An analysis from the Quality Outcomes Database, Part 1. Disability, quality of life, and pain outcomes following lumbar spine surgery: predicting likely individual patient outcomes for shared decision-making

Preoperative Oswestry Disability Index Should not be Utilized to Determine Surgical Eligibility for Patients Requiring Lumbar Fusion for Degenerative Lumbar Spine Disease

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate how preoperative Oswestry Disability Index (ODI) thresholds might affect minimal clinically important difference (MCID) achievement following lumbar fusion.

SUMMARY OF BACKGROUND DATA

As payers invest in alternative payment models, some are suggesting threshold cutoffs of patient-reported outcomes (PROMs) in reimbursement approvals for orthopedic procedures. The feasibility of this has not been investigated in spine surgery.

MATERIALS/METHODS

We included all adult patients undergoing one to three-level primary lumbar fusion at a single urban tertiary academic center from 2014 to 2020. ODI was collected preoperatively and one year postoperatively. We implemented theoretical threshold cutoffs at increments of 10. MCID was set at 14.3. The percent of patients meeting MCID were determined among patients "approved" or "denied" at each threshold. At each threshold, the positive predictive value (PPV) for MCID attainment was calculated.

RESULTS

A total 1368 patients were included and 62.4% (N=364) achieved MCID. As the ODI thresholds increased, a greater percent of patients in each group reached the MCID. At the lowest ODI threshold, 6.58% (N=90) of patients would be denied, rising to 20.2%, 39.5%, 58.4%, 79.9%, and 91.4% at ODI thresholds of 30, 40, 50, 60, and 70, respectively. The PPV increased from 0.072 among patients with ODI>20 to 0.919 at ODI>70. The number of patients denied a clinical improvement in the denied category per patient achieving the MCID increased at each threshold (ODI>20: 1.96; ODI>30: 2.40; ODI>40: 2.75; ODI>50: 3.03; ODI>60: 3.54; ODI>70: 3.75).

CONCLUSION

Patients with poorer preoperative ODI are significantly more likely to achieve MCID following lumbar spine fusion at all ODI thresholds. Setting a preoperative ODI threshold for surgical eligibility will restrict access to patients who may benefit from spine fusion despite ODI>20 demonstrating the lowest predictive value for MCID achievement.

LEVEL OF EVIDENCE

3.

The attainment of a patient acceptable symptom state in patients undergoing revision spine fusion

INTRODUCTION

Revision lumbar fusion is most commonly due to nonunion, adjacent segment disease (ASD), or recurrent stenosis, but it is unclear if diagnosis affects patient outcomes. The primary aim of this study was to assess whether patients achieved the patient acceptable symptom state (PASS) or minimal clinically important difference (MCID) after revision lumbar fusion and assess whether this was influenced by the indication for revision.

METHODS

We retrospectively identified all 1-3 level revision lumbar fusions at a single institution. Oswestry Disability Index (ODI) was collected at preoperative, three-month postoperative, and one-year postoperative time points. The MCID was calculated using a distribution-based method at each postoperative time point. PASS was set at the threshold of ≤ 22.

RESULTS

We identified 197 patients: 56% with ASD, 28% with recurrent stenosis, and 15% with pseudarthrosis. The MCID for ODI was 10.05 and 10.23 at three months and one year, respectively. In total, 61% of patients with ASD, 52% of patients with nonunion, and 65% of patients with recurrent stenosis achieved our cohort-specific MCID at one year postoperatively with ASD (p = 0.78). At one year postoperatively, 33.8% of ASD patients, 47.8% of nonunion patients, and 37% of patients with recurrent stenosis achieved PASS without any difference between indication (p = 0.47).

CONCLUSIONS

The majority of patients undergoing revision spine fusion experience significant postoperative improvements regardless of the indication for revision. However, a large proportion of these patients do not achieve the patient acceptable symptom state. While revision spine surgery may offer substantial benefits, these results underscore the need to manage patient expectations.

Preference Sensitive Care and Shared Decision-Making in Lumbar Spinal Stenosis: A Scoping Review

STUDY DESIGN

Scoping review.

OBJECTIVE

The objective of this study was to conduct a scoping review exploring the extent to which preference sensitivity has been studied in treatment decisions for lumbar spinal stenosis (LSS), utilizing shared decision-making (SDM) as a proxy.

BACKGROUND

Preference-sensitive care involves situations where multiple treatment options exist with significant tradeoffs in cost, outcome, recovery time, and quality of life. LSS has gained research focus as a preference-sensitive care scenario.

MATERIALS AND METHODS

A scoping review protocol in accordance with "Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews" regulations was registered with the Open Science Framework (ID: 9ewup) and conducted across multiple databases from January 2000 to October 2022. Study selection and characterization were performed by 3 independent reviewers and an unbiased moderator.

RESULTS

The search resulted in the inclusion of 16 studies varying in design and sample size, with most published between 2016 and 2021. The studies examined variables related to SDM, patient preferences, surgeon preferences, and decision aids (DAs). The outcomes assessed included treatment choice, patient satisfaction, and patient understanding. Several studies reported that SDM influenced treatment choice and patient satisfaction, while the impact on patient understanding was less clear. DAs were used in some studies to facilitate SDM.

CONCLUSION

The scoping review identified a gap in comprehensive studies analyzing the preference sensitivity of treatment for LSS and the role of DAs. Further research is needed to better understand the impact of patient preferences on treatment decisions and the effectiveness of DAs in LSS care. This review provides a foundation for future research in preference-sensitive care and SDM in the context of lumbar stenosis treatment.

Assessment of the External Validity of Dialogue Support for Predicting Lumbar Spine Surgery Outcomes in a US Cohort

STUDY DESIGN

External validation using prospectively collected data.

OBJECTIVES

To determine the model performance of "Dialogue Support" (DS) in predicting outcomes after lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

To help clinicians discuss risk versus benefit with patients considering lumbar fusion surgery, DS has been made available online. As DS was created using a Swedish sample, there is a need to study how well DS performs in alternative populations.

PATIENTS AND METHODS

Preoperative data from patients enrolled in the Quality Outcomes Database were entered into DS. The probability for each patient to report satisfaction, achieve success (leg pain improvement ≥3), or have no leg pain 12 months after surgery was extracted and compared with their actual 12-month postoperative data. The ability of DS to identify patients in the Quality Outcomes Database who report satisfaction, achieve success, or have no leg pain 12 months after surgery was determined using Receiver operating characteristic curve analysis, goodness-of-fit tests, and calibration plots.

RESULTS

There was a significant improvement in all outcomes in 23,928 cases included in the analysis from baseline to 12 months postoperative. Most (84%) reported satisfaction, 67% achieved success, and 44% were pain-free 12 months postoperative. Receiver operating characteristic analysis showed that DS had a low ability to predict satisfaction [area under the curve (AUC) = 0.606], success (AUC = 0.546), and being pain-free (AUC = 0.578) at 12 months postoperative; poor fit for satisfaction (<0.001) and being pain-free ( P = 0.004), but acceptable fit for success ( P = 0.052). Calibration plots showed underestimation for satisfaction and success, but acceptable estimates for being pain-free.

CONCLUSION

DS is not directly transferable to predict satisfaction and success after lumbar surgery in a US population. This may be due to differences in patient characteristics, weights of the variables included, or the exclusion of unknown variables associated with outcomes. Future studies to better understand and improve the transferability of these models are needed.

Addressing the Impact of Race and Ethnicity on Musculoskeletal Spine Care in the United States

➤ Despite being a social construct, race has an impact on outcomes in musculoskeletal spine care.➤ Race is associated with other social determinants of health that may predispose patients to worse outcomes.➤ The musculoskeletal spine literature is limited in its understanding of the causes of race-related outcome trends.➤ Efforts to mitigate race-related disparities in spine care require individual, institutional, and national initiatives.

Influence of Preoperative Pain, Cognitions, and Quantitative Sensory Testing Measures on the Effects of Perioperative Pain Neuroscience Education for People Receiving Surgery for Lumbar Radiculopathy: Secondary Analysis of a Randomized Controlled Trial

OBJECTIVE: To explore whether preoperative pain intensity, pain cognitions, and quantitative sensory measures influence the established effectiveness of perioperative pain neuroscience education (PPNE) on health-related quality of life at 1 year after surgery for lumbar radiculopathy. DESIGN: Secondary analysis of a triple-blinded randomized controlled trial. METHODS: Participants (n = 90) were Dutch-speaking adults (18-65 years) who were scheduled for surgery for lumbar radiculopathy in 3 Belgian hospitals. They were randomized (1:1) to receive PPNE (n = 41) or perioperative biomedical education (n = 49). Linear mixed models were built for health-related quality of life (ie, SF-6D utility values, Physical and Mental Component of the 36-item Short Form Health Survey) using the following independent variables: therapy, time, and preoperative scores for back and leg pain intensity, pain catastrophizing, kinesiophobia, hypervigilance, and quantitative sensory measures. RESULTS: The impact of PPNE on SF-6D utility values over time was influenced by kinesiophobia (F = 3.30, P = .02) and leg pain intensity (F = 3.48, P = .02). Regardless of the intervention, back pain intensity negatively influenced SF-6D values over time (F = 3.99, P = .009). The Physical Component scores were negatively impacted by back pain intensity (F = 9.08, P = .003) and were influenced over time by leg pain intensity (F = 2.87, P = .04). The Mental Component scores were negatively impacted by back pain intensity (F = 6.64, P = .01) and pain catastrophizing (F = 5.42, P = .02), as well as hypervigilance (F = 3.16, P = .03) and leg pain intensity (F = 3.12, P = .03) over time. CONCLUSION: PPNE may be more effective than perioperative biomedical education in improving postoperative health utility values in patients who reported higher kinesiophobia and leg pain intensity before surgery for lumbar radiculopathy. J Orthop Sports Phys Ther 2024;54(4):1-10. Epub 8 January 2024. doi:10.2519/jospt.2024.12051.

Performance of the streamlined quality outcomes database web-based calculator: internal and external validation

BACKGROUND CONTEXT

With an increasing number of web-based calculators designed to provide the probabilities of an individual achieving improvement after lumbar spine surgery, there is a need to determine the accuracy of these models.

PURPOSE

To perform an internal and external validation study of the reduced Quality Outcomes Database web-based Calculator (QOD-Calc).

STUDY DESIGN

Observational longitudinal cohort.

PATIENT SAMPLE

Patients enrolled study-wide in Quality Outcomes Database (QOD) and patients enrolled in DaneSpine at a single institution who had elective lumbar spine surgery with baseline data to complete QOD-Calc and 12-month postoperative data.

OUTCOME MEASURES

Oswestry Disability Index (ODI), Numeric Rating Scales (NRS) for back and leg pain, EuroQOL-5D (EQ-5D).

METHODS

Baseline data elements were entered into QOD-Calc to determine the probability for each patient having Any Improvement and 30% Improvement in NRS leg pain, back pain, EQ-5D and ODI. These probabilities were compared with the actual 12-month postop data for each of the QOD and DaneSpine cases. Receiver-operating characteristics analyses were performed and calibration plots created to assess model performance.

