 3.88, CI: 1.52-9.88, P=0.005). While correlations exist between outcome measures, when modeling these outcomes while controlling for confounders including cSVA change, surgical invasiveness, age and CCI, these HRQLs were not strongly correlated.ConclusionsImprovements in

Polymeric sublaminar cables have a number of advantages over metal cables in the field of spinal deformity surgery, with decreased risk of neurological injury and potential for higher correction forces as the two most predominant. However, currently available polymer cables are radiolucent, precluding postoperative radiological assessment of instrumentation stability and integrity. This study provides a preclinical assessment of a woven UHMWPE cable made with radiopaque UHMWPE fibers. Our primary goal was to determine if the addition of a radiopacifier negatively affects the mechanical properties of UHMWPE woven cables. Tensile mechanical properties were determined and compared to suitable controls. Radiopacity was evaluated and radiopacifier leaching was assessed in vitro and in vivo. Finally, in vivo bismuth organ content was quantified after a 24-week implantation period in sheep. Results show that the mechanical properties of woven UHMWPE cables were not deleteriously affected by the addition of homogenously dispersed bismuth oxide particles within each fiber. Limited amounts of bismuth oxide were released in vitro, well below the toxicological threshold. Tissue concentrations lower than generally accepted therapeutic dosages for use against gastrointestinal disorders, well below toxic levels, were discovered in vivo. These results substantiate controlled clinical introduction of these radiopaque UHMWPE cables. (c) 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 771-779, 2018.

Study Design. Lung volumes and thoracic anatomy were measured from low-dose computed tomography (CT) scans preoperatively and 2 years following thoracoscopic anterior spinal fusion (TASF) for adolescent idiopathic scoliosis (AIS). Objective. The aim of this study was to assess changes in lung volume after TASF surgical correction. Summary of Background Data. AIS patients are known to have decreased pulmonary function as a consequence of their spinal and ribcage deformity. Several studies have evaluated changes in pulmonary function clinically after scoliosis correction surgery showing varied results. To date, there have been no published studies using CT to evaluate lung volume changes following TASF. Methods. Twenty-three female AIS patients with both pre- and 2 years postoperative low-dose CT scans were selected from an ethically approved, historical databank. Three-dimensional lung volumes were reconstructed to determine anatomical lung volumes. Right and left lung volumes, total lung volume, and right-to-left lung volume ratio were obtained as well as hemithoracic symmetry, to indicate the extent of thorax deformity. Cobb angle, rib hump, levels fused in surgery, and patient height were used for correlation analysis with the lung volume results. Results. Left lung volume, total lung volume, and hemithoracic ratio all increased significantly 2 years after surgery. There was no significant change in right-to-left lung volume ratio (P¼0.36). Statistical regression found significant positive correlation between lung volume changes, reduction in Cobb angle, increase in height, and improvement in hemithoracic symmetry ratio. Conclusion. TASF resulted in a statistically significant increase in lung volume following surgery, as well as improvement in the symmetry of the thoracic architecture; however, the postoperative lung volumes remained in the lower 50th percentile relative to females without thoracic deformity. Furthermore, change in lung volume was significantly c

On 2 July, 2014 in the docking of the Copesmar fishing cooperative in Frontera, Tabasco, Mexico, an Ariopsis felis specimen was captured, which displayed kyphosis and scoliosis of the vertebral column, diagnosed by high resolution X-ray. This is the first report of axial skeleton deformities in the genus Ariopsis.

Progression of spinal deformity in children was studied with Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) to identify how gravity affects the deformity and to determine the full three-dimensional character of the deformity. The CT study showed that gravity is significant in deformity progression in some patients which has implications for clinical patient management. The world first MRI study showed that the standard clinical measure used to define the extent of the deformity is inadequate and further use of three-dimensional MRI should be considered by spinal surgeons.

INTRODUCTION Adolescent idiopathic scoliosis (AIS) is a spinal deformity, which may require surgical correction by attaching rods to the patient’s spine using screws inserted into the vertebrae. Complication rates for deformity correction surgery are unacceptably high. Determining an achievable correction without overloading the adjacent spinal tissues or implants requires an understanding of the mechanical interaction between these components. Our novel patient specific modelling software creates individualized finite element models (FEM) representing the thoracolumbar spine and ribcage of scoliosis patients. We have recently applied the model to investigate the influence of increasing magnitudes of surgically applied corrective force on predicted deformity correction...

