SWISSspine: a nationwide registry for health technology assessment of lumbar disc prostheses

Defining the relative utility of lumbar spine surgery: A systematic literature review of common surgical procedures and their impact on health states

Degenerative lumbar spondylosis is a common indication for patients undergoing spine surgery. As healthcare costs rise, measuring quality of life (QOL) gains after surgical procedures is critical in assessing value. We set out to: 1) compare baseline and postoperative EuroQol-5D (EQ-5D) scores for lumbar spine surgery and common surgical procedures to obtain post-operative quality-adjusted life year (QALY) gain, and 2) establish the relative utility of lumbar spine surgery as compared to other commonly performed surgical procedures. A systematic literature review was conducted to identify all studies reporting preoperative/baseline and postoperative EQ-5D scores for common surgical procedures. For each study, the number of patients included and baseline/preoperative and follow-up mean EQ-5D scores were recorded, and mean QALY gained for each intervention was calculated. A total of 67 studies comprising 95,014 patients were identified. Patients with lumbar spondylosis had the worst reported QOL at baseline compared to other surgical cohorts. The greatest QALY gain was seen in patients undergoing hip arthroplasty (0.38), knee arthroplasty (0.35) and lumbar spine surgery (0.32), nearly 2.5-fold greater QALY gained than for all other procedures. The low preoperative QOL, coupled with the improvements offered with surgery, highlight the utility and value of lumbar spine surgery compared to other common surgical procedures.

Development and Validation of Cervical Prediction Models for Patient-Reported Outcomes at 1 Year After Cervical Spine Surgery for Radiculopathy and Myelopathy

STUDY DESIGN

Retrospective analysis of prospectively collected registry data.

OBJECTIVE

To develop and validate prediction models for 12-month patient-reported outcomes of disability, pain, and myelopathy in patients undergoing elective cervical spine surgery.

SUMMARY OF BACKGROUND DATA

Predictive models have the potential to be utilized preoperatively to set expectations, adjust modifiable characteristics, and provide a patient-centered model of care.

METHODS

This study was conducted using data from the cervical module of the Quality Outcomes Database. The outcomes of interest were disability (Neck Disability Index:), pain (Numeric Rating Scale), and modified Japanese Orthopaedic Association score for myelopathy. Multivariable proportional odds ordinal regression models were developed for patients with cervical radiculopathy and myelopathy. Patient demographic, clinical, and surgical covariates as well as baseline patient-reported outcomes scores were included in all models. The models were internally validated using bootstrap resampling to estimate the likely performance on a new sample of patients.

RESULTS

Four thousand nine hundred eighty-eight patients underwent surgery for radiculopathy and 2641 patients for myelopathy. The most important predictor of poor postoperative outcomes at 12-months was the baseline Neck Disability Index score for patients with radiculopathy and modified Japanese Orthopaedic Association score for patients with myelopathy. In addition, symptom duration, workers' compensation, age, employment, and ambulatory and smoking status had a statistically significant impact on all outcomes (P < 0.001). Clinical and surgical variables contributed very little to predictive models, with posterior approach being associated with higher odds of having worse 12-month outcome scores in both the radiculopathy and myelopathy cohorts (P < 0.001). The full models overall discriminative performance ranged from 0.654 to 0.725.

CONCLUSIONS

These predictive models provide individualized risk-adjusted estimates of 12-month disability, pain, and myelopathy outcomes for patients undergoing spine surgery for degenerative cervical disease. Predictive models have the potential to be used as a shared decision-making tool for evidence-based preoperative counselling.

LEVEL OF EVIDENCE

2.

The effectiveness of ergonomic interventions in material handling operations

This study evaluated the effectiveness of ergonomic interventions in material handling operations involving 33 employers and 535 employees from 2012 to 2017. Outcomes included employee-reported low back/upper extremity pain and safety incidents at baseline, every three months, and annually for up to two years. A total of 32.5% of employees completed at least one survey, while 13.6% completed all nine surveys over two years. Among highly exposed employees (who reported handling >= 50 lbs. > 33% of the time), upper extremity pain frequency and severity were lower among those who reported using the intervention routinely versus those that reported using their body strength alone to handle objects >= 50 lbs. After excluding from analyses one employer that used anti-fatigue mats, low back pain frequency was also significantly lower among highly exposed intervention users. In conclusion, there was some evidence that the interventions were effective in reducing employee-reported pain for highly exposed employees.

We Need to Talk about Lumbar Total Disc Replacement

BACKGROUND

Replacement of a diseased lumbar intervertebral disc with an artificial device, a procedure known as lumbar total disc replacement (LTDR), has been practiced since the 1980s.

METHODS

Comprehensive review of published literature germane to LTDR, but comment is restricted to high-quality evidence reporting implantation of lumbar artificial discs that have been commercially available for at least 15 years at the time of writing and which continue to be commercially available.

RESULTS

LTDR is shown to be a noninferior (and sometimes superior) alternative to lumbar fusion in patients with discogenic low back pain and/or radicular pain attributable to lumbar disc degenerative disease (LDDD). Further, LTDR is a motion-preserving procedure, and evidence is emerging that it may also result in risk reduction for subsequent development and/or progression of adjacent segment disease.

CONCLUSIONS

In spite of the substantial logistical challenges to the safe introduction of LTDR to a health care facility, the procedure continues to gain acceptance, albeit slowly.

CLINICAL RELEVANCE

Patients with LDDD who are considering an offer of spinal surgery can only provide valid and informed consent if they have been made aware of all reasonable surgical and nonsurgical options that may benefit them. Accordingly, and in those cases in which LTDR may have a role to play, patients under consideration for other forms of spinal surgery should be informed that this valid procedure exists.

Rate of spinal surgery in a rapidly aging society: the 27-year changes in Miyagi prefecture, Japan

BACKGROUND

Japan has had a rapidly aging population during the past 30 years. This study aimed to investigate longitudinal changes in the surgical rate for spinal disorders in Miyagi Prefecture (2.35 million inhabitants) with a similar population composition to Japan.

METHODS

Data of spinal surgeries were collected using the spine registry by Tohoku University Spine Society. Data on the annual number of spinal surgeries between 1988 and 2014 of all populations, in those aged ≥65 years old, in those aged ≥75 years old, and for each pathology were collected. The annual surgical rate per 100,000 inhabitants was calculated.

RESULTS

The surgical rate in 2010-2014 in total, at ≥65 years old, and at ≥75 years old showed 3.2-, 3.8- and 7.1-fold increases, respectively, compared with that in 1988-1989. Degenerative spinal disorders, spinal trauma and pyogenic spondylitis markedly increased, while metastatic spinal tumor and tuberculous spondylitis decreased over time. The surgical rate at ≥75 years with lumbar spinal stenosis showed a 12.6-time increase.

CONCLUSIONS

During a rapid period of aging, the rate of spinal surgeries has markedly increased, particularly, that for degenerative disorders. This is the first report on the long-term longitudinal changes in the rate of spinal surgery.

Magnetically controlled growing rods in the treatment of early-onset scoliosis

The MAGnetic Expansion Control (MAGEC) system is used increasingly in the management of early-onset scoliosis. Good results have been published, but there have been recent reports identifying implant failures that may be associated with significant metallosis surrounding the implants. This article aims to present the current knowledge regarding the performance of this implant, and the potential implications and strategies that may be employed to identify and limit any problems.