RESULTS

24,755 QOD cases and 8,105 DaneSpine lumbar cases were included in the analysis. QOD-Calc had acceptable to outstanding ability (AUC: 0.694-0.874) to predict Any Improvement in the QOD cohort and moderate to acceptable ability (AUC: 0.658-0.747) to predict 30% Improvement. QOD-Calc had acceptable to exceptional ability (AUC: 0.669-0.734) to predict Any improvement and moderate to exceptional ability (AUC: 0.619-0.862) to predict 30% Improvement in the DaneSpine cohort. AUCs for the DaneSpine cohort was consistently lower that the AUCs for the QOD validation cohort.

CONCLUSION

QOD-Calc performs well in predicting outcomes in a patient population that is similar to the patients that was used to develop it. Although still acceptable, model performance was slightly worse in a distinct population, despite the fact that the sample was more homogenous. Model performance may also be attributed to the low discrimination threshold, with close to 90% of cases reporting Any Improvement in outcome. Prediction models may need to be developed that are highly specific to the characteristics of the population.

Severe Preoperative Disability Is Associated With Greater Mental Health Improvements Following Surgery for Degenerative Spondylolisthesis: A Cohort Matched Analysis

OBJECTIVE

To evaluate preoperative disability's influence on patient-reported outcomes (PROs) following surgery for degenerative spondylolisthesis (DS).

METHODS

DS patients who underwent surgical intervention were retrospectively identified from a single-surgeon spine registry. Cohorts based on Oswestry Disability Index (ODI) < 41 (milder disability) and ≥ 41 (severe disability) were created. Demographic differences were accounted for with 1:1 propensity score matching. For the matched sample, perioperative and PRO data were additionally collected. PROs assessed included mental health, physical function, pain, and disability. Pre- and up to 2-year postoperative PROs were utilized. Average time to final follow-up was 15.7 ± 8.8 months. Improvements in PROs and minimal clinically important difference (MCID) rates were calculated. Continuous variables were compared through Student t-test and categorical variables were compared through chi-square tests.

RESULTS

Altogether, 214 patients were included with 77 in the milder disability group. The severe disability group had worse postoperative day (POD) 1 pain scores and longer hospital stays (p ≤ 0.038, both). The severe disability group reported worse outcomes pre- and postoperatively (p < 0.011, all), but had greater average improvement in 12-item Short Form health survey mental composite score (SF-12 MCS), 9-Item Patient Health Questionnaire (PHQ-9), visual analogue scale (VAS)-back, and ODI by 6 weeks (p ≤ 0.037, all) and PHQ-9, VAS-back and ODI by final follow-up (p ≤ 0.015, all). The severe disability cohort was more likely to achieve MCID for SF-12 MCS, PHQ-9, and ODI (p ≤ 0.003, all).

CONCLUSION

Patients with greater baseline disability report higher POD 1 pain and discharge later than patients with milder disability. While these patients report inferior physical/mental health before and after surgery, they report greater improvements in mental health and disability postoperatively.

Posterior Instrumented Spinal Surgery Outcomes in the Elderly: A Comparison of the 5-Item and 11-Item Modified Frailty Indices

STUDY DESIGN

Retrospective Cohort.

OBJECTIVES

To validate the most concise risk stratification system to date, the 5-item modified frailty index (mFI-5), and compare its effectiveness with the established 11-item modified frailty index (mFI-11) in the elderly population undergoing posterior instrumented spine surgery.

METHODS

A single centre retrospective review of posterior instrumented spine surgeries in patients aged 65 years and older was conducted. The primary outcome was rate of post-operative major complications (Clavien-Dindo Classification ≥ 4). Secondary outcome measures included rate of all complications, 6-month mortality and surgical site infection. Multi-variate analysis was performed and adjusted receiver operating characteristic curves were generated and compared by DeLong's test. The indices were correlated with Spearman's rho.

RESULTS

272 cases were identified. The risk of major complications was independently associated with both the mFI-5 (OR 1.89, 95% CI 1.01-3.55, P = .047) and mFI-11 (OR 3.73, 95% CI 1.90-7.30, P = .000). Both the mFI-5 and mFI-11 were statistically significant predictors of risk of all complications (P = .007 and P = .003), surgical site infection (P = .011 and P = .003) and 6-month mortality (P = .031 and P = .000). Adjusted ROC curves determined statistically similar c-statistics for major complications (.68 vs .68, P = .64), all complications (.66 vs .64, P = .10), surgical site infection (.75 vs .75, P = .76) and 6-month mortality (.83 vs .81, P = .21). The 2 indices correlated very well with a Spearman's rho of .944.

CONCLUSIONS

The mFI-5 and mFI-11 are equally effective predictors of postoperative morbidity and mortality in this population. The brevity of the mFI-5 is advantageous in facilitating its daily clinical use.

Machine Learning Models for Predicting Disability and Pain Following Lumbar Disc Herniation Surgery

Importance

Lumber disc herniation surgery can reduce pain and disability. However, a sizable minority of individuals experience minimal benefit, necessitating the development of accurate prediction models.

Objective

To develop and validate prediction models for disability and pain 12 months after lumbar disc herniation surgery.

Design, Setting, and Participants

A prospective, multicenter, registry-based prognostic study was conducted on a cohort of individuals undergoing lumbar disc herniation surgery from January 1, 2007, to May 31, 2021. Patients in the Norwegian Registry for Spine Surgery from all public and private hospitals in Norway performing spine surgery were included. Data analysis was performed from January to June 2023.

Exposures

Microdiscectomy or open discectomy.

Main Outcomes and Measures

Treatment success at 12 months, defined as improvement in Oswestry Disability Index (ODI) of 22 points or more; Numeric Rating Scale (NRS) back pain improvement of 2 or more points, and NRS leg pain improvement of 4 or more points. Machine learning models were trained for model development and internal-external cross-validation applied over geographic regions to validate the models. Model performance was assessed through discrimination (C statistic) and calibration (slope and intercept).

Results

Analysis included 22 707 surgical cases (21 161 patients) (ODI model) (mean [SD] age, 47.0 [14.0] years; 12 952 [57.0%] males). Treatment nonsuccess was experienced by 33% (ODI), 27% (NRS back pain), and 31% (NRS leg pain) of the patients. In internal-external cross-validation, the selected machine learning models showed consistent discrimination and calibration across all 5 regions. The C statistic ranged from 0.81 to 0.84 (pooled random-effects meta-analysis estimate, 0.82; 95% CI, 0.81-0.84) for the ODI model. Calibration slopes (point estimates, 0.94-1.03; pooled estimate, 0.99; 95% CI, 0.93-1.06) and calibration intercepts (point estimates, -0.05 to 0.11; pooled estimate, 0.01; 95% CI, -0.07 to 0.10) were also consistent across regions. For NRS back pain, the C statistic ranged from 0.75 to 0.80 (pooled estimate, 0.77; 95% CI, 0.75-0.79); for NRS leg pain, the C statistic ranged from 0.74 to 0.77 (pooled estimate, 0.75; 95% CI, 0.74-0.76). Only minor heterogeneity was found in calibration slopes and intercepts.

Conclusion

The findings of this study suggest that the models developed can inform patients and clinicians about individual prognosis and aid in surgical decision-making.

How well can the clinician appraise the patient's perception of the severity and impact of their back problem?

PURPOSE

A main concern of patients with back problems is pain and its impact on function and quality of life. These are subjective phenomena, and should be probed during the clinical consultation so that the physician can ascertain the extent of the problem. This study evaluated the agreement between clinicians' and patients' independent ratings of patient status on the Core Outcome Measures Index (COMI).

METHODS

This was an analysis of the data from 5 spine specialists and 108 patients, in two centres. Prior to the consultation, the patient completed the COMI. After the consultation, the clinician (blind to the patient's version) also completed a COMI. Concordance was assessed by % agreement, Kappa values, Bland-Altman plots, Spearman rank, Intraclass Correlation Coefficients and comparisons of mean values, as appropriate.

RESULTS

Agreement regarding the "main problem" (back pain, leg/buttock pain, sensory disturbances, other) was 83%, Kappa = 0.70 (95%CI 0.58-0.81). Moderate/strong correlations were found between the doctors' and patients' COMI-item ratings (0.48-0.74; p < 0.0001), although compared with the patients' ratings the doctors systematically underestimated absolute values for leg pain (p = 0.002) and dissatisfaction with symptom state (p = 0.002), and overestimated how much the patient's function was impaired (p = 0.029).

CONCLUSION

The doctors were able to ascertain the location of the main problem and the multidimensional outcome score with good accuracy, but some individual domains were systematically underestimated (pain, symptom-specific well-being) or overestimated (impairment of function). More detailed/direct questioning on these domains during the consultation might deliver a better appreciation of the impact of the back problem on the patient's daily life.

Influence of radiological factors, psychosocial factors, and central sensitization-related symptoms on clinical symptoms in patients with lumbar spinal canal stenosis

BACKGROUND

No study to date has concurrently evaluated the impact of radiological factors, psychosocial factors, and central sensitization (CS) related symptoms in a single lumbar spinal canal stenosis (LSS) patient cohort.

OBJECTIVE

To investigate the associations between these factors and clinical symptoms in LSS patients.

METHODS

We recruited 154 patients with LSS scheduled for surgery. Patient-reported outcome measures and imaging evaluation including clinical symptoms, psychosocial factors, CS-related symptoms, and radiological classifications. Spearman's rank correlation coefficient and multiple regression analyses were employed.

RESULTS

Spearman's correlation revealed CS-related symptoms positively correlated with low back pain (r= 0.25, p< 0.01), leg pain (r= 0.26, p< 0.01), and disability (r= 0.32, p< 0.01). Pain catastrophizing positively correlated with leg pain (r= 0.23, p< 0.01) and disability (r= 0.36, p< 0.01). Regression analysis showed that pain catastrophizing was associated with disability (β= 0.24, 95%CI = 0.03-0.18), and CS-related symptoms with low back pain (β= 0.28, 95%CI = 0.01-0.09). Radiological classifications were not associated with clinical symptoms.

CONCLUSION

Our findings suggest that psychosocial factors and CS-related symptoms, rather than radiological factors, seem to contribute to clinical symptoms in patients with LSS.

Preoperative Motor Function Associated with Short-Term Gain of Health-Related Quality of Life after Surgery for Lumbar Degenerative Disease: A Pilot Prospective Cohort Study in Japan

This study aimed to estimate the relationship between preoperative motor function and short-term recovery of health-related quality of life after lumbar surgery in patients with lumbar degenerative disease. This prospective cohort study involved 50 patients with lumbar degenerative disease at a general hospital in Japan. The primary outcome was the achievement of minimal clinically important difference (MCID) for EuroQOL 5 dimensions (EQ-5D) at discharge. Preoperative demographic, medication, surgical, and physical function data were collected. Logistic regression analysis was performed using the achievement of MCID for EQ-5D as the dependent variable and preoperative characteristics, including the Five Times Sit to Stand test (FTSTS), Oswestry Disability Index (ODI), and Self-rating Depression Scale (SDS), as the independent variables. The logistic regression analysis showed that Model 1 had a moderate predictive accuracy (Nagelkerke R2: 0.20; Hosmer-Lemeshow test: p = 0.19; predictive accuracy: 70.0%). Among the independent variables in the logistic regression model, the FTSTS was the only independent variable related to the achievement of MCID for EQ-5D at discharge (odds ratio: 0.03; 95% CI: 1.79 × 10-3, 0.18). Our results highlighted the importance of baseline motor function in the postoperative recovery of health-related quality of life in individuals with lumbar degenerative disease.

