Outcome prediction following lumbar disc surgery: a longitudinal study of outcome trajectories, prognostic factors, and risk models.

OBJECTIVE: This study aimed to 1) describe the 2-year postoperative trajectories of leg pain and overall clinical outcome after surgery for radiculopathy, 2) identify the preoperative prognostic factors that predict trajectories representing poor clinical outcomes, and 3) develop and internally validate multivariable prognostic models to assist with clinical decision-making. METHODS: This retrospective cohort study included patients enrolled in the Canadian Spine Outcomes and Research Network who were diagnosed with lumbar disc pathology and radiculopathy and had undergone lumbar discectomy at one of 18 spine centers. Potential outcome predictors included preoperative demographic, health-related, and clinical prognostic factors. Clinical outcomes were 1) 2-year univariable latent trajectories of leg pain intensity (numeric pain rating scale) and 2) overall outcomes comprising multivariable trajectories showing the combined postoperative courses of leg and back pain intensity (numeric pain rating scale) together with pain-related disability (Oswestry Disability Index). Each outcome model identified a subgroup of patients classified as experiencing a poor outcome based on minimal change in their clinical status after surgery. Multivariable risk model performance and internal validity were evaluated with discrimination and calibration statistics based on bootstrap shrinkage with 500 resamplings. RESULTS: The authors included data from 1142 patients (47.6% female). The trajectory models identified 3 subgroups based on the patients' postoperative courses of pain or disability: 88.6% of patients in the leg pain model and 71.9% in the overall outcome model experienced a good-to-excellent outcome. The models classified 11.4% (leg pain outcome) and 28.2% (overall outcome) of patients as experiencing a poor clinical outcome, which was defined as minimal improvement in pain or disability after surgery. Eleven individual demographic, health, and clinical factors predicted patients' poor leg pain and overall outcomes. The performance of the multivariable risk model for leg pain was inadequate, while the overall outcome model had acceptable discrimination, calibration, and internal validity for predicting a poor surgical outcome. CONCLUSIONS: Patients with lumbar radiculopathy experience heterogeneous postoperative trajectories of pain and disability after lumbar discectomy. Individual preoperative factors are associated with postoperative outcomes and can be combined within a multivariable risk model to predict overall patient outcome. These results may inform clinical practice but require external validation before confident clinical implementation.

Impact of Undergoing Thoracolumbar Surgery on Patient Psychosocial Profiles.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: Investigate the impact of thoracolumbar surgery on patients' psychosocial profiles. METHODS: A prospective cohort study of thoracolumbar surgery patients (N = 177). Measures of interest collected at baseline and 24-months after surgery were: modified Oswestry Disability Index (mODI), Numerical Rating Scores for Back Pain (NRS-B), Leg Pain (NRS-L), Pain Catastrophizing Scale (PCS), Tampa Scale of Kinesiophobia (TSK), Chronic Pain Acceptance Questionnaire-8 (CPAQ-8), Multidimensional Scale of Perceived Social Support (MSPSS), Mental Component Summary (MCS) and patient expectations for surgery impacts on mental well-being. Cohorts were separated based on attaining meaningful change defined as either 30% improvement or minimal scores in NRS-B, NRS-L and mODI. Mixed measures ANOVAs were run (α = .05). RESULTS: Patients who showed meaningful change had significant improvements in PCS, TSK and CPAQ-8 scores but not in MSPSS scores. Patients had improvement in MCS scores over 24-months follow-up, but this change was not significantly different based on attainment of meaningful change. Overall, 75.9% of patients reported their mental well-being expectations were met. Patients who did not achieve meaningful change showed no change on any psychosocial measures with only 55.9% reporting their mental well-being expectations met. CONCLUSION: Thoracolumbar surgery results in significant improvement of psychosocial variables for patients who experienced meaningful change for pain and disability. Worsening of psychosocial health was not evident in patients who did not attain meaningful change.