Application of deformity correction spinal surgery has increased substantially over the past three decades in parallel with improvements in surgical techniques. Intraoperative neuromonitoring (IOM) techniques, including somatosensory evoked potentials (SEPs), muscle evoked potentials (MEPs), and spontaneous electromyography (free-run EMG), have also improved surgical outcome by reducing the risk of iatrogenic neural injury. In this article, we review IOM techniques and their applications in spinal deformity surgery. We also summarize results of selected studies including hundreds of spinal correction surgeries. These studies indicate that multimodal IOM of both motor and sensory responses is superior to either modality alone for reducing the incidence of neural injury during surgery.

Objective Laminectomy has normally been used as a standard approach for intradural spinal tumors but this procedure is associated with spinal instability and deformity. Laminoplasty was developed to overcome these limitations. Controversies still exist regarding its actual role in preventing spinal deformity in adults. The aim of our study was to determine the impact of laminoplasty on the prevention of spinal deformity's onset or worsening in adult patients submitted to intradural spinal tumors resection. Methods We retrospectively reviewed the data of 43 consecutive adult patients, who underwent either laminectomy or laminoplasty for spinal intradural tumor resection, between January 2006 and May 2011. We evaluated the role of sex, spinal segment (cervical, thoracic, lumbar), tumor location (intra- or extra-medullary), procedure (laminoplasty or laminectomy), number of treated levels (≤2 vs ;gt&2), presence of pre-operative deformity and pre-operative Modified McCormick Scale (≤2 vs >2) in the development or worsening of spinal deformity, using Fisher's exact test and multivariate logistic regression analysis. Results Nine patients developed deformity or experienced a worsening of pre-operative deformity at latest follow-up. Among the considered potential prognostic factors, laminectomy (p = 0.03) and evidence of pre-operative spinal deformity (p = 0.009) were significantly associated with new-onset or worsening of spinal deformity. At logistic regression analysis, only the performed surgical procedure emerged as independent prognostic factor (p = 0.044). No CSF leak was recorded in the laminoplasty cohort. Conclusions No new-onset spinal deformities, no CSF leaks and a lower rate of spinal deformity progression were observed after laminoplasty for intradural intra- or extra-medullary tumor resection. © 2014 Elsevier B.V.

Study Design. Retrospective Case Series.Objective. To demonstrate the microbial trends of spinal surgical site infections(SSI) in patients who had previously received crystallized vancomycin in the operative bed.Summary of Background Data. Prior large, case control series demonstrate the significant decrease in SSI with the administration of vancomycin in the wound bed.Methods. A single institution, electronic database search was conducted for all spinal surgery patients who had received prophylactic crystalline vancomycin powder in the wound bed. Patient's with a prior history of wound infection, intrathecal pumps, or spinal stimulators were excludedResults. 981 consecutive patients (494 male, 487 female, mean age 59.4 years, range 16-95 years) were identified from January 2011 to June 2013. The average dose of vancomycin powder was 1.13 grams(range: 1-6 grams). 66 patients (6.71%) were diagnosed with a SSI of which 51 patients had positive wound cultures (5.2%). Of the 51 positive cultures the most common organism was Staphylococcus aureus. The average dose of vancomycin was 1.3 grams in the 38 cases where a gram-positive organism was cultured. A number of gram-negative infections were encountered such as Serratia marcescens, Enterobacter aerogenes, Bacteroides fragilis, Enterobacter cloacae, Citrobacter koseri and Pseudomonas aeruginosa. The average dose of vancomycin was 1.2 grams in 23 cases where a gram negative infection was cultured. 15 of the 51 (29.4%) positive-cultures were polymicrobial. 8 (53%) of these 15 polymicrobial cultures contained three or more distinct organisms.Conclusion. Prophylactic intraoperative vancomycin use in the wound bed in spinal surgery may increase the incidence of gram-negative or polymicrobial spinal infections. The use of intraoperative vancomycin may correlate with postoperative seromas, due to the high incidence of non-positive cultures. Large, randomized, prospective trials are needed to demonstrate causation and dose-respo

We report the application of a novel scaffold design in a sheep thoracic spine model for spine deformity correction. The combination of the calcium-phosphate coated polycaprolactone scaffolds with recombinant human bone morphogenic protein-2 (rhBMP-2) are intended as a future bone graft substitute in ensuring the stability of bony intervertebral fusion. A solid free-form fabrication process based on melt extrusion has been utilized in the manufacturing of these scaffolds. To date there are no studies examining the use of such biodegradable implants in a sheep thoracic spine model. The success of anterior scoliosis surgery in humans depends on achieving a solid bony fusion between adjacent vertebrae after the intervertebral discs have been surgically cleared and the disc spaces filled with graft material. Due to limited availability of autograft, there is much current interest in the development of synthetic scaffolds in combination with growth factors such as recombinant human bone morphogenetic protein (rhBMP-2) to achieve a solid bony fusion following scoliosis surgery.