We urge surgeons to apply caution to patient and construct selection; engage in prospective patient registration using a spine registry; ensure close clinical monitoring until growth has ceased; and send all explanted MAGEC rods for independent analysis.

The MAGEC system may be a good instrumentation system for the treatment of early-onset scoliosis. However, it is innovative and like all new technology, especially when deployed in a paediatric population, robust systems to assess long-term outcome are required to ensure that patient safety is maintained.

Cite this article: Bone Joint J 2017;99-B:708–13.

INFLUENCE OF HEALTH TECHNOLOGY ASSESSMENT AND ITS MEASUREMENT

Objectives: The aim of this study was to obtain information on methods used to measure health technology assessment (HTA) influence, decisions that were influenced, and outcomes linked to HTA.

Methods: Electronic databases were used to locate studies in which HTA influence had been demonstrated. Inclusion criteria were studies that reliably reported consideration by decision makers of HTA findings; comparative studies of technology use before and after HTA; and details of changes in policy, health outcomes, or research that could be credibly linked to an HTA.

Results: Fifty-one studies were selected for review. Settings were national (24), regional (12), both national and regional (3) hospitals (9), and multinational (3). The most common approach to appraisal of influence was review of policy or administrative decisions following HTA recommendations (51 percent). Eighteen studies (35 percent) reported interview or survey findings, thirteen (26 percent) reviewed administrative data, and six considered the influence of primary studies. Of 142 decisions informed by HTA, the most common types were on routine clinical practice (67 percent of studies), coverage (63 percent), and program operation (37 percent). The most frequent indications of HTA influence were on decisions related to resource allocation (59 percent), change in practice pattern (31 percent), and incorporation of HTA details in reference material (18 percent). Few publications assessed the contribution of HTA to changing patient outcomes.

Conclusions: The literature on HTA influence remains limited, with little on longer term effects on practice and outcomes. The reviewed publications indicated how HTA is being used in different settings and approaches to measuring its influence that might be more widely applied, such as surveys and monitoring administrative data.

Surgical Resection of Intradural Extramedullary Spinal Tumors: Patient Reported Outcomes and Minimum Clinically Important Difference

STUDY DESIGN

Analysis of prospectively collected longitudinal web-based registry data.

OBJECTIVE

To determine relative validity, responsiveness, and minimum clinically important difference (MCID) thresholds in patients undergoing surgery for intradural extramedullary (IDEM) spinal tumors.

SUMMARY OF BACKGROUND DATA

Patient-reported outcomes (PROs) are vital in establishing the value of care in spinal pathology. There is limited availability of prospective, quality studies reporting PROs for IDEM spine tumors.

METHODS

. A total of 40 patients were analyzed. Baseline, postoperative 3-month, and 12-month PROs were recorded: Oswestry Disability Index or Neck disability Index (ODI/NDI), Quality of life EuroQol-5D (EQ-5D), Short Form-12 (SF-12), Numeric Rating Scale (NRS)-pain scores. Responders were defined as those who achieved a level of improvement one or two, after surgery, on health transition index (HTI) of SF-36. Receiver-operating characteristic curves were generated to assess the validity of PROs, and the difference between standardized response means (SRMs) in responders versus nonresponders was utilized to determine the relative responsiveness of each PRO measure. MCID thresholds were derived using previously reported minimal detectable change approach.

RESULTS

A significant improvement across all PROs at 3-months and 12-months follow up was noted. The derived MCID thresholds were 13.9 points: ODI/NDI, 0.14 quality adjusted life years: EQ-5D, 2.8 points: SF-12PCS and 10.7 points: SF-12MCS, 1.9 points: NRS-back/neck pain, and 1.8 points: NRS-leg/arm pain. SF-12PCS was most accurate discriminator of meaningful improvement (area under the curve, AUC-0.83) and most responsive (SRM-1.36) to postoperative improvement. EQ-5D, ODI/NDI, NRS-pain scores were all accurate discriminator (AUC-0.7-0.8) and responsive measures (0.97-0.67) of meaningful postoperative improvement. SF-12MCS was neither a valid discriminator (AUC-0.48) nor a responsive measure (SRM: -1.5) of outcome.

CONCLUSION

Surgical resection of IDEM spinal tumors provides significant and sustained improvement in quality of life, general health, disability, and pain at 12-month after surgery. The surgically resected IDEM-specific clinically meaningful thresholds are reported. All the PROs reported in this study can accurately discriminate responders and nonresponder based on SF-36 HTI index except for SF-12 MCS.

LEVEL OF EVIDENCE

3.

Inadequacy of 3-month Oswestry Disability Index outcome for assessing individual longer-term patient experience after lumbar spine surgery

OBJECTIVE Prospective longitudinal outcomes registries are at the center of evidence-driven health care reform. Obtaining real-world outcomes data at 12 months can be costly and challenging. In the present study, the authors analyzed whether 3-month outcome measurements sufficiently represent 12-month outcomes for patients with degenerative lumbar disease undergoing surgery. METHODS Data from 3073 patients undergoing elective spine surgery for degenerative lumbar disease were entered into a prospective multicenter registry (N(2)QOD). Baseline, 3-month, and 12-month follow-up Oswestry Disability Index (ODI) scores were recorded. The absolute differences between actual 12- and 3-month ODI scores was evaluated. Additionally, the authors analyzed the absolute difference between actual 12-month ODI scores and a model-predicted 12-month ODI score (the model used patients' baseline characteristics and actual 3-month scores). The minimal clinically important difference (MCID) for ODI of 12.8 points and the substantial clinical benefit (SCB) for ODI of 18.8 points were used based on the previously published values. The concordance rate of achieving MCID and SCB for ODI at 3-and 12-months was computed. RESULTS The 3-month ODI scores differed from 12-month scores by an absolute difference of 11.9 ± 10.8, and predictive modeling estimations of 12-month ODI scores differed from actual 12-month scores by a mean (± SD) of 10.7 ± 9.0 points (p = 0.001). Sixty-four percent of patients (n = 1982) achieved an MCID for ODI at 3 months in comparison with 67% of patients (n = 2088) by 12 months; 51% (n = 1731) and 61% (n = 1860) of patients achieved SCB for ODI at 3 months and 12 months, respectively. Almost 20% of patients had ODI scores that varied at least 20 points (the point span of an ODI functional category) between actual 3- and 12-month values. In the aggregate analysis of achieving MCID, 77% of patients were concordant and 23% were discordant in achieving or not achieving MCID at 3 and 12 months. The discordance rates of achieving or not achieving MCID for ODI were in the range of 19% to 27% for all diagnoses and treatments (decompression with and without fusion). The positive and negative predictive value of 3-months ODI to predict 12-month ODI was 86% and 60% for MCID and 82% and 67% for SCB. CONCLUSIONS Based on their findings, the authors conclude the following: 1) Predictive methods for functional outcome based on early patient experience (i.e., baseline and/or 3-month data) should be used to help evaluate the effectiveness of procedures in patient populations, rather than serving as a proxy for long-term individual patient experience. 2) Prospective longitudinal registries need to span at least 12 months to determine the effectiveness of spine care at the individual patient and practitioner level.

Generic Preference-based Measures for Low Back Pain: Which of Them Should Be Used?

STUDY DESIGN

Systematic review.

OBJECTIVE

This systematic review examines validity and responsiveness of three generic preference-based measures in patients with low back pain (LBP).

