Canadian Spine Outcomes And Research Network Research Articles

Satisfaction in surgically treated patients with degenerative cervical myelopathy: an observational study from the canadian spine outcomes and research network

Background ContextHealthcare reimbursement is evolving towards a value-based model, entwined and emphasizing patient satisfaction. Factors associated with satisfaction after degenerative cervical myelopathy (DCM) surgery have not been previously established. PurposeOur primary objective was to ascertain satisfaction rates and satisfaction predictors at 3 and 12 months following surgical treatment for DCM. DesignThis is a prospective cohort study within Canadian Spine Outcomes and Research Network (CSORN). Patient SamplePatients in the study were surgically treated for DCM patients who completed 3-month and 12-month follow-ups within CSORN between 2015 and 2021. Outcome MeasuresData analyzed included patient demographic, surgical variables, patient-reported outcomes (NDI, NRS-NP, NRS-AP, SF-12-MCS, SF-12-PCS, ED-5Q, PHQ-8), MJOA and self-reported satisfaction on a Likert scale. MethodsMultivariable regression analysis was conducted to identify significant factors associated with satisfaction, address multicollinearity and ensure predictive accuracy. This process was conducted separately for the 3-month and 12-month follow-ups. ResultsSix hundred and sixty-three patients were included, with an average age of 60, and an even distribution across MJOA scores (mild, moderate, severe). At 3-month and 12-month follow-up, satisfaction rates were 86% and 82%, respectively. At 12 months, logistic regression showed the odds of being satisfied varied by +24%, −3%, −10%, −14%, +3%, and +12% for each 1-point change between baseline and 12 months in MJOA, NDI, NRS-NP, NRS-AP, SF-12-MCS, SF-12-PCS. Satisfaction increased 11-fold for each 0.1-point increased in ED-5Q from baseline to 12 months. At baseline, for every 1-point increase in SF-12-MCS, the odds of being satisfied increased by 7%. At 3 months, all PROs (except for NRS-AP change and baseline SF-12-MCS) predicted satisfaction. All logistic regression analyses demonstrated excellent predictive accuracy, with the highest 12-month AUC of 0.86 (95%CI = 0.81–0.90). No patient demographic or surgical factors influenced satisfaction. ConclusionImprovement in Patient Reported Outcomes and MJOA are strongly associated with patient satisfaction after surgery for DCM. The only baseline PRO associated with 12-months satisfaction was SF-12-MCS. No modifiable patient baseline characteristic or surgical variables were associated with satisfaction.

Factors associated with increased length of stay in degenerative cervical spine surgery: a cohort analysis from the Canadian Spine Outcomes and Research Network.

Postoperative length of stay (LOS) significantly contributes to healthcare costs and resource utilization. The primary goal of this study was to identify patient, clinical, surgical, and institutional variables that influence LOS after elective surgery for degenerative conditions of the cervical spine. The secondary objectives were to examine the variability in LOS and institutional practices used to decrease LOS. This was a multicenter observational retrospective cohort study of patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN) between January 2015 and October 2020 who underwent elective anterior cervical discectomy and fusion (ACDF) (1-3 levels) or posterior cervical fusion (PCF) (between C2 and T2) with/without decompression for degenerative conditions of the cervical spine. Prolonged LOS was defined as LOS greater than the median for the ACDF and PCF populations. The principal investigators at each participating CSORN healthcare institution completed a survey to capture institutional practices implemented to reduce postoperative LOS. In total, 1228 patients were included (729 ACDF and 499 PCF patients). The median (IQR) LOS for ACDF and PCF were 1.0 (1.0) day and 5.0 (4.0) days, respectively. Predictors of prolonged LOS after ACDF were female sex, myelopathy diagnosis, lower baseline SF-12 mental component summary score, multilevel ACDF, and perioperative adverse events (AEs) (p < 0.05). Predictors of prolonged LOS after PCF were nonsmoking status, education less than high school, lower baseline numeric rating scale score for neck pain and EQ5D score, higher baseline Neck Disability Index score, and perioperative AEs (p < 0.05). Myelopathy did not significantly predict prolonged LOS within the PCF cohort after multivariate analysis. Of the 8 institutions (57.1%) with an enhanced recovery after surgery (ERAS) protocol or standardized protocol, only 3 reported using an ERAS protocol specific to patients undergoing ACDF or PCF. Patient and clinical factors predictive of prolonged LOS after ACDF and PCF are highly variable, warranting individual consideration for possible mitigation. Perioperative AEs remained a consistent independent predictor of prolonged LOS in both cohorts, highlighting the importance of preventing intra- and postoperative complications.

Temporal analysis of complication rates of cervical spine surgery for degenerative spine disease between younger and older cohorts using the CSORN registry: Is age just a number?

