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 ), an extant online tool which we have shown in unpublished work to be valid in our local population.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

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

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

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

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

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

Resident involvement in the operating room is a vital component of their medical education. Conflicting and limited research exists regarding the effects of surgical resident participation on spine surgery patient outcomes. Our objective was to determine the effect of resident involvement on surgery duration, length of hospital stay and 30-day post-operative complication rates. This study was a multicenter retrospective analysis of the prospectively collected American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database. All anterior cervical or posterior lumbar fusion surgery patients were identified. Patients who had missing trainee involvement information, surgery for cancer, preoperative infection or dirty wound classification, spine fractures, traumatic spinal cord injury, intradural surgery, thoracic surgery and emergency surgery were excluded. Propensity score for risk of any complication was calculated to account for baseline characteristic differences between the attending alone and trainee present group. Multivariate logistic regression was used to investigate the impact of resident involvement on surgery duration, length of hospital stay and 30 day post-operative complication rates. 1441 patients met the inclusion criteria: 1142 patients had surgeries with an attending physician alone and 299 patients had surgeries with trainee involvement. After adjusting using the calculated propensity score, the multivariate analysis demonstrated that there was no significant difference in any complication rates between surgeries involving trainees compared to surgeries with attending surgeons alone. Surgery times were found to be significantly longer for surgeries involving trainees. To further explore this relationship, separate analyses were performed for tertile of predicted surgery duration, cervical or lumbar surgery, instrumentation, inpatient or outpatient surgery. The effect of trainee involvement on increasing surgery time remained significant for medium predicted surgery duration, longer predicted surgery duration, cervical surgery, lumbar surgery, lumbar fusion surgery and inpatient surgery. There were no significant differences reported for any other factors. After adjusting for confounding, we demonstrated in a national database that resident involvement in surgeries did not increase complication rates, length of hospital stay or surgical duration of more routine surgical cases. We found that resident involvement in surgical cases that were generally more complexed resulted in increased surgery time. Further study is required to determine the relationship between surgery complexity and the effect of resident involvement on surgery duration

Post-operative infection is a serious complication of spine surgery and can contribute to the strain on the healthcare system's resources. The purpose of this study is to determine what factors affect the risk of developing postoperative infection. We hypothesize that female gender, smoking, diabetes, having thoracolumbar procedures, having a neurological deficit, increased age, body mass index (BMI), American Society of Anaesthesiologists (ASA) score, blood loss, number of operative levels, operative time and undergoing non-elective surgery will increase the patients' risk of developing a post-operative infection. A retrospective review of prospectively collected data within the Canadian Spine Outcome and Research Network (CSORN) was conducted. Data was analyzed using IBM-SPSS. Multivariable logistical regression analysis was conducted (odds ratios) to determine any association between the outcome and independent factors. Significance level was p < 0.05. There were 7747 patients identified from the registry that had completed at least 12 weeks of follow up. There were 199 infections recorded representing a 2.6% risk of infection. There were no association found between the risk of developing a post operative infection and gender, smoking, diabetes, having thoracolumbar procedures, having a neurological deficit, ASA score, blood loss, number of operative levels and undergoing non-elective surgery. The following were associated with an increased risk of developing a post operative infection: Older age (adjusted OR=1.021, 95% CI=1.005–1.038, p < 0 .05), having an elevated BMI (adjusted OR=1.042, 95% CI=1.013–1.072, p < 0 .005), longer operative time (adjusted OR=1.002, 95% CI=1.001–1.004, p < 0 .001). There is a 2.6% overall rate of post-operative spine infection across 20 Canadian centres. The factors that were associated with an increased risk of developing a post operative-infection were older age, increased BMI and longer operative time. This study establishes a benchmark against which the effectiveness of future interventions to reduce infection can be compared