The progression of spinal deformity is traditionally monitored on hard copy radiographs using the Cobb method with a protractor and pencil. The rotation of the spine and ribcage (rib hump) in scoliosis is measured with a hand-held inclinometer/Scoliometer. The iPhone and other smart phones, can accurately sense inclination, and can therefore be used to measure Cobb angles and rib hump angulation. The purpose of this study was to quantify the performance of the iPhone compared to the standard protractor (Cobb angles) and the Scoliometer (rib hump).

In Chapter 10, Adam and Dougherty describe the application of medical image processing to the assessment and treatment of spinal deformity, with a focus on the surgical treatment of idiopathic scoliosis. The natural history of spinal deformity and current approaches to surgical and non-surgical treatment are briefly described, followed by an overview of current clinically used imaging modalities. The key metrics currently used to assess the severity and progression of spinal deformities from medical images are presented, followed by a discussion of the errors and uncertainties involved in manual measurements. This provides the context for an analysis of automated and semi-automated image processing approaches to measure spinal curve shape and severity in two and three dimensions.

The progression of spinal deformity is traditionally monitored by spinal surgeons using the Cobb method on hardcopy radiographs with a protractor and pencil. The rotation of the spine and ribcage (rib hump) in scoliosis is measured with a simple hand-held inclinometer (Scoliometer). The iPhone and other smart phones have the capability to accurately sense inclination, and can therefore be used to measure Cobb angles and rib hump angulation. The purpose of this study was to quantify the performance of the iPhone compared to a standard protractor for measuring Cobb angles and the Scoliometer for measuring rib humps. The study concluded that the iPhone is a clinically equivalent measuring tool to the traditional protractor and Scoliometer

Magnetic Resonance Imaging (MRI) offers a valuable research tool for the assessment of 3D spinal deformity in AIS, however the horizontal patient position imposed by conventional scanners removes the axial compressive loading on the spine. The objective of this study was to design, construct and test an MRI compatible compression device for research into the effect of axial loading on spinal deformity using supine MRI scans. The device was evaluated by performing unloaded and loaded supine MRI scans on a series of 10 AIS patients. The patient group had a mean initial (unloaded) major Cobb angle of 43±7º, which increased to 50±9º on application of the compressive load. The 7° increase in mean Cobb angle is consistent with that reported by a previous study comparing standing versus supine posture in scoliosis patients (Torell et al, 1985. Spine 10:425-7).

Scoliosis is a three-dimensional spinal deformity which requires surgical correction in progressive cases. In order to optimize correction and avoid complications following scoliosis surgery, patient-specific finite element models (FEM) are being developed and validated by our group. In this paper, the modeling methodology is described and two clinically relevant load cases are simulated for a single patient. Firstly, a pre-operative patient flexibility assessment, the fulcrum bending radiograph, is simulated to assess the model's ability to represent spine flexibility. Secondly, intra-operative forces during single rod anterior correction are simulated. Clinically, the patient had an initial Cobb angle of 44 degrees, which reduced to 26 degrees during fulcrum bending. Surgically, the coronal deformity corrected to 14 degrees. The simulated initial Cobb angle was 40 degrees, which reduced to 23 degrees following the fulcrum bending load case. The simulated surgical procedure corrected the coronal deformity to 14 degrees. The computed results for the patient-specific FEM are within the accepted clinical Cobb measuring error of 5 degrees, suggested that this modeling methodology is capable of capturing the biomechanical behaviour of a scoliotic human spine during anterior corrective surgery.