An ambispective review of consecutive cervical spine surgery patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN) between January 2015 and September 2019. To compare complication rates of degenerative cervical spine surgery over time between older (> 65) and younger age groups (< 65). More elderly people are having spinal surgery. Few studies have examined the temporal nature of complications of cervical spine surgery by patient age groups. Adverse events were collected prospectively using adverse event forms. Binary logistic regression analysis was utilized to assess associations between risk modifiers and adverse events at the intra-, peri-operative and 3 months post-surgery. Of the 761 patients studied (age < 65, n = 581 (76.3%) and 65 + n = 180 (23.7%), the intra-op adverse events were not significantly different; < 65 = 19 (3.3%) vs 65 + = 11 (6.1%), p < 0.087. Peri-operatively, the < 65 group had significantly lower percentage of adverse events (65yrs (11.2%) vs. 65 + = (26.1%), p < 0.001). There were no differences in rates of adverse events at 3months post-surgery (< 65 = 39 (6.7%) vs. 65 + = 12 (6.7%), p < 0.983). Less blood loss (OR = 0.99, p < 0.010) and shorter length of hospital stay (OR = 0.97, p < 0.025) were associated with not having intra-op adverse events. Peri-operatively, > 1 operated level (OR = 1.77, p < 0.041), shorter length of hospital stay (OR = 0.86, p < 0.001) and being younger than 65years (OR = 2.11, p < 0.006) were associated with not having adverse events. Following degenerative cervical spine surgery, the older and younger age groups had significantly different complication rates at peri-operative time points, and the intra-operative and 3-month post-operative complication rates were similar in the groups.

Patient Selection Criteria in Ambulatory Spine Surgery: Single Canadian Provincial Experience

Ambulatory spinal surgery is a care delivery model meant to improve patient outcomes and reduce in-hospital length of stay (LOS). We reviewed the experience of implementing an outpatient spine surgery program in Manitoba, Canada and highlight elements that can be used to reduce LOS and re-presentation to hospital. This is a retrospective cohort study using data from the Canadian Spine Outcomes and Research Network and independent chart review of adult patients undergoing outpatient spinal surgery between 2015 and 2018. Patient demographics, comorbidities, perioperative course, LOS, and readmissions were analyzed. We included 217 patients in this analysis. The mean LOS was 36.2 hours; 71.98% of patients had a LOS <24 hours. A Kruskal-Wallis test by ranks analysis was conducted and identified 7 elements that correlated with prolonged length of stay (>1 day): age older than 55 (P= 0.027), body mass index >25 (P= 0.045), uncontrolled diabetes (P= 0.015), preoperative use of opioid medication (P= 0.024), American Society of Anesthesiologists classification of 3 (P= 0.023), non-minimally invasive surgical approach, and multilevel procedures. Most (94.1%) of the patients with none of these elements (i.e., age <55, low body mass index, normal/controlled diabetes, minimal preoperative opioid use, American Society of Anesthesiologist classification <3, minimally invasive surgical procedure) had a favorable LOS, <24 hours, compared with 84.8% with 1 risk factor, 80.4% of those with two, 69.8% with three, 53.1% with four, and 31.2% with 5 or more. A small number of patients (14.98%) presented to an emergency department within 90 days of their operation, and there was a 6.28% readmission rate. We identified several patient and surgical criteria that correlate with prolonged length of stays following planned ambulatory spine surgery. Our work provides some empiric evidence to help guide surgeons on which patients and approaches are ideal for ambulatory surgery.

Functional outcomes correlate with sagittal spinal balance in degenerative lumbar spondylolisthesis surgery

