Prolonged length of stay (LOS) is a significant contributor to the variation in surgical health care costs and resource utilization after elective spine surgery. The primary goal of this study was to identify patient, surgical and institutional variables that influence LOS. The secondary objective is to examine variability in institutional practices among participating centers. This is a retrospective study of a prospectively multicentric followed cohort of patients enrolled in the CSORN between January 2015 and October 2020. A logistic regression model and bootstrapping method was used. A survey was sent to participating centers to assessed institutional level interventions in place to decrease LOS. Centers with LOS shorter than the median were compared to centers with LOS longer than the median. A total of 3734 patients were included (979 discectomies, 1102 laminectomies, 1653 fusions). The median LOS for discectomy, laminectomy and fusion were respectively 0.0 day (IQR 1.0), 1.0 day (IQR 2.0) and 4.0 days (IQR 2.0). Laminectomy group had the largest variability (SD=4.4, Range 0-133 days). For discectomy, predictors of LOS longer than 0 days were having less leg pain, higher ODI, symptoms duration over 2 years, open procedure, and AE (p< 0.05). Predictors of longer LOS than median of 1 day for laminectomy were increasing age, living alone, higher ODI, open procedures, longer operative time, and AEs (p< 0.05). For posterior instrumented fusion, predictors of longer LOS than median of 4 days were older age, living alone, more comorbidities, less back pain, higher ODI, using narcotics, longer operative time, open procedures, and AEs (p< 0.05). Ten centers (53%) had either ERAS or a standardized protocol aimed at reducing LOS. In this study stratifying individual patient and institutional level factors across Canada, several independent predictors were identified to enhance the understanding of LOS variability in common elective lumbar spine surgery. The current study provides an updated detailed analysis of the ongoing Canadian efforts in the implementation of multimodal ERAS care pathways. Future studies should explore multivariate analysis in institutional factors and the influence of preoperative patient education on LOS

A stiff spine leads to increased demand on the hip, creating an increased risk of total hip arthroplasty (THA) dislocation. Several authors propose that a change in sacral slope of ≤10° between the standing and relaxed-seated positions (ΔSSstanding→relaxed-seated) identifies a patient with a stiff lumbar spine and have suggested use of dual-mobility bearings for such patients. However, such assessment may not adequately test the lumbar spine to draw such conclusions. The aim of this study was to assess how accurately ΔSSstanding→relaxed-seated can identify patients with a stiff spine. This is a prospective, multi-centre, consecutive cohort series. Two-hundred and twenty-four patients, pre-THA, had standing, relaxed-seated and flexed-seated lateral radiographs. Sacral slope and lumbar lordosis were measured on each functional X-ray. ΔSSstanding→relaxed-seated seated was determined by the change in sacral slope between the standing and relaxed-seated positions. Lumbar flexion (LF) was defined as the difference in lumbar lordotic angle between standing and flexed-seated. LF≤20° was considered a stiff spine. The predictive value of ΔSSstanding→relaxed-seated for characterising a stiff spine was assessed. A weak correlation between ΔSSstanding→relaxed-seated and LF was identified (r2= 0.15). Fifty-four patients (24%) had ΔSSstanding→relaxed-seated ≤10° and 16 patients (7%) had a stiff spine. Of the 54 patients with ΔSSstanding→relaxed-seated ≤10°, 9 had a stiff spine. The positive predictive value of ΔSSstanding→relaxed-seated ≤10° for identifying a stiff spine was 17%. ΔSSstanding→relaxed-seated ≤10° was not correlated with a stiff spine in this cohort. Utilising this simplified approach could lead to a six-fold overprediction of patients with a stiff lumbar spine. This, in turn, could lead to an overprediction of patients with abnormal spinopelvic mobility, unnecessary use of dual mobility bearings and incorrect targets for component alignment. Referring to patients ΔSSstanding→relaxed-seated ≤10° as being stiff can be misleading; we thus recommend use of the flexed-seated position to effectively assess pre-operative spinopelvic mobility

Sarcopenia has been observed to be a predictor of mortality in international studies of patients with metastatic disease of the spine. This study aimed to validate sarcopenia as a prognostic tool in a New Zealand setting. A secondary aim of this study was to assess the intra-observer reliability of measurements of psoas and vertebral body cross sectional areas on computed tomography imaging. A cohort of patients who had presented to Waikato Hospital with secondary neoplasia in the spinal column from 2014 to 2018 was selected. Cross sectional psoas and vertebral body areas were measured at the mid-pedicle L3 level, followed by calculation of the psoas to vertebral body cross sectional area ratio. Psoas to vertebral body cross sectional area ratio was compared with survivorship. The strength of the correlation between sarcopenia and survivorship was compared with the correlation between serum albumin and survivorship, as well as the correlation between the Metastatic Spine Risk Index (MSRI) and survivorship. A total of 110 patients who received operative (34) and non-operative (76) were included. The results demonstrate that psoas to vertebral body cross sectional area ratio is not statistically significantly correlated with survivorship (p=0.53). Serum albumin is significantly correlated with survivorship (p<0.0001), as was the MSRI. There is good intra-observer and inter-observer reliability for measurements of psoas to vertebral body cross sectional area. This study failed to demonstrate the utility for the psoas to vertebral body cross sectional area ratio that other studies have demonstrated in estimating survivorship. Serum albumin levels remain a useful prognostic indicator in patients with secondary tumours in the vertebral column

