Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 2: assessment of functional outcome following lumbar fusion

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 Use of 18F-Fluoride Positron Emission Tomography/Computed Tomography Scanning to Identify Sources of Pain after Posterior Lumbar Interbody Fusion-An Analysis in Patients with and without Symptoms

BACKGROUND

Identifying the cause of recurrent or persisting pain after posterior lumbar interbody fusion (PLIF) is essential for establishing optimal treatment. In this study, we evaluate patients after PLIF surgery by 18F-fluoride PET/CT scans and patient-reported outcome measures (PROMs).

METHODS

A total of 36 PLIF patients were included. Sixty minutes after intravenous injection of 18F-fluoride, PET/CT scanning was performed. Bone graft ingrowth, subsidence, screw loosening and damage of facet joints were scored by quantifying the level of bone metabolism of the vertebral endplates in the disc spaces, around screws and around the facet joints on the PET scans.

RESULTS

In contrast to asymptomatic patients, symptomatic patients showed abnormal PET values around pedicle screws and/or facet joints and at the lower endplates of the disc spaces, identifying a possible source of pain. On CT, no significant differences between these two groups were found.

CONCLUSION

The PET/CT findings appeared to correlate better with symptoms on PROMs compared to CT findings alone. When interpreting 18F-fluoride PET/CT findings after PLIF surgery, one should realize bone metabolism in the disc spaces of the operated segments and around pedicle screws or facet joint changes during follow-up, reflecting natural recovery.

Personalized Interventional Surgery of the Lumbar Spine: A Perspective on Minimally Invasive and Neuroendoscopic Decompression for Spinal Stenosis

Pain generator-based lumbar spinal decompression surgery is the backbone of modern spine care. In contrast to traditional image-based medical necessity criteria for spinal surgery, assessing the severity of neural element encroachment, instability, and deformity, staged management of common painful degenerative lumbar spine conditions is likely to be more durable and cost-effective. Targeting validated pain generators can be accomplished with simplified decompression procedures associated with lower perioperative complications and long-term revision rates. In this perspective article, the authors summarize the current concepts of successful management of spinal stenosis patients with modern transforaminal endoscopic and translaminar minimally invasive spinal surgery techniques. They represent the consensus statements of 14 international surgeon societies, who have worked in collaborative teams in an open peer-review model based on a systematic review of the existing literature and grading the strength of its clinical evidence. The authors found that personalized clinical care protocols for lumbar spinal stenosis rooted in validated pain generators can successfully treat most patients with sciatica-type back and leg pain including those who fail to meet traditional image-based medical necessity criteria for surgery since nearly half of the surgically treated pain generators are not shown on the preoperative MRI scan. Common pain generators in the lumbar spine include (a) an inflamed disc, (b) an inflamed nerve, (c) a hypervascular scar, (d) a hypertrophied superior articular process (SAP) and ligamentum flavum, (e) a tender capsule, (f) an impacting facet margin, (g) a superior foraminal facet osteophyte and cyst, (h) a superior foraminal ligament impingement, (i) a hidden shoulder osteophyte. The position of the key opinion authors of the perspective article is that further clinical research will continue to validate pain generator-based treatment protocols for lumbar spinal stenosis. The endoscopic technology platform enables spine surgeons to directly visualize pain generators, forming the basis for more simplified targeted surgical pain management therapies. Limitations of this care model are dictated by appropriate patient selection and mastering the learning curve of modern MIS procedures. Decompensated deformity and instability will likely continue to be treated with open corrective surgery. Vertically integrated outpatient spine care programs are the most suitable setting for executing such pain generator-focused programs.

Predictors of Pain and Disability Outcomes Following Spinal Surgery for Chronic Low Back and Radicular Pain: A Systematic Review

OBJECTIVES

Success rates of spinal surgeries to treat chronic back pain are highly variable and useable prognostic indicators are lacking. We aimed to identify and evaluate preoperative predictors of pain and disability after spinal surgery for chronic low back/leg pain.

METHODS

Electronic database (01/1984-03/2021) and reference searches identified 2622 unique citations. Eligible studies included adults with chronic low back/leg pain lasting ≥3 months undergoing first elective lumbar spine surgery, and outcomes defined as change in pain (primary)/disability (secondary) after ≥3 months. We included 21 reports (6899 participants), 7 were judged to have low and 14 high risks of bias. We performed narrative synthesis and determined the quality of evidence (QoE).

