Total disc arthroplasty versus anterior cervical interbody fusion: use of the Spine Tango registry to supplement the evidence from randomized control trials

Real-world data and evidence in pain research: a qualitative systematic review of methods in current practice

The use of routinely collected health data (real-world data, RWD) to generate real-world evidence (RWE) for research purposes is a growing field. Computerized search methods, large electronic databases, and the development of novel statistical methods allow for valid analysis of data outside its primary clinical purpose. Here, we systematically reviewed the methodology used for RWE studies in pain research. We searched 3 databases (PubMed, EMBASE, and Web of Science) for studies using retrospective data sources comparing multiple groups or treatments. The protocol was registered under the DOI:10.17605/OSF.IO/KGVRM. A total of 65 studies were included. Of those, only 4 compared pharmacological interventions, whereas 49 investigated differences in surgical procedures, with the remaining studying alternative or psychological interventions or epidemiological factors. Most 39 studies reported significant results in their primary comparison, and an additional 12 reported comparable effectiveness. Fifty-eight studies used propensity scores to account for group differences, 38 of them using 1:1 case:control matching. Only 17 of 65 studies provided sensitivity analyses to show robustness of their findings, and only 4 studies provided links to publicly accessible protocols. RWE is a relevant construct that can provide evidence complementary to randomized controlled trials (RCTs), especially in scenarios where RCTs are difficult to conduct. The high proportion of studies reporting significant differences between groups or comparable effectiveness could imply a relevant degree of publication bias. RWD provides a potentially important resource to expand high-quality evidence beyond clinical trials, but rigorous quality standards need to be set to maximize the validity of RWE studies.

There is no difference in perioperative results between posterior instrumentation with and without interbody cage and debridement in primary spondylodiscitis in adults. A multicenter surveillance study from the German Spine Registry (DWG-Register)

BACKGROUND

Primary spondylodiscitis is a medically challenging disease that can lead to recurrent back pain, progressive kyphotic deformity, and neurologic deficits. The incidence rate of primary non-tuberculosis spondylodiscitis has been estimated from 2.2 to 2.4 cases per 100,000 person-years, and it has been reported to be increasing because of the aging population. The objectives were to determine the safety and efficacy of posterior instrumentation (PI) with and without interbody cage, bony attachment and debridement in the treatment of primary spondylodiscitis by comparing perioperative data, functional outcomes, and overall infection-free survival.

METHODS

Analysis of data from the DWG registry on patients who have undergone posterior instrumentation with and without interbody cage, bony attachment and debridement in primary spondylodiscitis from the thoracolumbar junction to S1 (Th10-S1) at 10 institutions from January 2012 to December 2016.

RESULTS

In total, 420 posterior instrumentations with and without interbody cage, bony attachment and debridement in primary spondylodiscitis in the thoracolumbar junction to S1 were identified in the registry; n=138 were exclusively percutaneous posterior instrumented (PPI), while n=102 underwent open posterior instrumentation (OPI) without interbody cage, bony attachment and debridement and n=180 OPI with interbody cage, bony attachment and debridement. Clinical evaluation after surgery did not show a significant difference between groups including improvement of the mbilisation and infection-free survival. However, with PPI the duration of operation and blood loss was significantly less than OPI with and without interbody cage, bony attachment and debridement.

CONCLUSIONS

The results suggest interbody cage, bony attachment and debridement as not indispensable for treatment in primary spondylodiscitis. Therefore, we encourage the use of posterior stabilization alone in the treatment of spondylodiscitis as less invasive procedure reducing costs in instrumentation.

Invasiveness has no influence on the rate of incidental durotomies in surgery for multisegmental lumbar spinal canal stenosis (≥ 3 levels) with and without fusion. Analysis from the German Spine Registry data (DWG-Register)

BACKGROUND

Nowadays, perioperative complications as dural tear (DT) with subsequent neurological deficits are documented in independent registers. However, the relationship of these complications with the grade of invasiveness (≥3 levels) is still unclear. We attempted to evaluate perioperative complications, particularly DT with subsequent neurological deficits, between patients undergoing laminotomy and decompression and decompression and fusion in ≥3 levels.

METHODS

Retrospective analysis of the data pool of the DWG register based on cases described by 10 clinics between January 2012 and December 2016 was performed. Surgically treated LSS in ≥3 segments were divided into decompression with or without instrumentation and fusion. Cases with intraoperative DT in both subgroups were analysed for risk factor occurrence. The Surgical Invasive Index (SII) was used.

