Challenges in Total Hip Arthroplasty with Prior Spinal Arthrodesis: A Comprehensive Review of Biomechanics, Complications, and Surgical Strategies.

Total hip arthroplasty (THA) has revolutionized patients' lives with hip osteoarthritis. However, the increasing prevalence of THA in individuals with prior lumbar arthrodesis (LA) poses unique challenges. This review delves into the biomechanical alterations, complications, and surgical strategies specific to this patient subset, highlighting the need for tailored preoperative assessments and planning. Due to altered pelvic and spinal biomechanics, patients with LA undergoing THA face a higher risk of dislocation and revision. The complex interplay between spinal and hip biomechanics underscores the need for meticulous preoperative planning. Comprehensive clinical examination and radiographic evaluation are vital for understanding patient-specific challenges. Various radiographic techniques, including computed tomography (CT)/X-ray matching and standing/seated studies, provide insights into postural changes affecting pelvic and spinal alignment. Complications following THA in patients with LA highlight the necessity for personalized surgical strategies. Careful consideration of implant selection, the surgical approach, and component positioning are essential to prevent complications. In summary, THA in patients with prior LA demands individualized preoperative assessments and planning. This approach is crucial to optimize outcomes and mitigate the heightened risks of complications, underlining the importance of tailored surgical strategies.

Prevalence, Features, and Predictive Factors of Spontaneous Spinal Arthrodesis in Posttraumatic Thoracolumbar Kyphosis.

OBJECTIVE: Spontaneous spinal arthrodesis (SSA) is a phenomenon of spontaneous fusion, and SSA is not rare in posttraumatic thoracolumbar kyphosis (PTK). However, few reports have focused on SSA in patients with PTK. The objective of this study was to investigate the prevalence, features, and predictive factors of SSA in patients with PTK. METHODS: In this retrospective study, 70 patients with PTK were included. Data on the clinical and radiologic parameters were obtained and evaluated. According to whether there was SSA or not, patients were divided into an SSA group (n = 45) or a non-SSA group (n = 25). A binary logistic regression analysis was used to identify the predictive factors for SSA. RESULTS: The incidence of SSA in PTK was 64%. Among 45 patients with PTK with SSA, SSA was present as a solid bridging anterior osteophyte along the vertebral bodies in 11 patients, posterior contiguous bony growth through the facet joints bilaterally in 13 patients, bony formation in both anterior and posterior elements in 18 patients, and direct contiguous bony formation from the injured vertebral body to the adjacent one in 3 patients. Patients with longer disease duration, larger local Cobb angle, and anterior wall height loss (AWHL) ratio of injured vertebral body, and less kyphosis flexibility index were significantly more likely to develop SSA. The parameter of AWHL remained significant in binary logistic regression analysis. CONCLUSIONS: SSA in PTK was common, and the SSA sign presented in various patterns, which might have implications for surgical decisions. AWHL was the independent predictor for SSA.

Pedicle screw placement accuracy in robot-assisted versus image-guided freehand surgery of thoraco-lumbar spine (ROBARTHRODESE): study protocol for a single-centre randomized controlled trial.

BACKGROUND: Robotic spinal surgery may result in better pedicle screw placement accuracy, and reduction in radiation exposure and length of stay, compared to freehand surgery. The purpose of this randomized controlled trial (RCT) is to compare screw placement accuracy of robot-assisted surgery with integrated 3D computer-assisted navigation versus freehand surgery with 2D fluoroscopy for arthrodesis of the thoraco-lumbar spine. METHODS: This is a single-centre evaluator-blinded RCT with a 1:1 allocation ratio. Participants (n = 300) will be randomized into two groups, robot-assisted (Mazor X Stealth Edition) versus freehand, after stratification based on the planned number of pedicle screws needed for surgery. The primary outcome is the proportion of pedicle screws placed with grade A accuracy (Gertzbein-Robbins classification) on postoperative computed tomography images. The secondary outcomes are intervention time, operation room occupancy time, length of stay, estimated blood loss, surgeon's radiation exposure, screw fracture/loosening, superior-level facet joint violation, complication rate, reoperation rate on the same level or one level above, functional and clinical outcomes (Oswestry Disability Index, pain, Hospital Anxiety and Depression Scale, sensory and motor status) and cost-utility analysis. DISCUSSION: This RCT will provide insight into whether robot-assisted surgery with the newest generation spinal robot yields better pedicle screw placement accuracy than freehand surgery. Potential benefits of robot-assisted surgery include lower complication and revision rates, shorter length of stay, lower radiation exposure and reduction of economic cost of the overall care. TRIAL REGISTRATION: ClinicalTrials.gov NCT05553028. Registered on September 23, 2022.

Posterior Lateral Arthrodesis as a Treatment Option for Lumbar Spinal Stenosis: Safety and Early Clinical Outcomes.

