An evidence-based approach to spine surgery

Do we really apply evidence-based-recommendations to spine surgery? Results of an international survey

OBJECTIVE

This international survey investigated Evidence-Based Medicine (EBM) in spine surgery by measuring its acceptance among spine surgeons. It assessed their understanding of EBM and how they apply it in practice by analyzing responses to various clinical scenarios..

MATERIALS AND METHODS

Following the CHERRIES guidelines, an e-survey was distributed to multiple social media forums for neurosurgeons and orthopedic surgeons on Facebook, LinkedIn, and Telegram and circulated further through email via the authors' network. Three hundred participants from Africa, Asia, Europe, North America, and Oceania completed the survey.

RESULTS

Our study revealed that 67.7% (n = 203) of respondents used EBM in their practice, and 97.3% (n = 292) believed training in research methodology and EBM was necessary for the practice of spine surgery. Despite this endorsement of using EBM in spine surgery, we observed varied responses to how EBM is applied in practice based on example scenarios. The responders who had additional training tended to obey EBM guidelines more than those who had no additional training. Most surgeons responded as always or sometimes prescribing methylprednisolone to patients with acute spinal cord injury. Other significant differences were identified between geographical regions, training, practice settings, and other factors.

CONCLUSIONS

Most respondents used EBM in practice and believed training in research methodology and EBM is necessary for spine surgery; however, there were significant variations on how to use them per case. Thus, the appropriate application of EBM in clinical settings for spinal surgery must be further studied.

Optimizing Dual Antiplatelet Therapy in the Perioperative Period for Spine Surgery After Recent Percutaneous Coronary Intervention: A Comprehensive Review, Synthesis, and Catalyst for Protocol Formulation

The increased incidence of spine surgery within the past decade has highlighted the importance of robust perioperative management to improve patient outcomes overall. Coronary artery disease is a common medical comorbidity present in the population of individuals who receive surgery for spinal pathology that is often treated with dual antiplatelet therapy (DAPT) after percutaneous coronary intervention. Discontinuation of DAPT before surgical intervention is typically indicated; however, contradictory evidence exists in the literature regarding the timing of DAPT use and discontinuation in the perioperative period. We review the most recent cardiac and spine literature on the intricacies of percutaneous coronary intervention and its associated risks in the postoperative period. We further propose protocols for DAPT use after both elective and urgent spine surgery to optimize perioperative care.

Quality of life in lumbar spinal stenosis: Does it correlate with magnetic resonance imaging and spinopelvic parameters?

Purpose

Degenerative lumbar spinal stenosis (LSS) is a common degenerative spinal disorder with debilitating symptoms that can impact quality of life (QoL). However, the anatomical basis for typical complaints has been poorly quantified. This study aims to correlate QoL assessments of patients with LSS with radiographic spinopelvic parameters and magnetic resonance imaging (MRI) measurements.

Methods

We screened 371 patients hospitalized for LSS and excluded those with a history of spine surgery. Ultimately, we analyzed the data of 34 patients retrospectively. Two independent members of our research group evaluated the alignment parameters on preoperative spinal radiographs, MRI, and classified the images according to the Pfirrmann grading. The spinopelvic alignment was then compared with the clinical QoL scores Core Outcome Measures Index (COMI) and the Oswestry Disability Index (ODI) as collected by the Spine Tango registry. In addition, the interobserver reliability was analyzed.

Results

The individual MRI measurements correlated significantly. This correlation could not be found when compared with the spinopelvic parameters on radiographs. Neither the COMI nor the ODI scores showed a significant correlation with the MRI or radiographic imaging.

Conclusions

The severity of LSS related disability according to QoL questionnaires could not be quantified by any MRI or spinopelvic parameter that was measured. There was also no correlation of the MRI and spinopelvic parameters among themselves. Consequently, treatment recommendations for symptomatic LSS should never be based on radiological data only.

Association Between Industry Sponsorship of Spine-Related Clinical Trials, Publication Status, and Research Outcomes

STUDY DESIGN

Observational Database Study.