SUMMARY OF BACKGROUND DATA

LBP is a very common incapacitating disease with a significant impact on health-related quality of life (HRQoL). Health state utility values can be derived from various preference-based HRQoL instruments, and among them the most widely ones are EuroQol 5 dimensions (EQ-5D), Short Form 6 Dimensions (SF-6D), and Health Utilities Index 3 (HUI III). The ability of these instruments to reflect HRQoL has been tested in various contexts, but never for LBP populations.

METHODS

A systematic search on electronic literature databases was undertaken to identify studies of patients with LBP where health state utility values were reported. Records were screened using a set of predefined eligibility criteria. Data on validity (correlations and known group methods) and responsiveness (effect sizes, standardized response means, tests of statistical significance) of instruments were extracted using a customized extraction template, and assessed using predefined criteria.

RESULTS

There were substantial variations in the 37 included papers identified in relation to study design and outcome measures used. EQ-5D demonstrated good convergent validity, as it was able to distinguish between known groups. EQ-5D was also able to capture changes of health states as results of different interventions. Evidence for SF-6D and HUI III was limited to allow an appropriate evaluation.

CONCLUSION

EQ-5D performs well in LBP population and its scores seem to be suitable for economic evaluation of LBP interventions. However, the paucity of information on the other instruments makes it impossible to determine its relative validity and responsiveness compared with them.

Quality of Life and General Health After Elective Surgery for Cervical Spine Pathologies

BACKGROUND:

As part of the Affordable Care Act, health utility metrics are being investigated to define a cost-effective, value-based health care model. EuroQOL-5D (EQ-5D) and Short Form-6D (SF-6D) are commonly used quality-of-life instruments. Domains in the EQ-5D questionnaire are thought to be less responsive in measuring quality of life after cervical surgery.

OBJECTIVE:

To evaluate the validity and responsiveness of SF-6D and EQ-5D in determining health and quality of life after elective cervical spine surgery.

METHODS:

A total of 420 patients undergoing elective cervical spine surgery over a period of 2 years were enrolled in a prospective longitudinal registry. Patient-reported outcomes Neck Disability Index (NDI), EQ-5D, and SF-12 were recorded. Based on previously published equations, SF-6D was calculated using NDI and SF-12 scores. Patients were asked whether “surgery met their expectations” (meaningful improvement). The validity and relative responsiveness of SF-6D (NDI), SF-6D (SF-12), and EQ-5D to discriminate between meaningful and nonmeaningful improvement were calculated.

RESULTS:

Sixty-six percent of patients (277) reported a level of improvement after surgery that met their expectations (meaningful improvement). SF-6D (NDI) (area under the curve [AUC] = 0.69) was a more valid discriminator of meaningful improvement compared with the SF-6D (SF-12) (AUC = 0.65) and EQ-5D (AUC = 0.62). SF-6D (NDI) was also a more responsive measure compared with SF-6D (SF-12) and EQ-5D (standardized response mean difference: 0.66, 0.48, and 0.44, respectively).

CONCLUSION:

SF-6D is a more valid and responsive measure of general health and quality of life compared with EQ-5D. SF-6D derived from disease-specific disability scores was more valid and responsive than that derived from the generic preference-based SF-12. Cost-effective studies should use SF-6D as a measure of QALY after cervical spine surgery.

Predictors of improvement in quality of life and pain relief in lumbar spinal stenosis relative to patient age: a study based on the Spine Tango registry

BACKGROUND

An open decompression is the most common treatment for lumbar spinal canal stenosis (LSS), even in the elderly. However, it is not clear whether the treatment outcome is age dependent. The main purpose of this study was to evaluate the improvement in quality of life (QoL) and pain relief, after open decompression for LSS in relation to patient age.

METHODS

The study was performed on the basis of Spine Tango registry data. The database query resulted in 4768 patients from 40 international Spine Tango centres. The patients were subdivided into three age groups: (1) 20-64, (2) 65-74, and (3) ≥75 years. In multivariate logistic regression models, predictors for improvement in QoL and achievement of the minimum clinically relevant change in pain of two points were analysed.

RESULTS

All groups benefited from significant improvement in QoL and back and leg pain relief. Age group had no significant influence on the outcomes. The preoperative status of each outcome was a predictor for its own postoperative outcome. Fewer previous surgeries, rigid or dynamic stabilization, and lower patient comorbidity also had a partially predictive influence for one or the other outcome.

CONCLUSIONS

Our results confirm that all age groups significantly benefit from the open decompressive treatment of LSS. Age group had no significant influence on any outcome.

Viscoelastic Disc Arthroplasty Provides Superior Back and Leg Pain Relief in Patients with Lumbar Disc Degeneration Compared to Anterior Lumbar Interbody Fusion

BACKGROUND

Lumbar disc degeneration (LDD) is one of the most frequently diagnosed spinal diseases. The symptoms these disorders cause are anticipated to increase as the population in Western countries ages.

PURPOSE

Compare back and leg pain alleviation in patients with LDD and a viscoelastic disc prosthesis documented in the SWISSspine registry versus patients with anterior lumbar interbody fusion documented in the Spine Tango registry.

STUDY DESIGN

Prospectively collected clinical and outcome data in two independent spine registries. Outcome Measures were back and leg pain relief on 0 to 10 numerical rating scales.

MATERIALS AND METHODS

The analysis included a single surgeon series of 48 patients with viscoelastic total disc replacement (VTDR) from the SWISSspine registry which were compared to 131 patients with anterior lumbar interbody fusion (ALIF) from the Spine Tango registry. Two linear multivariate regression models were built to assess the associations of patient characteristics with back and leg pain relief. The following covariates were included in the models: patient age and sex, disc herniation as additional diagnosis, number of treated segments, level of treated segment, treatment type (VTDR, ALIF), preoperative back and leg pain levels and follow-up interval.

RESULTS

Both models showed VTDR to be associated with significantly higher back (2.76 points; 95% confidence interval (CI) 1.78 - 3.73; p < 0.001) and leg pain (2.12 points; 95% CI 1.12 to 3.13; p < 0.001) relief than ALIF. Other influential factors for higher back pain relief were female sex compared with male sex (1.03 additional points; 95% CI 0.27 to 1.78; p = 0.008), monosegmental surgery compared with bisegmental surgery (1.02 additional points; 95% CI 0.21 to 1.83; p = 0.014), and higher back pain at baseline (0.87 points additional pain relief per level of preoperative back pain; 95% CI 0.70 to 1.03; p < 0.001). Other influential factors for leg pain relief were monosegmental surgery (0.93 additional points; 95% CI 0.10 to 1.77; p = 0.029) and higher leg pain at baseline (0.83 points additional pain relief per level of preoperative leg pain; 95% CI 0.70 to 0.96). In both models the L3/4 segment showed 2.36 points (95% CI -4.27 to -0.45; p = 0.016) and 3.69 points (95% CI -5.66 to -1.71; p < 0.001) less pain relief than L5/S1.

DISCUSSION

Significantly higher back and leg pain relief were observed after viscoelastic total disc replacement in comparison with anterior lumbar interbody fusion. The new less rigid materials used in the second generation total disc replacements (TDRs) may make artificial disc replacement an increasingly attractive option for patients with degenerative lumbar disc disease. Further controlled and long-term follow-up studies are required for more detailed comparisons of the outcomes of these types of disc implants. The Freedom Lumbar Disc is limited by U.S. federal law to investigational use only.