RESULTS

Better pain outcomes were associated with younger age, higher education, and no spinal stenosis (low QoE); lower preoperative pain, fewer comorbidities, lower pain catastrophizing, anxiety and depression (very low QoE); but not with symptom duration (moderate QoE), other sociodemographic factors (low QoE), disability, or sensory testing (very low QoE). More favorable disability outcomes were associated with preoperative sensory loss (moderate QoE); lower job-related resignation and neuroticism (very low QoE); but not with socioeconomic factors, comorbidities (low QoE), demographics, pain, or pain-related psychological factors (very low QoE).

DISCUSSION

In conclusion, absence of spinal stenosis potentially predicts greater pain relief and preoperative sensory loss likely predicts reduction in disability. Overall, QoE for most identified associations was low/very low.

Developing a Prediction Model for Identification of Distinct Perioperative Clinical Stages in Spine Surgery With Smartphone-Based Mobility Data

BACKGROUND

Spine surgery outcomes assessment currently relies on patient-reported outcome measures, which satisfy established reliability and validity criteria, but are limited by the inherently subjective and discrete nature of data collection. Physical activity measured from smartphones offers a new data source to assess postoperative functional outcomes in a more objective and continuous manner.

OBJECTIVE

To present a methodology to characterize preoperative mobility and gauge the impact of surgical intervention using objective activity data garnered from smartphone-based accelerometers.

METHODS

Smartphone mobility data from 14 patients who underwent elective lumbar decompressive surgery were obtained. A time series analysis was conducted on the number of steps per day across a 2-year perioperative period. Five distinct clinical stages were identified using a data-driven approach and were validated with clinical documentation.

RESULTS

Preoperative presentation was correctly classified as either a chronic or acute mobility decline in 92% of patients, with a mean onset of acute decline of 11.8 ± 2.9 weeks before surgery. Postoperative recovery duration demonstrated wide variability, ranging from 5.6 to 29.4 weeks (mean: 20.6 ± 4.9 weeks). Seventy-nine percentage of patients ultimately achieved a full recovery, associated with an 80% ± 33% improvement in daily steps compared with each patient's preoperative baseline (P = .002). Two patients subsequently experienced a secondary decline in mobility, which was consistent with clinical history.

CONCLUSION

The perioperative clinical course of patients undergoing spine surgery was systematically classified using smartphone-based mobility data. Our findings highlight the potential utility of such data in a novel quantitative and longitudinal surgical outcome measure.

Are the Roland Morris Disability Questionnaire and Oswestry Disability Index interchangeable in patients after lumbar spinal fusion?

BACKGROUND

Low back pain is a common health problem for which there are several treatment options. For optimizing clinical decision making, evaluation of treatments and research purposes it is important that health care professionals are able to evaluate the functional status of patients. Patient reported outcome measures (PROMs) are widely accepted and recommended. The Roland Morris Disability Questionnaire (RMDQ) and the Oswestry Disability Index (ODI) are the two mainly used condition-specific patient reported outcomes. Concerns regarding the content and structural validity and also the different scoring systems of these outcome measures makes comparison of treatment results difficult.

OBJECTIVE

Aim of this study was to determine if the RMDQ and ODI could be used exchangeable by assessing the correlation and comparing different measurement properties between the questionnaires.

METHODS

Clinical data from patients who participated in a multicenter RCT with 2 year follow-up after lumbar spinal fusion were used. Outcome measures were the RMDQ, ODI, Short Form 36 - Health Survey (SF-36), leg pain and back pain measured on a 0-100 mm visual analogue scale (VAS). Cronbach's alpha coefficients, Spearman correlation coefficients, multiple regression analysis and Bland-Altman plots were calculated.

RESULTS

three hundred and seventy-six completed questionnaires filled out by 87 patients were used. The ODI and RMDQ had both a good level of internal consistency. There was a very strong correlation between the RMDQ and the ODI (r= 0.87; p< 0.001), and between the VAS and both the ODI and RMDQ. However, the Bland-Altman plot indicated bad agreement between the ODI and RMDQ.