Introduction: Lumbar spinal stenosis (LSS) is a common condition caused by degenerative changes in the lumbar spine with age. LSS is caused by a variety of factors, including degenerative spondylosis and spondylolisthesis. People suffering with LSS experience neurogenic claudication, which causes severe physical limitations, discomfort, and a decrease in quality of life. Less invasive procedures are now being researched to improve the prognosis, success rate, and safety of LSS treatments. Posterior lateral spinal arthrodesis (PLSA) is a new surgical treatment for LSS. This study looks at the procedural and patient safety of PLSA. Materials and methods: This study is a multicenter retrospective analysis of the safety of PLSA who met the clinical indications for PLSA and underwent the procedure at eight interventional spine practices. Data was collected on demographical information, pre-procedural numeric rating scale score (NRS), post-procedural NRS, and complication reporting. Patients who were included had LSS with or without spondylolisthesis and had failed conservative treatments. A descriptive statistical analysis was performed to report the outcomes. Results were reported as mean and standard deviations for continuous outcomes, and frequency (%) for categorical outcomes. Results: This retrospective analysis involved 191 patients and 202 PLSA implants. The majority of patients were male Caucasians with a mean age of 69.2 years and a BMI of 31.1. A large majority of implants were placed at the L4-5 level, and the average pre-procedural NRS was 6.3 while the average post-procedural NRS was 3.1, indicating a 50.8% reduction in pain (p < 0.0001). Two patients reported complications, but they were unrelated to the device or surgical procedure; no infections, device malfunctions, or migrations were reported in the patient cohort. Conclusion: Preliminary results with PLSA implants indicate that it is a safe treatment option for patients with moderate LSS who do not respond to conservative management.

Does diabetes affect outcome or reoperation rate after lumbar decompression or arthrodesis? A matched analysis of the Quality Outcomes Database data set.

OBJECTIVE: Diabetes mellitus (DM) is a known risk factor for postsurgical and systemic complications after lumbar spinal surgery. Smaller studies have also demonstrated diminished improvements in patient-reported outcomes (PROs), with increased reoperation and readmission rates after lumbar surgery in patients with DM. The authors aimed to examine longer-term PROs in patients with DM undergoing lumbar decompression and/or arthrodesis for degenerative pathology. METHODS: The Quality Outcomes Database was queried for patients undergoing elective lumbar decompression and/or arthrodesis for degenerative pathology. Patients were grouped into DM and non-DM groups and optimally matched in a 1:1 ratio on 31 baseline variables, including the number of operated levels. Outcomes of interest were readmissions and reoperations at 30 and 90 days after surgery in addition to improvements in Oswestry Disability Index, back pain, and leg pain scores and quality-adjusted life-years at 90 days after surgery. RESULTS: The matched decompression cohort comprised 7836 patients (3236 [41.3] females) with a mean age of 63.5 ± 12.6 years, and the matched arthrodesis cohort comprised 7336 patients (3907 [53.3%] females) with a mean age of 64.8 ± 10.3 years. In patients undergoing lumbar decompression, no significant differences in nonroutine discharge, length of stay (LOS), readmissions, reoperations, and PROs were observed. In patients undergoing lumbar arthrodesis, nonroutine discharge (15.7% vs 13.4%, p < 0.01), LOS (3.2 ± 2.0 vs 3.0 ± 3.5 days, p < 0.01), 30-day (6.5% vs 4.4%, p < 0.01) and 90-day (9.1% vs 7.0%, p < 0.01) readmission rates, and the 90-day reoperation rate (4.3% vs 3.2%, p = 0.01) were all significantly higher in the DM group. For DM patients undergoing lumbar arthrodesis, subgroup analyses demonstrated a significantly higher risk of poor surgical outcomes with the open approach. CONCLUSIONS: Patients with and without DM undergoing lumbar spinal decompression alone have comparable readmission and reoperation rates, while those undergoing arthrodesis procedures have a higher risk of poor surgical outcomes up to 90 days after surgery. Surgeons should target optimal DM control preoperatively, particularly for patients undergoing elective lumbar arthrodesis.

Hip loading asymmetry in Lenke type 1 idiopathic scoliosis: Effect of spinal fusion and sex.

BACKGROUND: Thoracic curvatures are most common in patients with idiopathic scoliosis. The literature highlights an imbalance of hip joint moments in the frontal plane quantified with a symmetry index. Spinal arthrodesis can reduce this symmetry index which then tends towards 0. Furthermore, asymptomatic women present lower hip moment in the frontal plane than asymptomatic men. This difference could influence the symmetry index in the case of patients with idiopathic scoliosis. Therefore, the main objective of this study was to show a significant positive effect of spinal arthrodesis on the symmetry index. The secondary objective was to compare the symmetry index between sexes before spinal fusion. METHOD: The retrospective study included 20 patients with Type-1 Lenke curve idiopathic scoliosis, who performed a gait analysis before and one year after spinal fusion. The gait analysis consisted of walking back and forth at spontaneous speed. FINDINGS: While significantly lower curvatures were depicted, the symmetry index showed a significantly lower value after spinal fusion (p < 0.03). The symmetry index showed no significant difference between sexes (p > 0.05). INTERPRETATION: The study shows the effect of surgical fusion on the symmetry index, although the latter remains significant compared to the norm. Literature reveals that spinal fusion tends to the symmetrisation of the body's center of mass and increases ranges of motion on the trunk and pelvis. This could favour symmetry of hip moment in the frontal plane. Future research should investigate other Type Lenke curves before and after surgery, and the effect of braces on this symmetry index.