Accurately measuring the quality and effectiveness of cervical spine surgery in registry efforts: determining the most valid and responsive instruments

BACKGROUND CONTEXT

There is a growing demand to measure the real-world effectiveness and value of care across all specialties and disease states. Prospective registries have emerged as a feasible way to capture real-world care across large patient populations. However, the proven validity of more robust and cumbersome patient-reported outcome instruments (PROi) must be balanced with what is feasible to apply in large-scale registry efforts. Hence, commercial registry efforts that measure quality and effectiveness of care in an attempt to guide quality improvement, pay for performance, or value-based purchasing should incorporate measures that most accurately represent patient-centered improvement.

PURPOSE

We set out to establish the relative validity and responsiveness of common PROi in accurately determining effectiveness of cervical surgery for neck and arm pain in registry efforts.

STUDY DESIGN

Prospective cohort study.

PATIENT SAMPLE

Eighty-eight patients undergoing primary anterior cervical discectomy and fusion (ACDF) for neck and arm pain.

OUTCOME MEASURES

Patient-reported outcome measures for pain (numeric rating scale for neck pain [NRS-NP] and arm pain [NRS-AP]), disability (neck disability index [NDI]), general health (short-form 12-item survey physical component summary [SF-12 PCS] and mental component summary [SF-12 MCS]), and quality of life (Euro-Qol-5D [EQ-5D]) were assessed.

METHODS

Eighty-eight patients undergoing primary ACDF for neck and arm pain were entered into a Web-based prospective registry. Baseline and 12-month patient-reported outcomes (NRS-NP, NRS-AP, NDI, SF-12 PCS, SF-12 MCS, and EQ-5D) were assessed. Patients were also asked whether they experienced a level of improvement after ACDF that met their expectation (meaningful improvement). To assess the validity of NRS-NP, NRS-AP, and NDI (measures of pain and disability) to discriminate between meaningful and nonmeaningful improvement and the validity of SF-12 PCS, SF-12 MCS, and EQ-5D (measures of general health and quality of life) to discriminate between meaningful and nonmeaningful improvement, receiver-operating characteristic curves were generated for each outcome instrument. The greater the area under the curve (AUC), the more valid the discriminator. The difference between standardized response means (SRMs) in patients reporting meaningful improvement versus not was calculated to determine the relative responsiveness of each outcome instrument to changes in pain and QOL after surgery.

RESULTS

For pain and disability, both NDI (AUC=0.75) and NRS-AP (AUC=0.74) were valid discriminators of meaningful improvement. Numeric rating scale for neck pain (AUC=0.69) was a poor discriminator. Neck disability index was also most responsive to postoperative improvement (SRM difference 0.78), followed by NRS-AP (SRM difference 0.59) and NRS-NP (SRM difference 0.46). For general health and quality of life, SF-12 PCS (AUC=0.79) was the only valid discriminator of meaningful improvement. Euro-Qol-5D (AUC=0.68) and SF-12 MCS (AUC=0.44) were poor discriminators. Short-form 12 physical component summary (SRM difference 1.08) was also most responsive compared with EQ-5D (SRM difference 0.89) and SF-12 MCS (SRM difference 0.01).

CONCLUSIONS

For pain and disability, NDI is the most valid and responsive measure of improvement after surgery for neck and arm pain. Numeric rating scale for neck pain and NRS-AP are poor substitutes for NDI when measuring effectiveness of care in registry efforts. For health-related quality of life, only SF-12 PCS could accurately discriminate meaningful improvement after cervical surgery and was found to be most valid and responsive. Large-scale registry efforts aimed at measuring effectiveness of cervical spine surgery should use NDI and SF-12 to accurately assess improvements in pain, disability, and quality of life.

ISASS Policy Statement - Lumbar Artificial Disc

PURPOSE

The primary goal of this Policy Statement is to educate patients, physicians, medical providers, reviewers, adjustors, case managers, insurers, and all others involved or affected by insurance coverage decisions regarding lumbar disc replacement surgery.

PROCEDURES

This Policy Statement was developed by a panel of physicians selected by the Board of Directors of ISASS for their expertise and experience with lumbar TDR. The panel's recommendation was entirely based on the best evidence-based scientific research available regarding the safety and effectiveness of lumbar TDR.

Accurately measuring the quality and effectiveness of lumbar surgery in registry efforts: determining the most valid and responsive instruments

BACKGROUND CONTEXT

Prospective registries have emerged as a feasible way to capture real-world care across large patient populations. However, the proven validity of more robust and cumbersome patient-reported outcomes instruments (PROis) must be balanced with what is feasible to apply in large-scale registry efforts.

PURPOSE

To determine the relative validity and responsiveness of common PROis in accurately determining effectiveness of lumbar fusion for degenerative lumbar spondylolisthesis in registry efforts.

STUDY DESIGN

Prospective cohort study.

PATIENT SAMPLE

Fifty-eight patients undergoing transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar spondylolisthesis

OUTCOME MEASURES

Patient-reported outcome measures for pain (numeric rating scale for back and leg pain [NRS-BP, NRS-LP]), disability (Oswestry Disability Index [ODI]), general health (Short Form [SF]-12), quality of life (QOL) (EuroQol five dimensions [EQ-5D]), and depression (Zung depression scale [ZDS]) were assessed.

METHODS

Fifty-eight patients undergoing primary TLIF for lumbar spondylolisthesis were entered into an institutional registry and prospectively followed for 2 years. Baseline and 2-year patient-reported outcomes were assessed. To assess the validity of PROis to discriminate between effective and noneffective improvements, receiver operating characteristic curves were generated for each outcomes instrument. An area under the curve (AUC) of ≥0.80 was considered an accurate discriminator. The difference between standardized response means (SRMs) in patients reporting meaningful improvement versus not was calculated to determine the relative responsiveness of each instrument.

RESULTS

For pain and disability, ODI had AUC=0.94, suggesting it as an accurate discriminator of meaningful improvement. Oswestry Disability Index was most responsive to postoperative improvement (SRM difference: 2.18), followed by NRS-BP and NRS-LP. For general health and QOL, SF-12 physical component score (AUC: 0.90), ZDS (AUC: 0.89), and SF-12 mental component score (AUC: 0.85) were all accurate discriminators of meaningful improvement, however, EQ-5D was most accurate (AUC: 0.97). EuroQol five dimensions was also most responsive (SRM difference: 2.83).

CONCLUSIONS

For pain and disability, ODI was the most valid and responsive measure of effectiveness of lumbar fusion. Numeric rating scale-BP and NRS-LP should not be used as substitutes for ODI in measuring effectiveness of care in registry efforts. For health-related QOL, EQ-5D was the most valid and responsive measure of improvement, however, SF-12 and ZDS are valid alternatives with less responsiveness.

Incidental durotomy in lumbar spine surgery--a three-nation survey to evaluate its management

BACKGROUND

Although it is generally accepted that incidental durotomies (ID) should be primarily repaired, the current literature shows no consensus regarding the peri- and postoperative management in case of ID during lumbar spine surgery. Because ID is a rather frequent complication and may be associated with significant disability, we were interested to analyze the current handling of ID in three European countries.

METHODS

In March 2014, members of the Swiss, German, and Austrian neurosurgical and spine societies were asked to complete an online questionnaire regarding the management of ID during and after lumbar spine surgery. Two, respectively 4 weeks after the first invitation, reminder requests were sent to all invitees, who had not already responded at that time.