OBJECTIVES

Prospective clinical trials in spinal surgery are expensive to conduct, especially when randomized, appropriately powered, and/or multicentered. Industry collaborations generate symbiotic relationships promoting technological advancement; however, they also allow for bias. To the authors' knowledge, there is no known analysis of correlations between industry sponsorship and publication rates of spine-related clinical trials. This observational work evaluates such potential associations.

METHODS

The ClinicalTrials.gov database was queried with terms spine, spinal, spondylosis, spondylolysis, cervical, lumbar, and compression fracture over an 11-year period. Design characteristics and outcomes were recorded from 822 spine surgery-related trials. Trials were stratified based on funding source and intervention class. Groups were compared via two-tailed chi-square test of independence or Fisher's exact test (α = .05), based on completion status and publication rates of positive vs negative results.

RESULTS

Industry-sponsored spine-related clinical trials were more likely to be terminated than their non-industry-sponsored counterparts (P < .001). Of the trials achieving publication, industry-sponsored trials reported positive results at a higher rate than did trials without industry funding (P = .037). Clinical trials examining devices were more likely to be terminated than those studying other intervention classes (P = .001).

CONCLUSIONS

High termination rates and positive result publication rates among industry-sponsored clinical trials in spinal surgery likely reflect industry's influence on the research community. Such partnership alleviates financial burden and provides accessibility to cutting-edge innovation. It is essential that all parties remain mindful of the significant bias that funding source may impart on study outcome.

Factors Affecting Postoperative Length of Stay in Patients Undergoing Anterior Lumbar Interbody Fusion

BACKGROUND

With hospital leaders and policy makers increasingly seeking ways to improve resource use, there has been heightened interest in reducing hospital length of stay (LOS) and performing spine procedures on an outpatient basis. We aimed to determine which risk factors correlated with prolonged LOS after anterior lumbar interbody fusion (ALIF).

METHODS

Medical records for patients who underwent ALIF were retrospectively reviewed. Patients were divided into those who had extended (≥3 days) versus nonextended (<3 days) LOS, and patient demographics, medical comorbidities, and preoperative medications were analyzed. Univariate and multivariate regression were then used to determine preoperative risk factors for extended LOS.

RESULTS

A total of 166 patients were included (mean age, 48.7 years). Medical comorbidities included hypertension (31.9%), diabetes (8.4%), and obesity (body mass index >30 kg/m²) (48.8%). LOS was not extended in 121 patients and extended in 45. Mean LOS was 2.2 days (95% confidence interval, 1.9-2.5). On multivariate logistic analysis, age ≥65 years (P = 0.001), preoperative benzodiazepine use (P = 0.014), 12-item Short Form mental component score (P = 0.008), estimated blood loss (P = 0.015), time to mobilization (P < 0.001), and total operative time (P = 0.020) were independent predictors for extended LOS.

CONCLUSIONS

As attempts are made to perform more spine procedure in ambulatory surgical centers, strict patient selection criteria are all critical in making this possible. Our results suggest that age, preoperative benzodiazepine use, higher intraoperative blood loss, delayed mobilization, and lower 12-item Short Form mental component score were correlated with increased LOS. Therefore, inpatient ALIF may be more suitable for patients with these risk factors.

Responsiveness of standard spine outcome tools: do they measure up?

OBJECTIVE

Over the past 2 decades, spine outcome research has become more standardized in response to recommendations from Deyo and others. By using the same generic and condition-specific patient-reported outcome (PRO) measures across studies, results are more easily compared. Given the challenges of maintaining high-quality data in clinical research studies, it would be important to evaluate the contribution of each PRO to confirm that it merits the respondent burden. This study aimed to examine the spine PROs' association with clinically important change and relative responsiveness in explaining variance in patients' global assessment of change (GAC).

METHODS

This prospective longitudinal cohort study included adults recruited from 4 active spine surgery practices at a Toronto-based hospital. Patients were diagnosed with a degenerative lumbar spinal condition and underwent spinal decompression and/or fusion surgery. Participants completed the RAND-36 (to generate the physical component score [PCS] and mental component score [MCS]), Oswestry Disability Index (ODI), the numeric rating scale (NRS) for pain, Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference, and a GAC item. Random-effects models were used to investigate the sensitivity of PROs to the GAC and their responsiveness over time (i.e., PRO main effects and PRO-by-time interactions, respectively).