Primary care physicians rely on radiology reports to confirm a scoliosis diagnosis and inform the need for spine specialist referral. In turn, spine specialists use these reports for triage decisions and planning of care. To be a valid predictor of disease and management, radiographic evaluation should include frontal and lateral views of the spine and a complete view of the pelvis, leading to accurate Cobb angle measurements and Risser staging. The study objectives were to determine 1) the adequacy of index images to inform treatment decisions at initial consultation by generating a score and 2) the utility of index radiology reports for appropriate triage decisions, by comparing reports to corresponding images. We conducted a retrospective chart and radiographic review including all idiopathic scoliosis patients seen for initial consultation, aged three to 18 years, between January 1-April 30, 2021. A score was generated based on the adequacy of index images to provide accurate Cobb angle measurements and determine skeletal maturity (view of full spine, coronal=two, lateral=one, pelvis=one, ribcage=one). Index images were considered inadequate if repeat imaging was necessary. Comparisons were made between index radiology report, associated imaging, and new imaging if obtained at initial consultation. Major discrepancies were defined by inter-reader difference >15°, discordant Risser staging, or inaccuracies that led to inappropriate triage decisions. Location of index imaging, hospital versus community-based private clinic, was evaluated as a risk factor for inadequate or discrepant imaging. There were 94 patients reviewed with 79% (n=74) requiring repeat imaging at initial consultation, of which 74% (n=55) were due to insufficient quality and/or visualization of the sagittal profile, pelvis or ribcage. Of index images available for review at initial consult (n=80), 41.2% scored five out of five and 32.5% scored two or below. New imaging showed that 50.0% of those patients had not been triaged appropriately, compared to 18.2% of patients with a full score. Comparing index radiology reports to initial visit evaluation with <60 days between imaging (n=49), discrepancies in Cobb angle were found in 24.5% (95% CI 14.6, 38.1) of patients, with 18.4% (95% CI 10.0, 31.4) categorized as major discrepancies. Risser stage was reported in only 14% of index radiology reports. In 13.8% (n=13) of the total cohort, surgical or brace treatment was recommended when not predicted based on index radiology report. Repeat radiograph (p=0.001, OR=8.38) and discrepancies (p=0.02, OR=7.96) were increased when index imaging was obtained at community-based private clinic compared to at a hospital. Re-evaluation of available index imaging demonstrated that 24.6% (95% CI 15.2, 37.1) of Cobb angles were mis-reported by six to 21 degrees. Most pre-referral paediatric spine radiographs are inadequate for idiopathic scoliosis evaluation. Standardization of spine imaging and reporting should improve measurement accuracy, facilitate triage and decrease unnecessary radiation exposure

Background. Surgical site infection following spine surgery is associated with increased morbidity, mortality and increased cost for the health care system. The reported pooled incidence is 3%. Perioperative antibiotic prophylaxis is a key factor in lowering the risk of acquiring an infection. Previous studies have assessed perioperative cefuroxime concentrations in the anterior column of the cervical spine with an anterior surgical approach. However, the majority of surgeries are performed in the posterior column and often involve the lumbar spine. Accordingly, the objective was to compare the perioperative tissue concentrations of cefuroxime in the anterior and posterior column of the same lumbar vertebra using microdialysis in an experimental porcine model. Method. The lumbar vertebral column was exposed in 8 female pigs. Microdialysis catheters were placed for sampling in the anterior column (vertebral body) and posterior column (posterior arch) within the same vertebra (L5). Cefuroxime (1.5 g) was administered intravenously over 10 min. Microdialysates and plasma samples were continuously obtained over 8 hours. Cefuroxime concentrations were quantified by Ultra High Performance Liquid Chromatography Tandem Mass Spectrometry. Microdialysis is a catheter-based pharmacokinetic tool, that allows dynamic sampling of unbound and pharmacologic active fraction of drugs e.g., cefuroxime. The primary endpoint was the time with cefuroxime above the clinical breakpoint minimal inhibitory concentration (T>MIC) for Staphylococcus aureus of 4 µg/mL as this has been suggested as the best predictor of efficacy for cefuroxime. The secondary endpoint was tissue penetration (AUC. tissue. /AUC. plasma. ). Results. Mean T>MIC 4 µg/mL (95% confidence interval) was 123 min (105–141) in plasma, 97 min (79–115) in the anterior column and 93 min (75–111) in the posterior column. Tissue penetration (95% confidence interval) was incomplete for both the anterior column 0.48 (0.40–0.56) and posterior column 0.40 (0.33–0.48). Conclusions. Open lumbar spine surgery often involves extensive soft tissue dissection, stripping and retraction of the paraspinal muscles which may impair the local blood flow exposing the lumbar vertebra to postoperative infections. A single intravenous administration of 1.5 g cefuroxime resulted in comparable T>MIC between the anterior and posterior column of the lumbar spine. Mean cefuroxime concentrations decreased below the clinical breakpoint MIC for S. aureus of 4 µg/mL after 123 min (plasma), 97 min (anterior column) and 93 min (posterior column). This is shorter than the duration of most lumbar spine surgeries, and therefore alternative dosing regimens should be considered in posterior open lumbar spine surgeries lasting more than 1.5 hours