BACKGROUND CONTEXTDegenerative lumbar spondylolisthesis (DLS) is a debilitating condition associated with poor preoperative functional status. Surgical intervention has been shown to improve functional outcomes in this population though the optimal surgical procedure remains controversial. The importance of maintaining and/or improving sagittal and pelvic spinal balance parameters has received increasing interest in the recent DLS literature. However, little is known about the radiographic parameters most associated with improved functional outcomes among patients undergoing surgery for DLS. PURPOSETo identify the effect of postoperative sagittal spinal alignment on functional outcome after DLS surgery. STUDY DESIGNRetrospective cohort study. PATIENT SAMPLETwo-hundred forty-three patients in the Canadian Spine Outcomes and Research Network (CSORN) prospective DLS study database. OUTCOME MEASURESBaseline and 1-year postoperative leg and back pain on the 10-point Numeric Rating Scale and baseline and 1-year postoperative disability on the Oswestry Disability Index (ODI). METHODSAll enrolled study patients had a DLS diagnosis and underwent decompression in isolation or with posterolateral or interbody fusion. Global and regional radiographic alignment parameters were measured at baseline and 1-year postoperatively including sagittal vertical axis (SVA), pelvic incidence and lumbar lordosis (LL). Both univariate and multiple linear regression was used to assess for the association between radiographic parameters and patient-reported functional outcomes with adjustment for possible confounding baseline patient factors. RESULTSTwo-hundred forty-three patients were available for analysis. Among participants, the mean age was 66 with 63% (153/243) female with the primary surgical indication of neurogenic claudication in 197/243 (81%) of patients. Worse pelvic incidence-LL mismatch was correlated with more severe disability [ODI, 0.134, p<.05), worse leg pain (0.143, p<.05) and worse back pain (0.189, p<.001) 1-year postoperatively. These associations were maintained after adjusting for age, BMI, gender, and preoperative presence of depression (ODI, R2 0.179, β, 0.25, 95% CI 0.08, 0.42, p=.004; back pain R2 0.152 (β, 0.05, 95% CI 0.022, 0.07, p<.001; leg pain score R2 0.059, β, 0.04, 95% CI 0.008, 0.07, p=.014). Likewise, reduction of LL was associated with worse disability (ODI, R2 0.168, β, 0.04, 95% CI -0.39, -0.02, p=.027) and worse back pain (R2 0.135, β, -0.04, 95% CI -0.06, -0.01, p=.007). Worsened SVA correlated with worse patient reported functional outcomes (ODI, R2 0.236, β, 0.12, 95% CI 0.05, 0.20, p=.001). Similarly, an increase (worsening) in SVA resulted in a worse NRS back pain (R2 0.136, β, 0.01, 95% CI .001, 0.02, p=.029) and worse NRS leg pain (R2 0.065, β, 0.02, 95% CI 0.002, 0.02, p=.018) scores regardless of surgery type. CONCLUSIONSPreoperative emphasis on regional and global spinal alignment parameters should be considered in order to optimize functional outcome in lumbar degenerative spondylolisthesis treatment.

Determining minimal clinically important difference estimates following surgery for degenerative conditions of the lumbar spine: analysis of the Canadian Spine Outcomes and Research Network (CSORN) registry

BACKGROUND CONTEXTThere is significant variability in minimal clinically important difference (MCID) criteria for lumbar spine surgery that suggests population and primary pathology specific thresholds may be required to help determine surgical success when using patient reported outcome measures (PROMs). PURPOSEThe purpose of this study was to estimate MCID thresholds for 3 commonly used PROMs after surgical intervention for each of 4 common lumbar spine pathologies. STUDY DESIGN/SETTINGObservational longitudinal study of patients from the Canadian Spine Outcomes and Research Network (CSORN) national registry. PATIENT SAMPLEPatients undergoing surgery from 2015 to 2018 for lumbar spinal stenosis (LSS; n = 856), degenerative spondylolisthesis (DS; n = 591), disc herniation (DH; n = 520) or degenerative disc disease (DDD n = 185) were included. OUTCOME MEASURESPROMs were collected presurgery and 1-year postsurgery: the Oswestry Disability Index (ODI), and back and leg Numeric Pain Rating Scales (NPRS). At 1-year, patients reported whether they were ‘Much better’/’Better’/’Same’/’Worse’/’Much worse’ compared to before their surgery. Responses to this item were used as the anchor in analyses to determine surgical MCIDs for benefit (‘Much better’/‘Better’) and substantial benefit (‘Much better’). METHODSMCIDs for absolute and percentage change for each of the 3 PROMs were estimated using a receiving operating curve (ROC) approach, with maximization of Youden's index as primary criterion. Area under the curve (AUC) estimates, sensitivity, specificity and correct classification rates were determined. All analyses were conducted separately by pathology group. RESULTSMCIDs for ODI change ranged from −10.0 (DDD) to −16.9 (DH) for benefit, and −13.8 (LSS) to −22.0 (DS,DH) for substantial benefit. MCID for back and leg NPRS change were −2 to −3 for each group for benefit and −4.0 for substantial benefit for all groups on back NPRS. MCID estimates for percentage change varied by PROM and pathology group, ranging from −11.1% (ODI for DDD) to −50.0% (leg NPRS for DH) for benefit and from −40.0% (ODI for DDD) to −66.6% (leg NPRS for DH) for substantial benefit. Correct classification rates for all MCID thresholds ranged from 71% to 89% and were relatively lower for absolute vs percent change for those with high or low presurgical scores. CONCLUSIONSOur findings suggest that the use of generic MCID thresholds across pathologies in lumbar spine surgery is not recommended. For patients with relatively low or high presurgery PROM scores, MCIDs based on percentage change, rather than absolute change, appear generally preferable. These findings have applicability in clinical and research settings, and are important for future surgical prognostic work.