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

In orthopaedic spine surgery pedicle screw systems are used for stabilisation of the spine after injuries or disorders. With an percutaneous operation method surgeons are faced with huge challenges compared to an open surgery, but it's less traumatic and the patient benefits with a faster rehabilitation and less traumatic injuries. The screw positions and the required rod dimensions for the stabilising connection between the screws are hard to define without an open view on the operating field. Because of these facts a new smart device based system for rod shape determination was invented. Therefore, an application was developed, which integrates a localiser module to get the position data of the pedicle screws, with help of rigid bodies placed on top of the pedicle screws down-tubes. An algorithm was developed to choose the best fitting rod to connect the pedicle screws with help of calculating the rod length and the rod radius. The system was tested in a test scenario where four pedicle screws were drilled into a wooden plate. The positions of the screws were adjusted to fit a curved and a straight rod. In the test scenario the application chose always the rod correctly

Inserting screws into the vertebral pedicles is a challenging step in spinal fusion and scoliosis surgeries. Errors in placement can lead to neurological complications. The more experienced the surgeon, the better the accuracy of the screw placement. A physical training system would provide residents with the feel of performing pedicle cannulation before operating on a patient. The proposed system consists of realistic bone models mimicking the geometry and material properties of typical patients, coupled with a force feedback probe. The purpose of the present study was to determine the forces encountered during pedicle probing to aid in the development of this training system. We performed two separate investigations: [1] 15 participants (9 expert surgeons, 3 fellows and 3 residents) were asked to press a standard pedicle awl three times onto a mechanical scale, blinded to the force, demonstrating what force they would apply during safe pedicle cannulation and during unsafe cortical breach; [2] three experienced surgeons used a standard pedicle awl fitted with a one-degree of freedom load cell to probe selected thoracolumbar vertebrae of eight cadaveric specimens to measure the forces required during pedicle cannulation and deliberate breaching. A total of 42 pedicles were tested. Both studies had wide variations in the results, but were in general agreement. Cannulation (safe) forces averaged approximately 90 N (20 lb) whereas breach (unsafe) forces averaged approximately 135–155 N (30–35 lb). The lowest average forces in the cadaveric study were for pedicle cannulation, averaging 86 N (range, 23–125 N), significantly lower (p<0.001) than for anterior breach (135 N; range, 80–195 N); medial breach (149 N; range, 98–186 N) and lateral breach (157 N; range, 114–228 N). There were no significant differences between the breach forces (p>0.1). Cannulation forces were on average 59% of the breach forces (range, 19–84%) or conversely, breach forces were 70% higher than cannulation forces. To our knowledge, these axial force data are the first available for pedicle cannulation and breaching. A large range of forces was measured, as is experienced clinically. Additional testing is planned with a six-degree-of-freedom load cell to determine all of the forces and moments involved in cannulation and breaching, throughout the thoracolumbar spine. These results will inform the development of a realistic bone model as well as a breach prediction algorithm for a physical training system for spine surgery

Revision surgery and surgery in previously operated areas are associated with an increased infection risk. In such situations, aggressive surgical debridement may be necessary to control and eradicate the infection. Full thickness defects resulting from such debridement present as a challenge. In most cases, an association of various methods, both surgical and non-surgical, is necessary.

Our goal is to describe the use of vaccum dressings as an effective way to deal with extensive and infected dorsolumbar surgical defects, while avoiding the use of myocutaneous flaps.

This is a retrospective and descriptive case report based on data from clinical records, patient observation and analysis of complementary exams.

We present the case of a 57-years-old obese woman with prior history of double approach with posterior instrumentation and spine arthrodesis (D3 to L4) due to severe dorsolumbar adolescent idiopathic scoliosis. She presented to our consult 42 years after surgery, complaining of lower back pain. Clinical observation and imaging exams demonstrated degenerative disc disease in L5-S1 and L5 anterolisthesis. There was also distal instrumentation breakage (right L4 pedicular screw and contralateral rod) with pseudarthrosis suspicion.