RESULTS

The study sample included 168 patients (mean age 61 years, 50% female) with preoperative and up to 12 months of postoperative data. Random-effects models revealed significant main effects for all PROs. Significant time-by-PRO interactions were detected for the PCS, PROMIS, ODI, and NRS (p < 0.0005 in all cases), but not for the MCS. Further examination revealed different sensitivity of the PROs to the GAC at different times. The NRS, PROMIS, and PCS showed higher sensitivity early after surgery, and the PCS evinced a marked drop in sensitivity to the GAC at about 8 months postsurgery.

CONCLUSIONS

All PROs currently included in the spine outcome core measures are associated with patients' subjective assessment of a clinically important change, and all but the MCS scores are responsive to such change. Based on these findings, the core spine PROs could be reduced to include fewer estimates of pain. The authors suggest replacing the less responsive measures with tools that help to characterize factors that are driving the patients' subjective assessment of change and that meaningfully address some of the higher levels in the hierarchy of quality-of-life outcomes.

State-of-the-Art Reviews: Safety in Complex Spine Surgery

The surgical correction of spinal deformities carries a high risk of perioperative morbidity. As the incidence of debilitating spinal deformities continues to increase, so too does our obligation to search for ways to enhance safety in our delivery of surgical care. Standardized work processes and other lean manufacturing methodologies have the potential to improve efficiency, safety, and hence value in our delivery of surgical care to patients with complex spine pathologies by reducing variability in our work processes. These principles can be applied to patient care from the initial preoperative assessment to long-term postoperative follow-up in the creation of comprehensive protocols that guide the management of these complex patients. Early evidence suggests that short-term outcomes can be improved by implementing packages of systems reform aimed at reducing variability in our work processes; however, contradicting evidence exists on the utility of several specific components of these systems-reform packages.

The Evaluation of a Novel Three-Dimensional Printed Expandable Pedicle Screw Sleeve Insert

When used in combination with decompression, spinal fusion is a successful procedure for treating patients with spinal stenosis and degenerative spondylolisthesis. While a number of auxiliary devices have been proposed to enhance the fixation of the screw within the pedicle and vertebral body, there is conflicting information regarding the efficacy of their use. Therefore, the aim of this study was to determine the ability of a novel expandable pedicle screw to improve the fixation of the pedicle screw within the pedicle and vertebral body. A three-dimensional (3D) printed, screw sleeve was designed that expanded within the pedicle and vertebral body when a standard pedicle screw was inserted into it. The left and right pedicle of ten (N = 10) cadaveric lumbar spine specimens (L3–L5) were randomly assigned to be instrumented with either a pedicle screw and the sleeve or a pedicle screw only. Following instrumentation, the screws were exposed to tensile load at 5 mm/min until failure. The failure force, failure deformation, and area under the force–deformation curve were determined and compared between screw conditions. There were no significant differences between the screws and sleeve, and the screw only conditions for the failure force (p = 0.24), failure displacement (p = 0.10), and area under the curve (p = 0.38). While the novel screw sleeve presented here performed as well as a screw without a sleeve, it was better than other screw augmentation devices reported previously. In addition, it is likely that this device would prove useful as an enhancement to revision.

Anterior Versus Transforaminal Lumbar Interbody Fusion: Perioperative Risk Factors and 30-Day Outcomes

Background

Operative management of lower back pain often necessitates anterior lumbar interbody fusion (ALIF) or transforaminal lumbar interbody fusion (TLIF). Specific pathoanatomic advantages and indications exist for both approaches, and few studies to date have characterized comparative early outcomes.