A novel rodent model of chronic spinal implant-associated infection.

BACKGROUND CONTEXT: Bacterial infection of spinal instrumentation is a significant challenge in spinal fusion surgery. Although the intraoperative local application of powdered vancomycin is common practice for mitigating infection, the antimicrobial effects of this route of administration are short-lived. Therefore, novel antibiotic-loaded bone grafts as well as a reliable animal model to permit the testing of such therapies are needed to improve the efficacy of infection reduction practices in spinal fusion surgery. PURPOSE: This study aims to establish a clinically relevant rat model of spinal implant-associated infection to permit the evaluation of antimicrobial bone graft materials used in spinal fusion. STUDY DESIGN: Rodent study of chronic spinal implant-associated infection. METHODS: Instrumentation anchored in and spanning the vertebral bodies of L4 and L5 was inoculated with bioluminescent methicillin-resistant Staphylococcus aureus bacteria (MRSA). Infection was monitored using an in vivo imaging system (IVIS) for 8 weeks. Spines were harvested and evaluated histologically, and colony-forming units (CFUs) were quantified in harvested implants and spinal tissue. RESULTS: Postsurgical analysis of bacterial infection in vivo demonstrated stratification between MRSA and phosphate-buffered saline (PBS) control groups during the first 4 weeks of the 8-week infection period, indicating the successful establishment of acute infection. Over the 8-week chronic infection period, groups inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU demonstrated significantly higher bioluminescence than groups inoculated with PBS control (p = 0.009 and p = 0.041 respectively). Histological examination at 8 weeks postimplantation revealed the presence of abscesses localized to implant placement in all MRSA inoculation groups, with the most pervasive abscess formation in samples inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU. Quantification of CFU plated from harvested spinal tissue at 8 weeks post-implantation revealed the 1 × 105 MRSA CFU inoculation group as the only group with a significantly greater average CFU count compared to PBS control (p = 0.017). Further, CFU quantification from harvested spinal tissue was greater than CFU quantification from harvested implants across all inoculation groups. CONCLUSION: Our model demonstrated that the inoculation dosage of 1 × 105 MRSA CFU exhibited the most robust chronic infection within instrumented vertebral bodies. This dosage had the greatest difference in bioluminescence signal from control (p < 0.01), the lowest mortality (0% compared to 50% for samples inoculated with 1 × 106 MRSA CFU), and a significantly higher amount of CFUs from harvested spine samples than CFUs from control harvested spine samples. Further, histological analysis confirmed the reliability of this novel rodent model of implanted-associated infection to establish infection and biofilm formation of MRSA for all inoculation groups. CLINICAL SIGNIFICANCE: This model is intended to simulate the infection of instrumentation used in spinal fusion surgeries concerning implant locality and material. This model may evaluate potential antimicrobial and osteogenic biomaterials and investigate the relationship between implant-associated infection and failed fusion.

Four-level anterior versus posterior cervical fusions: Perioperative outcomes and five-year reoperation rates: Outcomes after four-level anterior versus posterior cervical procedures.

Background: Multilevel cervical pathology can often be addressed via anterior cervical discectomy and fusion (ACDF) or posterior cervical fusion (PCF). While posterior procedures may be technically easier for four-level pathology, there are advantages and disadvantages to both approaches that make it of interest to compare outcomes. The purpose was to compare perioperative adverse events and long-term cervical reoperation rates of four-level ACDF and PCF. Methods: The 2010 to Q1 2020 PearlDiver MSpine database was queried. Patients undergoing isolated elective four-level ACDF or PCF were identified (excluding cases performed for trauma, neoplasm, and/or infections) and 1:1 matched based on age, sex, and comorbidities. Ninety-day adverse events were compared with univariate and multivariate analyses. Five-year incidences of subsequent cervical reoperations were also compared. Results: A total of 3,714 patients 1:1 matched for four-level ACDF and PCF performed for degenerative pathologies were identified (1,857 for each of the study groups). On multivariate analysis controlling for age, sex, and comorbidities, PCF was found to have significantly greater odds ratios (OR) for any (OR 2.12), serious (OR 2.31), and minor (OR 1.95) adverse events, as well as for length of stay ≥3 days (OR 1.76), p<0.001 for each. However, PCF had nearly three times lower odds of dysphagia compared to ACDF (OR 0.36, p<0.001). At five years, four-level ACDF cases were found to have significantly higher reoperation rates compared to four-level PCF cases (26.3% vs 18.3%, p<0.001). Conclusion: In evaluating four-level cervical cases, compared to anterior approach cases, posterior approach procedures were associated with approximately double the odds of any, serious, and minor adverse events, but around one third the rate of dysphagia and two thirds the rate of five-year reoperations. While the pathology may dictate surgical approach, this data suggests that the choice between four-level anterior versus posterior approach becomes a balance of risks/benefit considerations.