Severe spinal deformity in young children is a formidable challenge for optimal treatment. Standard interventions for adolescents, such as spinal deformity correction and fusion, may not be appropriate for young patients with considerable growth remaining. Alternative surgical options that provide deformity correction and protect the growth remaining in the spine are needed to treat this group of patients 1, 2. One such method is the use of shape memory alloy staples. We report our experience to date using video-assisted thoracoscopic insertion of shape memory alloy staples. A retrospective review was conducted of 13 patients with scoliosis, aged 7 to 13 years, who underwent video-assisted thoracoscopic insertion of shape memory staples. In our experience, video-assisted thoracoscopic insertion of shape memory alloy staples is a safe procedure with no complications noted. It is a reliable method of providing curve stability, however the follow up results to date indicate that the effectiveness of the procedure is greater in younger patients.

Magnetic Resonance Imaging (MRI) offers a valuable research tool for the assessment of 3D spinal deformity in AIS, however the horizontal patient position imposed by conventional scanners removes the axial compressive loading on the spine which is an important determinant of deformity shape and magnitude in standing scoliosis patients. The objective of this study was to design, construct and test an MRI compatible compression device for research into the effect of axial loading on spinal deformity using supine MRI scans. The compression device was designed and constructed, consisting of a vest worn by the patient, which was attached via straps to a pneumatically actuated footplate. An applied load of 0.5 x bodyweight was remotely controlled by a unit in the scanner operator’s console. The entire device was constructed using non-metallic components for MRI compatibility. The device was evaluated by performing unloaded and loaded supine MRI scans on a series of 10 AIS patients. The study concluded that an MRI compatible compression device had been successfully designed and constructed, providing a research tool for studies into the effect of axial loading on 3D spinal deformity in scoliosis. The 3D axially loaded MR imaging capability developed in this study will allow future research investigations of the effect of axial loading on spinal rotation, and for imaging the response of scoliotic spinal tissues to axial loading.

Scoliosis is a spinal deformity that requires surgical correction in progressive cases. In order to optimize surgical outcomes, patient-specific finite element models are being developed by our group. In this paper, a single rod anterior correction procedure is simulated for a group of six scoliosis patients. For each patient, personalised model geometry was derived from low-dose CT scans, and clinically measured intra-operative corrective forces were applied. However, tissue material properties were not patient-specific, being derived from existing literature. Clinically, the patient group had a mean initial Cobb angle of 47.3 degrees, which was corrected to 17.5 degrees after surgery. The mean simulated post-operative Cobb angle for the group was 18.1 degrees. Although this represents good agreement between clinical and simulated corrections, the discrepancy between clinical and simulated Cobb angle for individual patients varied between -10.3 and +8.6 degrees, with only three of the six patients matching the clinical result to within accepted Cobb measurement error of +-5 degrees. The results of this study suggest that spinal tissue material properties play an important role in governing the correction obtained during surgery, and that patient-specific modelling approaches must address the question of how to prescribe patient-specific soft tissue properties for spine surgery simulation.

The Paediatric Spine Research group was formed in 2002 to perform high quality research into the prevention and management of spinal deformity, with an emphasis on scoliosis. The group has successfully built collaborative bridges between the scientific and research expertise at QUT, and the clinical skills and experience of the spinal orthopaedic surgeons at the Mater Children’s Hospital in Brisbane. Clinical and biomechanical research is now possible as a result of the development of detailed databases of patients who have innovative and unique surgical interventions for spinal deformity such as thoracoscopic scoliosis correction, thoracoscopic staple insertion for juvenile idiopathic scoliosis and minimally invasive growing rods. The Mater in Brisbane provides these unique datasets of spinal deformity surgery patients, whose procedures are not being performed anywhere else in the Southern Hemisphere. The most detailed is a database of thoracoscopic scoliosis correction surgery which now contains 180 patients with electronic collections of X-Rays, photographs and patient questionnaires. With ethics approval, a subset of these patients has had CT scans, and a further subset have had MRI scans with and without a compressive load to simulate the erect standing position. This database has to date contributed to 17 international refereed journal papers, a further 7 journal papers either under review or in final preparation, 53 national conference presentations and 35 international conference presentations. Major findings from selected journal publications will be presented. It is anticipated that as the surgical databases grow they will continue to provide invaluable clinical data which will feed into clinically relevant projects driven by both medical and engineering researchers whose findings will benefit spinal deformity patients and scientific knowledge worldwide.