Methods

Adult patients undergoing elective ALIF or TLIF operations were abstracted from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) years 2011-2014. Univariate analyses were performed by surgery cohort for each outcome and adjusted for demographic/clinical variables (age ≥ 65, sex, race, body mass index, American Society of Anesthesiologists physical classification score, functional status, inpatient/outpatient status, smoking, hypertension, Charlson Comorbidity Index) using multivariable regression. Means, standard errors, mean differences (B), odds ratios (ORs), and associated 95% confidence intervals (CIs) are reported. Significance was assessed at P < .05.

Results

Of 8263 subjects (ALIF: 4325, TLIF: 3938), ALIF subjects were younger, less obese, less physically impaired, and had significantly lower rates of hypertension, diabetes, coagulopathy, and previous cardiac surgery. On multivariable analysis, ALIF associated with shorter operative time (B = -11.80 minutes, 95% CI [-16.48, -7.12]; P < .001). Transforaminal lumbar interbody fusion was associated with increased incidence of urinary tract infections (UTIs; OR = 1.57, 95% CI [1.10, 2.26]; P = .013) and of blood transfusions (OR = 1.19, 95% CI [1.04, 1.37]; P = .012). Multivariate analysis also demonstrated TLIF associated with shorter hospital length of stay (B = -0.27 days, 95% CI [-0.54, -0.01]; P = .041), and fewer cases of pneumonia (OR = 0.55, 95% CI [0.32, 0.94]; P = .029) and prolonged ventilator dependency (OR = 0.33, 95% CI [0.12, 0.84]; P = .021).

Conclusions

Comparatively, ALIF patients experienced decreased operative time and decreased incidence of postoperative UTIs and blood transfusions. Anterior lumbar interbody fusion patients were more likely to suffer postoperative pulmonary complications and longer hospital stays. Our data support the notion that both anterior and transforaminal surgical approaches perform comparably in context of 30-day perioperative outcomes.

Using Lean Process Improvement to Enhance Safety and Value in Orthopaedic Surgery: The Case of Spine Surgery

Lean methodology was developed in the manufacturing industry to increase output and decrease costs. These labor organization methods have become the mainstay of major manufacturing companies worldwide. Lean methods involve continuous process improvement through the systematic elimination of waste, prevention of mistakes, and empowerment of workers to make changes. Because of the profit and productivity gains made in the manufacturing arena using lean methods, several healthcare organizations have adopted lean methodologies for patient care. Lean methods have now been implemented in many areas of health care. In orthopaedic surgery, lean methods have been applied to reduce complication rates and create a culture of continuous improvement. A step-by-step guide based on our experience can help surgeons use lean methods in practice. Surgeons and hospital centers well versed in lean methodology will be poised to reduce complications, improve patient outcomes, and optimize cost/benefit ratios for patient care.

Spinal Surgeon Variation in Single-Level Cervical Fusion Procedures: A Cost and Hospital Resource Utilization Analysis

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

To compare perioperative costs and outcomes of patients undergoing single-level anterior cervical discectomy and fusions (ACDF) at both a service (orthopedic vs. neurosurgical) and individual surgeon level.

SUMMARY OF BACKGROUND DATA

Hospital systems are experiencing significant pressure to increase value of care by reducing costs while maintaining or improving patient-centered outcomes. Few studies have examined the cost-effectiveness cervical arthrodesis at a service level.

METHODS

A retrospective review of patients who underwent a primary 1-level ACDF by eight surgeons (four orthopedic and four neurosurgical) at a single academic institution between 2013 and 2015 was performed. Patients were identified by Diagnosis-Related Group and procedural codes. Patients with the ninth revision of the International Classification of Diseases coding for degenerative cervical pathology were included. Patients were excluded if they exhibited preoperative diagnoses or postoperative social work issues affecting their length of stay. Comparisons of preoperative demographics were performed using Student t tests and chi-squared analysis. Perioperative outcomes and costs for hospital services were compared using multivariate regression adjusted for preoperative characteristics.