Fear of movement was associated with sedentary behaviour 12 months after lumbar fusion surgery in patients with low back pain and degenerative disc disorder

BACKGROUND

Movement behaviours, such as sedentary behaviour (SB) and moderate to vigorous physical activity (MVPA), are linked with multiple aspects of health and can be influenced by various pain-related psychological factors, such as fear of movement, pain catastrophising and self-efficacy for exercise. However, the relationships between these factors and postoperative SB and MVPA remain unclear in patients undergoing surgery for lumbar degenerative conditions. This study aimed to investigate the association between preoperative pain-related psychological factors and postoperative SB and MVPA in patients with low back pain (LBP) and degenerative disc disorder at 6 and 12 months after lumbar fusion surgery.

METHODS

Secondary data were collected from 118 patients (63 women and 55 men; mean age 46 years) who underwent lumbar fusion surgery in a randomised controlled trial. SB and MVPA were measured using the triaxial accelerometer ActiGraph GT3X+. Fear of movement, pain catastrophising and self-efficacy for exercise served as predictors. The association between these factors and the relative time spent in SB and MVPA 6 and 12 months after surgery was analysed via linear regression models, adjusting for potential confounders.

RESULTS

Preoperative fear of movement was significantly associated with relative time spent in SB at 6 and 12 months after surgery (β = 0.013, 95% confidence interval = 0.004 to 0.022, p = 0.007). Neither pain catastrophising nor self-efficacy for exercise showed significant associations with relative time spent in SB and MVPA at these time points.

CONCLUSIONS

Our study demonstrated that preoperative fear of movement was significantly associated with postoperative SB in patients with LBP and degenerative disc disorder. This finding underscores the potential benefits of preoperative screening for pain-related psychological factors, including fear of movement, preoperatively. Such screenings could aid in identifying patients who might benefit from targeted interventions to promote healthier postoperative movement behaviour and improved health outcomes.

State-of-the-art Applications of Patient-Reported Outcome Measures in Spinal Care

Patient-reported outcome measures (PROMs) assign objective measures to patient's subjective experiences of health, pain, disability, function, and quality of life. PROMs can be useful for providers in shared decision making, outcome assessment, and indicating patients for surgery. In this article, we provide an overview of the legacy PROMs used in spinal care, recent advancements in patient-reported outcomes, and future directions in PROMs. Recent advances in patient-reported outcome assessments have included standardization of measurement tools, integration of data collection into workflow, and applications of outcome measures in predictive models and decision-making tools. Continual appraisal of instruments and incorporation into artificial intelligence and machine learning analytics will continue to augment the delivery of high-value spinal care.

Prognostic models for chronic postsurgical pain-Current developments, trends, and challenges

PURPOSE OF REVIEW

Prognostic models for chronic postsurgical pain (CPSP) aim to predict the likelihood for development and severity of CPSP in individual patients undergoing surgical procedures. Such models might provide valuable information for healthcare providers, allowing them to identify patients at higher risk and implement targeted interventions to prevent or manage CPSP effectively. This review discusses the latest developments of prognostic models for CPSP, their challenges, limitations, and future directions.

RECENT FINDINGS

Numerous studies have been conducted aiming to develop prognostic models for CPSP using various perioperative factors. These include patient-related factors like demographic variables, preexisting pain conditions, psychosocial aspects, procedure-specific characteristics, perioperative analgesic strategies, postoperative complications and, as indicated most recently, biomarkers. Model generation, however, varies and performance and accuracy differ between prognostic models for several reasons and validation of models is rather scarce.

SUMMARY

Precise methodology of prognostic model development needs advancements in the field of CPSP. Development of more accurate, validated and refined models in large-scale cohorts is needed to improve reliability and applicability in clinical practice and validation studies are necessary to further refine and improve the performance of prognostic models for CPSP.

Neck Disability Index as a Prognostic Factor for Outcomes Following Cervical Disc Replacement

STUDY DESIGN

Retrospective review.

OBJECTIVE

We aim to elucidate the potential relationship between neck disability index (NDI) and outcomes following cervical disk replacement (CDR).

SUMMARY OF BACKGROUND DATA

The use of preoperative disability scores as predictors of outcomes following spine surgery has previously been studied, yet no literature has been published regarding its use in CDR.

METHODS

A retrospective database of a single orthopedic spine surgeon was searched for single-level CDR patients with preoperative NDI scores, excluding those with trauma, infection, or malignancy. Patients were separated into 2 cohorts by NDI score: Mild-Moderately Disabled (MD) (NDI<50) and Severely Disabled (NDI≥50). Patient-reported outcome measures were collected and compared within and between groups up to 1 year postoperatively and included Patient-reported Outcome Measurement Information System Physical Function, 12-Item Short Form (SF-12) Physical Component Score and Mental Component Score, visual analog scale (VAS) neck and arm pain, and NDI. MCID achievement rates were compared between the groups.

RESULTS

All PROM scores significantly improved for both cohorts at one or more postoperative time points compared with preoperative baseline ( P ≤0.049, all), with the exception of SF-12 Mental Component Score, which only significantly improved in the MD cohort at 2 postoperative points ( P ≤0.007, both). Between groups, the MD cohort reported significantly superior scores at one or more time points for all studied patient-reported outcome measures ( P ≤0.047, all). MCID achievement rate did not significantly vary for any outcome at any time between cohorts.

CONCLUSION

Regardless of preoperative disability, both groups reported improvement in physical function, pain, and disability scores following CDR. While not finding significance, patients with severe disability preoperatively consistently demonstrated higher minimal clinically important difference achievement in NDI. These data do not promote the use of NDI as a prognostic factor for outcomes following CDR. Further study with larger patient populations may be useful to clarify this potential relationship.

Leveraging web-based prediction calculators to set patient expectations for elective spine surgery: a qualitative study to inform implementation

BACKGROUND

Prediction calculators can help set outcomes expectations following orthopaedic surgery, however effective implementation strategies for these tools are unknown. This study evaluated provider and patient perspectives on clinical implementation of web-based prediction calculators developed using national prospective spine surgery registry data from the Quality Outcomes Database.

METHODS

We conducted semi-structured interviews in two health systems, Vanderbilt University Medical Center (VUMC) and Duke University Health System (DUHS) of orthopedic and neurosurgery health care providers (VUMC: n = 19; DUHS: n = 6), health care administrators (VUMC: n = 9; DUHS: n = 9), and patients undergoing elective spine surgery (VUMC: n = 16). Qualitative template analysis was used to analyze interview data, with a focus on end-user perspectives regarding clinical implementation of web-based prediction tools.

RESULTS

Health care providers, administrators and patients overwhelmingly supported the use of the calculators to help set realistic expectations for surgical outcomes. Some clinicians had questions about the validity and applicability of the calculators in their patient population. A consensus was that the calculators needed seamless integration into clinical workflows, but there was little agreement on best methods for selecting which patients to complete the calculators, timing, and mode of completion. Many interviewees expressed concerns that calculator results could influence payers, or expose risk of liability. Few patients expressed concerns over additional survey burden if they understood that the information would directly inform their care.

CONCLUSIONS

Interviewees had a largely positive opinion of the calculators, believing they could aid in discussions about expectations for pain and functional recovery after spine surgery. No single implementation strategy is likely to be successful, and strategies vary, even within the same healthcare system. Patients should be well-informed of how responses will be used to deliver better care, and concerns over how the calculators could impact payment and liability should be addressed prior to use. Future research is necessary to determine whether use of calculators improves management and outcomes for people seeking a surgical consult for spine pain.

A Conceptual Model for Spine Surgery Recovery: A Qualitative Study of Patients' Expectations, Experiences, and Satisfaction

STUDY DESIGN

Qualitative interview study.

OBJECTIVE

The aim was to develop a conceptual model for Spine Surgery Recovery in order to better understand why patients undergo lumbar spine surgery and what factors influence patient satisfaction.

SUMMARY OF BACKGROUND DATA

Quantitative studies have assessed patients' expectations for lumbar spine surgery outcomes, with greater expectation fulfillment leading to higher satisfaction. However, there is limited literature using qualitative methods to understand the patient perspective from the decision to undergo lumbar spine surgery through long-term recovery.

MATERIALS AND METHODS

Semistructured phone interviews were conducted with 20 participants (nine females, mean age ±SD=61.2±11.1 yr) and three focus groups with 12 participants (nine females, mean age ±SD=62.0±10.9 yr). Sessions were audio recorded and transcribed. Two independent researchers coded the transcripts using a hierarchical coding system. Major themes were identified and a conceptual model was developed.

RESULTS

A total of 1355 coded quotes were analyzed. The decision to have lumbar spine surgery was influenced by chronic pain impact on daily function, pain coping, and patient expectations. Results demonstrated that fulfilled expectations and setting realistic expectations are key factors for patient satisfaction after surgery, while less known constructs of accepting limitations, adjusting expectations, and optimism were found by many patients to be essential for a successful recovery. Emotional factors of fear, anxiety, and depression were important aspects of presurgical and postsurgical experiences.

CONCLUSION

Our Spine Surgery Recovery conceptual model provides guidance for future research and clinical practice to optimize treatment and improve overall patient satisfaction. Recommendations based on this model include the assessment of patient expectations and mental well-being throughout postoperative recovery as well as preoperatively to help set realistic expectations and improve satisfaction. Educational, acceptance-based or positive psychological interventions may be potentially beneficial for addressing key factors identified in this model.

Long-Term Durability of Stand-Alone Lateral Lumbar Interbody Fusion

BACKGROUND

The long-term durability of stand-alone lateral lumbar interbody fusion (LLIF) remains unknown.

OBJECTIVE

To evaluate whether early patient-reported outcome measures after stand-alone LLIF are sustained on long-term follow-up.

METHODS

One hundred and twenty-six patients who underwent stand-alone LLIF between 2009 and 2017 were included in this study. Patient-reported outcome measures included the Oswestry Disability Index (ODI), EuroQOL-5D (EQ-5D), and visual analog score (VAS) scores. Durable outcomes were defined as scores showing a significant improvement between preoperative and 6-week scores without demonstrating any significant decline at future time points. A repeated measures analysis was conducted using generalized estimating equations (model) to assess the outcome across different postoperative time points, including 6 weeks, 1 year, 2 years, and 5 years.

RESULTS

ODI scores showed durable improvement at 5-year follow-up, with scores improving from 46.9 to 38.5 ( P = .001). Improvements in EQ-5D showed similar durability up to 5 years, improving from 0.48 to 0.65 ( P = .03). VAS scores also demonstrated significant improvements postoperatively that were durable at 2-year follow-up, improving from 7.0 to 4.6 ( P < .0001).