Adolescent Idiopathic Scoliosis (AIS) is the most common deformity of the spine, affecting 2-4% of the population. Previous studies have shown that the vertebrae in scoliotic spines undergo abnormal shape changes, however there has been little exploration of how scoliosis affects bone density distribution within the vertebrae. In this study, existing CT scans of 53 female idiopathic scoliosis patients with right-sided main thoracic curves were used to measure the lateral (right to left) bone density profile at mid-height through each vertebral body. Five key bone density profile measures were identified from each normalised bone density distribution, and multiple regression analysis was performed to explore the relationship between bone density distribution and patient demographics (age, height, weight, body mass index (BMI), skeletal maturity, time since Menarche, vertebral level, and scoliosis curve severity). Results showed a marked convex/concave asymmetry in bone density for vertebral levels at or near the apex of the scoliotic curve. At the apical vertebra, mean bone density at the left side (concave) cortical shell was 23.5% higher than for the right (convex) cortical shell, and cancellous bone density along the central 60% of the lateral path from convex to concave increased by 13.8%. The centre of mass of the bone density profile at the thoracic curve apex was located 53.8% of the distance along the lateral path, indicating a shift of nearly 4% toward the concavity of the deformity. These lateral bone density gradients tapered off when moving away from the apical vertebra. Multi-linear regressions showed that the right cortical shell peak bone density is significantly correlated with skeletal maturity, with each Risser increment corresponding to an increase in mineral equivalent bone density of 4-5%. There were also statistically significant relationships between patient height, weight and BMI, and the gradient of cancellous bone density along the central 6

Study Design. Biomechanical analysis. Objective. To investigate the relationship between gravity-induced torques acting on the scoliotic spine and rotation within the vertebrae. Summary of Background Data. Vertebral rotation is an important aspect of spinal deformity in idiopathic scoliosis, associated with ribcage asymmetry. Although both lateral curvature and rotation seem to increase together in progressive scoliosis, the mechanisms driving vertebral rotation are not clearly established and it is not known whether lateral curvature precedes rotation, or vice versa. Methods. Three-dimensional spinal curvature was measured for a small group of idiopathic scoliosis patients using standing radiographs, and equations of static equilibrium were used to calculate gravity-induced torque profiles along the length of each spine because of head, neck, and torso weight. Vertebral rotations were then measured for the same patients using Aaro and Dahlborn's technique with reformatted computed tomography images. The gravity-induced torque curves were compared with rotation measurements to see whether gravity-induced torque is a likely contributor to intravertebral rotation in scoliosis. Results. Gravity-induced torques as high as 7.5 Nm act on the spines of idiopathic scoliosis patients because of body weight in the standing position, and maximum intravertebral rotations (for a single vertebra) are approximately 4 degrees. There is a statistically significant relationship between gravity-induced torque and intravertebral rotation in the scoliotic spine. Conclusion. Gravity-induced torque is a likely cause of intravertebral rotation in progressive idiopathic scoliosis. Because the spine must be curved in 3-dimensions (out of plane) to produce such torques, vertebral rotation would be expected to occur subsequent to an initial lateral deviation, suggesting that lateral curvature precedes vertebral rotation in progressive idiopathic scoliosis.

Software was developed for the creation of parametric, patient-specific Finite Element models of the spine using bony anatomy from Computed Tomography scans. The sensitivity of predicted spinal stiffness to inter and intra-observer variations in 25 anatomical parameters was determined, based on a model of the Visible Man lumbar spine. Vertebral body height influenced predicted spinal stiffness the most. When deriving biomechanical models from patient-specific data, care must be taken to identify intervertebral disc dimensions accurately, in particular height. The modelling capability developed provides a means to rapidly create patient-specific biomechanical models of the spine to investigate both spinal degeneration and the effects of restorative surgery. The models can be generated and solved quickly, providing potential for future use in a clinical setting.

Prior studies have suggested that biomodels enhance patient education, pre-operative planning and intra-operative stereotaxy, however the usefulness of biomodels compared to regular imaging modalities such as x-ray, CT and MR has not been quantified. Our objective was to quantify surgeon’s perceptions on the usefulness of biomodels compared to standard visualisation modalities for pre-operative planning and intra-operative anatomical reference. Physical biomodels were manufactured for a series of 26 consecutive patients with complex spinal pathologies using a stereolithographic technique based on CT data. The biomodels were used pre-operatively for surgical planning and customising implants, and intra-operatively for anatomical reference. Following surgery, a detailed biomodel utility survey was completed by the surgeons, and informal telephone interviews were conducted with patients. Twenty one deformity and five tumour cases were performed using biomodels. Surgeons stated that the anatomical detail was better visible on the biomodel than on other imaging modalities in 65% of cases, and exclusively visible on the biomodel in 11% of cases. Preoperative use of the biomodel led to a different decision regarding the choice of osteosynthetic materials used in 52% of cases, and the implantation site of osteosynthetic material in 74% of cases. Surgeons reported that the use of biomodels reduced operating time by a mean of 8% in tumour patients, and 22% in deformity procedures. This study supports Biomodelling as a useful, and sometimes essential tool in the armamentarium of imaging techniques used for complex spinal surgery.