RESULTS

There were 175 responses from 397 requests (44.1 %). Responders were predominantly neurosurgeons (89.7 %; 10.3 % were orthopedic surgeons), of which 45.7, 40.0, and 17.8 % work in a non-university hospital, university hospital, and private clinic, respectively. As for the perioperative management of ID, 19.4 % of the responders suggest only bed rest, while, depending on the extent of the ID, 84.0 % suggest additional actions, TachoSil/Spongostan with fibrin glue or a similar product and single suture repair being the most mentioned. Concerning epidural wound drainage in case of ID, 37.2 % desist from placing an epidural wound drainage with or without aspiration, 30.9 % place it sometimes, and 33.7 % place it regularly, but only without aspiration. Most responders prescribe bed rest for 24 (34.9 %) or 48 h (28.0 %), with much fewer prescribing bed rest for 72 h (6.3 %) and none more than 72 h, and 14.9 % of participants never prescribe bed rest. The vast majority of physicians (82.9 %, n = 145) always inform their patients after the operation in case of ID.

CONCLUSIONS

There is substantial heterogeneity in the management of incidental durotomies. The majority of spine surgeons today aim at complete/sufficient primary repair of the ID with varying recommendations concerning postoperative bed rest. Still, there is a trend towards early mobilization if the incidental durotomy has been closed completely/sufficiently with no participant favoring bed rest for more than 72 h.

Five-year results of lumbar disc prostheses in the SWISSspine registry

PURPOSE

The Swiss Federal Office of Public Health demanded a nationwide HTA registry for lumbar total disc arthroplasty (TDA), to decide about its reimbursement. The goal of the SWISS spine registry is to generate evidence about the safety and efficiency of lumbar TDA.

METHODS

Two hundred forty-eight cases treated between 3-2005 and 6-2006, who were eligible for the 5-year follow-up were included in the study. Follow-up rates for 3-6 months, 1, 2 and 5 years were 85.9, 77.0, 44.0 and 51.2 %, respectively. Outcome measures were back and leg pain, medication consumption, quality of life, intraoperative and postoperative complication and revision rates. Additionally, segmental mobility, ossification, adjacent and distant segment degeneration were analysed at the 5-year follow-up.

RESULTS

There was a significant, clinically relevant and lasting reduction of back (preop/postop 73/29 VAS points) and leg pain (preop/postop VAS 55/22) and a consequently decreased analgesics consumption and quality of life improvement (preop/postop 0.30/0.76 EQ-5D score points) until 5 years after surgery. The rates for intraoperative and early postoperative complications were 4.4 and 3.2 %, respectively. The overall complication rate during five postoperative years was 23.4 %, and the adjacent segment degeneration rate was 10.7 %. In 4.4 % of patients, a revision surgery was performed. Cumulative survivorship probability for a revision/re-intervention-free 5-year postoperative course was 90.4 %. At the 5-year follow-up, the average range of motion of the mobile segments (86.8 %) was 9.7°. In 43.9 % of patients, osteophytes at least potentially affecting the range of motion were seen.

CONCLUSIONS

Lumbar TDA appeared as efficient in long-term pain alleviation, consequent reduction of pain medication consumption and improvement of quality of life. The procedure also appeared sufficiently safe, but surgeons have to be aware of a list of potential adverse events. The outcome is stable over the 5-year postoperative period. The vast majority of treated segments remained mobile after 5 years, although almost half of patients showed osteophytes.

Factor analysis of the North American Spine Society outcome assessment instrument: a study based on a spine registry of patients treated with lumbar and cervical disc arthroplasty

BACKGROUND CONTEXT

Studies involving factor analysis (FA) of the items in the North American Spine Society (NASS) outcome assessment instrument have revealed inconsistent factor structures for the individual items.

PURPOSE

This study examined whether the factor structure of the NASS varied in relation to the severity of the back/neck problem and differed from that originally recommended by the developers of the questionnaire, by analyzing data before and after surgery in a large series of patients undergoing lumbar or cervical disc arthroplasty.

STUDY DESIGN/SETTING

Prospective multicenter observational case series.

PATIENT SAMPLE

Three hundred ninety-one patients with low back pain and 553 patients with neck pain completed questionnaires preoperatively and again at 3 to 6 and 12 months follow-ups (FUs), in connection with the SWISSspine disc arthroplasty registry.

OUTCOME MEASURES

North American Spine Society outcome assessment instrument.

METHODS

First, an exploratory FA without a priori assumptions and subsequently a confirmatory FA were performed on the 17 items of the NASS-lumbar and 19 items of the NASS-cervical collected at each assessment time point. The item-loading invariance was tested in the German version of the questionnaire for baseline and FU.

RESULTS

Both NASS-lumbar and NASS-cervical factor structures differed between baseline and postoperative data sets. The confirmatory analysis and item-loading invariance showed better fit for a three-factor (3F) structure for NASS-lumbar, containing items on "disability," "back pain," and "radiating pain, numbness, and weakness (leg/foot)" and for a 5F structure for NASS-cervical including disability, "neck pain," "radiating pain and numbness (arm/hand)," "weakness (arm/hand)," and "motor deficit (legs)."

CONCLUSIONS

The best-fitting factor structure at both baseline and FU was selected for both the lumbar- and cervical-NASS questionnaires. It differed from that proposed by the originators of the NASS instruments. Although the NASS questionnaire represents a valid outcome measure for degenerative spine diseases, it is able to distinguish among all major symptom domains (factors) in patients undergoing lumbar and cervical disc arthroplasty; overall, the item structure could be improved. Any potential revision of the NASS should consider its factorial structure; factorial invariance over time should be aimed for, to allow for more precise interpretations of treatment success.

Lumbar total disc replacement: correlation of clinical outcome and radiological parameters

BACKGROUND

The objective of this study was to correlate various radiological parameters with clinical outcome in patients who had undergone lumbar total disc replacement (TDR). Lumbar TDR is one possible treatment option in patients with low back pain (LBP), offering an alternative to lumbar fusion. Favourable clinical outcome hinges on a number of radiological parameters, such as mobility, sintering, and-most importantly-accurate positioning of the implant.

METHODS

A total of 46 patients received a prosthetic disc because of degenerative lumbar disc disorders. Follow-up evaluation included analysis of radiographs and subjective rating of the clinical status by the patient using the North American Spine Society (NASS) patient questionnaire, visual analogue scale (VAS) for pain and state of health, and the EuroQol EQ-5D. Radiological follow-up took place after 2 years. Coronal and sagittal positions of the prosthesis, intervertebral disc height, facet joint pressure, mobility, sintering, and calcification were evaluated. Optimal positioning of the prosthesis was defined as a central coronal position and a most dorsal position in the sagittal plane. Based on the radiologically determined placement of the prosthesis, the patient population was divided into three groups, i.e., prosthesis ideally placed (<2 mm), discretely shifted (2-3 mm), or suboptimally placed (>3 mm).

RESULTS

Overall, 81 % of patients stated that they would undergo the operation again. Health status was stable at a VAS score of 7.04 points 2 years after TDR, compared to 3.97 points before TDR. Mean working capacity had increased from 53 % preoperatively to 88 % 2 years after TDR. Overall, 39 % of the prostheses were rated as ideally positioned, while 13 % were discretely shifted and 48 % were suboptimally placed with respect to one of the radiological criteria. In 80.4 % of patients, follow-up assessment after ≥2 years indicated good mobility at the operated segment, while calcification was noted in 4 % and sintering was detected in 15 % of the implants.

CONCLUSIONS

Our data indicate poor correlation between clinical outcome and position of the prosthesis. Although 48 % of the implants were suboptimally placed in either the coronal or sagittal plane, most of the patients reached a very good clinical outcome. However, suboptimally placed devices appeared to cause significantly more neurological symptoms in long-term follow-up.