RESULTS

A total of 137 patients diagnosed with cervical degeneration underwent single-level ACDF; 44 and 93 were performed by orthopedic surgeons and neurosurgeons, respectively. There was no difference in patient demographics. ACDF procedures performed by orthopedic surgeons demonstrated shorter operative times (89.1 ± 25.5 vs. 96.0 ± 25.5 min; P = 0.002) and higher laboratory costs (Δ+$6.53 ± $5.52 USD; P = 0.041). There were significant differences in operative time (P = 0.014) and labor costs (P = 0.034) between individual surgeons. There was no difference in total costs between specialties or individual surgeons.

CONCLUSION

Surgical subspecialty training does not significantly affect total costs of ACDF procedures. Costs can, however, vary between individual surgeons based on operative times. Variation between individual surgeons highlights potential areas for improvement of the cost effectiveness of spinal procedures.

LEVEL OF EVIDENCE

4.

Complication avoidance with pre-operative screening: insights from the Seattle spine team

Complication rates for complex adult lumbar scoliosis surgery are unacceptably high. Standardized preoperative evaluation protocols have been shown to significantly reduce the likelihood of a spectrum of negative outcomes associated with complex adult lumbar scoliosis surgery. To increase patient safety and reduce complication risk, an entire medical and surgical team should work together to care for adult lumbar scoliosis patients. This article describes preoperative patient evaluation strategies with a particular focus on adult lumbar scoliosis surgery involving six or more levels of spinal fusion. Domains considered include recent preoperative evaluation literature, predictive risk modeling, the appropriate management of medical conditions, and the composition and activities of a multidisciplinary conference review team. An evidence-based comprehensive systematic preoperative surgical evaluation process is described.

Clinical outcome in lumbar decompression surgery for spinal canal stenosis in the aged population: a prospective Swiss multicenter cohort study

STUDY DESIGN

This is a prospective, multicenter cohort study including 8 medical centers in the metropolitan area of the Canton Zurich, Switzerland.

OBJECTIVES

To examine whether outcome and quality of life might improve after decompression surgery for degenerative lumbar spinal stenosis (DLSS) even in patients older than 80 years and to compare data with a younger patient population from our own patient collective.

SUMMARY AND BACKGROUND DATA

Lumbar decompression surgery without fusion has been shown to improve quality of life in lumbar spinal canal stenosis. In the population older than 80 years, treatment recommendations for DLSS show conflicting results.

METHODS

Eight centers in the metropolitan area of Zurich, Switzerland agreed on the classification of DLSS, surgical principles, and follow-up protocols. Patients were followed from baseline, at 6 months, and 12 months. Baseline characteristics were analyzed with 5 different questionnaires "Spinal Stenosis Measure, Feeling Thermometer, Numeric Rating Scale, 5D-3L, and Roland and Morris Disability Questionnaire." In addition, our study population was compared with a younger control group. Furthermore, we calculated the minimal clinically important differences.

RESULTS

Thirty-seven patients with an average age of 82.5 ± 2.5 years reached the 12-month follow-up. Spinal Stenosis Measure scores, the Feeling Thermometer, the Numeric Rating Scale, and the Roland and Morris Disability Questionnaire showed significant improvements at the 6-month and 12-month follow-ups (P < 0.001). One EQ-5D-3Lsubgroup "anxiety/depression" showed no significant improvement (P = 0.109) at 12-month follow-up. The minimal clinically important difference for the "Symptom Severity scale" in the Spinal Stenosis Measure was achieved with improvement of 70% in the older patient population.

CONCLUSION

Patients 80 years or older can expect a clinically meaningful improvement after lumbar decompression for symptomatic DLSS. Our patient population showed significant positive development in quality of life in the short- and long-term follow-ups.

LEVEL OF EVIDENCE

3.

Patient preferences for treatment of low back pain-a discrete choice experiment

BACKGROUND

Back pain imposes a substantial economic and social burden, and treatment decisions are distorted by conflicting evidence. Thus, it is important to include patient preferences in decision making and policy making.

OBJECTIVE

To contribute to the understanding of patient preferences in relation to the choice of treatment for low back pain.