CONCLUSIONS

The RMDQ and ODI cannot be used interchangeably, nor is there a possibility of converting the score from one questionnaire to the other. However, leg pain and back pain seemed to be predictors for both the ODI and the RMDQ.

The Impact of Incorporating Evidence-Based Guidelines for Lumbar Fusion Surgery in Neurosurgical Resident Education

BACKGROUND

Instrumented fusion procedures are essential in the treatment of degenerative lumbar spine disease to alleviate pain and improve neurological function, but they are being performed with increasing incidence and variability. We implemented a training module for neurosurgery residents that is based on evidence-based criteria for lumbar fusion surgery and measured its effectiveness in residents' decision making regarding whether patients should or should not undergo instrumented fusion.

METHODS

The study design was a pretest versus posttest experiment conducted from September 2019 until July 2020 to measure improvement after formalized instruction on evidence-based guidelines. Neurosurgery residents of all training levels at our institution participated. A test was administered at the beginning of each academic year. The highest possible score was 18 points in each pretest and posttest.

RESULTS

There was a general trend of test score improvement across all levels of training with a greater degree of change for participants with lower compared with higher pretest scores, indicating a possible ceiling effect. Paired t test demonstrated an overall mean score increase of 2 points (P < 0.0001), equivalent to an 11.11% increase (P < 0.0001). Stratified by training group, mean absolute change in test score was 2 (P = 0.0217), 1.67 (P = 0.0108), and 2.25 (P = 0.0173) points for junior, midlevel, and senior training groups, respectively.

CONCLUSIONS

Incorporating a targeted evidence-based learning module for lumbar spine fusion surgery can improve neurosurgery residents' clinical decision making toward a more uniform practice supported by published data.

Health-related quality-of-life improvement after hallux valgus corrective surgery

BACKGROUND

Hallux valgus is a common forefoot deformity that affects function of foot and quality of life (QoL). This study aims to identify factors associated with clinically important improvements in QoL after hallux valgus corrective surgery.

METHODS

A retrospective analysis on 591 cases of hallux valgus corrective surgery performed between 2007 and 2013 was conducted. Patients' preoperative and 2-year postoperative Physical Component Score (PCS) and Mental Component Score (MCS) were compared to identify the presence of clinically significant improvements in patient-reported QoL. A multiple logistic regression model was developed through a stepwise variable-selection model building approach. Age, BMI, preoperative patient reported outcome score, PCS, MCS, pain score, gender, side of surgery, type of surgery, and presence of lesser toe deformities or metatarsalgia were considered.

RESULTS

Median PCS significantly improved from 49 to 53 (p < 0.001), and median MCS remained at 56 (p = 0.724). Age, preoperative MCS and PCS were independent predictors for significant improvements of PCS at 2-year postoperatively.

CONCLUSION

Three groups of patients were more likely to have significant QoL improvements after hallux valgus corrective surgery. These were the younger patients, those with better preoperative mental health or those with poorer preoperative physical health.

LEVEL OF EVIDENCE

III.

Using Smartphone-Based Accelerometer Data to Objectively Assess Outcomes in Spine Surgery

BACKGROUND

In order to deliver optimal patient care, spine surgeons must integrate technological changes to arrive at novel measures of functional outcomes. Historically, subjective patient-reported outcome (PRO) surveys have been used to determine the relative benefit of surgical treatments. Using smartphone-based accelerometers, surgeons now have the ability to arrive at objective outcome metrics.

OBJECTIVE

To use Apple Health (Apple Inc, Cupertino, California) data to approximate physical activity levels before and after spinal fusion as an objective outcome measurement.

METHODS

Personal activity data were acquired retrospectively from the cellphones of consenting patients. These data were used to measure changes in activity level (daily steps, flights climbed, and distance traveled) before and after patients underwent spine surgery at a single institution by a single surgeon. After data collection, we investigated the demographic information and daily physical activity pre- and postoperatively of participating patients.

RESULTS

Twenty-three patients were included in the study. On average, patients first exceeded their daily 1-yr average distance walked, flights climbed, and steps taken at 10.3 ± 14, 7.6 ± 21.1, and 8 ± 9.9 wk, respectively. Mean flights climbed, distance traveled, and steps taken decreased significantly from 6 mo prior to surgery to 2 wk postoperatively. Distance traveled and steps taken significantly increased from 6 mo prior to surgery to 7 to 12 mo postoperatively.