Percutaneous Endoscopic Surgery Alone to Treat Severe Infectious Spondylodiscitis in the Thoracolumbar Spine: A Reparative Mechanism of Spontaneous Spinal Arthrodesis.

BACKGROUND: Infective spondylodiscitis has been treated solely with antibiotics based on the pathogen identified. Surgical intervention was used in cases of unidentified pathogens, failed antibiotic treatment, neurological deficit, or instability. The standard surgical procedure was debridement and interbody fusion with a bone graft through the anterior approach, followed by posterior instrumentation. Recently, percutaneous endoscopic surgery has been proven to be safe and effective for treating infectious spondylodiscitis. The results of endoscopy surgery treatment alone for infectious spondylodiscitis with severe bony destruction were analyzed in this study. OBJECTIVE: To describe the clinical and radiological outcomes in patients with infectious spondylodiscitis and severe bony destruction, who were treated with minimally invasive endoscopic surgery alone. STUDY DESIGN: Retrospective observational study (Institutional Review Board: CMUH 105-REC2-101). SETTING: An inpatient surgery center. METHODS: The study included 24 patients with infectious spondylodiscitis and severe bony destruction treated with endoscopy surgery. The patients were treated according to the endoscopic surgical protocol and were followed up for at least 5 years. A retrospective chart review was conducted to evaluate the locations, symptoms and signs, comorbidity, pain scale, and functional outcome. Laboratory data, such as erythrocyte sedimentation rate and C-reactive protein level, and clinical outcomes, including the pain scale, visual analogue scale, and functional score of Oswestry disability index, were recorded. All patients underwent a preoperative magnetic resonance imaging (MRI) scan and were carefully reviewed and classified based on the severity, including endplate erosion, bone edema (low T1, high T2), loss of vertebral height, paravertebral inflammation, paravertebral abscess, and epidural abscess. All patients underwent a plain film follow-up at 3, 6, 9, 12, and 18 months after surgery and computed tomography at 12 months postoperatively. RESULTS: The comorbidities of patients were categorized according to the Charlson Comorbidity Index. The results revealed 10 lesions on the thoracic or upper lumbar spine (between T10 and L3) and 14 on the lower lumbar spine (between L3 and S1). Bone destruction as a result of severe infection and loss of disc height was observed in most cases. During the final follow-up, no significant changes were observed in the sagittal alignment, and a kyphotic angle change of less than 10° was observed in 20 cases. Syndesmophyte formation along the anterior longitudinal ligament (ALL), paravertebral syndesmophyte formation, intervertebral bony fusion, and bony ankylosis of the facet joints in the form of osteophyte formation and fusion were noted. No posterior instrumentation surgery was performed for instability in our case series. LIMITATIONS: This was a retrospective observational clinical case series with small sample size. CONCLUSIONS: A trend of spontaneous spinal arthrodesis, including syndesmophyte formation along the ALL, paravertebral ligaments, direct intervertebral bone growth, and bony ankylosis of the facet joint were observed after a minimally invasive endoscopy treatment for infectious spondylodiscitis. The stability of the 3 columns resulted in segmental stability, which prevented the progression of the kyphotic deformity. Percutaneous endoscopic surgery is safe and effective for treating infectious spondylodiscitis even in patients with severe bony destruction.

Spinal pathology and outcome post-THA: does segment of arthrodesis matter?

INTRODUCTION: The presence of lumbar spine arthrodesis (SA) is associated with abnormal spinopelvic characteristics and inferior outcome post total hip arthroplasty (THA). However, whether patients with upper segment SA are also at increased risk of complications is unknown. This study aims to (1) determine if upper segment SA is associated with inferior THA outcomes; (2) assess spino-pelvic characteristics; and (3) test whether static or dynamic spinopelvic characteristics correlate with outcome post-THA. MATERIALS AND METHODS: In this retrospective, case-matched, cohort study from a tertiary referral centre, 40 patients (59 hips) that had undergone both THA and any level of spinal arthrodesis (49 THA-Lumb and 10 THA-Cerv) were compared with 41 patients (59 hips) who had THA-only without known spinal pathology. Spino-pelvic characteristics [including severity of Degenerative-Disc-Disease (DDD); spinal balance and stiffness] and outcome, including patient reported outcome measures (PROMs), at minimum of 1-year post-THA were assessed. RESULTS: THA-Lumb and THA-Cerv groups had greater number of complications and inferior hip and spinal PROMs compared to THA-Only (p < 0.001). Similar spinopelvic characteristics were seen between the THA-Cerv and THA-Lumb, which were significantly different to the THA-only group. The presence of DDD and unbalanced or stiff spine was associated with increased dislocation and inferior PROMs in the whole cohort. CONCLUSIONS: THA in the presence of SA, regardless of level, is associated with inferior outcomes and an increased risk for dislocation. The presence of a SA is associated with increased risk of adverse spinopelvic characteristics. Such characteristics were strongly associated with increased dislocation-risk and inferior PROMs. It is likely that these adverse characteristics are the most important adverse predictor, rather than segment of SA per se.