METHODS

A discrete choice experiment was conducted with consecutive patients referred to a regional spine center. The respondents (n = 348) were invited to respond to a choice of two hypothetical treatment options and an opt-out option. The treatment attributes included the treatment modality, the risk of relapse, the reduction in pain, and the expected increase in the ability to perform activities of daily living. In addition, the wait time to achieve the treatment effect was used as a payment vehicle. Mixed logit models were created to perform analysis. Subgroup analysis, dividing respondents into sociodemographic and disease-related categories, further explored the willingness to wait.

RESULTS

Respondents assigned positive utilities to positive treatment outcomes and disutility to higher risks and longer waits for effects of treatment and to surgical interventions. The model captured significant heterogeneity within the sample for the outcomes of pain reduction and the ability to pursue activities of daily living and for the treatment modality. The subgroup analysis revealed differences in the willingness to wait, especially with regard to treatment modality, the level of pain experienced at the time of data collection, and the respondents' preferences for surgery.

CONCLUSIONS

The majority of the respondents prefer nonsurgical interventions, but patients are willing to wait for more ideal outcomes and preferred interventions. The results show that health care professionals have a very important task in communicating clearly about the expected results of treatment and the basis of their treatment decisions, as patients' preferences are highly individual.

Research in spinal surgery: Evaluation and practice of evidence-based medicine

Evidence-based medicine (EBM) is a common concept among medical practitioners, yet unique challenges arise when EBM is applied to spinal surgery. Due to the relative rarity of certain spinal disorders, and a lack of management equipoise, randomized controlled trials may be difficult to execute. Despite this, responsibility rests with spinal surgeons to design high quality studies in order to justify certain treatment modalities. The authors therefore review the tenets of implementing evidence-based research, through the lens of spinal disorders. The process of EBM begins with asking the correct question. An appropriate study is then designed based on the research question. Understanding study designs allows the spinal surgeon to assess the level of evidence provided. Validated outcome measurements allow clinicians to communicate the success of treatment strategies, and will increase the quality of a given study design. Importantly, one must recognize that the randomized controlled trial is not always the optimal study design for a given research question. Rather, prospective observational cohort studies may be more appropriate in certain circumstances, and would provide superior generalizability. Despite the challenges involved with EBM, it is the future of medicine. These issues surrounding EBM are important for spinal surgeons, as well as health policy makers and editorial boards, to have familiarity.

The Seattle Spine Team Approach to Adult Deformity Surgery: A Systems-Based Approach to Perioperative Care and Subsequent Reduction in Perioperative Complication Rates

STUDY DESIGN

Retrospective consecutive case review pre- and postintervention.

OBJECTIVES

Characterize the effects of the intervention.

SUMMARY OF BACKGROUND DATA

Complication rates in adult spinal deformity surgery are unacceptable. System approaches are necessary to increase patient safety. This group reported on the dual-attending surgeon approach, a live multidisciplinary preoperative screening conference, and the intraoperative protocol for the management of coagulopathy. The outcomes were demonstrated by complication rates before and after the institution of this protocol.

METHODS

Forty consecutive patients in Group A were managed without the 3-pronged approach. A total of 124 consecutive patients in Group B had a dual-attending surgeon approach, were presented and cleared by a live multidisciplinary preoperative conference, and were managed according to the intraoperative protocol.

RESULTS

Group A had an average age of 62 years (range, 39-84 years). Group B had an average age of 64 years (range, 18-84 years). Most patients in both groups had fusions from 9 to 15 levels. Complication rates in Group B were significantly lower (16% vs. 52%) (p < .001). Group B showed significantly lower return rates to the operating room during the perioperative 90-day period (0.8% vs. 12.5%) (p < .001). Group B also had lower rates of wound infection requiring debridement (1.6% vs. 7.5%), lower rates of deep vein thrombosis/pulmonary embolism (3.2% vs. 10%), and lower rates of postoperative neurological complications (0.5% vs. 2.5%) (not significant). Group B had significantly lower rates of urinary tract infection requiring antibiotics (9.7% vs. 32.5%) (p < .001).

CONCLUSIONS

These data suggests that a team approach consisting of a dual-attending surgeon approach in the operating room, a live preoperative screening conference, and an intraoperative protocol for managing coagulopathy will significantly reduce perioperative complication rates and enhance patient safety in patients undergoing complex spinal reconstructions for adult spinal deformity.