Patient, clinical, surgical, and institutional factors associated with length of stay in scheduled degenerative thoracolumbar spine surgery: National Multicenter Cohort Analysis from the Canadian Spine Outcomes and Research Network.

Length of stay (LOS) is a contributor to costs and resource utilization. The primary goal of this study was to identify patient, clinical, surgical, and institutional variables that influence LOS after elective surgery for thoracolumbar degenerative pathology. The secondary objective was to examine variability in LOS and institutional strategies used to decrease LOS. This is a retrospective study of prospectively collected data from a multicentric cohort enrolled in the Canadian Spine Outcomes and Research Network (CSORN) between January 2015 and October 2020 who underwent elective thoracolumbar surgery (discectomy [1 or 2 levels], laminectomy [1 or 2 levels], and posterior instrumented fusion [up to 5 levels]). Prolonged LOS was defined as LOS greater than the median. Logistic regression models were used to determine factors associated with prolonged LOS for each procedure. A survey was sent to the principal investigators of the participating healthcare institutions to understand institutional practices that are used to decrease LOS. A total of 3700 patients were included (967 discectomies, 1094 laminectomies, and 1639 fusions). The median LOSs for discectomy, laminectomy, and fusion were 0.0 (IQR 1.0), 1.0 (IQR 2.0), and 4.0 (IQR 2.0) days, respectively. On multivariable analysis, predictors of prolonged LOS for discectomy were having more leg pain, higher Oswestry Disability Index (ODI) scores, symptom duration more than 2 years, having undergone an open procedure, occurrence of an adverse event (AE), and treatment at an institution without protocols to reduce LOS (p < 0.05). Predictors of prolonged LOS for laminectomy were increased age, living alone, higher ODI scores, higher BMI, open procedures, longer operative time, AEs, and treatment at an institution without protocols to reduce LOS (p < 0.05). For posterior instrumented fusion, predictors of prolonged LOS were older age, living alone, more comorbidities, higher ODI scores, longer operative time, AEs, and treatment at an institution without protocols to reduce LOS (p < 0.05). The laminectomy group had the largest variability in LOS (SD 4.4 days, range 0-133 days). Three hundred fifty-four patients (22%) had an LOS above the 75th percentile. Ten institutions (53%) had either Enhanced Recovery After Surgery or standardized protocols in place. Among the factors identified in this study, worse baseline ODI scores, experiencing AEs, and treatment at an institution without protocols aimed at reducing LOS were predictive of prolonged LOS in all surgical groups. The laminectomy group had the largest variability in LOS.

Patient's expectations of surgery for lumbar degenerative spondylolisthesis: analysis by type of surgery and patient factors from the Canadian Spine Outcomes and Research Network (CSORN)

BACKGROUND CONTEXTPreoperative expectations influence postoperative outcomes. Patients with lumbar degenerative spondylolisthesis have especially high expectations of pain relief and overall functional well-being compared to patients with lumbar stenosis. PURPOSEThe primary objective was to analyze preoperative expectations of lumbar DS patients with respect to the type of surgery proposed (decompression vs decompression and fusion). Secondarily, we aimed to assess the associations between preoperative expectations and patient and clinical factors as well as postoperative expectations fulfillment. STUDY DESIGN/SETTINGPatients were prospectively enrolled in a multicenter, prospective cohort study evaluating the assessment and management of degenerative spondylolisthesis utilizing the infrastructure of the Canadian Spine Outcomes and Research Network (CSORN) surgical registry. PATIENT SAMPLEPatients with a diagnosis of degenerative spondylolisthesis with symptoms of neurogenic claudication or radiculopathy with or without back pain, unresponsive to nonoperative management over at least 3 months were included. Patients who underwent decompression, decompression and posterolateral fusion or decompression and interbody fusion at Canadian spine centers between January 2015 and September 2021 were included. OUTCOME MEASURESThe North American Spine Society Lumbar Spine Questionnaire was utilized for expectations measurement. The expectation questionnaire was completed following consent and before surgery and at 1 year. METHODSExpectations for pain relief and improvements in overall functional well-being were rated on a scale of 0 to 100. Preoperative expectation in terms of pain relief and functional well-being score were calculated. Multivariate linear regression was used to evaluate the association between expected preoperative patient factors and pain relief and functional well-being. The factors associated with the most important expectation were evaluated using multivariable multinomial logistic regression. RESULTSThree hundred fifty-two patients were included with 100 patients undergoing decompression and 252 patients also undergoing fusion. The seven items of preoperative expectations did not differ between the procedure groups nor did expected change. The mean pain relief and overall functional well-being expectation scores did not significantly differ between procedures.Higher expectations were associated with having more comorbidities [β=-2.0 (SE 0.8), p=.020], being physically active [β=8.4 (SE 3.2), p=.010] and having more leg pain [β=1.6 (SE 0.7), p=.015]. Better perceived physical health measured by SF12 PCS was associated with lower expectation of pain relief [β= -0.4 (SE 0.2), p=.039] and functional well-being [β=-0.84 (SE 0.2), p=.001]. Better perceived mental health measured by SF12 MCS was associated with lower expectation of functional well-being [β=-0.8 (SE 0.2), p=.001].Postoperative expectations fulfillment did not differ between procedures. CONCLUSIONPreoperative expectations in terms of pain relief and functional well-being were similar between the two most common procedures performed, decompression ± fusion. Secondarily, higher preoperative expectations were associated with greater pain, disability and being physically active. Expectations fulfillment did not differ between procedures.