Aim. To evaluate efficacy of a one stage posterior approach in decompression and eradication of infection in TB spine. Background. The classic operation for TB spine is anterior spine debridement. This involves a trans-thoracic, or retroperitoneal approach, thus increasing morbidity in an already compromised patient. The anterior procedure in the form of the Hong Kong operation is aimed at decompressing the spine, and debridement of necrotic tissue. If kyphosis is a major problem, its correction requires a posterior procedure, often not at the same sitting. Material and Method. A retrospective review of patients treated surgically for TB Spine during the time period 2009–2012. We examined the records of those patients that were treated by a posterior only approach. We took note of the demographics of the patients. We measured the efficacy of the decompression by measuring the pre op and post op neurologic status as measured by the Frankel grading. The efficacy of debridemide was assessed by measuring the preoperative and follow up ESR. Results. We identified 11 patients for review, 8 male and 3 females. 8 were HIV positive. The disease affected the thoracic spine. The average follow up was 12 months. There was good correction of the deformity and this was maintained throughout the follow up period. The ESR decreased in all the patients. Neurologic improvement was noted in 5 patients and no patients deteriorated. Statistical methods to quantify these changes were not significant because of the small numbers. Conclusion. In our environment a number of patients are immunocompromised by the HIV virus. A trans thoracic approach increases the morbidity in these patients. Effective decompression and debridement can be achieved by the posterior only approach. NO DISCLOSURES

Numerous prediction tools are available for estimating postoperative risk following spine surgery. External validation studies have shown mixed results. We present the development, validation, and comparative evaluation of novel tool (NZSpine) for modelling risk of complications within 30 days of spine surgery. Data was gathered retrospectively from medical records of patients who underwent spine surgery at Waikato Hospital between January 2019 and December 2020 (n = 488). Variables were selected a priori based on previous evidence and clinical judgement. Postoperative adverse events were classified objectively using the Comprehensive Complication Index. Models were constructed for the occurrence of any complication and significant complications (based on CCI >26). Performance and clinical utility of the novel model was compared against SpineSage (. https://depts.washington.edu/spinersk/. ), an extant online tool which we have shown in unpublished work to be valid in our local population. Overall complication rate was 34%. In the multivariate model, higher age, increased surgical invasiveness and the presence of preoperative anemia were most strongly predictive of any postoperative complication (OR = 1.03, 1.09, 2.1 respectively, p <0.001), whereas the occurrence of a major postoperative complication (CCI >26) was most strongly associated with the presence of respiratory disease (OR = 2.82, p <0.001). Internal validation using the bootstrapped models showed the model was robust, with an AUC of 0.73. Using sensitivity analysis, 80% of the model's predictions were correct. By comparison SpineSage had an AUC of 0.71, and in decision curve analysis the novel model showed greater expected benefit at all thresholds of risk. NZSpine is a novel risk assessment tool for patients undergoing acute and elective spine surgery and may help inform clinicians and patients of their prognosis. Use of an objective tool may help to provide uniformity between DHBs when completing the “clinician assessment of risk” section of the national prioritization tool

Surgical site infections (SSIs) after spinal fusion surgery increase healthcare costs, morbidity and mortality. Routine measures of obesity fail to consider site specific fat distribution. We aimed to assess the association between the spine adipose index and deep surgical site infection and determine a threshold value for spine adipose index that can assist in preoperative risk stratification in patients undergoing posterior instrumented lumbar fusion (PILF). A multicentre retrospective case-control study was completed. We reviewed patients who underwent PILF from January 1, 2010 to December 31, 2018. All patients developing a deep primary incisional or organ-space SSI within 90 days of surgery as per US Centre for Disease Control and Prevention criteria were identified. We gathered potential pre-operative and intra-operative deep infection risk factors for each patient. Spine adipose index was measured on pre-operative mid-sagittal cuts of T2 weighted MRI scans. Each measurement was repeated twice by three authors in a blinded fashion, with each series of measurement separated by a period of at least six weeks. Forty-two patients were included in final analysis, with twenty-one cases and twenty-one matched controls. The spine adipose index was significantly greater in patients developing deep SSI (p =0.029), and this relationship was maintained after adjusting for confounders (p=0.046). Risk of developing deep SSI following PILF surgery was increased 2.0-fold when the spine adipose index was ≥0.51. The spine adipose index had excellent (ICC >0.9; p <0.001) inter- and intra-observer reliabilities. The spine adipose index is a novel radiographic measure and an independent risk factor for developing deep SSI, with 0.51 being the ideal threshold value for pre-operative risk stratification in patients undergoing PILF surgery