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

STUDY DESIGN: Retrospective cohort. OBJECTIVES: To compare outcomes of minimally invasive surgery (MIS) vs open surgery (OPEN) for lumbar spinal stenosis (LSS) in patients with diabetes. METHODS: 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, 6-18 weeks, and 1-year post-operation. The number of patients meeting minimum clinically important difference (MCID) or minimum pain/disability at 1-year was compared. RESULTS: MIS approaches had less blood loss (decompression alone difference 100 mL, P = .002; with fusion difference 244 mL, P < .001) and shorter length of stay (LOS) (decompression alone difference 1.2 days, P = .008; with fusion difference 1.2 days, 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). CONCLUSIONS: MIS approaches were associated with more favorable outcomes for patients with diabetes undergoing decompression with fusion for LSS.

Prediction of 2-year clinical outcome trajectories in patients undergoing anterior cervical discectomy and fusion for spondylotic radiculopathy.

OBJECTIVE: Anterior cervical discectomy and fusion (ACDF) is often described as the gold standard surgical technique for cervical spondylotic radiculopathy. Although outcomes are considered favorable, there is little prognostic evidence to guide patient selection for ACDF. This study aimed to 1) describe the 24-month postoperative trajectories of arm pain, neck pain, and pain-related disability; and 2) identify perioperative prognostic factors that predict trajectories representing poor clinical outcomes. METHODS: In this retrospective cohort study, patients with cervical spondylotic radiculopathy who underwent ACDF at 1 of 12 orthopedic or neurological surgery centers were recruited. Potential outcome predictors included demographic, health, clinical, and surgery-related prognostic factors. Surgical outcomes were classified by trajectories of arm pain intensity, neck pain intensity (numeric pain rating scales), and pain-related disability (Neck Disability Index) from before surgery to 24 months postsurgery. Trajectories of postoperative pain and disability were estimated with latent class growth analysis, and prognostic factors associated with poor outcome trajectory were identified with robust Poisson models. RESULTS: The authors included data from 352 patients (mean age 50.9 [SD 9.5] years; 43.8% female). The models estimated that 15.5%-23.5% of patients followed a trajectory consistent with a poor clinical outcome. Lower physical and mental health-related quality of life, moderate to severe risk of depression, and longer surgical wait time and procedure time predicted poor postoperative trajectories for all outcomes. Receiving compensation and smoking additionally predicted a poor neck pain outcome. Regular exercise, physiotherapy, and spinal injections before surgery were associated with a lower risk of poor disability outcome. Patients who used daily opioids, those with worse general health, or those who reported predominant neck pain or a history of depression were at greater risk of poor disability outcome. CONCLUSIONS: Patients who undergo ACDF for cervical spondylotic radiculopathy experience heterogeneous postoperative trajectories of pain and disability, with 15.5%-23.5% of patients experiencing poor outcomes. Demographic, health, clinical, and surgery-related prognostic factors can predict ACDF outcomes. This information may further assist surgeons with patient selection and with setting realistic expectations. Future studies are needed to replicate and validate these findings prior to confident clinical implementation.