Tranexamic acid use is associated with reduced intraoperative blood loss during spine surgery for Marfan syndrome.

PURPOSE: The utility of tranexamic acid (TXA) in patients with Marfan syndrome (MFS) is uncertain given associated aberrations within the vasculature and clotting cascade. Therefore, this study aimed to assess the association of TXA use with intraoperative blood loss and allogeneic blood transfusions in patients with MFS who underwent spinal arthrodesis. METHODS: We queried our institutional database for MFS patients who underwent spinal arthrodesis for scoliosis between 2000 and 2020 by one surgeon. We excluded procedures spanning < 4 vertebral levels, those using anterior or combined anterior/posterior approaches, and those involving growing rods, postoperative infection, or spondylolisthesis. Fifty-two patients met our criteria, of whom 22 were treated with TXA and 30 were not. Mean differences in blood loss, transfusion volume, and proportions receiving transfusion were compared between TXA and the control groups using Student t, chi-squared, or Fisher exact tests. Alpha = 0.05. RESULTS: MFS patients treated with TXA experienced less mean (± standard deviation) intraoperative blood loss (1023 ± 534 mL) compared to the control group (1436 ± 1022 mL) (p = 0.01). The TXA group had estimated blood volume loss of 27% ± 16% compared to 36% ± 21% for controls (p = 0.05). No differences were found in allogeneic transfusion rate (p = 0.66) or transfusion volume (p = 0.15). CONCLUSIONS: We found an association between TXA use and reduced blood loss during surgical treatment of MFS-associated scoliosis, suggesting that the connective tissue deficiency in MFS does not interfere with TXA's mechanism of action. LEVEL OF EVIDENCE: III.

Spinal cord injury-related thermoregulatory impairment masks a fatal malignant hyperthermia crisis: a case report.

PURPOSE: Malignant hyperthermia (MH) is a hypermetabolic disorder that can occur in genetically susceptible individuals exposed to halogenated anesthetics and succinylcholine. Spinal cord injury (SCI) above the sixth thoracic vertebra is associated with dysfunction of the sympathetic/parasympathetic nervous pathways, including thermoregulatory dysfunction, presenting as hypothermia in cold environments because of vasodilation and heat loss. This effect could mitigate or obscure an MH episode. Here, we describe development of a fatal MH crisis in a patient with SCI. CLINICAL FEATURES: A 27-yr-old male patient with an SCI after fracture of the sixth cervical vertebra was admitted for spinal arthrodesis. Anesthetic medications included remifentanil, propofol, succinylcholine, rocuronium, and isoflurane. After the start of the surgery, muscular contractures resembling myoclonus were noted, which resolved with pancuronium administration. Four hours after the start of anesthesia, the patient presented with hyperthermia, hypercarbia, hypotension, muscle rigidity, arrhythmia, and cardiogenic shock, with metabolic/respiratory acidosis. Malignant hyperthermia was suspected and the treatment was started, but he developed cardiopulmonary arrest and died an hour and a half after the first cardiac arrest. Both parents were investigated and were found to have normal creatine kinase levels and positive in vitro contracture tests. His mother carried a variant in the ryanodine receptor type 1 (RYR1) gene (c.14918C>T), which is associated with MH. CONCLUSION: Spinal cord injury-induced thermoregulatory dysfunction may obscure the early diagnosis of MH and lead to fatal outcome.

RéSUMé: OBJECTIF: L'hyperthermie maligne est un trouble hypermétabolique qui peut survenir chez les personnes génétiquement susceptibles exposées à des anesthésiques volatils et à la succinylcholine. Les lésions médullaires situées au-dessus de la sixième vertèbre thoracique sont associées à un dysfonctionnement des voies nerveuses sympathiques / parasympathiques, y compris un trouble de la thermorégulation, et se présentent sous forme d'hypothermie dans des environnements froids en raison de la vasodilatation et de la perte de chaleur. Cet effet pourrait atténuer ou occulter un épisode d'hyperthermie maligne. Nous décrivons ici l'apparition d'une crise mortelle d'hyperthermie maligne chez un patient atteint de lésion médullaire. CARACTéRISTIQUES CLINIQUES: Un patient de 27 ans atteint d'une lésion médullaire après une fracture de la sixième vertèbre cervicale a été admis pour une arthrodèse rachidienne. Les médicaments anesthésiques comprenaient du rémifentanil, du propofol, de la succinylcholine, du rocuronium et de l'isoflurane. Après le début de la chirurgie, des contractures musculaires ressemblant à une myoclonie ont été notées, lesquelles se sont résolues avec l'administration de pancuronium. Quatre heures après l'induction d'anesthésie, le patient a présenté une hyperthermie, une hypercarbie, une hypotension, une rigidité musculaire, une arythmie et un choc cardiogénique, avec acidose métabolique / respiratoire. Une hyperthermie maligne a été suspectée et le traitement a été amorcé, mais le patient a subi un arrêt cardiorespiratoire et est décédé une heure et demie après le premier arrêt cardiaque. Les deux parents ont passés des tests et se sont avérés avoir des taux normaux de créatine kinase et des tests de contracture in vitro positifs. La mère du patient était porteuse d'un variant du gène récepteur de ryanodine de type 1 (RYR1) (c.14918C>T), lequel est associé à l'hyperthermie maligne. CONCLUSION: Un trouble de la thermorégulation induit par une lésion médullaire peut masquer un diagnostic précoce d'hyperthermie maligne et entraîner une issue fatale.