Distal instrumentation was removed and no pseudarthrosis was found. Therefore, posterior instrumentation and arthrodesis was performed, from L4 to S1. Surgery went without complications.

One week after surgery, patient developed fever and inflammatory signs at the surgical incision, with purulent oozing. Escherichia coli and Proteus mirabilis were identified as the causative agents.

Decision was made to remove both lumbar and distal dorsal instrumentation and perform aggressive debridement and lavage, with debridement surgery being repeated twice. Finally, a full thickness defect with approximately 20cm long and 6cm wide resulted from the debridement.

A vacuum dressing was then applied, for 5 weeks, with progressive decrease in clinical and analytical inflammatory parameters and wound closure.

Four months after the initial surgery, patient was discharged with complete defect closure and reepithelialization.

This dressing technique provided a sound solution for defect resolution, as well as an important aid for infection control. It proved to be a viable option in an extensive defect, when surgical flap techniques and traditional dressing techniques could not provide a complete solution.

Introduction

We report a single-centre, prospective, randomised study for pedicle screw insertion, by using a Computer Assisted Surgery (CAS) technique with three dimension (3D) intra-operative images intensifier versus conventional surgical procedure.

While image guidance and neuro-navigation have enabled a more accurate positioning of pedicle implants, robot-assisted placement of pedicle screws appears to overcome the disadvantages of the two first systems. However, recent data concerning the superiority of robots currently available to assist spinal surgeons in the accurate positioning of implants are conflicting. The aim of our study was to evaluate the percentage of accurate positioning of pedicle screws inserted using a new robotic-guidance system.

Patients were operated on successively by the same surgeon using robotic-assistance (RA; n=40) or by the freehand conventional technique (FH; n=54). Ten and eleven patients from the robot (RG) and freehand (FHG) groups respectively, age-matched and all suffering from degenerative lumbar spine disease were compared. Patient characteristics as well as the duration of the operation and of exposure to X-rays were recorded. The Gertzbein Robbins classification was used to evaluate implant placement. Data wer compared between the groups. Pedicle screw placement in RG patients was achieved using the ROSA™ (Medtech) robot comprising a compact robotic arm on a floor-fixable mobile base. By permanently monitoring the patient's movements, this image-guided tool helps more accurately to pinpoint the pedicle entry point and to control the trajectory.

The mean age of patients in each group (RG and FHG) was 63 years. Mean BMI and operating time among the RG and FHG were respectively 26 and 27 kg/m², and 187 and 119 min. Accurate placement of the implant (score A-B) was achieved in 97.2% of patients in the RG (n=36) and in 92.6% of those in the FHG (n=54). Four implants in the RG were placed manually following failed robotic assistance. The mean duration of X-ray exposure per patient was 1 min 42s in the RG and 41s in the FHG.

We report a higher rate of accuracy with robotic assistance as compared to the FH technique. Exposure time was greater in the RG partly due to the fluoroscopic control of the implants required for this pilot study of feasibility. Limitations of the study include its small sized and non-randomised sample. Nevertheless, these preliminary results are encouraging for the development of new robotic techniques for spinal surgery.

Cervical spine fusion have gained interest in the literature since these procedures are now ever more frequently being performed in an outpatient setting with few complications and acceptable results. The purpose of this study was to assess the rate of blood transfusion after cervical fusion surgery, and its effect, if any on complication rates.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent cervical fusion surgery from 2010 to 2013. Univariate and multivariate regression analysis was used to determine post-operative complications associated with transfusion and cervical fusion.