Predicting Health-Related Quality of Life Outcomes Following Major Scoliosis Surgery in Adolescents: A Latent Class Growth Analysis.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To identify patient trajectories of recovery defined by change in health-related quality of life (HRQOL) following surgery for adolescent idiopathic scoliosis (AIS). To explore possible predictors of trajectory membership. METHODS: Adolescent patients scheduled to undergo spinal fusion for AIS were enrolled in the Post-Operative Recovery following Spinal Correction: Home Experience (PORSCHE) study. Responses to the Pediatric Quality of Life Inventory-version 4 (PedsQL-4.0) were collected prior to surgery and 4 to 6 weeks, 3, 6, and 12 months post-operatively. Latent class growth analyses identified patient subgroups based on their unique trajectories of physical health (PH) and psychosocial health (PSH) outcomes using the PedsQL-4.0 subscale scores. Predictors included demographic, clinical, and psychosocial factors. RESULTS: Data from up to 190 patients were included (87.4% female; mean±SD age = 14.6 ± 1.9 years). Three trajectory subgroups were identified for PH and 4 trajectories were found for PSH, with a majority of patients scoring within the established range of healthy adolescents 12 months post-surgery. Increased child and parent pain catastrophizing, child trait anxiety and previous hospitalizations were associated with poorer PH outcomes, whereas increased child and parent pain catastrophizing, child state and trait anxiety, and parent state and trait anxiety were associated with poorer PSH trajectories. CONCLUSIONS: The PH and PSH trajectories identified in this study and the factors associated with their membership may inform surgical decision-making for AIS while facilitating patient and family counselling regarding peri-operative recovery and expectations.

Postoperative recovery patterns following discectomy surgery in patients with lumbar radiculopathy.

This retrospective study of prospectively collected data aimed to identify unique pain and disability trajectories in patients following lumbar discectomy surgery. Patients of this study population presented chiefly with lumbar radiculopathy and underwent discectomy surgery from thirteen sites enrolled in the CSORN registry. Outcome variables of interest included numeric rating scales for leg/back pain and modified Oswestry disability index scores at baseline, 3, 12, and 24 months post-operatively. Latent class growth analysis was used to identify distinct courses in each outcome. Data from 524 patients revealed three unique trajectories for leg pain (excellent = 18.4%, good = 55.4%, poor = 26.3%), disability (excellent = 59.7%, fair = 35.6%, poor = 4.7%) and back pain (excellent = 13.0%, good = 56.4%, poor = 30.6%). Construct validity was supported by statistically significant differences in the proportions of patients attaining the criteria for minimal important change (MIC; 30%) or clinical success in disability (50% or Oswestry score ≤ 22) (p < 0.001). The variable proportions of patients belonging to poor outcome trajectories shows a disconnect between improved disability and persistence of pain. It will be beneficial to incorporate this information into the realm of patient expectation setting in concert with future findings of potential factors predictive of subgroup membership.

Instrumentation Removal following Minimally Invasive Posterior Percutaneous Pedicle Screw-Rod Stabilization (PercStab) of Thoracolumbar Fractures Is Not Always Required.

BACKGROUND: Percutaneous stabilization for spinal trauma confers less blood loss, reduces postoperative pain, and is less invasive than open stabilization and fusion. The current standard of care includes instrumentation removal. OBJECTIVE: 1. Reporting patient outcomes following minimally invasive posterior percutaneous pedicle screw-rod stabilization (PercStab). 2. Evaluating the results of instrumentation retention. METHODS: A prospective observational study of 32 consecutive patients receiving PercStab without direct decompression or fusion. Baseline data demographics were collected. Operative outcomes of interest were operative room (OR) time, blood loss, and length of hospital stay. Follow-up variables of interest included patient satisfaction, Numeric Rating Scales for Back and Leg (NRS-B/L) pain, Oswestry Disability Index (ODI), and return to work. Clinical outcome data (ODI and NRS-B/L) were collected at 3, 12, 24 months and continued at a 24-month interval up to a maximum of 8 years postoperatively. RESULTS: 81.25% of patients (n = 26) retained their instrumentation and reported minimal disability, mild pain, and satisfaction with their surgery and returned to work (mean = 6 months). Six patients required instrumentation removal due to prominence of the instrumentation or screw loosening, causing discomfort/pain. Instrumentation removal patients reported moderate back and leg pain until removal occurred; after removal, they reported minimal disability and mild pain. Neither instrumentation removal nor retention resulted in complications or further surgical intervention. CONCLUSIONS: PercStab without instrumentation removal provided high patient satisfaction, mild pain, and minimal disability and relieved the patient from the burden of finances and resources allocation of a second surgery.