[Innovation and care: the RAAC program in the context of spinal surgery]. / Innovation et soins : le programme RAAC dans le contexte d'une chirurgie du rachis.

Spinal arthrodesis remains a major and decisive surgery. Faced with a constantly increasing number of operated patients, professional practices are evolving at the Robert-Debré pediatric hospital (Assistance publique - Hôpitaux de Paris). In favor of the well-being of children and their parents, the implementation of improved rehabilitation after surgery has revolutionized the accompaniment of scoliosis patients: considerable reduction in length of stay, improvement in postoperative management and parent/child satisfaction.

Anatomical study of the ideal positioning of the s2 iliac screw / Estudo anatômico do posicionamento ideal do parafuso s2 ilíaco / Estudio anatómico de la posición ideal del tornillo s2 ilíaco

ABSTRACT Objective: To evaluate the morphometry of the pelvis to determine the safe trajectory for the insertion of the S2-iliac screw, and to correlate it with studies reported in the literature for other populations. Method: The computed tomography (CT) pelvic exams of 36 Brazilian patients without congenital malformations, tumors, pelvic ring fractures or dysplasias were selected from the database of a radiological clinic. To define the ideal trajectory of the S2-iliac screw, the following variables were measured: 1- maximum sacroiliac screw length; 2- thickness of the iliac dipole for planning the choice of screw dimensions (length and diameter); 3 - distance between the insertion point of the iliac S2 screw and the posterior sacral cortex; 4 - angulation for insertion of the screw in the mediolateral direction, representing the angle formed between the "iliac line" and the anatomical sagittal plane; 5- Angulation for insertion of the screw in the craniocaudal direction. The Pearson's chi squared and student's t tests were used for statistical analysis. Results: The sample consisted of 36 patients, 50% (18/36) of whom were women. The mean age was 63.7 years, ranging from 23 to 96 years. All the pelvic morphometric variables analyzed presented values similar to those described in the literature for other populations. Conclusion: Prior evaluation of the tomography exams was important for preoperative planning, and there was a statistically significant difference between the sexes only in relation to the variables left craniocaudal and length of the left internal table. Level of evidence III; Observational cross-sectional study.

RESUMO Objetivo: Avaliar a morfometria da pelve para determinar a trajetória de segurança de introdução do parafuso S2-ilíaco e correlacionar com estudos relatados na literatura para outras populações. Métodos: A partir do banco de dados de uma clínica radiológica, foram selecionados 36 exames de tomografia computadorizada (TC) da pelve de pacientes brasileiros sem achados de malformações congênitas, tumorações, fraturas do anel pélvico ou displasias. Para definição da trajetória ideal do parafuso S2-ilíaco foram mensuradas as seguintes variáveis: 1 - comprimento máximo do parafuso sacro-ilíaco; 2 - espessura da díploe ilíaca para planejar a escolha das dimensões do parafuso (comprimento e diâmetro); 3 - distância entre o ponto de inserção do parafuso S2-ilíaco e a cortical posterior do sacro; 4 - angulação para inserção do parafuso no sentido médio-lateral, representando o ângulo formado entre a "reta ilíaca" e o plano sagital anatômico; 5 - angulação para inserção do parafuso no sentido craniocaudal. Para análise estatística foram usados os testes Qui-quadrado de Pearson e t de Student. Resultados: A amostra foi constituída de 36 pacientes, sendo 50% (18/36) mulheres. A média de idade foi de 63,7 anos, variando de 23 a 96 anos. Todas as variáveis morfométricas pélvicas analisadas apresentaram valores semelhantes aos descritos na literatura para outras populações. Conclusões: A avaliação prévia dos exames de tomografia foi importante para o planejamento pré-operatório, assim como a diferença estatisticamente significante entre os sexos somente com relação às variáveis craniocaudal esquerda e comprimento da tábua interna esquerda. Nível de evidência III; Estudo observacional de corte transversal.