CONCLUSION

We demonstrated a valuable supplement to traditional PROs by using smartphone-based activity data. This methodology yields a rich data set that has the potential to augment our understanding of patient recovery.

Invasive Treatments for Low Back Disorders

OBJECTIVE

This abbreviated version of the American College of Occupational and Environmental Medicine's Low Back Disorders guideline reviews the evidence and recommendations developed for invasive treatments used to manage low back disorders.

METHODS

Comprehensive systematic literature reviews were accomplished with article abstraction, critiquing, grading, evidence table compilation, and guideline finalization by a multidisciplinary expert panel and extensive peer-review to develop evidence-based guidance. Consensus recommendations were formulated when evidence was lacking and often relied on analogy to other disorders for which evidence exists. A total of 47 high-quality and 321 moderate-quality trials were identified for invasive management of low back disorders.

RESULTS

Guidance has been developed for the invasive management of acute, subacute, and chronic low back disorders and rehabilitation. This includes 49 specific recommendations.

CONCLUSION

Quality evidence should guide invasive treatment for all phases of managing low back disorders.

Impact of surgeon and hospital factors on surgical decision-making for grade 1 degenerative lumbar spondylolisthesis: a Quality Outcomes Database analysis

OBJECTIVE

Surgical treatment for degenerative spondylolisthesis has been proven to be clinically challenging and cost-effective. However, there is a range of thresholds that surgeons utilize for incorporating fusion in addition to decompressive laminectomy in these cases. This study investigates these surgeon- and site-specific factors by using the Quality Outcomes Database (QOD).

METHODS

The QOD was queried for all cases that had undergone surgery for grade 1 spondylolisthesis from database inception to February 2019. In addition to patient-specific covariates, surgeon-specific covariates included age, sex, race, years in practice (0-10, 11-20, 21-30, > 30 years), and fellowship training. Site-specific variables included hospital location (rural, suburban, urban), teaching versus nonteaching status, and hospital type (government, nonfederal; private, nonprofit; private, investor owned). Multivariable regression and predictor importance analyses were performed to identify predictors of the treatment performed (decompression alone vs decompression and fusion). The model was clustered by site to account for site-specific heterogeneity in treatment selection.

RESULTS

A total of 12,322 cases were included with 1988 (16.1%) that had undergone decompression alone. On multivariable regression analysis clustered by site, adjusting for patient-level clinical covariates, no surgeon-specific factors were found to be significantly associated with the odds of selecting decompression alone as the surgery performed. However, sites located in suburban areas (OR 2.32, 95% CI 1.09-4.84, p = 0.03) were more likely to perform decompression alone (reference = urban). Sites located in rural areas had higher odds of performing decompression alone than hospitals located in urban areas, although the results were not statistically significant (OR 1.33, 95% CI 0.59-2.61, p = 0.49). Nonteaching status was independently associated with lower odds of performing decompression alone (OR 0.40, 95% CI 0.19-0.97, p = 0.04). Predictor importance analysis revealed that the most important determinants of treatment selection were dominant symptom (Wald χ2 = 34.7, accounting for 13.6% of total χ2) and concurrent diagnosis of disc herniation (Wald χ2 = 31.7, accounting for 12.4% of total χ2). Hospital teaching status was also found to be relatively important (Wald χ2 = 4.2, accounting for 1.6% of total χ2) but less important than other patient-level predictors.

CONCLUSIONS

Nonteaching centers were more likely to perform decompressive laminectomy with supplemental fusion for spondylolisthesis. Suburban hospitals were more likely to perform decompression only. Surgeon characteristics were not found to influence treatment selection after adjustment for clinical covariates. Further large database registry experience from surgeons at high-volume academic centers at which surgically and medically complex patients are treated may provide additional insight into factors associated with treatment preference for degenerative spondylolisthesis.

Construct validity and responsiveness of commonly used patient reported outcome instruments in decompression for lumbar spinal stenosis

BACKGROUND

Validity and responsiveness of Oswestry disability index (ODI), Roland Morris disability questionnaires (RMDQ), Short Form-12 Physical Component Score (SF-12 PCS) and Short Form-12 Mental Component Score (SF-12 MCS) in patients undergoing open decompression for lumbar canal stenosis has not been previously reported.