POST-INTRODUCTION OBSERVATION OF HEALTHCARE TECHNOLOGIES AFTER COVERAGE: THE SPANISH PROPOSAL

Objectives: When a new health technology has been approved by a health system, it is difficult to guarantee that it is going to be efficiently adopted, adequately used, and that effectiveness, safety, and consumption of resources and costs are in line with what was expected in preliminary investigations. Many governmental institutions promote the idea that efficient mechanisms should be established aimed at developing and incorporating continuous evidence into health technologies management. The purpose of this article is to stimulate the discussion on systematic post-introduction observation of health technologies.

Methods: Literature review and input of HTA experts.

Results: The study addresses the key issues related to post-introduction observation and presents a summary of the guide commissioned by the Spanish Ministry of Health, Social Policy and Equality to the Galician HTA agency for the prioritization and implementation of systematic post-introduction observation in Spain. The manuscript describes the prioritization tool developed as part of this project and discusses the main aspects of protocol development, observation implementation, and assessment of results.

Conclusions: The observation of prioritized health technologies after they are introduced in standard clinical practice can provide useful information for health organizations. However, implementing the observation of health technologies can require specific policy frameworks, commitment from different stakeholders, and dedicated funding.

Clinicians' and patients' views of metrics of change derived from patient reported outcome measures (PROMs) for comparing providers' performance of surgery

BACKGROUND

Patient reported outcome measures (PROMs) are increasingly being used to compare the performance of health care providers. Our objectives were to determine the relative frequency of use of different metrics that can be derived from PROMs, explore clinicians' and patients' views of the options available, and make recommendations.

METHODS

First a rapid review of the literature on metrics derived from two generic (EQ-5D and EQ-VAS) and three disease-specific (Oxford Hip Score; Oxford Knee Score; Aberdeen Varicose Vein Questionnaire) PROMs was conducted. Next, the findings of the literature review were mapped onto our typology of metrics to determine their relative frequency of use, Finally, seven group meetings with surgical clinicians (n = 107) and six focus groups with patients (n = 45) were held which were audio-taped, transcribed and analysed thematically.

RESULTS

Only nine studies (9.3% of included papers) used metrics for comparing providers. These were derived from using either the follow-up PROM score (n = 3) or the change in score as an outcome (n = 5), both adjusted for pre-intervention score. There were no recorded uses of the proportion reaching a specified ('good') threshold and only two studies used the proportion reaching a minimally important difference (MID).Surgical clinicians wanted multiple outcomes, with most support expressed for the mean change in score, perceiving it to be more interpretable; there was also some support for the MID. For patients it was apparent that rather than the science behind these measures, the most important aspects were the use of language that would make the metrics personally meaningful and linking the metric to a familiar scale.

CONCLUSIONS

For clinicians the recommended metrics are the mean change in score and the proportion achieving a MID, both adjusted for pre-intervention score. Both need to be clearly described and explained. For patients we recommend the proportion achieving a MID or proportion achieving a significant improvement in hip function, both adjusted for pre-intervention score.

Study protocol: the Back Pain Outcomes using Longitudinal Data (BOLD) registry

Background

Back pain is one of the most important causes of functional limitation, disability, and utilization of health care resources for adults of all ages, but especially among older adults. Despite the high prevalence of back pain in this population, important questions remain unanswered regarding the comparative effectiveness of commonly used diagnostic tests and treatments in the elderly. The overall goal of the Back pain Outcomes using Longitudinal Data (BOLD) project is to establish a rich, sustainable registry to describe the natural history and evaluate prospectively the effectiveness, safety, and cost-effectiveness of interventions for patients 65 and older with back pain.

Methods/design

BOLD is enrolling 5,000 patients ≥ 65 years old who present to a primary care physician with a new episode of back pain. We are recruiting study participants from three integrated health systems (Kaiser-Permanente Northern California, Henry Ford Health System in Detroit and Harvard Vanguard Medical Associates/ Harvard Pilgrim Health Care in Boston). Registry patients complete validated, standardized measures of pain, back pain-related disability, and health-related quality of life at enrollment and 3, 6 and 12 months later. We also have available for analysis the clinical and administrative data in the participating health systems’ electronic medical records. Using registry data, we will conduct an observational cohort study of early imaging compared to no early imaging among patients with new episodes of back pain. The aims are to: 1) identify predictors of early imaging and; 2) compare pain, functional outcomes, diagnostic testing and treatment utilization of patients who receive early imaging versus patients who do not receive early imaging. In terms of predictors, we will examine patient factors as well as physician factors.

Discussion

By establishing the BOLD registry, we are creating a resource that contains patient-reported outcome measures as well as electronic medical record data for elderly patients with back pain. The richness of our data will allow better matching for comparative effectiveness studies than is currently possible with existing datasets. BOLD will enrich the existing knowledge base regarding back pain in the elderly to help clinicians and patients make informed, evidence-based decisions regarding their care.

Coverage with evidence development, only in research, risk sharing, or patient access scheme? A framework for coverage decisions

BACKGROUND

Until recently, purchasers' options regarding whether to pay for the use of medical technologies have been binary in nature: a treatment is either covered or not. Policies, however, have emerged that expand the decision options, for example, linking coverage to evidence development, an option increasingly used for treatments with limited/uncertain evidence. There has been little effort to reconcile the features of technologies with the available decision options.

METHODS

We described a framework within which different decision options can be evaluated. We distinguished two sources of value in terms of health: the value of the technology per se and the value of reducing decision uncertainty. The costs of reversing decisions were also considered.

FINDINGS

Purchasers should weigh the expected benefits of coverage against the possibility that the decision may need to be reversed and the chance that adoption will hinder evidence generation. Based on the purchaser's range of authority over access, research, and price and on the characteristics of the technology with regard to reversibility and evidence, different decisions may be appropriate. The framework clarified the assessments needed to establish the appropriateness of different decisions. A taxonomy of coverage decisions was suggested.

CONCLUSIONS

A range of decision options may facilitate paying for the use of promising medical technologies despite their uncertain evidence. It is important that the option be chosen on the basis of not only the expected value of a technology but also the value of further research, the anticipated effect of coverage on further research, and the costs associated with reversing the decision.

Comparative effectiveness research across two spine registries

BACKGROUND

Comparative effectiveness research in spine surgery is still a rarity. In this study, pain alleviation and quality of life (QoL) improvement after lumbar total disc arthroplasty (TDA) and anterior lumbar interbody fusion (ALIF) were anonymously compared by surgeon and implant.

METHODS

A total of 534 monosegmental TDAs from the SWISSspine registry were analyzed. Mean age was 42 years (19-65 years), 59% were females. Fifty cases with ALIF were documented in the international Spine Tango registry and used as concurrent comparator group for the pain analysis. Mean age was 46 years (21-69 years), 78% were females. The average follow-up time in both samples was 1 year. Comparison of back/leg pain alleviation and QoL improvement was performed. Unadjusted and adjusted probabilities for achievement of minimum clinically relevant improvements of 18 VAS points or 0.25 EQ-5D points were calculated for each surgeon.

RESULTS

Mean preoperative back pain decreased from 69 to 30 points at 1 year (ØΔ 39pts) after TDA, and from 66 to 27 points after ALIF (ØΔ 39pts). Mean preoperative QoL improved from 0.34 to 0.74 points at 1 year (ØΔ 0.40pts). There were surgeons with better patient selection, indicated by lower adjusted probabilities reflecting worsening of outcomes if they had treated an average patient sample. ALIF had similar pain alleviation than TDA.