RESUMEN Objetivo: Evaluar la morfometría de la pelvis para determinar la trayectoria de seguridad de introducción del tornillo S2-ilíaco y correlacionarla con estudios relatados en la literatura para otras poblaciones. Método: A partir de la base de datos de una clínica radiológica, se seleccionaron 36 exámenes de tomografía computarizada (TC) de la pelvis de pacientes brasileños sin hallazgos de malformaciones congénitas, tumores, fracturas del anillo pélvico o displasias. Para definir la trayectoria ideal del tornillo S2-ilíaco, se midieron las siguientes variables: 1- longitud máxima del tornillo sacro-ilíaco; 2- espesor del díploe ilíaco: para planificar la elección de las dimensiones del tornillo (longitud y diámetro); 3- distancia entre el punto de inserción del tornillo S2ilíaco y la cortical posterior del sacro; 4- angulación para inserción del tornillo en el sentido medio-lateral, que representa el ángulo formado entre la "recta ilíaca" y el plano sagital anatómico; 5- angulación para inserción del tornillo en el sentido craneocaudal. Para el análisis estadístico se utilizaron las pruebas Chi-cuadrado de Pearson y t de Student. Resultados: La muestra fue constituida de 36 pacientes, siendo 50% (18/36) mujeres. La edad promedio fue de 63,7 años, variando de 23 a 96 años. Todas las variables morfométricas pélvicas analizadas presentaron valores similares a los descritos en la literatura para otras poblaciones. Conclusiones: Fue importante la evaluación previa de los exámenes de tomografía para la planificación preoperatoria; así como la diferencia estadísticamente significativa entre géneros sólo en relación a las variables craneocaudal izquierda y longitud de la tabla interna izquierda. Nivel de evidencia III; Estudio observacional de corte transversal.

Impact of surgeon rhBMP-2 cost awareness on complication rates and health system costs for spinal arthrodesis.

OBJECTIVE: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is used in spinal arthrodesis procedures to enhance bony fusion. Research has suggested that it is the most cost-effective fusion enhancer, but there are significant upfront costs for the healthcare system. The primary objective of this study was to determine whether intraoperative dosing and corresponding costs changed with surgeon cost awareness. The secondary objective was to describe surgical complications before and after surgeon awareness of rhBMP-2 cost. METHODS: A retrospective medical record review was conducted to identify patients who underwent spinal arthrodesis procedures performed by a single surgeon, supplemented with rhBMP-2, from June 2016 to June 2018. Collected data included rhBMP-2 dosage, rhBMP-2 list price, and surgical complications. Expected Medicare reimbursement was calculated. Data were analyzed before and after surgeon awareness of rhBMP-2 cost. RESULTS: Forty-eight procedures were performed using rhBMP-2, 16 before and 32 after surgeon cost awareness. Prior to cost awareness, the most frequent rhBMP-2 dosage level was x-small (38.9%, n = 7), followed by large (27.8%, n = 5) and small (22.2%, n = 4). After cost awareness, the most frequent rhBMP-2 dosage was xx-small (56.8%, n = 21), followed by x-small (21.6%, n = 8) and large (13.5%, n = 5). The rhBMP-2 average cost per surgery was $4116.56 prior to surgeon cost awareness versus $2268.38 after. Two complications were observed in the pre-cost awareness surgical group; 2 complications were observed in the post-cost awareness surgical group. CONCLUSIONS: Surgeon awareness of rhBMP-2 cost resulted in use of smaller rhBMP-2 doses, decreased rhBMP-2 cost per surgery, and decreased overall hospital admission charges, without a detectable increase in surgical complications.

Local insulin application has a dose-dependent effect on lumbar fusion in a rabbit model.

The purpose of this study was to determine if locally applied insulin has a dose-responsive effect on posterolateral lumbar fusion. Adult male New Zealand White rabbits underwent posterolateral intertransverse spinal fusions (PLFs) at L5-L6 using suboptimal amounts of autograft. Fusion sites were treated with collagen sponge soaked in saline (control, n = 11), or with insulin at low (5 or 10 units, n = 13), mid (20 units, n = 11), and high (40 units, n = 11) doses. Rabbits were euthanized at 6 weeks. The L5-L6 spine segment underwent manual palpation and radiographic evaluation performed by two fellowship trained spine surgeons blinded to treatment. Differences between groups were evaluated by analysis of variance on ranks followed by post-hoc Dunn's tests. Forty-three rabbits were euthanized at the planned 6 weeks endpoint, while three died or were euthanized prior to the endpoint. Radiographic evaluation found bilateral solid fusion in 10%, 31%, 60%, and 60% of the rabbits from the control and low, mid, and high-dose insulin-treated groups, respectively (p < 0.05). As per manual palpation, 7 of 10 rabbits in the mid-dose insulin group were fused as compared to 1 of 10 rabbits in the control group (p < 0.05). This study demonstrates that insulin enhanced the effectiveness of autograft to increase fusion success in the rabbit PLF model. The study indicates that insulin or insulin-mimetic compounds can be used to promote bone regeneration.

How is staging of ALIF following posterior spinal arthrodesis to the pelvis related to functional improvement in patients with adult spinal deformity?