CONCLUSION

Patients undergoing stand-alone LLIF were found to have significant improvements in ODI and EQ-5D at 6-week follow-up that remained durable up to 5 years postoperatively. VAS scores were found to be significantly improved at 6 weeks and up to 2 years postoperatively but failed to reach significance at 5 years. These findings demonstrate that patients undergoing stand-alone LLIF show significant improvement in overall disability after surgery that remains durable at long-term follow-up.

Socioeconomic Effects on Lumbar Fusion Outcomes

BACKGROUND

Recent studies suggest that socioeconomic status (SES) influences outcomes after spinal fusion. The influence of SES on postoperative outcomes is increasingly relevant as rates of lumbar fusion rise.

OBJECTIVE

To determine the influence of SES variables including race, education, net worth, and homeownership on postoperative outcomes.

METHODS

Optum's deidentified Clinformatics Data Mart Database was used to conduct a retrospective review of SES variables for patients undergoing first-time, inpatient lumbar fusion from 2003 to 2021. Primary outcomes included hospital length of stay (LOS) and 30-day reoperation, readmission, and postoperative complication rates. Secondary outcomes included postoperative emergency room visits, discharge status, and total hospital charges.

RESULTS

In total, 217 204 patients were identified. On multivariate analysis, Asian, Black, and Hispanic races were associated with increased LOS (Coeff. [coefficient] 0.92, 95% CI 0.68-1.15; Coeff. 0.61, 95% CI 0.51-0.71; Coeff. 0.43, 95% CI 0.32-0.55). Less than 12th grade education (vs greater than a bachelor's degree) was associated with increased odds of reoperation (OR [odds ratio] 1.88, 95% CI 1.03-3.42). Decreased net worth was associated with increased odds of readmission (OR 1.32, 95% CI 1.25-1.40) and complication (OR 1.14, 95% CI 1.10-1.20). Renting a home (vs homeownership) was associated with increased LOS, readmissions, and total charges (Coeff. 0.30, 95% CI 0.17-0.43; OR 1.19, 95% CI 1.11-1.30; Coeff. 13 200, 95% CI 9000-17 000).

CONCLUSION

Black race, less than 12th grade education, <$25K net worth, and lack of homeownership were associated with poorer postoperative outcomes and increased costs. Increasing perioperative support for patients with these sociodemographic risk factors may improve postoperative outcomes.

Predicting patient-reported outcomes following lumbar spine surgery: development and external validation of multivariable prediction models

BACKGROUND

This study aimed to develop and externally validate prediction models of spinal surgery outcomes based on a retrospective review of a prospective clinical database, uniquely comparing multivariate regression and random forest (machine learning) approaches, and identifying the most important predictors.

METHODS

Outcomes were change in back and leg pain intensity and Core Outcome Measures Index (COMI) from baseline to the last available postoperative follow-up (3-24 months), defined as minimal clinically important change (MCID) and continuous change score. Eligible patients underwent lumbar spine surgery for degenerative pathology between 2011 and 2021. Data were split by surgery date into development (N = 2691) and validation (N = 1616) sets for temporal external validation. Multivariate logistic and linear regression, and random forest classification and regression models, were fit to the development data and validated on the external data.

RESULTS

All models demonstrated good calibration in the validation data. Discrimination ability (area under the curve) for MCID ranged from 0.63 (COMI) to 0.72 (back pain) in regression, and from 0.62 (COMI) to 0.68 (back pain) in random forests. The explained variation in continuous change scores spanned 16%-28% in linear, and 15%-25% in random forests regression. The most important predictors included age, baseline scores on the respective outcome measures, type of degenerative pathology, previous spinal surgeries, smoking status, morbidity, and duration of hospital stay.

CONCLUSIONS

The developed models appear robust and generalisable across different outcomes and modelling approaches but produced only borderline acceptable discrimination ability, suggesting the need to assess further prognostic factors. External validation showed no advantage of the random forest approach.

Comorbidity data collection across different spine registries: an evidence map

INTRODUCTION

Comorbidities are significant patient factors that contribute to outcomes after surgery. There is highly variable collection of this information across the literature. To help guide the systematic collection of best practice data, the Australian Spine Registry conducted an evidence map to investigate (i) what comorbidities are collected by spine registries, (ii) how they are collected and (iii) the compliance and completeness in collecting comorbidity data.

METHOD

A literature search was performed to identify published studies of adult spine registry data reporting comorbidities. In addition, targeted questionnaires were sent to existing global spine registries to identify the maximum number of relevant results to build the evidence map.

RESULTS

Thirty-six full-text studies met the inclusion criteria. There was substantial variation in the reporting of comorbidity data; 55% of studies reported comorbidity collection, but only 25% reported the data collection method and 20% reported use of a comorbidity index. The variation in the literature was confirmed with responses from 50% of the invited registries (7/14). Of seven, three use a recognised comorbidity index and the extent and methods of comorbidity collection varied by registry.

CONCLUSION

This evidence map identified variations in the methodology, data points and reporting of comorbidity collection in studies using spine registry data, with no consistent approach. A standardised set of comorbidities and data collection methods would encourage collaboration and data comparisons between patient cohorts and could facilitate improved patient outcomes following spine surgery by allowing data comparisons and predictive modelling of risk factors.

Preoperative Oswestry Disability Index Cannot Reliably Predict Patient Satisfaction After Single and Double Level Lumbar Transforaminal Interbody Fusion Surgery

Introduction

The role of patient-reported outcomes in preoperative assessment is not well studied. There is recent interest in studying whether Patient-reported outcomes scores can be used either independently, or in conjunction with clinical findings, in the assessment of patients for surgery.

Aims

To investigate if improvement in clinically significant scores correlate with post-operative patient satisfaction in 1-2 level transforaminal lumbar interbody fusion (TLIF) surgery. We also aim to define a threshold Oswestry Disability Index (ODI) which correlate with achieving post-operative MCID and patient satisfaction.

Methods

1001 patients who underwent single or double level TLIF (Minimally invasive and Open) in our institution with at least 2 years follow up were included in this study. We studied self-reported measures including patient satisfaction and ODI score.

Results

At 2-year follow-up, the overall mean ODI score improved from 49.7 ± 18.3 to 13.9 ± 15.2 (P < 0.001) with 74.6% of patients meeting the MCID. Patient satisfaction was achieved in 95.3% of all patients. In the MIS group, the preoperative cut-off was determined to be 37.2 at maximal Youden index associated with AUC of 0.72 (95% CI 0.65-0.86). In the open group, the preoperative cut-off was determined to be 37.2 at maximal Youden index associated with AUC of 0.70 (95% CI 0.62-0.77). Using the preoperative cut-offs found, there was no significant difference in patient satisfaction in both MIS and open groups.

Conclusions

Overall, our patients undergoing TLIF had good 2-year ODI score improvement and patient satisfaction after surgery. While meeting the MCID for ODI score correlates with patients' satisfaction postoperatively, 75% of patients not meeting the MCID for ODI score remained satisfied with the surgery. We are unable to define a threshold pre-operative ODI which correlates with achieving post-operative MCID and patient satisfaction.

The Effect of Preoperative Symptom Duration on Patient-Reported Outcomes After Anterior Cervical Discectomy and Fusion in Nonmyelopathic Patients: Analyses From the Michigan Spine Surgery Improvement Collaborative (MSSIC)

BACKGROUND

The effect of preoperative symptom duration (PSD) on patient-reported outcomes (PROs) in anterior cervical discectomy and fusion (ACDF) for radiculopathy is unclear.

OBJECTIVE

To determine whether PSD is a predictor for PRO after ACDF for radiculopathy.

METHODS

The Michigan Spine Surgery Improvement Collaborative registry was queried between March, 2014, and July, 2019, for patients who underwent ACDF without myelopathy and PROs (baseline, 90 days, 1 year, 2 years). PROs were measured by numerical rating scales for neck/arm pain, Patient-Reported Outcomes Measurement Information System Short Form-Physical Function (PROMIS-PF), EuroQol-5D (EQ5D), and North American Spine Society satisfaction. Univariate analyses were used to evaluate the proportion of patients reaching minimal clinically important differences (MCID). PSD was <3 months, 3 month-1 year, or >1 years. Multiple logistic regression models were used to estimate the association between PSD and PRO reaching MCID. The discriminative ability of the model was evaluated by receiver operating characteristic curve.

RESULTS

We included 2233 patients who underwent ACDF with PSD <3 months (278, 12.4%), 3 month-1 year (669, 30%), and >1 years (1286, 57.6%). Univariate analyses demonstrated a greater proportion of patients achieving MCID in <3-month cohort for arm numerical rating scales, PROMIS-PF, EQ5D, and North American Spine Society Satisfaction. Multivariable analyses demonstrated using <3 months PSD as a reference, PSD >1 years was associated with decreased odds of achieving MCID for EQ5D (odds ratio 0.5, CI 0.32-0.80, P = .004). Private insurance and increased baseline PRO were associated with significantly higher odds for achieving PROMIS-PF MCID and EQ5D-MCID.

CONCLUSION

Preoperative symptom duration greater than 1 year in patients who underwent ACDF for radiculopathy was associated with worse odds of achieving MCID for multiple PROs.

Complex Regional Pain Syndrome after Spine Surgery: A Rare Complication in Mini-Invasive Lumbar Spine Surgery: An Updated Comprehensive Review

BACKGROUND

Complex regional pain syndrome (CRPS) is a postoperative, misdiagnosed condition highlighted only by pain therapists after numerous failed attempts at pain control by the treating surgeon in the case of prolonged pain after surgery. It only occurs rarely after spine surgery, causing the neurosurgeon's inappropriate decision to resort to a second surgical treatment.

METHODS

We performed a systematic review of the literature reporting and analyzing all recognized and reported cases of CRPS in patients undergoing spinal surgery to identify the best diagnostic and therapeutic strategies for this unusual condition. We compare our experience with the cases reported through a review of the literature.

RESULTS

We retrieve 20 articles. Most of the papers are clinical cases showing the disorder's rarity after spine surgery. Most of the time, the syndrome followed uncomplicated lumbar spine surgery involving one segment. The most proposed therapy was chemical sympathectomy and spinal cord stimulation.

CONCLUSION

CRPS is a rare pathology and is rarer after spine surgery. However, it is quite an invalidating disorder. Early therapy and resolution, however, require a rapid diagnosis of the syndrome. In our opinion, since CRPS occurs relatively rarely following spinal surgery, it should not have a substantial impact on the indications for and timing of these operations. Therefore, it is essential to diagnose this rare occurrence and treat it promptly and appropriately.

The Effect of the Severity of Preoperative Leg Pain on Patient-Reported Outcomes, Minimum Clinically Important Difference Achievement, and Patient Satisfaction After Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

To compare patient-reported outcome measures (PROMs), satisfaction, and minimum clinically important difference (MCID) achievement after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in patients stratified by preoperative leg pain.