CONCLUSIONS

Pain alleviation after TDA and ALIF was similar. Differences in surgeon's patient selection based on pain and QoL were revealed. Some surgeons seem to miss the full therapeutic potential of TDA by selecting patients with lower symptom severity.

Influence of preoperative nucleus pulposus status and radiculopathy on outcomes in mono-segmental lumbar total disc replacement: results from a nationwide registry

Background

Currently, herniated nucleus pulposus (HNP) with radiculopathy and other preconditions are regarded as relative or absolute contraindications for lumbar total disc replacement (TDR). In Switzerland it is left to the surgeon's discretion when to operate. The present study is based on the dataset of SWISSspine, a governmentally mandated health technology assessment registry. We hypothesized that preoperative nucleus pulposus status and presence or absence of radiculopathy has an influence on clinical outcomes in patients treated with mono-segmental lumbar TDR.

Methods

Between March 2005 and April 2009, 416 patients underwent mono-segmental lumbar TDR, which was documented in a prospective observational multicenter mode. The data collection consisted of perioperative and follow-up data (physician based) and clinical outcomes (NASS, EQ-5D).

Patients were divided into four groups according to their preoperative status: 1) group degenerative disc disease ("DDD"): 160 patients without HNP and no radiculopathy, classic precondition for TDR; 2) group "HNP-No radiculopathy": 68 patients with HNP but without radiculopathy; 3) group "Stenosis": 73 patients without HNP but with radiculopathy, and 4) group "HNP-Radiculopathy": 132 patients with HNP and radiculopathy. The groups were compared regarding preoperative patient characteristics and pre- and postoperative VAS and EQ-5D scores using general linear modeling.

Results

Demographics in all four groups were comparable. Regarding the improvement of quality of life (EQ-5D) there were no differences across the four groups. For the two main groups DDD and HNP-Radiculopathy no differences were found in the adjusted postoperative back- and leg pain alleviation levels, in the stenosis group back- and leg pain relief were lower.

Conclusions

Despite higher preoperative leg pain levels, outcomes in lumbar TDR patients with HNP and radiculopathy were similar to outcomes in patients with the classic indication; this because patients with higher preoperative leg pain levels benefit from a relatively greater leg pain alleviation. The group with absence of HNP but presence of radiculopathy showed considerably less benefits from the operation, which is probably related to ongoing degenerative processes of the posterior segmental structures. This observational multicenter study suggests that the diagnoses HNP and radiculopathy, combined or alone, may not have to be considered as absolute or relative contraindications for mono-segmental lumbar TDR anymore, whereas patients without HNP but with radiculopathy seem to be suboptimal candidates for the procedure.

Validity and responsiveness of the Core Outcome Measures Index (COMI) for the neck

PURPOSE

Patient-orientated outcome questionnaires are essential to evaluate treatment success. To compare different treatments, hospitals, and surgeons, standardised questionnaires are required. The present study examined the validity and responsiveness of the Core Outcome Measurement Index for neck pain (COMI-neck), a short, multidimensional outcome instrument.

METHODS

Questionnaires were completed by patients with degenerative problems of the cervical spine undergoing cervical disc arthroplasty before (N = 89) and 3 months after (N = 75) surgery. The questionnaires comprised the EuroQol-Five Dimension (EQ-5D), the North American Spine Society Cervical Spine Outcome Assessment Instrument (NASS-cervical) and the COMI-neck.

RESULTS

The COMI and NASS-cervical scores displayed no notable floor or ceiling effects at any time point whereas for the EQ-5D, the highest values [corrected] were reached in around 32.5% of patients at follow-up. With one exception (symptom-specific well-being), the individual COMI items and the COMI summary score correlated to the expected extent (R = 0.4-0.8) with the scores of the chosen reference questionnaires. The area under the curve (AUC) generated by ROC analysis was significantly higher for the COMI (0.96) than for any other instrument/subscale when self reported treatment outcome was used as the external criterion, dichotomised as "good" (operation helped a lot/helped) versus "poor" (operation helped only a little/didn't help/made things worse). The COMI had a high effect size (standardised response mean; SRM) (2.34) for the good global outcome group and a low SRM for the poor outcome group (0.34). The EQ-5D and the NASS-cervical lacked this ability to differentiate between the two groups, showing less distinct SRMs for good and poor outcome groups.

CONCLUSIONS

This study provides evidence that the COMI-neck is a valid and responsive questionnaire in the population of patients examined. Further investigations should examine its applicability in other patient groups with less severe neck pain or undergoing other treatment modalities.

Influence of preoperative leg pain and radiculopathy on outcomes in mono-segmental lumbar total disc replacement: results from a nationwide registry

PURPOSE

Currently, many pre-conditions are regarded as relative or absolute contraindications for lumbar total disc replacement (TDR). Radiculopathy is one among them. In Switzerland it is left to the surgeon's discretion when to operate if he adheres to a list of pre-defined indications. Contraindications, however, are less clearly specified. We hypothesized that, the extent of pre-operative radiculopathy results in different benefits for patients treated with mono-segmental lumbar TDR. We used patient perceived leg pain and its correlation with physician recorded radiculopathy for creating the patient groups to be compared.

METHODS

The present study is based on the dataset of SWISSspine, a government mandated health technology assessment registry. Between March 2005 and April 2009, 577 patients underwent either mono- or bi-segmental lumbar TDR, which was documented in a prospective observational multicenter mode. A total of 416 cases with a mono-segmental procedure were included in the study. The data collection consisted of pre-operative and follow-up data (physician based) and clinical outcomes (NASS form, EQ-5D). A receiver operating characteristic (ROC) analysis was conducted with patients' self-indicated leg pain and the surgeon-based diagnosis "radiculopathy", as marked on the case report forms. As a result, patients were divided into two groups according to the severity of leg pain. The two groups were compared with regard to the pre-operative patient characteristics and pre- and post-operative pain on Visual Analogue Scale (VAS) and quality of life using general linear modeling.

RESULTS

The optimal ROC model revealed a leg pain threshold of 40 ≤ VAS > 40 for the absence or the presence of "radiculopathy". Demographics in the resulting two groups were well comparable. Applying this threshold, the mean pre-operative leg pain level was 16.5 points in group 1 and 68.1 points in group 2 (p < 0.001). Back pain levels differed less with 63.6 points in group 1 and 72.6 in group 2 (p < 0.001). Pre-operative quality of life showed considerable differences with an 0.44 EQ-5D score in group 1 and 0.29 in group 2 (p < 0.001, possible score range -0.6 to 1). At a mean follow-up time of 8 months, group 1 showed a mean leg pain improvement of 3.6 points and group 2 of 41.1 points (p < 0.001). Back pain relief was 35.6 and 39.1 points, respectively (p = 0.27). EQ-5D score improvement was 0.27 in group 1 and 0.41 in group 2 (p = 0.11).

CONCLUSIONS

Patients labeled as having radiculopathy (group 2) do mostly have pre-operative leg pain levels ≥ 40. Applying this threshold, the patients with pre-operative leg pain do also have more severe back pain and a considerably lower quality of life. Their net benefit from the lumbar TDR is higher and they do have similar post-operative back and leg pain levels as well as the quality of life as patients without pre-operative leg pain. Although randomized controlled trials are required to confirm these findings, they put leg pain and radiculopathy into perspective as absolute contraindications for TDR.