STUDY DESIGN: Retrospective cohort. OBJECTIVES: To compare postoperative functional improvement in patients who underwent staged versus non-staged anterior-posterior spinal arthrodesis for adult spinal deformity (ASD). In patients with ASD, spinal arthrodesis can be performed in 2 stages to avoid the physiologic insult of a lengthy surgery. The association between staged surgery and postoperative functional improvement has not been well studied. METHODS: We included 87 patients (59 women) with ASD who underwent anterior-posterior spinal arthrodesis of > 5 levels with fixation to the pelvis from 2010-2014. Primary outcomes were the frequency of achieving at least a minimal clinically important difference (MCID) in the Scoliosis Research Society-22r (SRS-22r) Activity domain and the timeframe in which it was achieved. The secondary outcome was patient satisfaction (SRS-22r Patient Satisfaction domain). A Cox proportional hazard model was used to compare functional improvement over time between staged and non-staged groups. Our study was powered to detect a relative hazard ratio of 0.53, ß = 0.20. α = 0.05. RESULTS: The frequency of achieving an MCID in SRS-22r Activity score did not differ significantly between the staged group (33/41 patients) and the non-staged group (34/46 patients) (hazard ratio 0.74; 95% confidence interval 0.41-1.36). Median times to achieving an MCID in SRS-22r Activity score were 191 days (interquartile range: 86-674) in the staged group and 181 days (interquartile range: 72-474) in the non-staged group (p = .75). The staged and non-staged groups had similar SRS-22r Patient Satisfaction scores at 3-9 months postoperatively and at final follow-up (both, p > .05). CONCLUSION: Patients with ASD who underwent staged anterior-posterior spinal arthrodesis within 3 months after index surgery were similarly likely to experience functional improvement in the same timeframe as patients who underwent non-staged surgery. Patient satisfaction did not differ significantly between staged and non-staged groups. LEVEL OF EVIDENCE: III.

Cervical spine tuberculosis.

Tuberculosis of the cervical spine differs from other vertebral localizations by its extreme rarity, the clinical images are very diversified, the radiological measurements allow a good diagnostic orientation and specifically the MRI which allows a multi-planar study of the various lesions. Only bacteriological evidence can confirm the diagnosis. The treatment is based on a 12-month antituberculosis multidrug therapy and much debate upon the surgical indication. In our case, the patient presented with bilateral cervicobrachialgia with pain on examination at the mobilization of the cervical spine. A standard X-ray, a cervical CT scan, and a cervical MRI were performed, showing a C4 vertebral body compression of a probably infectious origin. The biopsy confirmed the diagnosis of a Cervical Pott's Disease that had been treated with anterior arthrodesis and TB treatment with rehabilitation, the patients' neurological symptoms improved, and he was doing well.

Static Magnetic Fields within Spinal Interbody Cages for the Promotion of Spinal Arthrodesis: A Pilot Study.

BACKGROUND: Spinal arthrodesis is a commonly performed spinal operation. Spinal arthrodesis can be complicated by pseudoarthrosis and resultant hardware failure. Static magnetic fields (SMF) have the ability to improve bone fusion. We seek to assess the feasibility of the construction and implantation of a lumbar interbody cage equipped with a SMF in a caprine model. METHODS: Six skeletally mature female Boer goats underwent a lateral approach for placement of an interbody graft at lumbar (L) 1-2 and 3-4. The goats were divided into 2 groups of 3 animals. The interbody graft contained a neodymium iron boron magnet in the experimental group and a nonmagnetic titanium sham in the control group. Both groups contained a synthetic bone graft. Blinded radiographic and histologic evaluation was performed at predetermined timepoints to assess degree of bony fusion and osseointegration. RESULTS: All 6 goats underwent successful placement of lumbar interbody grafts. At the 1-month postoperative computed tomography, 1 goat in the experimental group and 1 goat in the control group were noted to have dislodged their intervertebral cage. Qualitative radiographic and histologic evaluation identified enhanced bone formation, bone density, and osteointegration of the graft in the experimental group. CONCLUSIONS: A spinal interbody cage containing a neodymium iron boron magnet for the production of a local SMF is feasible. Preliminary data suggests enhanced bone formation, bone density, and osseointegration of the graft.

Double-blind randomized clinical trial of vancomycin in spinal arthrodesis: no effects on surgical site infection.

OBJECTIVE: Surgical site infection (SSI) results in high morbidity and mortality in patients undergoing spinal fusion. Using intravenous antibiotics in anesthesia induction reduces the rate of postoperative infection, but it is not common practice to use them topically, despite recent reports that this procedure helps reduce infection. The objective of this study was to determine whether the topical use of vancomycin reduces the rate of postoperative SSI in patients undergoing thoracolumbar fusion. METHODS: A randomized, double-blind clinical trial in a single hospital was performed comparing vancomycin and placebo in thoracolumbar fusion patients. RESULTS: A total of 96 patients were randomized to placebo or vancomycin treatment. The mean patient age was 43 ± 14.88 years, 74% were male, and the most common etiology was fall from height (46.9%). The overall rate of postoperative SSI was 8.3%, and no difference was found between the groups: postoperative infection rates in the vancomycin and placebo groups were 8.2% and 8.5% (relative risk [RR] of SSI not using vancomycin 1.04, 95% confidence interval [CI] 0.28-3.93, p = 0.951), respectively. Patients with diabetes mellitus had higher SSI rates (RR 8.98, 95% CI 1.81-44.61, p = 0.007). CONCLUSIONS: This is the first double-blind randomized clinical trial to evaluate the effects of topical vancomycin on postoperative infection rates in thoracolumbar fusion patients, and the results did not differ significantly from placebo.Clinical trial registration no.: RBR-57wppt (ReBEC; http://www.ensaiosclinicos.gov.br/).