RESULTS

DT occurred in 102/941 (10.8%) patients. Difference in DT between groups was non- significant. The likelihood of DT increased by 2.12-fold with previous spinal surgery at the same level and by 1.9-fold for BMI 30-34 and >35 in comparison with BMI 26-29, respectively. Postoperative deep wound infection was increased by 2.39-fold after DT than without. Significance in outcomes between patients with/without DT was not found. The invasiveness index explained 48% of the variation in blood loss and 51% of the variation in surgery duration.

CONCLUSIONS

The rate of incidental DT during decompression for LSS with and without fusion in ≥3 levels was associated with BMI and previous surgery at the same spinal level. Invasivness (SII) is valid rather for variables proper to surgery such as bledding and Op-time but no with incidence for DT and subsequent CSF-leackage.

Effectiveness of an annular closure device in a "real-world" population: stratification of registry data using screening criteria from a randomized controlled trial

Purpose

Increased focus has been put on the use of “‘real-world” data to support randomized clinical trial (RCT) evidence for clinical decision-making. The objective of this study was to assess the performance of an annular closure device (ACD) after stratifying a consecutive series of “real-world” patients by the screening criteria of an ongoing RCT.

Materials and methods

This was a single-center registry analysis of 164 subjects who underwent limited discectomy combined with ACD for symptomatic lumbar disc herniation. Patients were stratified into two groups using the selection criteria of a pivotal RCT on the same device: Trial (met inclusion; n=44) or non-Trial (did not meet inclusion; n=120). Patient-reported outcomes, including Oswestry Disability Index (ODI) and visual analog scale (VAS) for leg and back pain, and adverse events were collected from baseline to last follow-up (mean: Trial – 15.6 months; non-Trial – 14.6 months). Statistical analyses were performed with significance set at p<0.05.

Results

Patient-reported outcomes were not significantly different between groups at last (p≥0.15) and clinical success (≥15-point improvement in ODI score; ≥20-point improvement in VAS scores) was achieved in both the groups. Three non-Trial (2.5%) and three Trial (6.8%) patients experienced symptomatic reherniation (p=0.34). Rates of reoperation, ACD mesh dislocation/separation, and other radiographic findings were similar between groups (p=1.00).

Conclusion

Outcomes with the ACD appeared advantageous in both the groups, particularly in comparison with historical reherniation rates reported in the same high-risk, large annular defect population. Stratification of this “real-world” series on the basis of RCT screening criteria did not result in significant between-group differences. These findings suggest that the efficacy of the ACD extends beyond the strictly defined patient population being studied in the RCT of this device. Furthermore, reducing the reherniation rate following lumbar discectomy has positive clinical and economic implications.

Prospective, randomized multicenter study of cervical arthroplasty versus anterior cervical discectomy and fusion: 5-year results with a metal-on-metal artificial disc

OBJECTIVE

Seven cervical total disc replacement (TDR) devices have received FDA approval since 2006. These devices represent a heterogeneous assortment of implants made from various biomaterials with different biomechanical properties. The majority of these devices are composed of metallic endplates with a polymer core. In this prospective, randomized multicenter study, the authors evaluate the safety and efficacy of a metal-on-metal (MoM) TDR (Kineflex|C) versus anterior cervical discectomy and fusion (ACDF) in the treatment of single-level spondylosis with radiculopathy through a long-term (5-year) follow-up.

METHODS

An FDA-regulated investigational device exemption (IDE) pivotal trial was conducted at 21 centers across the United States. Standard validated outcome measures including the Neck Disability Index (NDI) and visual analog scale (VAS) for assessing pain were used. Patients were randomized to undergo TDR using the Kineflex|C cervical artificial disc or anterior cervical fusion using structural allograft and an anterior plate. Patients were evaluated preoperatively and at 6 weeks and 3, 6, 12, 24, 36, 48, and 60 months after surgery. Serum ion analysis was performed on a subset of patients randomized to receive the MoM TDR.