Canadian Spine Society

# Abstract 57. Radiographic reporting in adolescent idiopathic scoliosis: Is there a discrepancy comparing radiologists’ reports and surgeons’ assessments? {#article-title-2} Cobb angle measurement is the standard method for quantification of scoliosis in adolescent idiopathic scoliosis (AIS),

Beneficial Effects of Preoperative Exercise on the Outcomes of Lumbar Fusion Spinal Surgery.

Purpose: To determine whether there was an association between self-reported preoperative exercise and postoperative outcomes after lumbar fusion spinal surgery. Method: We performed a retrospective multivariable analysis of the prospective Canadian Spine Outcomes and Research Network (CSORN) database of 2,203 patients who had elective single-level lumbar fusion spinal surgeries. We compared adverse events and hospital length of stay between patients who reported regular exercise (twice or more per week) prior to surgery ("Regular Exercise") to those exercising infrequently (once or less per week) ("Infrequent Exercise") or those who did no exercise ("No Exercise"). For all final analyses, we compared the Regular Exercise group to the combined Infrequent Exercise or No Exercise group. Results: After making adjustments for known confounding factors, we demonstrated that patients in the Regular Exercise group had fewer adverse events (adjusted odds ratio0.72; 95%CI: 0.57,0.91; p=0.006) and significantly shorter lengths of stay (adjusted mean2.2 vs. 2.5 d, p=0.029) than the combined Infrequent Exercise or No Exercise group. Conclusions: Patients who exercised regularly twice or more per week prior to surgery had fewer postoperative adverse events and significantly shorter hospital lengths of stay compared to patients that exercised infrequently or did no exercise. Further study is required to determine effectiveness of a targeted prehabilitation programme.

Effects of Workload on Return to Work After Elective Lumbar Spine Surgery.

Retrospective analysis was performed of a multi-center Canadian Spine Outcomes and Research Network (CSORN) surgical database. To determine the rate and time to return to work (RTW) based on workload intensity after elective degenerative lumbar spine surgery. Patients working pre-operatively, aged greater than 18, who underwent a primary one- or two-level elective lumbar spine surgery for degenerative conditions between January 2015 and October 2020 were evaluated. The percentage of patients who returned to work at 1year and the time to RTW post-operatively were analyzed based on workload intensity. Of the 1290 patients included in the analysis, the overall rate of RTW was 82% at 1 year. Based on workload there was no significant difference in time to RTW after a fusion procedure, with median time to RTW being 10 weeks. For non-fusion procedure, the sedentary group had a statistically significantly quicker time to RTW than the light-moderate (P < .005) and heavy-very heavy (<.027) groups. The rate of RTW ranged between 84% for patients with sedentary work to 77% for patient with a heavy-very heavy workload. Median time to resumption of work was about 10weeks following a fusion regardless of work intensity. There was more variability following non-fusion surgeries such as laminectomy and discectomy reflecting the patient's job demands.

Time to return to work after elective lumbar spine surgery.

Time to return to work (RTW) after elective lumbar spine surgery is variable and dependent on many factors including patient, work-related, and surgical factors. The primary objective of this study was to describe the time and rate of RTW after elective lumbar spine surgery. Secondary objectives were to determine predictors of early RTW (< 90 days) and no RTW in this population. A retrospective analysis of prospectively collected data from the multicenter Canadian Spine Outcomes and Research Network (CSORN) surgical registry was performed to identify patients who were employed and underwent elective 1- or 2-level discectomy, laminectomy, and/or fusion procedures between January 2015 and December 2019. The percentage of patients who returned to work and the time to RTW postoperatively were calculated. Predictors of early RTW and not returning to work were determined using a multivariable Cox regression model and a multivariable logistic regression model, respectively. Of the 1805 employed patients included in this analysis, 71% returned to work at a median of 61 days. The median RTW after a discectomy, laminectomy, or fusion procedure was 51, 46, and 90 days, respectively. Predictors of early RTW included male gender, higher education level (high school or above), higher preoperative Physical Component Summary score, working preoperatively, a nonfusion procedure, and surgery in a western Canadian province (p < 0.05). Patients who were working preoperatively were twice as likely to RTW within 90 days (HR 1.984, 95% CI 1.680-2.344, p < 0.001) than those who were employed but not working. Predictors of not returning to work included symptoms lasting more than 2 years, an increased number of comorbidities, an education level below high school, and an active workers' compensation claim (p < 0.05). There were fourfold odds of not returning to work for patients who had not been working preoperatively (OR 4.076, 95% CI 3.087-5.383, p < 0.001). In the Canadian population, 71% of a preoperatively employed segment returned to work after 1- or 2-level lumbar spine surgery. Most patients who undergo a nonfusion procedure RTW after 6 to 8 weeks, whereas patients undergoing a fusion procedure RTW at 12 weeks. Working preoperatively significantly increased the likelihood of early RTW.