We identified 11,588 patients who had cervical spine fusion between 2010 and 2013. The overall rate of transfusion was found to be 1.47%. All transfused patients were found to have increased risk of: venous thromboembolism (TBE) (OR 3.19, CI: 1.16–8.77), myocardial infarction (MI) (OR 9.12, CI: 2.53–32.8), increased length of stay (LOS) (OR 28.03, CI: 14.28–55.01) and mortality (OR 4.14, CI: 1.44–11.93). Single level fusion had increased risk of: TBE (OR 3.37, CI: 1.01–11.33), MI (OR 10.5, CI: 1.88–59.89), and LOS (OR 14.79, CI: 8.2–26.67). Multilevel fusion had increased risk of: TBE (OR 5.64, CI: 1.15–27.6), surgical site infection (OR 16.29, CI: 3.34–79.49), MI (OR 10.84, CI: 2.01–58.55), LOS (OR 26.56, CI: 11.8–59.78) and mortality (OR 10.24, CI: 2.45–42.71). ACDF surgery had an increased risk of: TBE (OR 4.87, CI: 1.04–22.82), surgical site infection (OR 9.73, CI: 2.14–44.1), MI (OR 9.88, CI: 1.87–52.2), LOS (OR 28.34, CI: 13.79–58.21) and mortality (OR 6.3, CI: 1.76–22.48). Posterior fusion surgery had increased risk of: MI (OR 10.45, CI: 1.42–77.12) and LOS (OR 4.42, CI: 2.68–7.29).

Our results demonstrate that although cervical fusions can be done as outpatient procedures special precautions and investigations should be done for patients who receive transfusion after cervical fusion surgery. These patients are demonstrated to have higher rate of MI, DVT, wound infection and mortality when compared to those who do not receive transfusion.

We reported the first single surgeon series comparing outcome of microscopic and open primary single level unilateral lumbar decompression or discectomy. We aimed to determine any difference in outcomes between the two techniques.

Forty-six decompressions were performed with use of an operating microscope (microscopic), and forty without (open) at two different hospitals. All procedures were performed by the senior author. Information was obtained by analysis of the patients' notes. The average age of the patients in both groups was comparable. Operating time was shorter in the microscopic group (68min, range 30-130) compared to the open group (83 mins, range 30-180). Dural tear rate was 4.3% with use of a microscope (0% symptomatic dural tear rate) and 7.5% without (2.5% symptomatic dural tear rate). Nerve damage incidence was 0% with use of a microscope and 5% (two patients) without. One of these was a neurapraxia and the patient made a full recovery. Wound infection rates, diagnosed on grounds of clinical suspicion, were 4.3% and 2.5% for microscopic and open respectively. There were no incidences of deep infection or post-operative discitis. Average inpatient stay was under 48 hours in both groups.

Using the modified Macnab criteria, results using the microscope were 0% poor, 14% fair, 32% good, and 55% excellent. The results for the open group were 0% poor, 10% fair, 37% good and 53% excellent. Average follow-up was six months (1-19) for the microscope group, and seven months (2-16) for the open group.

We conclude that primary single level unilateral lumbar decompressive surgery, performed without the use of a microscope, has a higher dural tear rate than the same surgery performed with the benefit of an operating microscope. Surgical time and incidence of nerve damage are also reduced by use of the microscope.

The purpose of this study is to determine whether the mode of anaesthesia chosen for patients undergoing lumbar microdiscectomy surgery has any significant influence on the immediate outcome in terms of safety, efficacy or patient satisfaction.

This prospective randomised study compared safety, efficacy and satisfaction levels in patients having spinal versus general anaesthesia for single level lumbar microdiscectomy.

Fifty consecutive healthy and cooperative patients were recruited and prospectively randomised into two equal groups; half the patients received a spinal anaesthetic (SA), the remainder a general anaesthetic (GA). Each specific mode of anaesthesia was standardised.

Comprehensive post-operative evaluation concentrated on documenting any complications specific to the particular mode of anaesthesia, recording the pace at which the various milestones of physiological and functional recovery were reached, and the level of patient satisfaction with the type of anaesthesia used.