METHODS

Outcome assessment was prospectively evaluated using the ODI, RMDQ, SF-12 PCS and SF-12 MCS pre-intervention and at average follow-up of three months post-intervention. Pearson correlation coefficient was used to evaluate the association between change in values of ODI, RMDQ, SF-12 PCS and SF-12 MCS. Distribution based methods (Effect size [ES], standardised response mean [SRM]) and anchor based method (Area under the curve [AUC] of receiver operating curve [ROC]) were used to determine responsiveness. AUC value ≥ 0.70 is considered as adequate level of responsiveness and the outcome instrument with the largest AUC is considered to be the most responsive outcome instrument.

RESULTS

This study included 77 participants. Responsiveness was assessed at a mean follow-up of 12 weeks postoperatively. There was significant strong correlation between ODI and RMDQ (r = 0.65, p < 0.0001). The ES of ODI, RMDQ, SF-12 PCS and SF-12 MCS were 1.54, 1.48, 1.85 and 0.51 respectively. The SRM of RMDQ, ODI, SF-12 PCS and SF-12 MCS were 1.22, 1.17, 1.0 and 0.47 respectively. AUC of ODI, RMDQ, SF-12 PCS and SF-12 MCS were 0.83-0.88, 0.82 to 0.86, 0.78 to 0.81 and 0.69 to 0.70 respectively.

CONCLUSION

It is recommended to use either ODI or RMDQ as region specific patient reported outcome instrument and SF-12 PCS as a health related quality of life outcome instrument to evaluate outcome after decompressive laminectomy for lumbar canal stenosis.

Correlation of return to work with patient satisfaction after surgery for lumbar spondylolisthesis: an analysis of the Quality Outcomes Database

OBJECTIVE

Return to work (RTW) and satisfaction are important outcome measures after surgery for degenerative spine disease. The authors queried the prospective Quality Outcomes Database (QOD) to determine if RTW correlated with patient satisfaction.

METHODS

The QOD was queried for patients undergoing surgery for degenerative lumbar spondylolisthesis. The primary outcome of interest was correlation between RTW and patient satisfaction, as measured by the North American Spine Society patient satisfaction index (NASS). Secondarily, data on satisfied patients were analyzed to see what patient factors correlated with RTW.

RESULTS

Of 608 total patients in the QOD spondylolisthesis data set, there were 292 patients for whom data were available on both satisfaction and RTW status. Of these, 249 (85.3%) were satisfied with surgery (NASS score 1–2), and 224 (76.7%) did RTW after surgery. Of the 68 patients who did not RTW after surgery, 49 (72.1%) were still satisfied with surgery. Of the 224 patients who did RTW, 24 (10.7%) were unsatisfied with surgery (NASS score 3–4). There were significantly more people who had an NASS score of 1 in the RTW group than in the non-RTW group (71.4% vs 42.6%, p < 0.05). Failure to RTW was associated with lower level of education, worse baseline back pain (measured with a numeric rating scale), and worse baseline disability (measured with the Oswestry Disability Index [ODI]).

CONCLUSIONS

There are a substantial number of patients who are satisfied with surgery even though they did not RTW. Patients who were satisfied with surgery and did not RTW typically had worse preoperative back pain and ODI and typically did not have a college education. While RTW remains an important measure after surgery, physicians should be mindful that patients who do not RTW may still be satisfied with their outcome.

Hospital and Surgeon Variation in Patient-reported Functional Outcomes After Lumbar Spine Fusion: A Statewide Evaluation

STUDY DESIGN

Statewide retrospective cohort study using prospectively collected data from the Spine Care and Outcomes Assessment Program, capturing ∼75% of the state's spine fusion procedures.

OBJECTIVE

The aim of this study was to estimate the variation in patient-reported outcomes (PROs) 1 year after elective lumbar fusion surgery across surgeons and hospitals; and to discuss the potential impact of guiding patient selection using a PRO prediction tool.

SUMMARY OF BACKGROUND DATA

Despite an increasing interest in incorporating PROs as part of the move toward value-based payment and to improve quality, limited evidence exists on how PROs vary across hospitals and surgeons, a key aspect of using these metrics for quality profiling.