National adverse event profile after lumbar spine surgery for lumbar degenerative disorders and comparison of complication rates between hospitals: a CSORN registry study.

Previous works investigating rates of adverse events (AEs) in spine surgery have been retrospective, with data collection from administrative databases, and often from single centers. To date, there have been no prospective reports capturing AEs in spine surgery on a national level, with comparison among centers. The Spine Adverse Events Severity system was used to define the incidence and severity of AEs after spine surgery by using data from the Canadian Spine Outcomes and Research Network (CSORN) prospective registry. Patient data were collected prospectively and during hospital admission for those undergoing elective spine surgery for degenerative conditions. The Spine Adverse Events Severity system defined minor and major AEs as grades 1-2 and 3-6, respectively. There were 3533 patients enrolled in this cohort. There were 85 (2.4%) individual patients with at least one major AE and 680 (19.2%) individual patients with at least one minor AE. There were 25 individual patients with 28 major intraoperative AEs and 260 patients with 275 minor intraoperative AEs. Postoperatively there were 61 patients with a total of 80 major AEs. Of the 487 patients with minor AEs postoperatively there were 698 total AEs. The average enrollment was 321 patients (range 47-1237 patients) per site. The rate of major AEs was consistent among sites (mean 2.9% ± 2.4%, range 0%-9.1%). However, the rate of minor AEs varied widely among sites-from 7.9% to 42.5%, with a mean of 18.8% ± 9.7%. The rate of minor AEs varied depending on how they were reported, with surgeon reporting associated with the lowest rates (p < 0.01). The rate of major AEs after lumbar spine surgery is consistent among different sites but the rate of minor AEs appears to vary substantially. The method by which AEs are reported impacts the rate of minor AEs. These data have implications for the detection and reporting of AEs and the design of strategies aimed at mitigating complications.

Low-back pain after lumbar discectomy for disc herniation: what can you tell your patient?

Lumbar discectomy (LD) is frequently performed to alleviate radicular pain resulting from disc herniation. While this goal is achieved in most patients, improvement in low-back pain (LBP) has been reported inconsistently. The goal of this study was to characterize how LBP evolves following discectomy. The authors performed a retrospective analysis of prospectively collected patient data from the Canadian Spine Outcomes and Research Network (CSORN) registry. Patients who underwent surgery for lumbar disc herniation were eligible for inclusion. The primary outcome was a clinically significant reduction in the back pain numerical rating scale (BPNRS) assessed at 12 months. Binary logistic regression was used to model the relationship between the primary outcome and potential predictors. There were 557 patients included in the analysis. The chief complaint was radiculopathy in 85%; 55% of patients underwent a minimally invasive procedure. BPNRS improved at 3 months by 48% and this improvement was sustained at all follow-ups. LBP and leg pain improvement were correlated. Clinically significant improvement in BPNRS at 12 months was reported by 64% of patients. Six factors predicted a lack of LBP improvement: female sex, low education level, marriage, not working, low expectations with regard to LBP improvement, and a low BPNRS preoperatively. Clinically significant improvement in LBP is observed in the majority of patients after LD. These data should be used to better counsel patients and provide accurate expectations about back pain improvement.