METHODS

Patients undergoing MIS-TLIF were collected through retrospective review of a prospectively maintained single-surgeon database. PROMs administered preoperatively/postoperatively included Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), visual analog scale (VAS) back/leg pain, Oswestry Disability Index (ODI), and 12-Item Short Form (SF-12) Physical/Mental Component Score (PCS/MCS). Patients were grouped based on preoperative VAS leg scores: VAS leg ≤7 or VAS leg >7. Inferential statistics were used to compare PROMs, MCID achievement rates, and postoperative satisfaction between groups.

RESULTS

A total of 562 patients were eligible (168 VAS leg score ≤7; 394 VAS leg score >7). Significant differences between cohorts in postoperative mean PROMs were noted for PROMIS-PF at 6 weeks/2 years, SF-12 PCS at 6 weeks/2 years, SF-12 MCS at 6 weeks/12 weeks/6 months/1 year, VAS back score at 6 weeks/12 weeks/6 months, VAS leg score at 6 weeks/12 weeks/6 months/2 years and ODI at all postoperative time points (P < 0.045, all). In the VAS leg score >7 cohort, a greater proportion achieving MCID for VAS leg score at all postoperative time points and ODI at 12 weeks (P < 0.010, all). Postoperative satisfaction was greater in VAS back score ≤7 cohort for VAS leg score at 6 weeks/12 weeks/6 months/2 years, VAS back score at 12 weeks/2 years, and ODI at 6 weeks/12 weeks/6 months/2 years (P < 0.046, all).

CONCLUSIONS

Patients with severe preoperative leg pain showed worse postoperative PROM scores and patient satisfaction for disability and back/leg pain. MCID achievement rates across cohorts were similar. Patients with severe leg pain may have expectations for surgical benefits incongruent with their postoperative outcomes, and physicians may seek to manage the preoperative expectations of their patients to reflect likely outcomes after MIS-TLIF.

Complications, readmissions, reoperations and patient-reported outcomes in patients with multiple sclerosis undergoing elective spine surgery - a propensity matched analysis

BACKGROUND CONTEXT

Multiple sclerosis (MS) is an autoimmune, neurodegenerative disease that can lead to significant functional disability. Improving treatment regimens have extended life expectancy and led to an increase in the number of elective spine surgeries for degenerative conditions in the MS population. Recent literature has reported mixed results regarding the efficacy of elective spine surgery for patients with MS. There is also a paucity of literature comparing postoperative patient reported outcomes (PROs) and reoperation rates between patients with and without MS.

PURPOSE

To determine if patients with MS have worse PROs and higher complication, readmission and reoperation rates after elective spine surgery compared with patients without neurodegenerative conditions when adjusting for baseline covariates through propensity matching.

STUDY DESIGN/SETTING

Retrospective review of prospectively collected data from the Quality Outcomes Database (QOD), a national, longitudinal, multicenter spine outcomes registry.

PATIENT SAMPLE

For the lumbar cohort, 312 patients with MS and 46,738 patients without MS were included. The cervical myelopathy cohort included 91 patients with MS and 6,426 patients without MS. The cervical radiculopathy cohort consisted of 103 patients with MS and 13,751 patients without MS.

OUTCOME MEASURES

1) complication rates, 2) readmission rates, 3) reoperation rates, and 4) PROs at 3- and 12-months including ODI/NDI, NRS back/neck/arm/leg pain, mJOA scores and patient satisfaction ratings.

METHODS

Data from the QOD was queried for patients with surgeries occurring between 04/2013-01/2019. Three surgical groups were included: 1) Elective lumbar surgery, 2) Elective cervical surgery for myelopathy, 3) Elective cervical surgery for radiculopathy. Patients with any neurodegenerative condition other than MS were excluded. Patients without MS were propensity matched against patients with MS in a 5 to 1 ratio without replacement based on ASA grade, arthrodesis, surgical approach, number of operated levels, age, and baseline ODI/NDI, NRS leg/arm pain, NRS back/neck pain, and EQ-5D. Multivariable regressions with cluster-robust standard errors were used to estimate average effect of how the outcome would change if the MS patient didn't have the disease. The mean difference was used for continuous outcomes and the risk difference was used for binary outcomes.

RESULTS

For the lumbar cohort, no differences were found between the 2 groups at 3 or 12 months in any of the outcome measures. For the myelopathy cohort, patients with MS patients had a lower rate of reoperation at 12 months (risk difference=-0.036, p=.007) and worse 3-month mJOA scores (mean difference=-1.044, p=.004) compared with patients without MS. For the radiculopathy cohort, patients with MS had a lower rate of reoperation at 3 months (risk difference=-0.019, p=.018) and 12 months (risk difference=-0.029, p=.007) compared with those without MS.

CONCLUSIONS

Patients with MS had similar PROs compared with patients without MS when adjusting for baseline covariates through propensity matching, except for 3-month mJOA scores in the myelopathy cohort. Reoperation rates were found to be lower in patients with MS undergoing elective cervical surgery for both myelopathy and radiculopathy. These results suggest that when analyzed independently, a diagnosis of MS does not significantly impact complication, readmission and reoperation rates or PROs, and therefore should not represent a major contraindication to elective spine surgery. Surgical decisions in this patient population should be made based on careful consideration of patient factors including other comorbidities as well as baseline patient functional status.

Impact of Ambulatory Setting for Workers' Compensation Patients Undergoing One-Level Minimally Invasive Transforaminal Lumbar Interbody Fusion and Review of the Literature

OBJECTIVE

To compare perioperative characteristics and patient-reported outcome measures (PROMs) in workers' compensation (WC) patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in either the inpatient/outpatient setting.

METHODS

Patients with WC undergoing 1-level MIS-TLIF were included. Patients were separated into inpatient/outpatient groups and demographically propensity score matched. PROMs included visual analog scale (VAS) back/VAS leg/Oswestry Disability Index (ODI)/12-item Short Form Physical Composite Score (SF-12 PCS)/Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF) preoperatively and 6 weeks, 12 weeks, 6 months, and 1 year postoperatively. Results were compared preoperatively and postoperatively and between cohorts. Minimum clinically important difference (MCID) achievement was determined through comparison with values established in the literature.

RESULTS

A total of 216 patients were included (184 inpatient). The inpatient cohort (IC) showed worse perioperative outcomes in multiple measures (P < 0.034; all). The IC improved in all PROMs (P < 0.038; all), besides ODI at 6 weeks, SF-12 PCS at 6 weeks/6 months/1 year, and PROMIS-PF at 6 weeks. The outpatient cohort (OC) improved in VAS back at all time points and VAS leg at 6 months (P < 0.033; all). Between cohorts, the OC showed better scores with VAS leg/ODI/SF-12 PCS/PROMIS-PF at multiple time points (P < 0.031; all). Most of the IC achieved MCID, aside from ODI, whereas the OC achieved MCID in SF-12 PCS. MCID achievement between cohorts was higher in the IC at PROMIS-PF at 1 year and VAS back overall (P < 0.034; all).

CONCLUSIONS

Despite more comorbidities and worse perioperative measures, the IC showed improved PROMs from preoperative to ≥1 follow-up visit, whereas the OC had improvement with only VAS back and leg. The IC showed multiple MCID achievements, whereas the OC showed MCID in only SF-12 PCS. These findings may help guide a surgeon's decision making between inpatient/outpatient lumbar surgery in the WC population.

Complications, Readmissions, Revisions, and Patient-reported Outcomes in Patients With Parkinson Disease Undergoing Elective Spine Surgery: A Propensity-matched Analysis

STUDY DESIGN

Retrospective analysis on prospectively collected data.

OBJECTIVE

To determine the effectiveness of elective spine surgery in patients with Parkinson disease (PD).

BACKGROUND CONTEXT

PD has become increasingly prevalent in an aging population. While surgical treatment for degenerative spine pathology is often required in this population, previous literature has provided mixed results regarding its effectiveness.

METHODS

Data from the Quality Outcomes Database (QOD) was queried between April 2013 and January 2019. Three surgical groups were identified: (1) elective lumbar surgery, (2) elective cervical surgery for myelopathy, (3) elective cervical surgery for radiculopathy. Patients without PD were propensity matched against patients with PD in a 5:1 ratio without replacement based on American Society of Anesthesiology grade, arthrodesis, surgical approach, number of operated levels, age, and baseline Oswestry Disability Index, Numerical Rating Scale (NRS) extremity pain, NRS back pain, and EuroQol 5-Dimensions (EQ-5D). The mean difference was calculated for continuous outcomes (Oswestry Disability Index, NRS leg pain, NRS back pain, and EQ-5D at 3 and 12 mo after surgery) and the risk difference was calculated for binary outcomes (patient satisfaction, complications, readmission, reoperation, and mortality).

RESULTS

For the lumbar analysis, PD patients had a higher rate of reoperation at 12 months (risk difference=0.057, P =0.015) and lower mean EQ-5D score at 12 months (mean difference=-0.053, P =0.005) when compared with patients without PD. For the cervical myelopathy cohort, PD patients had lower NRS neck pain scores at 3 months (mean difference=-0.829, P =0.005) and lower patient satisfaction at 3 months (risk difference=-0.262, P =0.041) compared with patients without PD. For the cervical radiculopathy cohort, PD patients demonstrated a lower readmission rate at 3 months (risk difference=-0.045, P =0.014) compared with patients without PD.

CONCLUSION

For the matched analysis, in general, patients with and without PD had similar patient-reported outcomes and complication, readmission, and reoperation rates. These results demonstrate that a diagnosis of PD alone should not represent a major contraindication to elective spine surgery.

Outcomes Following Direct Versus Indirect Decompression Techniques for Lumbar Spondylolisthesis: A Propensity-Matched Analysis

STUDY DESIGN

Retrospective review.

OBJECTIVE

The aim was to compare outcomes at 3 and 12 months for patients with lumbar spondylolisthesis treated with direct decompression (DD) versus indirect decompression (ID) techniques.

SUMMARY OF BACKGROUND DATA

Debate persists regarding the optimal surgical strategy to treat lumbar spondylolisthesis. Novel techniques relying on ID have shown superior radiographic outcomes compared to DD, however, doubt remains regarding their effectiveness in achieving adequate decompression. Currently, there is a paucity of data comparing the clinical efficacy of DD to ID.

METHODS

The Quality Outcomes Database (QOD), a national, multicenter prospective spine registry, was queried for patients who underwent DD and ID between April 2013 and January 2019. Propensity scores for each treatment were estimated using logistic regression dependent on baseline covariates potentially associated with outcomes. The propensity scores were used to exclude nonsimilar patients. Multivariable regression analysis was performed with the treatment and covariate as independent variables and outcomes as dependent variables.

RESULTS

A total of 4163 patients were included in the DD group and 86 in the ID group. The ID group had significantly lower odds of having a longer hospital stay and for achieving 30% improvement in back and leg pain at 3 months. These trends were not statistically significant at 12 months. There were no differences in ED5D scores or Oswestry disability index 30% improvement scores at 3 or 12 months. ID patient had a significantly higher rate of undergoing a repeat operation at 3 months (4.9% vs. 1.5%, P =0.015).

CONCLUSION

Our study suggests that both DD and ID for the treatment of lumbar spondylolisthesis result in similar clinical outcomes, with the exception that those treated with ID experienced a lower reduction in back and leg pain at 3 months and a higher 3-month reoperation rate. This data can provide surgeons with additional information when counseling patients on the pros and cons of ID versus DD surgery.