METHODS

We examined patient-reported functional improvement (≥15-point reduction in the Oswestry Disability Index [ODI]) and minimal disability (reaching ≤22 on the ODI) 1 year after surgery in 17 hospitals and 58 surgeons between 2012 and 2017. Outcomes were risk-adjusted for patient characteristics with multiple logistic regressions and reliability-adjusted using hierarchical models.

RESULTS

Of the 737 patients who underwent lumbar fusion (mean [SD] age, 63 [12] years; 60% female; 84% had stenosis; 70% had spondylolisthesis), 58.7% achieved functional improvement and 42.5% reached minimal disability status at 1 year. After adjusting for patient factors, there was little variation between hospitals and surgeons (maximum interclass correlation was 3.5%), and this variation became statistically insignificant after further reliability adjustment. Avoiding operation on patients with <50% chance of functional improvement may reduce current surgical volume by 63%.

CONCLUSION

Variations in PROs across hospitals and surgeons were mainly driven by differences in patient populations undergoing lumbar fusion, suggesting that PROs may not be useful indicators of hospital or surgeon quality. Careful patient selection using validated prediction tools may decrease differences in outcomes across hospitals and providers and improve overall quality, but would significantly reduce surgical volumes.

LEVEL OF EVIDENCE

3.

Development and Validation of a Prediction Model for Pain and Functional Outcomes After Lumbar Spine Surgery

Importance

Functional impairment and pain are common indications for the initiation of lumbar spine surgery, but information about expected improvement in these patient-reported outcome (PRO) domains is not readily available to most patients and clinicians considering this type of surgery.

Objective

To assess population-level PRO response after lumbar spine surgery, and develop/validate a prediction tool for PRO improvement.

Design, Setting, and Participants

This statewide multicenter cohort was based at 15 Washington state hospitals representing approximately 75% of the state's spine fusion procedures. The Spine Surgical Care and Outcomes Assessment Program and the survey center at the Comparative Effectiveness Translational Network prospectively collected clinical and PRO data from adult candidates for lumbar surgery, preoperatively and postoperatively, between 2012 and 2016. Prediction models were derived for PRO improvement 1 year after lumbar fusion surgeries on a random sample of 85% of the data and were validated in the remaining 15%. Surgical candidates from 2012 through 2015 were included; follow-up surveying continued until December 31, 2016, and data analysis was completed from July 2016 to April 2017.

Main Outcomes and Measures

Functional improvement, defined as a reduction in Oswestry Disability Index score of 15 points or more; and back pain and leg pain improvement, defined a reduction in Numeric Rating Scale score of 2 points or more.

Results

A total of 1965 adult lumbar surgical candidates (mean [SD] age, 61.3 [12.5] years; 944 [59.6%] female) completed baseline surveys before surgery and at least 1 postoperative follow-up survey within 3 years. Of these, 1583 (80.6%) underwent elective lumbar fusion procedures; 1223 (77.3%) had stenosis, and 1033 (65.3%) had spondylolisthesis. Twelve-month follow-up participation rates for each outcome were between 66% and 70%. Improvements were reported in function, back pain, and leg pain at 12 months by 306 of 528 surgical patients (58.0%), 616 of 899 patients (68.5%), and 355 of 464 patients (76.5%), respectively, whose baseline scores indicated moderate to severe symptoms. Among nonoperative patients, 35 (43.8%), 47 (53.4%), and 53 (63.9%) reported improvements in function, back pain, and leg pain, respectively. Demographic and clinical characteristics included in the final prediction models were age, sex, race, insurance status, American Society of Anesthesiologists score, smoking status, diagnoses, prior surgery, prescription opioid use, asthma, and baseline PRO scores. The models had good predictive performance in the validation cohort (concordance statistic, 0.66-0.79) and were incorporated into a patient-facing, web-based interactive tool (https://becertain.shinyapps.io/lumbar_fusion_calculator).

Conclusions and Relevance

The PRO response prediction tool, informed by population-level data, explained most of the variability in pain reduction and functional improvement after surgery. Giving patients accurate information about their likelihood of outcomes may be a helpful component in surgery decision making.

Comparison of Nitinol and Titanium Nails Effectiveness for Lumbosacral Spine Fixation in Surgical Treatment of Degenerative Spine Diseases

Relevance. Surgical decompression and decompression with stabilization are highly effective for treatment of spinal canal stenosis at the level of lumbar spine. However, complications developing after application of rigid fixation systems resulted in active introduction of dynamic implants into clinical practice.