Aims. The aim of this paper is to describe the impact of COVID-19 on spine surgery services in a district general hospital in England in order to understand the spinal service provisions that may be required during a pandemic. Methods. A prospective cohort study was undertaken between 17 March 2020 and 30 April 2020 and compared with retrospective data from same time period in 2019. We compared the number of patients requiring acute hospital admission or orthopaedic referrals and indications of referrals from our admission sheets and obtained operative data from our theatre software. Results. Between 17 March to 30 April 2020, there were 48 acute spine referrals as compared to 68 acute referrals during the same time period last year. In the 2019 period, 69% (47/68) of cases referred to the on-call team presented with back pain, radiculopathy or myelopathy compared to 43% (21/48) in the 2020 period. Almost 20% (14/68) of spine referrals consisted of spine trauma as compared to 35% (17/48) this year. There were no confirmed cases of cauda equine last year during this time. Overall, 150 spine cases were carried out during this time period last year, and 261 spine elective cases were cancelled since 17 March 2020. Recommendations. We recommend following steps can be helpful to deal with similar situations or new pandemics in future:. 24 hours on-call spine service during the pandemic. Clinical criteria in place to prioritize urgent spinal cases. Pre-screening spine patients before elective operating. Start of separate specialist trauma list for patients needing urgent surgeries. Conclusion. This paper highlights the impact of COVID-19 pandemic in a district general hospital of England. We demonstrate a decrease in hospital attendances of spine pathologies, despite an increase in emergency spine operations. Cite this article: Bone Joint Open 2020;1-6:281–286

Adverse events (AEs) following spine surgery are very common. It is important to monitor the incidence of AEs to ensure that appropriate practices are implemented to minimise AEs and improve patient outcomes. The Spine Adverse Events Severity System (SAVES) is a validated AE recording tool specifically designed for spine surgery and the Orthopaedic Surgical Adverse Events Severity System (OrthoSAVES) is a similar tool intended for general orthopaedic surgery. The main objective was to prospectively collect AE data from spine surgery patients using SAVES and OrthoSAVES and compare their viability and applicability for use. The longterm objective is to enhance patient safety by tracking AEs with a view towards potentially changing future healthcare practices to eliminate the risk factors for AEs. For a 10-week period in June-September 2015, three spine surgeons used SAVES to record AEs experienced by any elective spine surgery patients. In addition, a trained independent clinical reviewer with access to electronic records, medical charts, and allied health professionals (e.g. nurses, physioterhapists) used SAVES and OrthoSAVES to record AEs for the same patients. At discharge, the SAVES forms from the surgeons and SAVES and OrthoSAVES forms from the independent reviewer were collected and all AEs were recorded in a database. In 48 patients, the independent reviewer recorded a total of 45 AEs (4 intra-operative, 41 post-operative), compared to the surgeons who recorded a total of 8 AEs (2 intra-operative, 6 post-operative) (P2) were recorded by both the independent reviewer and surgeons. OrthoSAVES had the capacity to directly record 3 additional AEs that had to be included in the “Other” section on SAVES. SAVES and OrthoSAVES are valuable tools for recording AEs. Use of SAVES and OrthoSAVES has the potential to enhance patient care and safety by ensuring AEs are followed by the surgeon during their in-hospital stay and prior to discharge. Independent reviewers are more effective at capturing AEs following spine surgery, and thus, could be recruited in order to capture more AEs and maximise different complication diagnoses in alignment with proposed diagnosis-based funding models. The next step is to analyse AE data identified by the hospital discharge abstract to determine whether retrospective administrative coding can adequately record AEs compared to prospectively-collected AE data with SAVES/OrthoSAVES