Background. Scoliosis has been associated with reduced pulmonary capacity, however the source of the reduction in capacity (left, right or both lungs) is not clear. The objective of this study was to investigate trends in left, right and total lung volume and left/right lung volume asymmetry with spinal curve severity in scoliosis. Methods. Three-dimensional volumetric reconstruction of the pulmonary system was performed on existing pre-operative CT scans for 28 idiopathic scoliosis patients. Left, right and total lung volumes, and left/right lung volume ratios were calculated and correlated with the following spinal curve parameters; major Cobb angle, rib hump, number of vertebrae in the major curve, most cephalad vertebra in the major curve, and thoracic kyphosis. Results: Left/right lung volume ratio increases significantly with increasing rib hump. Left, right and total lung volumes were significantly correlated with rib hump and number of vertebrae in the major curve (P<0.05), and near-significantly correlated with most cephalad vertebra in the major curve (P<0.10). Shorter, higher, more rotated thoracic curves therefore restrict lung volume more than longer, lower, less rotated curves. The mean lung volume ratio for scoliosis patients was lower than for age-matched controls (P<0.10) Conclusions: CT-based volumetric reconstruction of the pulmonary system in scoliosis patients shows differences in both lung volumes and lung volume ratios compared to normal controls. Level of Evidence: Level 1 diagnostic study - Testing of previously developed diagnostic criteria in series of consecutive patients.

Spine biomechanics is the study of motions and forces in the human spine, investigated in order to gain a better understanding of various spinal disorders and to develop optimal treatments. This article discusses the kinetics, kinematics, and tissue material properties of the healthy spine, followed by a summary of the biomechanics of pathology and treatment for three classes of spinal disorder; disc degeneration, fracture, and deformity. The role of experimental, theoretical and numerical analysis techniques is discussed, and likely future directions in spine biomechanics research are suggested.

Introduction Spinal deformity disfigures the torso and reduces lung capacity. Consequently, it has a major detrimental effect on both the physical and psychological wellbeing of its sufferers. The main goal of this project is to improve the outcome of surgical deformity correction by providing patient-specific Finite Element (FE) models derived from pre-operative CT scans to predict the effects of surgical procedures. Methods The FE models developed in this project are parametric, meaning they are not derived by directly meshing CT data, but by detecting bony landmarks from CT data to which a predefined mesh is fitted. Landmarks are identified using a custom-developed Graphical User Interface (GUI) which contains algorithms for automatic detection of specific groups of landmarks such as ribs and endplates. Landmark properties are fed directly into a preprocessor that generates the FE mesh. Results Identifying all required landmarks of a complete spine takes between one and two hours. Intraobserver variations in coordinates and angles are small (standard deviations usually below 2mm and 3deg respectively). Discussion & Conclusion Many of the commercially available algorithms can derive FE meshes directly from CT data in seconds, but high mesh densities and tetrahedral elements make these models unsuitable for whole-spine FE simulations. The semi-automated preprocessor presented allows better control over the FE mesh and material property assignment, and should eventually lead to a process where the surgeon is provided with a reliable FE prediction of the biomechanical outcome of the proposed surgery within a day or two of taking the CT scans.

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The original proposal hypothesized that through the use of telemedicine, spine specialists would be able to diagnose and treat patients in remote locations. The initial proposal requested $350,000 to accomplish stated objectives. Awarded less than half of our original request, the project was revised to reflect the awarded amount. An exempt protocol "A retrospective and controlled study to evaluate the ability of scoliosis/spine specialists to arrive at a treatment decision by telemedicine" was submitted to the WRAMC Department of Clinical Investigation and sent to Louise Pascal, Human Subjects Protection Specialist (AMDEX Corporation), U.S. Army Medical Research and Materiel Command, Office for Regulatory Compliance and Quality at Fort Detrick, Maryland.