Minimally Invasive versus Open Thoracolumbar Surgery for Lumbar Spinal Stenosis in Patients with Diabetes: A CSORN Study

Introduction: This study was aimed at comparing outcomes of minimally invasive (MIS) versus OPEN surgery for lumbar spinal stenosis (LSS) in patients with diabetes.&#x0D; Methodology: This retrospective cohort study included patients with diabetes who underwent spinal decompression alone or with fusion for LSS within the Canadian Spine Outcomes and Research Network (CSORN) database. Outcomes of MIS and OPEN approaches were compared for two cohorts: (i) patients with diabetes who underwent decompression alone (N = 116; MIS, n = 58, OPEN, n = 58) and (ii) patients with diabetes who underwent decompression with fusion (N = 108; MIS, n = 54, OPEN, n = 54). Mixed measures analyses of covariance compared modified Oswestry Disability Index (mODI) and back and leg pain at one-year post operation. The number of patients meeting minimum clinically important difference (MCID) or minimum pain/disability at one year were compared.&#x0D; Result: MIS approaches had less blood loss (decompression alone difference 99.66 mL, p = 0.002; with fusion difference 244.23, p &lt; 0.001) and shorter LOS (decompression alone difference 1.15 days, p = 0.008; with fusion difference 1.23 days, p = 0.026). MIS compared to OPEN decompression with fusion had less patients experience an adverse event (difference, 13 patients, p = 0.007). The MIS decompression with fusion group had lower one-year mODI (difference, 14.25, p &lt; 0.001) and back pain (difference, 1.64, p = 0.002) compared to OPEN. More patients in the MIS decompression with fusion group exceeded MCID at one year for mODI (MIS 75.9% vs OPEN 53.7%, p = 0.028) and back pain (MIS 85.2% vs OPEN 70.4%, p = 0.017).&#x0D; Conclusion: MIS approaches were associated with more favorable outcomes for patients with diabetes undergoing decompression with fusion for LSS.

Differentiation of pain-related functional limitations in surgical patients with lumbar spinal stenosis (LSS) using the Oswestry Disability Index: a Canadian Spine Outcomes and Research Network (CSORN) study

Background ContextThe Oswestry Disability Index (ODI) is the most commonly used outcome measure of functional outcome in spine surgery. The ability of the ODI to differentiate pain related functional limitation specifically related to degenerative lumbar spinal stenosis (LSS) is unclear. PurposeThe purpose of this study was to determine the ability of the functional subsections of the ODI to differentiate the specific patient limitation(s) from symptomatic LSS and the functional impact of surgery. Study DesignAnalysis of prospectively collected data from the Canadian Spine Outcomes and Research Network (CSORN). Patient sampleA total of 1,497 lumbar spinal stenosis patients with a dominant complaint of neurogenic claudication, radiculopathy or back pain were identified in the CSORN registry. Outcome MeasuresThe ODI questionnaire version 2.0 was assessed as an outcome measure. MethodsThe difference at baseline and the pre-to-post (1-year) surgical change of the ODI individual questions was assessed. Analysis of variance, two-tailed paired sample Student t test were used for statistical analysis. Cohen d was used as an index of effect size, defined as "large" when d ≥0.8. ResultsThe mean age at surgery was 65 (±11) years and (50.8%) of the patients were female. Preoperatively, highest functional limitations were noted for standing, lifting, walking, pain intensity and social life (mean 3.2, 2.9, 2.5, 2.9, 2.5 respectively). At 1-year follow-up, overall there was a significant improvement in all individual questions and the overall ODI (all p<.001), with similar patterns seen for each dominant complaint. The greatest effect of surgery was noted in the walking, social life and standing domains (all d≥0.81), while personal care, sitting and lifting showed the least improvement (all d≤0.51). In subgroup analyses, the overall ODI baseline scores and subsection limitations were statistically significantly higher in females, those without degenerative spondylolisthesis and those undergoing fusion, although these differences were not considered clinically significant. Preoperative differentiation of LSS specific functional limitation and postoperative changes in all subgroups was similar to the overall LSS cohort. ConclusionsThe results of this study support the ability of the ODI to differentiate the self-reported pain related functional effects of neurogenic claudication, radiculopathy or back pain from LSS and changes associated with surgical intervention. Disaggregated use of the ODI could be a simple tool to aid in preoperative education regarding specific areas of pain related dysfunction and potential for improvement with LSS surgery.

Minimally Invasive vs. Open Surgery for Lumbar Spinal Stenosis in Patients with Diabetes - A Canadian Spine Outcomes and Research Network Study.