The results showed no serious complication specific to their particular mode of anaesthesia in either group. Thirteen out of 25 SA patients required temporary urinary catheterisation (9 males, 4 females) while among the GA group 4 patients required urinary catheterisation (4 males and 1 female). Post-operative pain perception was significantly lower in the SA group. The SA patients achieved the milestones of physiological and functional recovery more rapidly. While both groups were satisfied with their procedure, the level of satisfaction was significantly higher in the SA group.

In conclusion, lumbar spinal microdiscectomy can be carried out with equal safety, employing either spinal or general anaesthesia. While they require more temporary urinary catheterisation associated with the previous use of intrathecal morphine, patients undergoing SA suffer less pain in association with their procedure and recover more rapidly. Blinded to an extent by not having experienced the alternative, both groups appeared satisfied with their anaesthetic. However, the level of satisfaction was significantly higher in the SA group.

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

Pain management in spine surgery can be challenging. Cannabis might be an interesting choice for analgesia while avoiding some side effects of opioids. Recent work has reported on the potential benefits of cannabinoids for multimodal pain control, but very few studies focus on spinal surgery patients. This study aims to examine demographic and health status differences between patients who report the use of (1) cannabis, (2) narcotics, (3) cannabis and narcotics or (4) no cannabis/narcotic use. Retrospective cohort study of thoracolumbar patients enrolled in the CSORN registry after legalization of cannabis in Canada. Variables included: age, sex, modified Oswestry Disability Index (mODI), Numerical Rating Scales (NRS) for leg and back pain, tingling/numbness leg sensation, SF-12 Quality of Life- Mental Health Component (MCS), Patient Health Questionnaire (PHQ-9), and general health state. An ANCOVA with pathology as the covariate and post-hoc analysis was run. The majority of the 704 patients enrolled (mean age: 59; female: 46.9%) were non-users (41.8%). More patients reported narcotic-use than cannabis-use (29.7% vs 12.9%) with 13.4% stating concurrent-use. MCS scores were significantly lower for patients with concurrent-use compared to no-use (mean of 39.95 vs 47.98, p=0.001) or cannabis-use (mean=45.66, p=0.043). The narcotic-use cohort had significantly worse MCS scores (mean=41.37, p=0.001) than no-use. Patients reporting no-use and cannabis-use (mean 41.39 vs 42.94) had significantly lower ODI scores than narcotic-use (mean=54.91, p=0.001) and concurrent-use (mean=50.80, p=0.001). Lower NRS-Leg pain was reported in cannabis-use (mean=5.72) compared to narcotic-use (mean=7.19) and concurrent-use (mean=7.03, p=0.001). No-use (mean=6.31) had significantly lower NRS-Leg pain than narcotic-use (p=0.011), and significantly lower NRS-back pain (mean=6.17) than narcotic-use (mean=7.16, p=0.001) and concurrent-use (mean=7.15, p=0.012). Cannabis-use reported significantly lower tingling/numbness leg scores (mean=4.85) than no-use (mean=6.14, p=0.022), narcotic-use (mean=6.67, p=0.001) and concurrent-use (mean=6.50, p=0.01). PHQ-9 scores were significantly lower for the no-use (mean=6.99) and cannabis-use (mean=8.10) than narcotic-use (mean=10.65) and concurrent-use (mean=11.93) cohorts. Narcotic-use reported a significantly lower rating of their overall health state (mean=50.03) than cannabis-use (mean=60.50, p=0.011) and no-use (mean=61.89, p=0.001). Patients with pre-operative narcotic-use or concurrent use of narcotics and cannabis experienced higher levels of disability, pain and depressive symptoms and worse mental health functioning compared to patients with no cannabis/narcotic use and cannabis only use. To the best of our knowledge, this is the first and largest study to examine the use of cannabis amongst Canadian patients with spinal pathology. This observational study lays the groundwork to better understand the potential benefits of adding cannabinoids to control pain in patients waiting for spine surgery. This will allow to refine recommendations about cannabis use for these patients