Degenerative lumbar spinal stenosis in older people: current treatment options

BACKGROUND

Degenerative lumbar spinal stenosis is increasingly being diagnosed in persons over age 65. In 2011, 55 793 older people with this condition were treated as inpatients in German hospitals. Among physicians, there is much uncertainty about the appropriate treatment strategy.

METHOD

Selective literature review.

RESULTS

Lumbar spinal stenosis in older people is characterized by spinal claudication and neurological deficits. A precise clinical history and physical examination and ancillary radiological studies are the necessary prerequisites for treatment. Magnetic resonance imaging is the radiological study of choice. Conservative treatment consists of physiotherapy, drugs, and local injections; various surgical treatments can be considered, depending on the severity of the problem. The main purpose of surgery is to decompress the spinal canal. If the lumbar spine is demonstrably unstable, an instrumented fusion should be performed in addition. There is, however, only moderately good evidence supporting the superiority of surgery over conservative treatment. In a prospective study, the complication rate of purely decompressive surgery was found to be 18%. The utility of the current operative techniques cannot be definitively assessed, because they are applied to a wide variety of patients in different stages of the disease and at different degrees of severity, and the reported results are thus not comparable from one trial to another.

CONCLUSION

No evidence-based recommendation on the diagnosis and treatment of lumbar spinal stenosis in older people can be formulated at present because of the lack of pertinent randomized trials.

Variation in outcomes across centers after surgery for lumbar stenosis and degenerative spondylolisthesis in the spine patient outcomes research trial

STUDY DESIGN

Retrospective review of a prospectively collected database.

OBJECTIVE

To examine whether short- and long-term outcomes after surgery for lumbar stenosis (SPS) and degenerative spondylolisthesis (DS) vary across centers.

SUMMARY OF BACKGROUND DATA

Surgery has been shown to be of benefit for both SPS and DS. For both conditions, surgery often consists of laminectomy with or without fusion. Potential differences in outcomes of these overlapping procedures across various surgical centers have not yet been investigated.

METHODS

Spine Patient Outcomes Research Trial cohort participants with a confirmed diagnosis of SPS or DS undergoing surgery were followed from baseline at 6 weeks, 3, 6, and 12 months, and yearly thereafter, at 13 spine clinics in 11 US states. Baseline characteristics and short- and long-term outcomes were analyzed.

RESULTS

A total of 793 patients underwent surgery. Significant differences were found between centers with regard to patient race, body mass index, treatment preference, neurological deficit, stenosis location, severity, and number of stenotic levels. Significant differences were also found in operative duration and blood loss, the incidence of durotomy, the length of hospital stay, and wound infection. When baseline differences were adjusted for, significant differences were still seen between centers in changes in patient functional outcome (Short Form-36 bodily pain and physical function, and Oswestry Disability Index) at 1 year after surgery. In addition, the cumulative adjusted change in the Oswestry Disability Index Score at 4 years significantly differed among centers, with Short Form-36 scores trending toward significance.

CONCLUSION

There is a broad and statistically significant variation in short- and long-term outcomes after surgery for SPS and DS across various academic centers, when statistically significant baseline differences are adjusted for. The findings suggest that the choice of center affects outcome after these procedures, although further studies are required to investigate which center characteristics are most important.

Lumbar spine fusion for chronic low back pain due to degenerative disc disease: a systematic review

STUDY DESIGN

Systematic literature review.

OBJECTIVE

To categorize published evidence systematically for lumbar fusion for chronic low back pain (LBP) in order to provide an updated and comprehensive analysis of the clinical outcomes.

SUMMARY OF BACKGROUND DATA

Despite a large number of publications of outcomes of spinal fusion surgery for chronic LBP, there is little consensus on efficacy.