This study aims to 1) determine reported cannabis use among patients waiting for thoracolumbar surgery and to 2) identify demographics and health differences between cannabis-users and non-cannabis users. This observational cohort study is a retrospective national multicenter review data from the Canadian Spine Outcomes and Research Network registry. Patients were dichotomized as cannabis users and non-cannabis users. Variables of interest: age, sex, BMI, smoking status, education, work status, exercise, modified Oswestry Disability Index (mODI), the Numerical Rating Scales (NRS) for leg and back pain, tingling/numbness scale, SF-12 Quality of Life Questionnaire - Mental Health Component (MCS), use of prescription cannabis, recreational cannabis, and narcotic pain medication. Continuous variables were compared using an independent t-test and categorical variables were compared using chi-square analyses. Cannabis-use was reported by 28.4% of pre-operative patients (N=704), 47% of whom used prescription cannabis. Cannabis-use was reported most often by patients in Alberta (43.55%), British Colombia (38.09%) and New Brunswick (33.73%). Patients who reported using cannabis were significantly younger (mean=52.9 versus mean=61.21,). There was a higher percentage of concurrent narcotic-use (51.54 %) and smoking (21.5%) reported in cannabis-users in comparison to non-cannabis users (41.09%,p=0.001; 9.51%, p=0.001, respectively). There were significant differences in cannabis-use based on pathology (p=0.01). Patients who report using cannabis had significantly worse MCS scores (difference=3.93, p=0.001), and PHQ-8 scores (difference=2.51, p=0.001). There was a significant difference in work status (p=0.002) with cannabis-users reporting higher rates (20%) of being employed, but not working compared to non-cannabis users (11.13%). Non-cannabis users were more likely to be retired (45.92%) compared to cannabis-users (31.31%). There were no significant differences based on cannabis use for sex, education, exercise, NRS-back, NRS-Leg, tingling-leg, mODI, or health state. Thoracolumbar spine surgery patients are utilizing cannabis prior to surgery both through recreational use and prescription. Patients who are using cannabis pre-operatively did not differ in regards to reported pain or disability from non-users, though they did in demographic and mental health variables

This study aims to 1) determine reported cannabis use among patients waiting for thoracolumbar surgery and to 2) identify demographics and health differences between cannabis-users and non-cannabis users. This observational cohort study is a retrospective national multicenter review data from the Canadian Spine Outcomes and Research Network registry. Patients were dichotomized as cannabis users and non-cannabis users. Variables of interest: age, sex, BMI, smoking status, education, work status, exercise, modified Oswestry Disability Index (mODI), the Numerical Rating Scales (NRS) for leg and back pain, tingling/numbness scale, SF-12 Quality of Life Questionnaire - Mental Health Component (MCS), use of prescription cannabis, recreational cannabis, and narcotic pain medication. Continuous variables were compared using an independent t-test and categorical variables were compared using chi-square analyses. Cannabis-use was reported by 28.4% of pre-operative patients (N=704), 47% of whom used prescription cannabis. Cannabis-use was reported most often by patients in Alberta (43.55%), British Colombia (38.09%) and New Brunswick (33.73%). Patients who reported using cannabis were significantly younger (mean=52.9 versus mean=61.21,). There was a higher percentage of concurrent narcotic-use (51.54 %) and smoking (21.5%) reported in cannabis-users in comparison to non-cannabis users (41.09%,p=0.001; 9.51%, p=0.001, respectively). There were significant differences in cannabis-use based on pathology (p=0.01). Patients who report using cannabis had significantly worse MCS scores (difference=3.93, p=0.001), and PHQ-8 scores (difference=2.51, p=0.001). There was a significant difference in work status (p=0.002) with cannabis-users reporting higher rates (20%) of being employed, but not working compared to non-cannabis users (11.13%). Non-cannabis users were more likely to be retired (45.92%) compared to cannabis-users (31.31%). There were no significant differences based on cannabis use for sex, education, exercise, NRS-back, NRS-Leg, tingling-leg, mODI, or health state. Thoracolumbar spine surgery patients are utilizing cannabis prior to surgery both through recreational use and prescription. Patients who are using cannabis pre-operatively did not differ in regards to reported pain or disability from non-users, though they did in demographic and mental health variables

Abstract. Introduction. Specialist Spinal Services provide operative and non-operative management strategies for a variety of conditions ranging from simple pathologies to complex disabling conditions. The existing spinal hub and spoke model implemented in 2015 nationally across the NHS. We aim to assess the effectiveness and pitfalls of the Spinal hub and spoke model in this questionnaire-based study. Methods. We conducted a prospective questionnaire-based study in the Northwest England and attendees of the BOA conference in 2021. Questionnaires included from the hospitals with no local spinal services and those with on-site services were excluded. Questions specific to initial assessment, referrals process, MRI availability, and awareness of Spine Hub and Spoke model. Results. Data collected from 254 orthopaedic surgeons including residents from different regions. Ninety per cent of initial assessments done in the emergency department by doctors without spinal experience. The spinal referral process took between 4–12 hours to receive an opinion. The initial advice given by middle grades of hub following the spinal referrals. 86% of hospitals had no provision to obtain MRI scans out of hours. 90% of orthopaedic surgeons were not confident to convey spine referral outcomes and review them in local clinics. Only 46% surgeons satisfaction with the current model. 78% of middle grades were not aware of the Hub and spoke model. Conclusions. Our survey identified that orthopaedic surgeons expressed the need for local spinal services for non-urgent cases. Based on this survey we recommend a restructuring of the hub and spoke model across hospitals in the NHS