Retrospective cohort. To compare outcomes of minimally invasive surgery (MIS) vs open surgery (OPEN) for lumbar spinal stenosis (LSS) in patients with diabetes. Patients with diabetes who underwent spinal decompression alone or with fusion for LSS within the Canadian Spine Outcomes and Research Network (CSORN) database were included. MIS vs OPEN outcomes were compared for 2 cohorts: (1) patients with diabetes who underwent decompression alone (N = 116; MIS n = 58 and OPEN n = 58), (2) patients with diabetes who underwent decompression with fusion (N = 108; MIS n = 54 and OPEN n = 54). Modified Oswestry Disability Index (mODI) and back and leg pain were compared at baseline, 6-18weeks, and 1-year post-operation. The number of patients meeting minimum clinically important difference (MCID) or minimum pain/disability at 1-year was compared. MIS approaches had less blood loss (decompression alone difference 100mL, P = .002; with fusion difference 244mL, P < .001) and shorter length of stay (LOS) (decompression alone difference 1.2days, P = .008; with fusion difference 1.2days, P = .026). MIS compared to OPEN decompression with fusion had less patients experiencing adverse events (AEs) (difference 13 patients, P = .007). The MIS decompression with fusion group had lower 1-year mODI (difference 14.5, 95% CI [7.5, 21.0], P < .001) and back pain (difference 1.6, 95% CI [.6, 2.7], P = .002) compared to OPEN. More patients in the MIS decompression with fusion group exceeded MCID at 1-year for mODI (MIS 75.9% vs OPEN 53.7%, P = .028) and back pain (MIS 85.2% vs OPEN 70.4%, P = .017). MIS approaches were associated with more favorable outcomes for patients with diabetes undergoing decompression with fusion for LSS.

Minimally Invasive Tubular Lumbar Discectomy Versus Conventional Open Lumbar Discectomy: An Observational Study From the Canadian Spine Outcomes and Research Network.

Retrospective cohort study. We evaluated the effectiveness of minimally invasive (MIS) tubular discectomy in comparison to conventional open surgery among patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN). We performed an observational analysis of data that was prospectively collected. We implemented Minimum Clinically Important Differences (MCIDs), and we adjusted for potential confounders with multiple logistic regression. Adverse events were collected according to the Spinal Adverse Events Severity (SAVES) protocol. Three hundred thirty-nine (62%) patients underwent MIS tubular discectomy and 211 (38%) underwent conventional open discectomy. There were no significant differences between groups for improvement of leg pain and disability, but the MIS technique was associated with reduced odds of achieving the MCID for back pain (OR 0.66, 95% CI 0.44 to 0.99, P < 0.05). We identified statistically significant differences in favor of MIS for each of operating time (MIS mean (SD) 72.2 minutes (30.0) vs open 93.5 (40.9)), estimated blood loss (MIS 37.9 mL (36.7) vs open 76.8 (71.4)), length of stay in hospital (MIS 73% same-day discharge vs open 40%), rates of incidental durotomy (MIS 4% vs open 8%), and wound-related complications (MIS 3% vs open 9%); but not for overall rates of reoperation. Open and MIS techniques yielded similar improvements of leg pain and disability at up to 12 months of follow-up, but MIS patients were less likely to experience improvement of associated back pain. Small differences favored MIS for operating time, blood loss, and adverse events but may have limited clinical importance.

2021 Canadian Spine Society Abstracts.

# Abstract 45. Determining clinically important improvement following surgery for degenerative conditions of the spine: analysis of the Canadian Spine Outcomes and Research Network (CSORN) Registry {#article-title-2} There is significant variability in clinically important improvement (CII)

The impact of pathoanatomical diagnosis on elective spine surgery patient expectations: a Canadian Spine Outcomes and Research Network study.

Patients undergoing spine surgery generally have high expectations for improvement postoperatively. Little is known about how these expectations are affected by the diagnosis. The purpose of this study was to examine whether preoperative expectations differ based on diagnostic pathoanatomical patterns in elective spine surgery patients. Patients with common degenerative cervical/lumbar pathology (lumbar/cervical stenosis, lumbar spondylolisthesis, and cervical/lumbar disc herniation) who had given their consent for surgery were analyzed using the Canadian Spine Outcomes and Research Network (CSORN). Patients reported the changes they expected to experience postoperatively in relation to 7 separate items using a modified version of the North American Spine Society spine questionnaire. Patients were also asked about the most important item that would make them consider the surgery a success. Sociodemographic, lifestyle, and clinical variables were also collected. There were 3868 eligible patients identified within the network for analysis. Patients with lumbar disc herniation had higher expectations for relief of leg pain compared with stenosis and lumbar degenerative spondylolisthesis cohorts within the univariate analysis. Cervical stenosis (myelopathy) patients were more likely to rank general physical capacity as their most important expectation from spine surgery. The multinomial regression analysis showed that cervical myelopathy patients have lower expectations for relief of arm or neck pain from surgery (OR 0.54, 0.34-0.88; p < 0.05). Patient factors, including age, symptoms (pain, disability, depression), work status, and lifestyle factors, were significantly associated with expectation, whereas the diagnoses were not. Patients with degenerative spinal conditions consenting for spine surgery have high expectations for improvement in all realms of their daily lives. With the exception of patients with cervical myelopathy, patient symptoms rather than diagnoses had a more substantial impact on the dimensions in which patients expected to improve or their most important expected change. Determination of patient expectation should be individualized and not biased by pathoanatomical diagnosis.