METHODS

A MEDLINE and Cochrane database search was performed to identify published articles reporting on validated patient-reported clinical outcomes measures (2 or more of visual analogue scale, Oswestry Disability Index, Short Form [36] Health Survey [SF-36] PCS, and patient satisfaction) with minimum 12 months of follow-up after lumbar fusion surgery in adult patients with LBP due to degenerative disc disease. Twenty-six total articles were identified and stratified by level of evidence: 18 level 1 (6 studies of surgery vs. nonoperative treatment, 12 studies of alternative surgical procedures), 2 level 2, 2 level 3, and 4 level 4 (2 prospective, 2 retrospective). Weighted averages of each outcomes measure were computed and compared with established minimal clinically important difference values.

RESULTS

Fusion cohorts included a total of 3060 patients. The weighted average improvement in visual analogue scale back pain was 36.8/100 (standard deviation [SD], 14.8); in Oswestry Disability Index 22.2 (SD, 14.1); in SF-36 Physical Component Scale 12.5 (SD, 4.3). Patient satisfaction averaged 71.1% (SD, 5.2%) across studies. Radiographical fusion rates averaged 89.1% (SD, 13.5%), and reoperation rates 12.5% (SD, 12.4%) overall, 9.2% (SD, 7.5%) at the index level. The results of the collective studies did not differ statistically in any of the outcome measures based on level of evidence (analysis of variance, P > 0.05).

CONCLUSION

The body of literature supports fusion surgery as a viable treatment option for reducing pain and improving function in patients with chronic LBP refractory to nonsurgical care when a diagnosis of disc degeneration can be made.

Histomorphometric and radiographical changes after lumbar implantation of the PEEK nonfusion interspinous device in the BB.4S rat model

STUDY DESIGN

An experimental animal study.

OBJECTIVE

To investigate histomorphometric and radiographical changes in the BB.4S rat model after PEEK (polyetheretherketone) nonfusion interspinous device implantation.

SUMMARY OF BACKGROUND DATA

Clinical effectiveness of the PEEK nonfusion spine implant Wallis (Abbott, Bordeaux, France; now Zimmer, Warsaw, IN) is well documented. However, there is a lack of evidence on the long-term effects of this implant on bone, in particular its influence on structural changes of bone elements of the lumbar spine.

METHODS

Twenty-four male BB.4S rats aged 11 weeks underwent surgery for implantation of a PEEK nonfusion interspinous device or for a sham procedure in 3 groups of 8 animals each: (1) implantation at level L4-L5; (2) implantation at level L5-L6; and (3) sham surgery. Eleven weeks postoperatively osteolyses at the implant-bone interface were measured via radiograph, bone mineral density of vertebral bodies was analyzed using osteodensitometry, and bone mineral content as well as resorption of the spinous processes were examined by histomorphometry. RESULTS.: Resorption of the spinous processes at the site of the interspinous implant was found in all treated segments. There was no significant difference in either bone density of vertebral bodies or histomorphometric structure of the spinous processes between adjacent vertebral bodies, between treated and untreated segments and between groups.

CONCLUSION

These findings indicate that resorption of spinous processes because of a result of implant loosening, inhibit the targeted load redistribution through the PEEK nonfusion interspinous device in the lumbar spinal segment of the rat. This leads to reduced long-term stability of the implant in the animal model. These results suggest that PEEK nonfusion interspinous devices like the Wallis implants may have time-limited effects and should only be used for specified indications.

[Symptomatic lumbar spinal stenosis: diagnostic evaluation and therapeutic strategies]

Lumbar spinal stenosis is a common problem in daily routine practice. In the vast majority of cases stenosis is caused by degenerative changes of the lumbar spine with neurogenic claudication being the typical symptom. This is defined as sciatic pain and discomfort which deteriorates during walking and standing, leading to progressive neurological deficits. The diagnostic evaluation is based on the typical history of the patient and the clinical examination followed by magnetic resonance imaging (MRI) and flexion-extension X-ray films as the most sensitive diagnostic tool. When clinical symptoms are mild, conservative treatment might be an option but in severely disabled patients and/or in cases of relevant neurological deficits surgical decompression, in special cases combined with instrumentation should be favoured when clinical and radiological findings match. In these cases an improvement of the clinical symptoms can be achieved in up to 90% of the patients.