Spine surgery is common and costly. Researchers and policy makers believe that utilization of spine surgery in the US is significantly higher than in other industrialized countries. Although within-country variation in spine surgery utilization is well studied, there has been little exploration of variation in spine surgery between countries. We used population level administrative data from Ontario (years 2011–2015) and New York (2011–2014) to identify all adults who underwent inpatient spinal decompression or fusion surgery. We compared Ontario and New York with respect to patient demographics and the percentage of hospitals performing spine surgery. We compared rates of decompression and fusion surgery (procedures per-10,000 population per-year) in Ontario and New York for all procedures, emergent procedures alone, and elective procedures and after stratifying by patient age. Patients in Ontario were older than patients in New York for decompression (mean age 58.8 vs. 51.3 years, P<.001) and fusion (58.1 vs. 54.9, P<.001). A smaller percentage of hospitals in Ontario performed decompression or fusion compared to New York (decompression, 26.1% in Ontario vs 54.9% in New York: fusion 15.2% vs 56.7%, both P<.001). Overall, utilization of spine surgery in Ontario was 6.6 procedures per-10,000 population per-year and in New York was 18 per-10,000 per-year (P<.001). Ontario-New York differences in utilization were small for emergent cases (2 per-10,000 in Ontario vs. 2.8 in New York, P<.001), but large for elective cases (4.6 vs 15.2, P<.001). In analyses stratified by surgical subtype, differences in utilization of decompression in New York and Ontario were relatively modest (2.4 vs 3.1, P<.001), while utilization of fusion was approximately 400% higher in New York than Ontario (15.7 vs 3.5, P<.001). Further analysis demonstrated that the New York-Ontario difference in utilization was substantially larger among younger patients and smaller for older patients. For example, utilization of spine procedures in New York was 340% greater than Ontario for patients less-than 50 years of age (11.7 vs 3.4), but only 25% greater in patients age 80 and above (10 vs 12.6). After adjusting for patient demographics, hospital LOS and surgical urgency, differences in mortality in Ontario and New York were not significant for either decompression or fusion. In adjusted analyses differences in hospital LOS were slightly greater for decompression in Ontario, but similar for fusion and readmission rates in Ontario were significantly lower than in New York. In conclusion, we found significantly lower utilization of spine surgery in Ontario when compared to New York. The difference in utilization was attributable to less elective fusion surgery, primarily in younger (i.e. non-Medicare) patients. These findings can serve inform broader spine surgery policy reforms in both jurisdictions

En bloc resection for primary bone tumours and isolated metastasis are complex surgeries associated with a high rate of adverse events (AEs). The primary objective of this study was to explore the relationship between frailty/sarcopenia and major perioperative AEs following en bloc resection for primary bone tumours or isolated metastases of the spine. Secondary objectives were to report the prevalence and distribution of frailty and sarcopenia, and determine the relationship between these factors and length of stay (LOS), unplanned reoperation, and 1-year postoperative mortality in this population. This is a retrospective study of prospectively collected data from a single quaternary care referral center consisting of patients undergoing an elective en bloc resection for a primary bone tumour or an isolated spinal metastasis between January 1st, 2009 and February 28th, 2020. Frailty was calculated with the modified frailty index (mFI) and spine tumour frailty index (STFI). Sarcopenia, determined by the total psoas area (TPA) vertebral body (VB) ratio (TPA/VB), was measured at L3 and L4. Regression analysis produced ORs, IRRs, and HRs that quantified the association between frailty/sarcopenia and major perioperative AEs, LOS, unplanned reoperation and 1-year postoperative mortality. One hundred twelve patients met the inclusion criteria. Using the mFI, five patients (5%) were frail (mFI ³ 0.21), while the STFI identified 21 patients (19%) as frail (STFI ³ 2). The mean CT ratios were 1.45 (SD 0.05) and 1.81 (SD 0.06) at L3 and L4 respectively. Unadjusted analysis demonstrated that sarcopenia and frailty were not significant predictors of major perioperative AEs, LOS or unplanned reoperation. Sarcopenia defined by the CT L3 TPA/VB and CT L4 TPA/VB ratios significantly predicted 1-year mortality (HR of 0.32 per one unit increase, 95% CI 0.11-0.93, p=0.04 vs. HR of 0.28 per one unit increase, 95% CI 0.11-0.69, p=0.01) following unadjusted analysis. Frailty defined by an STFI score ≥ 2 predicted 1-year postoperative mortality (OR of 2.10, 95% CI 1.02-4.30, p=0.04). The mFI was not predictive of any clinical outcome in patients undergoing en bloc resection for primary bone tumours or isolated metastases of the spine. Sarcopenia defined by the CT L3 TPA/VB and L4 TPA/VB and frailty assessed with the STFI predicted 1-year postoperative mortality on univariate analysis but not major perioperative AEs, LOS or reoperation. Further investigation with a larger cohort is needed to identify the optimal measure for assessing frailty and sarcopenia in this spine population