Frailty and Sarcopenia: Impact on Outcomes Following Elective Degenerative Lumbar Spine Surgery

STUDY DESIGN

This is a retrospective review of prospectively collected data.

OBJECTIVE

The aim was to evaluate the impact of frailty and sarcopenia on outcomes after lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

Elderly patients are commonly diagnosed with degenerative spine disease requiring surgical intervention. Frailty and sarcopenia result from age-related decline in physiological reserve and can be associated with complications after elective spine surgery. Little is known about the impact of these factors on patient-reported outcomes (PROs).

METHODS

Patients older than 70 years of age undergoing elective lumbar spine surgery were included. The modified 5-item frailty index (mFI-5) was calculated. Sarcopenia was defined using total psoas index, which is obtained by dividing the mid L3 total psoas area by VB area (L3-TPA/VB). PROs included Oswestry disability index (ODI), EuroQual-5D (EQ-5D), numeric rating scale (NRS)-back pain, NRS leg pain (LP), and North American Spine Society (NASS) at postoperative 12 months. Clinical outcomes included length of stay (LOS), 90-day readmission and complications. Univariate and multivariable regression analyses were performed.

RESULTS

Total 448 patients were included. The mean mFI-5 index was 1.6±1.0 and mean total psoas index was 1.7±0.5. There was a significant improvement in all PROs from baseline to 12 months ( P <0.0001). After adjusting for age, body mass index, smoking status, levels fused, and baseline PROs, higher mFI-5 index was associated with higher 12-month ODI ( P <0.001), lower 12-month EQ-5D ( P =0.001), higher NRS-L P ( P =0.039), and longer LOS ( P =0.007). Sarcopenia was not associated with 12-month PROs or LOS. Neither sarcopenia or mFI-5 were associated with 90-day complication and readmission.

CONCLUSIONS

Elderly patients demonstrate significant improvement in PROs after elective lumbar spine surgery. Frailty was associated with worse 12 months postoperative ODI, EQ-5D, NRS-LP scores, and longer hospital stay. While patients with sarcopenia can expect similar outcomes compared with those without, the mFI-5 should be considered preoperatively in counseling patients regarding expectations for disability, health-related quality of life, and leg pain outcomes after elective lumbar spine surgery.

LEVEL OF EVIDENCE

3.

The Charlson Comorbidity Index and depression are associated with satisfaction after short-segment lumbar fusion in patients 75 years and older

Background

The rate and volume of lumbar spinal fusion (LSF) surgery performed for patients aged 75 years and older increased in recent years. The purposes of our study were to identify factors associated with postoperative dissatisfaction and evaluate the predictive value of comprehensive geriatric assessment (CGA) for dissatisfaction at 2 years after elective short-segment (one- or two- level) LSF in patients aged 75 and older.

Methods

This was a retrospective study using a prospectively collected database of consecutive patients (aged 75 and older) who underwent elective short-segment transforaminal lumbar interbody fusion surgery for degenerative diseases from June 2018 to May 2020. Preoperative CGA consisting six domains was performed for each patient 1 day before the operative day. Univariate and multivariate analyses were performed to identify factors that predict for dissatisfaction with surgical treatment. The primary outcome was patient satisfaction with LSF surgery, as measured by the North American Spine Society (NASS) satisfaction scale. Secondary outcomes included postoperative complications, the length of stay, visual analog scale (VAS), and Oswestry Disability Index.

Results

A total of 211 patients were available for a follow-up at 2 years and included in our final study cohort with a mean age of 80.0 years. A total of 175 patients (82.9%) were included in the satisfied group, and 36 patients (17.1%) were included in the not dissatisfied group. In the dissatisfied group, there was a higher incidence of postoperative complications (30.6% vs. 14.3%, p = 0.024) and greater VAS scores for lower back (4.3 ± 1.9 vs. 1.3 ± 1.4, p = 0.001) and leg (3.9 ± 2.1 vs. 0.9 ± 1.3, p = 0.001). Multivariate regression analysis revealed that patients with greater CCI score [odd ratio (OR) 2.56, 95% CI, 1.12–5.76; p = 0.030 for CCI 1 or 2 and OR 6.20, 95% CI, 1.20–28.69; p = 0.024], and depression (OR 3.34, 95% CI, 1.26–9.20; p = 0.016) were more likely to be dissatisfied compared with patients with the CCI score of 0 and without depression.

Conclusions

Satisfaction after LSF in older patients (aged 75 and older) was similar to that of previously reported younger patients. Preoperative depression and higher CCI scores were independent risk factors for postoperative dissatisfaction two years after LSF surgery. These results help inform decision-making when considering LSF surgery for patients aged 75 and older.

Classification of older adults who underwent lumbar-related surgery using pre-operative biopsychosocial predictors and relationships with surgical recovery: An observational study conducted in the United States

Lumbar surgery is a commonly prescribed intervention for low back pain but poses higher risks and worse outcomes for older adults. Identifying clinical phenotypes based on biopsychosocial factors may help identify older adults who are at greatest risk for poor postoperative recovery. This study aimed to (a) classify older adults who underwent lumbar surgery based on preoperative biopsychosocial factors, and (b) quantify the association between preoperative biopsychosocial classifications and 3 and 12 months postoperative improvement outcomes. Latent class analysis was used to identify biopsychosocial classifications in 10,283 individuals aged ≥60 from the Quality Outcomes Database (the United States, 2021-2018). Logistic regression models measured the association between biopsychosocial classifications and 3 and 12 months postoperative outcomes (back/leg pain intensity, disability and quality of life), adjusting for covariates. Three classes were identified based on 19 a priori biopsychosocial factors and were characterised as 'high-risk' (15%), 'physical-/social health-risk' (44%) and 'low-risk' (41%). The high-risk class demonstrated increased odds of failing to recover post-operatively compared to the other classes. Similarly, the physical-/social-risk class demonstrated increased odds of failing to recover in all outcomes and time points compared to the low-risk class. Biopsychosocial factors with higher prevalence in the high versus low-risk class were depression (92.5% vs. 10.6%), multiple morbidities (55.3% vs. 25.7%) and obesity (59.5% vs. 37.2%). This study introduces novel non-recovery phenotypes for older adults undergoing lumbar surgery and may lead to the development of tailored interventions to improve clinical care and outcomes for this population.

Use of machine learning to model surgical decision-making in lumbar spine surgery

PURPOSE

The majority of lumbar spine surgery referrals do not proceed to surgery. Early identification of surgical candidates in the referral process could expedite their care, whilst allowing timelier implementation of non-operative strategies for those who are unlikely to require surgery. By identifying clinical and imaging features associated with progression to surgery in the literature, we aimed to develop a machine learning model able to mirror surgical decision-making and calculate the chance of surgery based on the identified features.

MATERIAL AND METHODS

In total, 55 factors were identified to predict surgical progression. All patients presenting with a lumbar spine complaint between 2013 and 2019 at a single Australian Tertiary Hospital (n = 483) had their medical records reviewed and relevant data collected. An Artificial Neural Network (ANN) was constructed to predict surgical candidacy. The model was evaluated on its accuracy, discrimination, and calibration.

RESULTS

Eight clinical and imaging predictive variables were included in the final model. The ANN was able to predict surgical progression with 92.1% accuracy. It also exhibited excellent discriminative ability (AUC = 0.90), with good fit of data (Calibration slope 0.938, Calibration intercept - 0.379, HLT > 0.05).

CONCLUSION

Through use of machine learning techniques, we were able to model surgical decision-making with a high degree of accuracy. By demonstrating that the operating patterns of single centres can be modelled successfully, the potential for more targeted and tailored referrals becomes possible, reducing outpatient wait-list duration and increasing surgical conversion rates.

Correlation between the degree of pain relief following discoblock and short-term surgical disability outcome among patients with suspected discogenic low back pain

OBJECTIVES

To evaluate how well the degree of pain relief after discoblock predicts the disability outcome of subsequent fusion or total disc replacement (TDR) surgery, based on short-term Oswestry Disability Index (ODI) scores.

METHODS

We retrospectively analyzed a set of patients who had undergone discoblock and subsequent fusion or TDR surgery of the same lumbar intervertebral disc due to suspected discogenic chronic LBP between 2011 and 2018. We calculated the degree of pain relief following discoblock (ΔNRS) and the changes in both absolute and percentual ODI scores (ΔODI and ΔODI%, respectively) following fusion or TDR surgery. We analyzed the statistical significance of ΔNRS and ΔODI and the correlation (Spearman's rho) between ΔNRS and ΔODI%. The fusion and TDR group were analyzed both in combination and separately.

RESULTS

Fifteen patients were eligible for the current study (fusion n=9, TDR n=6). ΔNRS was statistically significant in all groups, and ΔODI was statistically significant in the combined group and in the fusion group alone. The parameters of both decreased. We found a Spearman's rho of 0.57 (p=0.026) between ΔNRS and ΔODI% for the combined group. The individual Spearman's rho values were 0.85 (p=0.004) for the fusion group and 0.62 (p=0.191) for the TDR group.

CONCLUSIONS

We suggest that discoblock is a useful predictive criterion for disability outcome prior to surgery for discogenic LBP, especially when stabilizing spine surgery is under consideration.

ETHICAL COMMITTEE NUMBER

174/2019 (Oulu University Hospital Ethics Committee).

Feasibility and Assessment of a Machine Learning-Based Predictive Model of Outcome After Lumbar Decompression Surgery

STUDY DESIGN

Retrospective study at a unique center.

OBJECTIVE

The aim of this study is twofold, to develop a virtual patients model for lumbar decompression surgery and to evaluate the precision of an artificial neural network (ANN) model designed to accurately predict the clinical outcomes of lumbar decompression surgery.

METHODS

We performed a retrospective study of complete Electronic Health Records (EHR) to identify potential unfavorable criteria for spine surgery (predictors). A cohort of synthetics EHR was created to classify patients by surgical success (green zone) or partial failure (orange zone) using an Artificial Neural Network which screens all the available predictors.

RESULTS

In the actual cohort, we included 60 patients, with complete EHR allowing efficient analysis, 26 patients were in the orange zone (43.4%) and 34 were in the green zone (56.6%). The average positive criteria amount for actual patients was 8.62 for the green zone (SD+/- 3.09) and 10.92 for the orange zone (SD 3.38). The classifier (a neural network) was trained using 10,000 virtual patients and 2000 virtual patients were used for test purposes. The 12,000 virtual patients were generated from the 60 EHR, of which half were in the green zone and half in the orange zone. The model showed an accuracy of 72% and a ROC score of 0.78. The sensitivity was 0.885 and the specificity 0.59.

CONCLUSION

Our method can be used to predict a favorable patient to have lumbar decompression surgery. However, there is still a need to further develop its ability to analyze patients in the "failure of treatment" zone to offer precise management of patient health before spinal surgery.

Success and failure after surgery of degenerative disease of the lumbar spine: an operational definition based on satisfaction, pain, and disability from a prospective cohort

Background

To describe success and failure (S&F) after lumbar spine surgery in terms equally understandable across the entire health ecosystem.