SWISSspine: the case of a governmentally required HTA-registry for total disc arthroplasty: results of cervical disc prostheses

STUDY DESIGN

Prospective multicenter observational case-series.

OBJECTIVE

The goal of the SWISSspine registry is to generate evidence about the safety and efficiency of these Medtech innovations.

SUMMARY OF BACKGROUND DATA

The Swiss federal office of public health required a mandatory nationwide HTA-registry for cervical total disc arthroplasty (TDA), among other technologies, to decide about reimbursement of these interventions.

METHODS

Between March 2005 and June 2008, 808 interventions with implantation of 925 discs from 5 different suppliers were performed. Surgeon-administered outcome instruments were primary intervention, implant, and follow-up forms; patient self-reported measures were EQ-5D, COSS, and a comorbidity questionnaire. Data are recorded perioperative, at 3 months and 1 year postoperative, and annually thereafter. RESULTS. There was significant and clinically relevant reduction of neck (preoperative/postoperative 59.3/24.8 points) and arm pain (preoperative/postoperative 64.9/17.6) on visual analogue scale (VAS) and consequently decreased analgesics consumption. Similarly, quality of life (QoL) improved from preoperative 0.42 to postoperative 0.82 points on EQ-5D scale. There were 4 intraoperative complications and 23 revisions during the same hospitalization for 691 monosegmental TDAs, and 2 complications and 6 revisions for 117 2-level surgeries. A pharmacologically treated depression was identified as important risk factor for achieving a clinically relevant pain alleviation >20 points on VAS. Two-level surgery resulted in similar outcomes compared with the monosegmental interventions.

CONCLUSION

Cervical TDA appeared as safe and efficacious in short-term pain alleviation, consequent reduction of pain killer consumption, and in improvement of QoL. A clinically relevant pain reduction of ≥20 points was most probable if patients had preoperative pain levels ≥40 points on VAS. A pharmacologically treated depression and 2-level surgery were identified as risk factors for less pronounced pain alleviation or QoL improvement.

Benchmarking in the SWISSspine registry: results of 52 Dynardi lumbar total disc replacements compared with the data pool of 431 other lumbar disc prostheses

The SWISSspine registry is the first mandatory registry of its kind in the history of Swiss orthopaedics and it follows the principle of "coverage with evidence development". Its goal is the generation of evidence for a decision by the Swiss federal office of health about reimbursement of the concerned technologies and treatments by the basic health insurance of Switzerland. Recently, developed and clinically implemented, the Dynardi total disc arthroplasty (TDA) accounted for 10% of the implanted lumbar TDAs in the registry. We compared the outcomes of patients treated with Dynardi to those of the recipients of the other TDAs in the registry. Between March 2005 and October 2009, 483 patients with single-level TDA were documented in the registry. The 52 patients with a single Dynardi lumbar disc prosthesis implanted by two surgeons (CE and OS) were compared to the 431 patients who received one of the other prostheses. Data were collected in a prospective, observational multicenter mode. Surgery, implant, 3-month, 1-year, and 2-year follow-up forms as well as comorbidity, NASS and EQ-5D questionnaires were collected. For statistical analyses, the Wilcoxon signed-rank test and chi-square test were used. Multivariate regression analyses were also performed. Significant and clinically relevant reduction of low back pain and leg pain as well as improvement in quality of life was seen in both groups (P < 0.001 postop vs. preop). There were no inter-group differences regarding postoperative pain levels, intraoperative and follow-up complications or revision procedures with a new hospitalization. However, significantly more Dynardi patients achieved a minimum clinically relevant low back pain alleviation of 18 VAS points and a quality of life improvement of 0.25 EQ-5D points. The patients with Dynardi prosthesis showed a similar outcome to patients receiving the other TDAs in terms of postoperative low back and leg pain, complications, and revision procedures. A higher likelihood for achieving a minimum clinically relevant improvement of low back pain and quality of life in Dynardi patients was observed. This difference might be due to the large number of surgeons using other TDAs compared to only two surgeons using the Dynardi TDA, with corresponding variations in patient selection, patient-physician interaction and other factors, which cannot be assessed in a registry study.

Development of a documentation instrument for the conservative treatment of spinal disorders in the International Spine Registry, Spine Tango

Spine Tango is the first and only International Spine Registry in operation to date. So far, only surgical spinal interventions have been recorded and no comparable structured and comprehensive documentation instrument for conservative treatments of spinal disorders is available. This study reports on the development of a documentation instrument for the conservative treatment of spinal disorders by using the Delphi consensus method. It was conducted with a group of international experts in the field. We also assessed the usability of this new assessment tool with a prospective feasibility study on 97 outpatients and inpatients with low back or neck pain undergoing conservative treatment. The new 'Spine Tango conservative' questionnaire proved useful and suitable for the documentation of pathologies, conservative treatments and outcomes of patients with low back or neck problems. A follow-up questionnaire seemed less important in the predominantly outpatient setting. In the feasibility study, between 43 and 63% of patients reached the minimal clinically important difference in pain relief and Core Outcome Measures Index at 3 months after therapy; 87% of patients with back pain and 85% with neck pain were satisfied with the received treatment. With 'Spine Tango conservative' a first step has been taken to develop and implement a complementary system for documentation and evaluation of non-surgical spinal interventions and outcomes within the framework of the International Spine Registry. It proved useful and feasible in a first pilot study, but it will take the experience of many more cases and therapists to develop a version similarly mature as the surgical instruments of Spine Tango.

National revision burden for lumbar total disc replacement in the United States: epidemiologic and economic perspectives

STUDY DESIGN

Retrospective cohort study using a nationally representative inpatient database.

OBJECTIVE

To quantify the national revision burden for lumbar total disc replacements (TDRs) in the United States following Food and Drug Administration approval, for comparison with lumbar fusion and other common orthopedic procedures, including hip and knee replacement.

SUMMARY OF BACKGROUND DATA

Previous studies of revision lumbar TDR surgery have been based on IDE studies. The epidemiology and costs of TDR revision surgery from a national perspective have not yet been reported.

METHODS

The Nationwide Inpatient Sample was used to identify primary and revision TDR and anterior fusion procedures in 2005 and 2006. Surgeries were identified in the Nationwide Inpatient Sample using ICD9-CM codes. The prevalence of TDR and fusion surgery was calculated as a function of age, gender, race, census region, primary payer class, and type of hospital. Average length of stay and total hospitalization costs were also computed for each type of procedure.

RESULTS

During the study period, there was a national total of 7172 TDR and 62,731 anterior fusion surgeries, including both primary and revisions. Overall, TDR patients were younger and had less comorbidity than fusion surgery patients. The average revision burden for lumbar TDR and anterior fusion was 11.2% and 5.8%, respectively. The average length of stay for primary lumbar TDR was significantly shorter compared to revision TDR, primary anterior fusion, and revision anterior fusion (P < 0.0001). Both the primary and the revision surgery using the TDR surgery involved significantly lower total hospital costs relative to anterior fusion surgery (P < 0.0001). Including revision, the average costs per TDR procedure were lower than anterior and posterior lumbar fusion.

CONCLUSION

Although the revision burden for TDR was significantly higher than fusion surgery, the TDR revision burden fell within the revision burden range of hip and knee replacement, which are generally considered successful and cost-effective procedures. Economically, the higher revision burden for TDRs was offset by lower costs for both the primary as well as the revision procedures relative to fusion.