Frailty has been shown to be a risk predictor for peri-operative adverse events (AEs) in patients undergoing various type of spine surgery. However, its relationship with Patient Related Outcome Measures (PROMS) remains unknown. The primary objective of this study was to determine the impact of frailty on PROMS in patients undergoing surgery for thoraco-lumbar degenerative conditions. The secondary objective was to determine the association between frailty and baseline PROMS. This is a retrospective study of a prospective cohort of patients >55 years old who underwent surgery between 2012 and 2018. Patient data and PROMS (EQ-5D, SF-12, ODI, back and leg pain NRS) were extracted from the Canadian Spine Outcomes and Research Network registry for a single academic centre. Frailty was retrospectively calculated using the modified frailty index (mFI) and patient were classified as frail, pre-frail and non-frail. Patient characteristics and outcomes were analyzed using ANOVA or Kruskal-Wallis test for continuous variables and Chi square or Fisher's exact test for proportions. A generalized estimating equations (GEEs) regression model was used to assess the association between patients' baseline frailty status and PROMs measures at three and 12 months. 293 patients were included with a mean age of 67 ± 7 years. Twenty-two percent of the patients (n= 65) were frail, 59 % (n=172) were pre-frail and 19% (n=56) were non-frail. At baseline, the three groups had similar PROMS, except for the PCS which was worse in the frail group (mean difference [95% CI], −4.9 [−8.6;-1.1], p= 0.0083). The improvement in the EQ-5D, PCS, MCS, ODI, back and leg pain NRS scores was not significantly different between the three groups (p> 0.05). The was no difference in the evolution of the PROMS at three and 12 months between the three groups (p> 0.05). Although frailty is a known predictor of AEs, it does not predict worse PROMS after spine surgery in that population. At baseline, non-frail, pre-frail and frail patients have similar PROMS

INTRODUCTION. Tibiofemoral contact at the base of the articular surface spine in posterior-stabilized total knee arthroplasty (TKA) implants can lead to spine fracture [1]. Revision TKA implants also have an articular surface spine to provide sufficient constraint when soft tissues are compromised. While some revision TKA designs have metal reinforcement in the articular surface spine, others rely solely on a polyethylene spine. This study used finite element analysis (FEA) to study the effect of metal reinforcement on stresses in the spine when subjected to posteriorly directed loading. METHODS. Two clinically successful Zimmer Biomet revision TKA designs were selected; NexGen LCCK with metal reinforcement and all-poly Vanguard SSK. The largest sizes were selected. FEA models consisted of the polyethylene articular surface and a CoCr femoral component; LCCK also included a CoCr metal reinforcement in the spine. A 7° and 0° tibial slope, as well as 3° and 0.7° femoral hyperextension, were used for the LCCK and SSK, respectively. A posteriorly directed load was applied to the spine through the femoral component (Figure 1). The base of the articular surface was constrained. The articular surfaces for both designs are made from different polyethylene materials. However, for the purpose of this study, to isolate the effect of material differences on stresses, both were modeled using conventional GUR1050 nonlinear polyethylene material properties. Femoral component and metal reinforcement were modeled using linear elastic CoCr properties. Additionally, the LCCK was reanalyzed by replacing the metal reinforcement component with polyethylene material, in order to isolate the effect of metal reinforcement for an otherwise equivalent design. Frictional sliding contact was modeled between the spine and femoral/metal reinforcement components. Nonlinear static analyses were performed using Ansys version 17 software and peak von mises stresses in the spine were compared. RESULTS. Peak von mises stresses were predicted towards the base of the anterior aspect of the spine in both designs (Figure 2). In LCCK, the high stresses were also predicted on the medial and lateral edges of the anterior spine, matching the tibiofemoral contact (Figure 3). The LCCK with metal reinforcement design predicted 14% and 31% lower stress than LCCK and SSK all-poly designs. DISCUSSION. Clinical reports of spine fracture in TKA highlight the need for further understanding of the biomechanics of spine loading. Here, through comparison of two clinically successful devices, the effect of multiple design factors was quantified. Inclusion of metal reinforcement in the spine, as well as differences in the conforming geometry between the femoral component and the articular surface, resulted in a 31% decrease in polyethylene stress for the LCCK as compared to the all-poly SSK; of which only 16% was attributed to the metal reinforcement. Further improvements to articular surface design, as well as polyethylene material advances, have the potential to result in all-poly designs with strength characteristics equivalent to or exceeding those of designs with metal reinforcement