Preoperative Factors Predict Postoperative Trajectories of Pain and Disability Following Surgery for Degenerative Lumbar Spinal Stenosis.

STUDY DESIGN: Longitudinal analysis of prospectively collected data. OBJECTIVE: Investigate potential predictors of poor outcome following surgery for degenerative lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: LSS is the most common reason for an older person to undergo spinal surgery, yet little information is available to inform patient selection. METHODS: We recruited LSS surgical candidates from 13 orthopedic and neurological surgery centers. Potential outcome predictors included demographic, health, clinical, and surgery-related variables. Outcome measures were leg and back numeric pain rating scales and Oswestry disability index scores obtained before surgery and after 3, 12, and 24 postoperative months. We classified surgical outcomes based on trajectories of leg pain and a composite measure of overall outcome (leg pain, back pain, and disability). RESULTS: Data from 529 patients (mean [SD] age = 66.5 [9.1] yrs; 46% female) were included. In total, 36.1% and 27.6% of patients were classified as experiencing a poor leg pain outcome and overall outcome, respectively. For both outcomes, patients receiving compensation or with depression/depression risk were more likely, and patients participating in regular exercise were less likely to have poor outcomes. Lower health-related quality of life, previous spine surgery, and preoperative anticonvulsant medication use were associated with poor leg pain outcome. Patients with ASA scores more than two, greater preoperative disability, and longer pain duration or surgical waits were more likely to have a poor overall outcome. Patients who received preoperative chiropractic or physiotherapy treatment were less likely to report a poor overall outcome. Multivariable models demonstrated poor-to acceptable (leg pain) and excellent (overall outcome) discrimination. CONCLUSION: Approximately one in three patients with LSS experience a poor clinical outcome consistent with surgical non-response. Demographic, health, and clinical factors were more predictive of clinical outcome than surgery-related factors. These predictors may assist surgeons with patient selection and inform shared decision-making for patients with symptomatic LSS. LEVEL OF EVIDENCE: 2.

Patients undergoing surgery for lumbar spinal stenosis experience unique courses of pain and disability: A group-based trajectory analysis.

OBJECTIVE: Identify patient subgroups defined by trajectories of pain and disability following surgery for degenerative lumbar spinal stenosis, and investigate the construct validity of the subgroups by evaluating for meaningful differences in clinical outcomes. METHODS: We recruited patients with degenerative lumbar spinal stenosis from 13 surgical spine centers who were deemed to be surgical candidates. Study outcomes (leg and back pain numeric rating scales, modified Oswestry disability index) were measured before surgery, and after 3, 12, and 24 months. Group-based trajectory models were developed to identify trajectory subgroups for leg pain, back pain, and pain-related disability. We examined for differences in the proportion of patients achieving minimum clinically important change in pain and disability (30%) and clinical success (50% reduction in disability or Oswestry score ≤22) 12 months from surgery. RESULTS: Data from 548 patients (mean[SD] age = 66.7[9.1] years; 46% female) were included. The models estimated 3 unique trajectories for leg pain (excellent outcome = 14.4%, good outcome = 49.5%, poor outcome = 36.1%), back pain (excellent outcome = 13.1%, good outcome = 45.0%, poor outcome = 41.9%), and disability (excellent outcome = 30.8%, fair outcome = 40.1%, poor outcome = 29.1%). The construct validity of the trajectory subgroups was confirmed by between-trajectory group differences in the proportion of patients meeting thresholds for minimum clinically important change and clinical success after 12 postoperative months (p < .001). CONCLUSION: Subgroups of patients with degenerative lumbar spinal stenosis can be identified by their trajectories of pain and disability following surgery. Although most patients experienced important reductions in pain and disability, 29% to 42% of patients were classified as members of an outcome trajectory subgroup that experienced little to no benefit from surgery. These findings may inform appropriate expectation setting for patients and clinicians and highlight the need for better methods of treatment selection for patients with degenerative lumbar spinal stenosis.