Methods

Back and leg pain and disability were prospectively recorded before and up to 12 months after the procedure. Satisfaction was recorded using a Likert scale. Initially, patients were classified as satisfied or unsatisfied. Optimal satisfaction/unsatisfaction cutoff values for disability and pain were estimated with ROC curves. Satisfied and unsatisfied groups underwent a second subdivision into four subcategories: success (satisfied AND pain and disability concordant with cutoff values), incomplete success (satisfied AND pain and disability nonconformant with cutoff values), incomplete failure (unsatisfied AND pain and disability nonconformant with cutoff values), and failure (unsatisfied AND pain and disability concordant with cutoff values).

Results

A total of 486 consecutive patients were recruited from 2019–2021. The mean values of preoperative PROMs were ODI 42.2 (+ 16.4), NPRS back 6.6 (+ 2.6) and NPRS leg 6.2 points (+ 2.9). Of the total, 80.7% were classified as satisfied, and 19.3% were classified as unsatisfactory. The optimal disability and pain cutoff values for satisfaction/unsatisfaction (NPRS = 6, AND ODI = 27) defined a subdivision: 59.6% were classified as success, 20.4% as incomplete success, 7.1% as incomplete failure and 12.4% as failure. The descriptions of each group were translated to the following: success—all patients were satisfied and presented no or only mild to tolerable pain and no or borderline disability; incomplete success – all patients were satisfied despite levels of pain and/or disability worse than ideal for success; incomplete failure – all patients were not satisfied despite levels of pain and/or disability better than expected for failure; failure – all patients were unsatisfied and presented moderate to severe pain and disability.

Conclusion

It is possible to report S&F after surgery for DDL with precise and meaningful operational definitions focused on the experience of the patient.

Predicting Residual Angina After Chronic Total Occlusion Percutaneous Coronary Intervention: Insights from the OPEN‐CTO Registry

Background

Given that percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) is indicated primarily for symptom relief, identifying patients most likely to benefit is critically important for patient selection and shared decision‐making. Therefore, we identified factors associated with residual angina frequency after CTO PCI and developed a model to predict postprocedure anginal burden.

Methods and Results

Among patients in the OPEN‐CTO (Outcomes, Patient Health Status, and Efficiency in Chronic Total Occlusion Hybrid Procedures) registry, we evaluated the association between patient characteristics and residual angina frequency at 6 months, as assessed by the Seattle Angina Questionnaire Angina Frequency Scale. We then constructed a prediction model for angina status after CTO PCI using ordinal regression. Among 901 patients undergoing CTO PCI, 28% had no angina, 31% had monthly angina, 30% had weekly angina, and 12% had daily angina at baseline. Six months later, 53% of patients had a ≥20‐point increase in Seattle Angina Questionnaire Angina Frequency Scale score. The final model to predict residual angina after CTO PCI included baseline angina frequency, baseline nitroglycerin use frequency, dyspnea symptoms, depressive symptoms, number of antianginal medications, PCI indication, and presence of multiple CTO lesions and had a C index of 0.78. Baseline angina frequency and nitroglycerin use frequency explained 71% of the predictive power of the model, and the relationship between model components and angina improvement at 6 months varied by baseline angina status.

Conclusions

A 7‐component OPEN‐AP (OPEN‐CTO Angina Prediction) score can predict angina improvement and residual angina after CTO PCI using variables commonly available before intervention. These findings have implications for appropriate patient selection and counseling for CTO PCI.

Racial Differences in Patients Undergoing Anterior Cervical Discectomy and Fusion: A Multi-Site Study

STUDY DESIGN

This was a retrospective chart review.

OBJECTIVE

The objective of this study was to examine disparities within patients undergoing anterior cervical discectomy and fusion (ACDF) at a multi-site tertiary referral center with specific focus on factors related to length of stay (LOS).

SUMMARY OF BACKGROUND DATA

There are previously described racial disparities in spinal surgery outcomes and quality metrics.

METHODS

A total of 278 consecutive patients undergoing ACDF by 8 different surgeons over a 5-year period were identified retrospectively. Demographic data, including age at time of surgery, sex, smoking status, and self-identified race [White or African American (AA)], as well as surgical data and postoperative course were recorded. Preoperative health status was recorded, and comorbidities were scored by the Charlson Comorbidity Index. Univariable and multivariable linear regression models were employed to quantify the degree to which a patient's LOS was related to their self-identified race, demographics, and perioperative clinical data.

RESULTS

Of the 278 patients who received an ACDF, 71.6% (199) self-identified as White and 28.4% (79) identified as AA. AA patients were more likely to have an ACDF due to myelopathy, while White patients were more likely to have an ACDF due to radiculopathy (P=0.001). AA patients had longer LOS by an average of half a day (P=0.001) and experienced a larger percentage of extended stays (P=0.002). AA patients experienced longer overall operation times on average (P=0.001) across all different levels of fusion. AA race was not an independent driver of LOS (β=0.186; P=0.246).

CONCLUSIONS

As hypothesized, and consistent with previous literature on racial surgical disparities, AA race was associated with increased LOS, increased operative times, and increased indication of myelopathy in this study. Additional research is necessary to evaluate the underlying social determinants of health and other factors that may contribute to this study's results.

LEVEL OF EVIDENCE

Level III.

One-Year Clinical Outcomes of Minimal-Invasive Dorsal Percutaneous Fixation of Thoracolumbar Spine Fractures

Introduction: Minimal-invasive instrumentation techniques have become a workhorse in spine surgery and require constant clinical evaluations. We sought to analyze patient-reported outcome measures (PROMs) and clinicopathological characteristics of thoracolumbar fracture stabilizations utilizing a minimal-invasive percutaneous dorsal screw-rod system. Methods: We included all patients with thoracolumbar spine fractures who underwent minimal-invasive percutaneous spine stabilization in our clinics since inception and who have at least 1 year of follow-up data. Clinical characteristics (length of hospital stay (LOS), operation time (OT), and complications), PROMs (preoperative (pre-op), 3-weeks postoperative (post-op), 1-year postoperative: eq5D, COMI, ODI, NRS back pain), and laboratory markers (leucocytes, c-reactive protein (CRP)) were analyzed, finding significant associations between these study variables and PROMs. Results: A total of 68 patients (m: 45.6%; f: 54.4%; mean age: 76.9 ± 13.9) were included. The most common fracture types according to the AO classification were A3 (40.3%) and A4 (40.3%), followed by B2 (7.46%) and B1 (5.97%). The Median American Society of Anesthesiologists (ASA) score was 3 (range: 1−4). Stabilized levels ranged from TH4 to L5 (mean number of targeted levels: 4.25 ± 1.4), with TH10-L2 (12/68) and TH11-L3 (11/68) being the most frequent site of surgery. Mean OT and LOS were 92.2 ± 28.2 min and 14.3 ± 6.9 days, respectively. We observed 9/68 complications (13.2%), mostly involving screw misalignments and loosening. CRP increased from 24.9 ± 33.3 pre-op to 34.8 ± 29.9 post-op (p < 0.001), whereas leucocyte counts remained stable. All PROMs showed a marked significant improvement for both 3-week and 1-year evaluations compared to the preoperative situation. Interestingly, we did not find an impact of OT, LOS, lab markers, complications, and other clinical characteristics on PROMs. Notably, a higher number of stabilized levels did not affect PROMs. Conclusions: Minimal-invasive stabilization of thoracolumbar fractures utilizing a dorsal percutaneous approach resulted in significant PROM outcome improvements, although we observed a complication rate of 13.2% for up to 1 year of follow-up. PROMs were not significantly associated with clinicopathological characteristics, technique-related variables, or the number of targeted levels.

Does the Predominant Pain Location Influence Functional Outcomes, Satisfaction, and Return to Work After Minimally Invasive Transforaminal Lumbar Interbody Fusion For Degenerative Spondylolisthesis?

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

The objective of this study was to determine how different combinations of preoperative back pain (BP) and leg pain (LP) may influence functional outcomes, patient satisfaction and return to work (RTW) in patients undergoing minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for degenerative spondylolisthesis.

SUMMARY OF BACKGROUND DATA

Surgical decision-making is often based on the traditional assumption that the predominance of lower extremity symptoms is a stronger indication for lumbar spine surgery. Surprisingly, there is a paucity of literature supporting this notion and the isolated impact of the preoperative pattern of pain on outcome remains unclear.

METHODS

Prospectively collected data for patients who underwent primary MIS-TLIF for degenerative spondylolisthesis were reviewed. Patients were categorized into 3 groups depending on predominant pain location: LP predominant (LP>BP), back pain predominant [(BPP); BP>LP] and equal pain predominance (BP=LP). Patients were prospectively followed for at least 2 years.

RESULTS

In total, 781 patients were included: 33.4% LP predominant, 28.7% BPP and 37.9% equal pain predominance cases. The BPP group was significantly younger (P=0.005) and showed a trend towards poorer baseline Short-Form-36 Mental Component Summary (P=0.069). After adjusting for baseline differences, there was no significant difference in BP, LP, Oswestry Disability Index (ODI), SF-36 Physical Component Summary, and SF-36 Mental Component Summary between the 3 groups at all time points (P>0.05) except for poorer 1-month ODI in the BPP group (P=0.010). The rate of minimal clinically important difference attainment for ODI and SF-36 Physical Component Summary, satisfaction, expectation fulfilment and RTW were also similar (P>0.05).

CONCLUSIONS

The functional outcomes, quality of life and satisfaction after MIS-TLIF were similar, regardless of the predominant pain location. Equal proportions of patients achieved the minimal clinically important difference and RTW. In the context of proper indications, these results suggest that MIS-TLIF can be equally effective for patients with varying combinations of BP or LP.

LEVEL OF EVIDENCE

Level III-nonrandomized cohort study.

The Effect of the Severity of Preoperative Disability on Patient-Reported Outcomes and Patient Satisfaction Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

To compare patient-reported outcomes (PROMs), satisfaction, and minimum clinically important difference (MCID) achievement following minimally invasive transforaminal lumbar interbody fusion stratified by preoperative disability.

METHODS

Minimally invasive transforaminal lumbar interbody fusions were grouped by preoperative Oswestry Disability Index (ODI) score: ODI <41 or ODI ≥41. PROMs administered pre/postoperatively included Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF), visual analog scale (VAS) back/leg, ODI, and 12-Item Short-Form Physical Composite Score (SF-12 PCS)/12-Item Short-Form Mental Composite Score (SF-12 MCS). Satisfaction scores were collected for VAS back/leg and ODI. Coarsened exact match controlled for differences between cohorts. T tests compared mean PROMs and postoperative improvement/satisfaction between cohorts. Simple logistic regression compared MCID achievement.