Symptomatic lumbar spinal stenosis is a common entity and increasing in prevalence. Limited evidence is available regarding patient reported outcomes comparing primary vs revision surgery for those undergoing lumbar decompression, with or without fusion. Evidence available suggest a lower rate of improvement in the revision group. The aim of this study was to assess patient reported outcomes in patients undergoing revision decompression, with or without fusion, when compared to primary surgery. Patient data was collected from the Canadian Spine Outcomes Research Network (CSORN) database. Patients undergoing lumbar decompression without or without fusion were included. Patients under 18, undergoing discectomy, greater than two level decompressions, concomitant cervical or thoracic spine surgery were excluded. Demographic data, smoking status, narcotic use, number of comorbidities as well as individual comorbidities were included in our propensity scores. Patients undergoing primary vs revision decompression were matched in a four:one ratio according to their scores, whilst a separate matched cohort was created for those undergoing primary vs revision decompression and fusion. Continuous data was compared using a two-tailed t-test, whilst categorical variables were assessed using chi-square test. A total of 555 patients were included, with 444 primary patients matched to 111 revision surgery patients, of which 373 (67%) did not have fusion. Patients undergoing primary decompression with fusion compared to revision patients were more likely to answer yes to “feel better after surgery” (87.8% vs 73.8%, p=0.023), “undergo surgery again” (90.1% vs 76.2%, P=0.021) and “improvement in mental health” (47.7% vs 28.6%, p=0.03) at six months. There was no difference in either of these outcomes at 12 or 24 months. There was no difference between the groups ODI, EQ-5D, SF 12 scores at any time point. Patients undergoing primary vs revision decompression alone showed no difference in PROMs at any time point. In a matched cohort, there appears to be no difference in improvement in PROMS between patients undergoing primary vs revision decompression, with or without fusion, at two year follow-up. This would suggest similar outcomes can be obtained in revision cases

Abstract. Aim. With resumption of elective spine surgery services following the first wave of COVID-19 pandemic, we conducted a multi-centre BASS collaborative study to examine the clinical outcomes of surgeries. Methods. Prospective data was collected from eight spinal centres in the first month of operating following restoration of elective spine surgery following the first wave. Primary outcomes measures were the 30-day mortality rate and postoperative Covid-19 infection rate. Secondary outcomes analysed were the surgical, medical adverse events and length of inpatient stay. Results. 257 patients (128 Male) with an age range of 2–88 years formed the study cohort. The average workload from each unit was 32(range 16–101) with 118 procedures (46%) done as category 3 prioritisation level (Procedures performed in < 3 month). 87% of patients were low-medium “risk stratification” category. 195 patients (75.8%) isolated for two weeks preoperatively and all but four patients had COVID-19 negative test prior to surgery. None of the patients were diagnosed with COVID-19 infection nor was any mortality related to COVID-19 in the 30 day follow up period, with 25 patients having been tested for symptoms. 32 patients (12%) developed a total of 34 complications with 19/34 being grade 1–2 Clavien-Dindo classification of surgical complications. Median LOS 5.2 days and 78.4 % patients stayed less than a week. Conclusions. As per our study safe and effective planned spinal surgical services can be restored avoiding viral transmission, with adherence to national guidelines and COVID-secure pathways tailored according to the resources of the individual spinal units

The Bernese periacetabular osteotomy (PAO) is a well-established procedure in the management of symptomatic hip dysplasia. The associated Smith-Petersen exposure offers excellent visualization of the acetabulum and control of acetabular osteotomy and mobilization. The traditional exposure of the true pelvis involves osteotomy of the iliac wing in order to mobilize the sartorial and inguinal ligament insertion. However, full osteotomy of the iliac spine may necessitate screw fixation if a relatively large segment of bone is included. A known complication with screw fixation of the iliac wing osteotomy involves failure of fixation and screw back out. Moreover, the screw may be irritative to the patient even in the setting of adequate fixation. A larger osteotomy may also injure the lateral femoral cutaneous nerve as it travels near the anterior superior spine. To minimize the risk of these potential complications, a wafer osteotomy may be used to develop a sleeve of tissue involving the sartorial insertion. Markings may be made so that the curvilinear incision is centered about the anterior-superior iliac spine (ASIS). The sartorial sleeve also mobilizes the entirety of the lateral femoral cutaneous nerve medially as it runs and branches to varying degrees in a fatty tissue layer in the tensor-sartorius interval directly beneath the subcutaneous layer, thereby affording protection throughout the procedure. When the ASIS is first osteotomized as a several millimeter-thick mobile fragment and reflected, the sartorius attachment to the mobile fragment of the wafer osteotomy may be preserved. Furthermore, the wafer osteotomy may be re-fixed to the stable pelvis during closure with simple heavy suture fixation alone, avoiding screw insertion or associated removal. Because only a wafer or bone is taken during the spine osteotomy, more bone is available at the ASIS for fixation of the mobile fragment after repositioning. In this technical note, we describe the wafer osteotomy technique in further detail. For any figures or tables, please contact authors directly