Improving postoperative patient reported benefits and satisfaction following spinal fusion with a single preoperative education session.

BACKGROUND CONTEXT: Patient expectations have been demonstrated to influence recovery following spine surgery. Addressing patient expectations specifically in regards to pain and postsurgical healing is an important factor in improving recovery patterns. Presurgical education can potentially help manage patient expectations. PURPOSE: The primary objective was to determine if participation in a single preoperative multidisciplinary educational session would result in reduced patient dissatisfaction with surgical expectations. A secondary objective was to determine if participation resulted in improvements in postsurgical pain, disability, and reductions in emergency room visits following surgery. STUDY DESIGN: A retrospective cohort study utilizing data from the Canadian Spine Outcomes and Research Network (CSORN) registry and hospital electronic medical records. PATIENT SAMPLE: Participants were patients receiving elective spinal fusion for 2-5 levels (N=206). Cohort 1 included patients who participated in preoperative multidisciplinary education (n=103). Cohort 2 included patients who opted out of the educational session (n=103). OUTCOME MEASURES: Outcomes measured included the Oswestry Disability Index (ODI), NRS scales for back and leg pain (NRS-B/NRS-L), CSORN questions pertaining to patient satisfaction with surgery and whether or not the surgery met expectations. Electronic chart review quantified emergency room visits following surgery. METHODS: Spinal fusion patients are encouraged to attend a one time, two-hour education session 3-6 weeks prior to their surgery. The education session includes interactive discussions with nursing, physiotherapy, and occupational therapy staff concentrating on what patients should expect, how to best prepare for surgery and proper care postsurgery. A one-way ANOVA was conducted for continuous variables of interest (age, number of levels operated on, ASA score, and number of visits to the emergency room following surgery). Chi-squared analysis was conducted for categorical variables of interest (pathology, gender, patient satisfaction, and patient expectations). A two (Cohort; education: no education) × 2 (Time; baseline: follow-up) repeated measure ANOVA was conducted for NRS-B, NRS-L, and ODI. Significance was set at p<.05. RESULTS: Patients (n=103) who took part in the presurgical education sessions were significantly more satisfied with their surgery compared to the control cohort (p=.014). Patients (n=103) who did not participate in the education session failed to have their expectations met in terms of improvement in daily activities (p=.03), improvement in walking capacity (p=.03) and their expectation of back pain reduction (p=.001). There was a statistically significant effect of participation in the educational session reducing postoperative back pain (p=0.03), although this improvement did not reach a minimally clinically important difference. Number of visits to the emergency room in the 12 weeks following spine surgery was significantly lower (p=.04) for patients in the education cohort. CONCLUSIONS: Reduced emergency room utilization, improved patient satisfaction, achievement of expected improvements and alleviation of back pain were documented with greater success following participation in a single 2-hour educational session prior to surgery. A single education session is a viable tool for improving patient outcomes due to its low administrative burden.

Avoidable Emergency Department Utilization Within 6 Months Following Elective Thoracolumbar Spine Surgery for Degenerative Pathologies.