Purpose of the study — to compare effectiveness of nitinol and titanium nails for lumbosacral fixation in surgical treatment of degenerative spine diseases.

Materials and methods. 220 patients who underwent surgeries in 4 hospitals were randomized into two groups, each consisting of 110 patients (1:1 ratio): a group of patients who underwent stabilization of the vertebral motor segments with rods of nitinol with the required volume of decompression at the operation level and a group of patients who underwent stabilization of the vertebral motor segments with standard rods of titanium with the required volume of decompression at the intervention level. Patients suffered clinically significant spinal canal stenosis in one or two adjacent segments: from L3 to S1. Outcomes were evaluated during three years postoperatively by VAS scale for spine and lower limbs, and by ODI and SF-36 scales.

Results. All scales demonstrated better values in both groups of patients, namely, significant decrease of pain syndrome and improvement in mental and physical health. X-ray examination of all patients during the study period demonstrated restoration of lumbar lordosis. Group of patients with dynamic nails featured less complications rate related to metal implants including adjacent segment disease.

Conclusion. Transpedicular fixation of lumbosacral spine by nitinol nails is an effective technique allowing to preserve motion along with stable fixation.

Influence of Gender on Health-Related Quality of Life and Disability at 1 Year After Surgery for Thoracolumbar Burst Fractures

STUDY DESIGN

Case series.

OBJECTIVE

Thoracolumbar burst fractures (TLBF) are the most frequent type of spinal fractures. Approximately half of the patients are neurologically intact and their treatment is still debatable. Gender could influence outcome after surgical procedures, but this is still unclear in patients sustaining a spinal fracture. The aim of this study was to investigate how gender influences health-related quality of life (HRQOL) and disability in patients operated on for TLBF.

METHODS

We identified 44 neurologically intact patients from a consecutive series of patients treated surgically for a single-level traumatic burst fracture (AOSpine Subaxial Classification System A3) in the thoracolumbar transition area (Th12-L2). At 1 year after surgery, they were evaluated using the SF-36v2 questionnaire to assess HRQOL and Oswestry Disability Index (ODI) questionnaire to evaluate disability.

RESULTS

Male patients scored higher in each item of the SF-36v2, with significant differences (P < .05) for Physical Function (PF), Bodily Pain (BP), and Social Function (SF). Male patients also had lower disability scores. Overall ODI score had a strong correlation with Physical Function, Role-Physical, Bodily Pain, Vitality, Mental Health, and overall Physical Component Summary (PCS) of the SF-36 in women, but only with Physical Function, Role-Physical, Role-Emotional, and PCS in men.

CONCLUSIONS

In this study, male patients reported better outcomes at 1 year after surgery for TLBF than women. Disability strongly correlated with the overall HRQOL, physical and mental health in women, but not in men. We found gender-related differences favoring men after surgical interventions for spinal fractures.

Minimum Clinically Important Difference: Current Trends in the Spine Literature

STUDY DESIGN

Review of the 2011 to 2015 minimum clinically important difference (MCID)-related publications in Spine, Spine Journal, Journal of Neurosurgery-Spine, and European Spine Journal.

OBJECTIVE

To summarize the various determinations of MCID and to analyze its usage in the spine literature of the past 5 years in order to develop a basic reference to help practitioners interpret or utilize MCID.

SUMMARY OF BACKGROUND DATA

MCID represents the smallest change in a domain of interest that is considered beneficial to a patient or clinician. The many sources of variation in calculated MCID values and inconsistency in its utilization have resulted in confusion in the interpretation and use of MCID.

METHODS

All articles from 2011 to 2015 were reviewed. Only clinical science articles utilizing patient reported outcome scores (PROs) were included in the analysis. A keyword search was then performed to identify articles that used MCID. MCID utilization in the selected papers was characterized and recorded.

RESULTS

MCID was referenced in 264/1591 (16.6%) clinical science articles that utilized PROs: 22/264 (8.3%) independently calculated MCID values and 156/264 (59.1%) used previously published MCID values as a gauge of their own results. Despite similar calculation methods, there was a two- or three-fold range in the recommended MCID values for the same instrument. Half the studies recommended MCID values within the measurement error. Most studies (97.2%) using MCID to evaluate their own results relied on generic MCID. The few studies using specific MCID (MCID calculated for narrowly defined indications or treatments) did not consistently match the characteristics of their sample to the specificity of the MCID. About 48% of the studies compared group averages instead of individual scores to the MCID threshold.