RESULTS

After coarsened exact matching, there were 118 patients in the ODI ≤41 and 377 patients in the ODI >41 cohort. The ODI >41 cohort saw greater postoperative inpatient VAS pain score and narcotic consumption on days 0/1 (P < 0.018, all). PROMs differed between cohorts: PROMIS-PF, SF-12 PCS, ODI, VAS back/leg at all postoperative time points and SF-12 MCS at 6 weeks/12 weeks/6 months/1 year (P < 0.045, all). Patients in the ODI >41 cohort demonstrated greater proportion achieving MCID for ODI at all postoperative time points and for SF-12 MCS 6-week/12-week/6-month/1-year (P < 0.040, all). The ODI ≤41 cohort demonstrated greater MCID achievement for overall PROMIS-PF and SF-12 PCS 6 months (P < 0.047, all). Postoperative satisfaction was greater in the ODI ≤41 cohort for VAS leg 6 weeks/12 weeks, VAS back 6 weeks/12 weeks, and ODI all postoperative time points (P < 0.048, all).

CONCLUSIONS

Preoperative disability associated with worse postoperative PROMs and patient satisfaction for disability, back/leg pain at multiple time points. MCID achievement rates across cohorts were similar for most PROMs at most postoperative time points. Patients with severe disability may have unrealistic expectations for surgical benefits, influencing corresponding postoperative satisfaction.

The Influence of Baseline Clinical Status and Surgical Strategy on Early Good to Excellent Result in Spinal Lumbar Arthrodesis: A Machine Learning Approach

The study aims to create a preoperative model from baseline demographic and health-related quality of life scores (HRQOL) to predict a good to excellent early clinical outcome using a machine learning (ML) approach. A single spine surgery center retrospective review of prospectively collected data from January 2016 to December 2020 from the institutional registry (SpineREG) was performed. The inclusion criteria were age ≥ 18 years, both sexes, lumbar arthrodesis procedure, a complete follow up assessment (Oswestry Disability Index-ODI, SF-36 and COMI back) and the capability to read and understand the Italian language. A delta of improvement of the ODI higher than 12.7/100 was considered a "good early outcome". A combined target model of ODI (Δ ≥ 12.7/100), SF-36 PCS (Δ ≥ 6/100) and COMI back (Δ ≥ 2.2/10) was considered an "excellent early outcome". The performance of the ML models was evaluated in terms of sensitivity, i.e., True Positive Rate (TPR), specificity, i.e., True Negative Rate (TNR), accuracy and area under the receiver operating characteristic curve (AUC ROC). A total of 1243 patients were included in this study. The model for predicting ODI at 6 months' follow up showed a good balance between sensitivity (74.3%) and specificity (79.4%), while providing a good accuracy (75.8%) with ROC AUC = 0.842. The combined target model showed a sensitivity of 74.2% and specificity of 71.8%, with an accuracy of 72.8%, and an ROC AUC = 0.808. The results of our study suggest that a machine learning approach showed high performance in predicting early good to excellent clinical results.

The association of patient education level with outcomes after elective lumbar surgery: a Michigan Spine Surgery Improvement Collaborative study

OBJECTIVE

Socioeconomic factors have been shown to impact a host of healthcare-related outcomes. Level of education is a marker of socioeconomic status. This study aimed to investigate the relationship between patient education level and outcomes after elective lumbar surgery and to characterize any education-related disparities.

METHODS

The Michigan Spine Surgery Improvement Collaborative registry was queried for all lumbar spine operations. Primary outcomes included patient satisfaction determined by the North American Spine Society patient satisfaction index, and reaching the minimum clinically important difference of Patient-Reported Outcomes Measurement Information System Physical Function score and return to work up to 2 years after surgery. Multivariate Poisson generalized estimating equation models reported adjusted risk ratios.

RESULTS

A total of 26,229 lumbar spine patients had data available for inclusion in this study. On multivariate generalized estimating equation analysis all comparisons were done versus the high school (HS)/general equivalency development (GED)-level cohort. For North American Spine Society satisfaction scores after surgery the authors observed the following: at 90 days the likelihood of satisfaction significantly decreased by 11% (p < 0.001) among < HS, but increased by 1% (p = 0.52) among college-educated and 3% (p = 0.011) among postcollege-educated cohorts compared to the HS/GED cohort; at 1 year there was a decrease of 9% (p = 0.02) among < HS and increases of 3% (p = 0.02) among college-educated and 9% (p < 0.001) among postcollege-educated patients; and at 2 years, there was an increase of 5% (p = 0.001) among postcollege-educated patients compared to the < HS group. The likelihood of reaching a minimum clinically important difference of Patient-Reported Outcomes Measurement Information System Physical Function score at 90 days increased by 5% (p = 0.005) among college-educated and 9% (p < 0.001) among postcollege-educated cohorts; at 1 year, all comparison cohorts demonstrated significance, with a decrease of 12% (p = 0.007) among < HS, but an increase by 6% (p < 0.001) among college-educated patients and 14% (p < 0.001) among postcollege-educated compared to the HS/GED cohort; at 2 years, there was a significant decrease by 19% (p = 0.003) among the < HS cohort, an increase by 8% (p = 0.001) among the college-educated group, and an increase by 16% (p < 0.001) among the postcollege-educated group. For return to work, a significant increase was demonstrated at 90 days and 1 year when comparing the HS or less group with college or postcollege cohorts.

CONCLUSIONS

This study demonstrated negative associations on all primary outcomes with lower levels of education. This finding suggests a potential disparity linked to education in elective spine surgery.

Big Data in the Clinical Neurosciences

The clinical neurosciences have historically been at the forefront of innovation, often incorporating the newest research methods into practice. This chapter will explore the adoption, implementation, and refinement of big data and predictive modeling using machine learning within neurosurgery. Initial development of national databases arose from surgeons aiming to improve outcome predictions for patients with traumatic brain injury in the 1960s. In the following decades, other surgical specialties began building databases that left a lasting impact on the current national neurosurgical databases, particularly in spine surgery. Significant contributions to the literature have been made as a result of the numerous registries today, leading to broad quality improvements for neurosurgical patients. Important limitations of large databases do exist, including lack of standardized reporting and challenges in data extraction from medical records. New vistas will include the use of metadata to track human function, performance, and pain in a real-time manner to augment the reliance on traditional patient-reported outcome measures (PROMs). Overall, big data has demonstrated significant utility within neurosurgical research and machine learning-powered analyses have highlighted several promising areas of interest for future exploration.

Insurance status as a mediator of clinical presentation, type of intervention, and short-term outcomes for patients with metastatic spine disease

BACKGROUND

It is well established that insurance status is a mediator of disease management, treatment course, and clinical outcomes in cancer patients. Our study assessed differences in clinical presentation, treatment course, mortality rates, and in-hospital complications for patients admitted to the hospital with late-stage cancer - specifically, metastatic spine disease (MSD), by insurance status.

METHODS

The United States National Inpatient Sample (NIS) database (2012-2014) was queried to identify patients with visceral metastases, metastatic spinal cord compression (MSCC) or pathological fracture of the spine in the setting of cancer. Clinical presentation, type of intervention, mortality rates, and in-hospital complications were compared amongst patients by insurance coverage (Medicare, Medicaid, commercial or unknown). Multivariable logistical regression and age sensitivity analyses were performed.

RESULTS

A total of 48,560 MSD patients were identified. Patients with Medicaid coverage presented with significantly higher rates of MSCC (p < 0.001), paralysis (0.008), and visceral metastases (p < 0.001). Patients with commercial insurance were more likely to receive surgical intervention (OR 1.43; p < 0.001). Patients with Medicaid < 65 had higher rates of prolonged length of stay (PLOS) (OR 1.26; 95% CI, 1.01-1.55; p = 0.040) while both Medicare and Medicaid patients < 65 were more likely to have non-routine discharges. In-hospital mortality rates were significantly higher for patients with Medicaid (OR 2.66; 95% CI 1.20-5.89; p = 0.016) and commercial insurance (OR 1.58; 95% CI 1.09-2.27;p = 0.013) older than 65.

CONCLUSION

Given the differing severity in MSD presentation, mortality rates, and rates of PLOS by insurance status, our results identify disparities based on insurance coverage.

Prediction of outcome after spinal surgery-using The Dialogue Support based on the Swedish national quality register

PURPOSE

To evaluate the predictive precision of the Dialogue Support, a tool for additional help in shared decision-making before surgery of the degenerative spine.

METHODS

Data in Swespine (Swedish national quality registry) of patients operated between 2007 and 2019 found the development of prediction algorithms based on logistic regression analyses, where socio-demographic and baseline variables were included. The algorithms were tested in four diagnostic groups: lumbar disc herniation, lumbar spinal stenosis, degenerative disc disease and cervical radiculopathy. By random selection, 80% of the study population was used for the prediction of outcome and then tested against the actual outcome of the remaining 20%. Outcome measures were global assessment of pain (GA), and satisfaction with outcome.

RESULTS

Calibration plots demonstrated a high degree of concordance on a group level. On an individual level, ROC curves showed moderate predictive capacity with AUC (area under the curve) values 0.67-0.68 for global assessment and 0.6-0.67 for satisfaction.

CONCLUSION

The Dialogue Support can serve as an aid to both patient and surgeon when discussing and deciding on surgical treatment of degenerative conditions in the lumbar and cervical spine.

LEVEL OF EVIDENCE

I.

Role of psychosocial factors on the effect of physical activity on physical function in patients after lumbar spine surgery

Background

The purpose of this study was to investigate the longitudinal postoperative relationship between physical activity, psychosocial factors, and physical function in patients undergoing lumbar spine surgery.

Methods

We enrolled 248 participants undergoing surgery for a degenerative lumbar spine condition. Physical activity was measured using a triaxial accelerometer (Actigraph GT3X) at 6-weeks (6wk), 6-months (6M), 12-months (12M) and 24-months (24M) following spine surgery. Physical function (computerized adaptive test domain version of Patient-Reported Outcomes Measurement Information System) and psychosocial factors (pain self-efficacy, depression and fear of movement) were assessed at preoperative visit and 6wk, 6M, 12M and 24M after surgery. Structural equation modeling (SEM) techniques were utilized to analyze data, and results are represented as standardized regression weights (SRW). Overall SRW were computed across five imputed datasets to account for missing data. The mediation effect of each psychosocial factor on the effect of physical activity on physical function were computed [(SRW for effect of activity on psychosocial factor X SRW for effect of psychosocial factor on function) ÷ SRW for effect of activity on function]. Each SEM model was tested for model fit by assessing established fit indexes.

Results

The overall effect of steps per day on physical function (SRW ranged from 0.08 to 0.19, p<0.05) was stronger compared to the overall effect of physical function on steps per day (SRW ranged from non-existent to 0.14, p<0.01 to 0.3). The effect of steps per day on physical function and function on steps per day remained consistent after accounting for psychosocial factors in each of the mediation models. Depression and fear of movement at 6M mediated 3.4% and 5.4% of the effect of steps per day at 6wk on physical function at 12M, respectively. Pain self-efficacy was not a statistically significant mediator.

Conclusions

The findings of this study suggest that the relationship between physical activity and physical function is stronger than the relationship of function to activity. However, future research is needed to examine whether promoting physical activity during the early postoperative period may result in improvement of long-term physical function. Since depression and fear of movement had a very small mediating effect, additional work is needed to investigate other potential mediating factors such as pain catastrophizing, resilience and exercise self-efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04622-w.