STUDY DESIGN: Retrospective study. OBJECTIVE: To identify prevalence of, reasons for, and predictors of emergency department (ED) utilization 6 months following elective thoracolumbar spine surgery. METHODS: A retrospective review of a patient database was conducted (N = 577). Visits were divided by orthopedic spinal surgeons into (1) avoidable ED visit, (2) appropriate/no visit, and (3) unrelated visit. MEASURES: Demographics, pain scores, patient characteristics, and surgical factors. RESULTS: A total of 14.38% of patients made an ED visit the majority for avoidable reasons (11.43%). Avoidable ED visits were predominately attributed to pain (45.5%) and physiology-related issues (50.0%). Significant differences in the Numerical Rating Scale-leg pain (NRS-L); U = 13 931, P = .031) were found. Patients with avoidable visits had higher leg pain prior to surgery than those without an avoidable visit. Marital status was also statistically significant, χ2(2, N = 535) = 8.189, P = .017. Patients were more likely to make an avoidable postoperative ED visit if they were either single or divorced/separated compared to patients who were married. A multivariate logistic regression model including NRS-L and marital status was statistically significant, χ2(3) = 10.14, P = .017; however only explained 3.7% of the variance. CONCLUSION: A large percentage of elective thoracolumbar surgery patients returned to the ED within 6 months for avoidable reasons. Patients likely to make avoidable visits could not be identified prior to surgery in a clinically meaningful way. Reasons for patients returning to the ED for avoidable reasons focused on pain management and minor physiological symptoms. Enhanced presurgical education may manage postsurgical expectations helping to prevent avoidable ED visits.

Biopsychosocial factors predict quality of life in thoracolumbar spine surgery.

PURPOSE: Surgical intervention is a treatment option for various spinal pathology but many patients report no improvement or even an exacerbation of symptoms like pain. This study examined the association of preoperative (pre-op) biopsychosocial risk factors with poor quality of life at 2 and 6 months using hierarchical models controlling demographic and medical variables. METHOD: Participants undergoing thoracolumbar spine surgery (N = 214) were provided with questionnaire packages to complete pre-op, at 2 and at 6-month postoperative clinical follow-ups (i.e., demographics, psychosocial measures, SF-12, medical, and clinical measures). The surgeon recorded surgical measures. RESULTS: Examining the pre-op period only, greater age and medication use (for back symptoms) were associated with poorer physical quality of life [physical component summary score (PCS)], while greater catastrophizing, depression, and lower social support were associated with poorer mental QoL [mental component summary score (MCS)]. Lower preoperative PCS, social support, and greater kinesiophobia were associated with diminished PCS at 2-month. Higher pre-op MCS and higher social support was associated with better MCS at 2-month. Poorer PCS at 6-month was associated with older age and low social support, while diminished MCS was associated with lower pre-op social support, MCS, and longer time in the operation room. Preoperative kinesiophobia partially mediated the relationship between pre-op PCS and 2-month PCS. Age partially mediated the relationship between pre-op PCS and at 6-month. For MCS, social support was the lone partial mediator of baseline MCS and both 2 and 6-month MCS. CONCLUSION: These results show that preoperative psychosocial variables are significantly associated with poorer postoperative health-related QoL outcomes following spinal surgeries, supporting a biopsychosocial pre-op care map.

Object memory impairment at post-drug Day 15 but not at Day 1 after a regimen of repeated treatment with oral methylphenidate.

Methylphenidate (MPH) is a dopamine and norepinephrine reuptake inhibitor that is widely used for the treatment of attention-deficit/hyperactivity disorder in children and adults. Its similarity to other psychostimulants suggests that, at certain doses, the drug may generate lasting neuroadaptations that can be detrimental to the recipient. Some investigators have found that, in rats, the residual effects of the drug (i.e., following a 10-14 day washout period) can interfere with memory for objects when the retention interval is 3h or more. The present experiment replicated this result and demonstrated the critical importance of the washout period. Long-Evans male rats treated with MPH (5.0mg/kg po b.i.d.) on 21 days (during a post-natal period ranging from Day 29 to Day 57) and then twice-assessed for their performance in an object recognition task were able to recognize a familiar object on Day 1 after the last dose of the drug had been administered, behaving the same as the untreated control group. However, on Day 15 post-drug, the same MPH group failed to distinguish between a familiar and a novel object, exploring both nearly equally, while the control group continued to investigate the novel object to a greater extent than the familiar one. This suggests that, if a test for object recognition is conducted too early after the MPH treatment period ceases, a memory impairment may not be detected. In general, this finding has implications for studies of other behavioral or neurophysiological consequences of MPH that may appear following a drug-free withdrawal period.