CONCLUSION

Despite a clear interest in MCID as a measure of patient improvement, its current developments and uses have been inconsistent.

LEVEL OF EVIDENCE

N/A.

Laminectomy plus Fusion versus Laminectomy Alone for Lumbar Spondylolisthesis

BACKGROUND

The comparative effectiveness of performing instrumented (rigid pedicle screws affixed to titanium alloy rods) lumbar spinal fusion in addition to decompressive laminectomy in patients with symptomatic lumbar grade I degenerative spondylolisthesis with spinal stenosis is unknown.

METHODS

In this randomized, controlled trial, we assigned patients, 50 to 80 years of age, who had stable degenerative spondylolisthesis (degree of spondylolisthesis, 3 to 14 mm) and symptomatic lumbar spinal stenosis to undergo either decompressive laminectomy alone (decompression-alone group) or laminectomy with posterolateral instrumented fusion (fusion group). The primary outcome measure was the change in the physical-component summary score of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36; range, 0 to 100, with higher scores indicating better quality of life) 2 years after surgery. The secondary outcome measure was the score on the Oswestry Disability Index (range, 0 to 100, with higher scores indicating more disability related to back pain). Patients were followed for 4 years.

RESULTS

A total of 66 patients (mean age, 67 years; 80% women) underwent randomization. The rate of follow-up was 89% at 1 year, 86% at 2 years, and 68% at 4 years. The fusion group had a greater increase in SF-36 physical-component summary scores at 2 years after surgery than did the decompression-alone group (15.2 vs. 9.5, for a difference of 5.7; 95% confidence interval, 0.1 to 11.3; P=0.046). The increases in the SF-36 physical-component summary scores in the fusion group remained greater than those in the decompression-alone group at 3 years and at 4 years (P=0.02 for both years). With respect to reductions in disability related to back pain, the changes in the Oswestry Disability Index scores at 2 years after surgery did not differ significantly between the study groups (-17.9 in the decompression-alone group and -26.3 in the fusion group, P=0.06). More blood loss and longer hospital stays occurred in the fusion group than in the decompression-alone group (P<0.001 for both comparisons). The cumulative rate of reoperation was 14% in the fusion group and 34% in the decompression-alone group (P=0.05).

CONCLUSIONS

Among patients with degenerative grade I spondylolisthesis, the addition of lumbar spinal fusion to laminectomy was associated with slightly greater but clinically meaningful improvement in overall physical health-related quality of life than laminectomy alone. (Funded by the Jean and David Wallace Foundation and others; SLIP ClinicalTrials.gov number, NCT00109213.).

Appraisal of the Quality of Neurosurgery Clinical Practice Guidelines

OBJECTIVE

The rate of neurosurgery guidelines publications was compared over time with all other specialties. Neurosurgical guidelines and quality of supporting evidence were then analyzed and compared by subspecialty.

METHODS

The authors first performed a PubMed search for "Neurosurgery" and "Guidelines." This was then compared against searches performed for each specialty of the American Board of Medical Specialties. The second analysis was an inventory of all neurosurgery guidelines published by the Agency for Healthcare Research and Quality Guidelines clearinghouse. All Class I evidence and Level 1 recommendations were compared for different subspecialty topics.

RESULTS

When examined from 1970-2010, the rate of increase in publication of neurosurgery guidelines was about one third of all specialties combined (P < 0.0001). However, when only looking at the past 5 years the publication rate of neurosurgery guidelines has converged upon that for all specialties. The second analysis identified 49 published guidelines for assessment. There were 2733 studies cited as supporting evidence, with only 243 of these papers considered the highest class of evidence (8.9%). These papers were used to generate 697 recommendations, of which 170 (24.4%) were considered "Level 1" recommendations.

CONCLUSION

Although initially lagging, the publication of neurosurgical guidelines has recently increased at a rate comparable with that of other specialties. However, the quality of the evidence cited consists of a relatively low number of high-quality studies from which guidelines are created. Wider implications of this must be considered when defining and measuring quality of clinical performance in neurosurgery.