RESULTS

A total of 269 patients were enrolled and randomly assigned to undergo either TDR (136 patients) or ACDF (133 patients). There were no significant differences between the TDR and ACDF groups in terms of operative time, blood loss, or length of hospital stay. In both groups, the mean NDI scores improved significantly by 6 weeks after surgery and remained significantly improved throughout the 60-month follow-up (both p < 0.01). Similarly, VAS pain scores improved significantly by 6 weeks and remained significantly improved through the 60-month follow-up (both p < 0.01). There were no significant changes in outcomes between the 24- and 60-month follow-ups in either group. Range of motion in the TDR group decreased at 3 months but was significantly greater than the preoperative mean value at the 12- and 24-month follow-ups and remained significantly improved through the 60-month period. There were no significant differences between the 2 groups in terms of reoperation/revision surgery or device-/surgery-related adverse events. The serum ion analysis revealed cobalt and chromium levels significantly lower than the levels that merit monitoring.

CONCLUSIONS

Cervical TDR with an MoM device is safe and efficacious at the 5-year follow-up. These results from a prospective randomized study support that Kineflex|C TDR as a viable alternative to ACDF in appropriately selected patients with cervical radiculopathy.

Clinical trial registration no.: NCT00374413 (clinicaltrials.gov)

National outcomes following single-level cervical disc arthroplasty versus anterior cervical discectomy and fusion

Background

To compare the differences in the thirty-day postoperative outcomes between cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF).

Methods

Patients undergoing primary single-level ACDF and CDA from 2010-2014 were identified by unique Current Procedural Terminology (CPT) codes within the American College of Surgeon's National Surgical Quality Improvement Program (NSQIP) database. Primary outcomes included surgical and medical complications, length of hospital stay (LOS), unplanned readmission, return to operating room, and mortality all occurring within 30 days of the initial procedure. Patients were propensity score-matched to reduce selection bias and differences in preoperative characteristics. Multivariate logistic regression models were utilized to determine associations between covariates and primary outcomes of interest.

Results

Propensity score-matching produced a cohort of 1,305 patients with 652 (50.0%) ACDF and 653 (50.0%) CDA patients. There were no statistically significant differences in the development of major surgical or medical complications between the groups. ACDF patients experienced a significantly longer LOS (2.3±14.8 vs. 1.1±1.0 days, P=0.034) and unplanned hospital readmission (1.8% vs. 0.2%, P=0.002). For ACDF patients, increased LOS [odds ratios (OR), 4.21; 95% confidence interval (CI), 1.29-13.73; P=0.017] and increased readmission (OR, 12.17; 95% CI, 1.16-127.23; P=0.037) persisted in the multivariate model. Elevated ASA classification, preoperative anemia and elevated white blood cell count (WBC) were also associated with a significantly increased LOS.

Conclusions

Although ACDF and CDA can be indicated for similar cervical pathologies, the latter can be performed safely and effectively with comparable perioperative risk of major complications. The increased readmission rate and LOS for patients undergoing ACDF may have significant impact on patient cost and outcomes.

Incidental durotomy in decompression for lumbar spinal stenosis: incidence, risk factors and effect on outcomes in the Spine Tango registry

PURPOSE

The three aims of this Spine Tango registry study of patients undergoing decompression for spinal stenosis were to: report the rate of dural tear (DT) stratified by treatment centre; find factors associated with an increased likelihood of incurring a DT; and compare treatment outcomes in relation to DT (none vs. repaired vs. unrepaired DT).

METHODS

Multivariate logistic regression was used to assess the association between DT and patient and treatment characteristics. Patient-rated and surgical outcomes were compared in patients with no DT, repaired DT, and unrepaired DT, while adjusting for case-mix.

RESULTS

DT occurred in 328/3254 (10.1%) of included patients. The rate for all 29 contributing hospitals was within 95% confidence intervals of the average. The likelihood of DT increased by 2% per year of age, 1.78 times with previous spine surgery, 1.67 for a minimally/less invasive surgery, 1.58 times with laminectomy, and 1.40, and 2.12 times for BMI 31-35, and >35 in comparison with BMI 26-30, respectively. The majority of DTs (272/328; 82.9%) were repaired. Repairing the DT was associated with a longer duration of surgery (p < 0.001). More patients with repaired than with unrepaired DTs were satisfied with treatment, but the difference was not statistically significant. There was no association between DT and patient-reported outcomes.

CONCLUSION

The unadjusted rate of incidental DT during decompression for LSS was homogeneous across the participating centres and was associated with age, BMI, previous surgery at the same spinal level, minimally/less invasive surgery, and laminectomy. Non-repair of DTs had no negative association with treatment outcome; however, the unrepaired DTs may have been those that were smaller in size.

The Norwegian Cervical Arthroplasty Trial (NORCAT): 2-year clinical outcome after single-level cervical arthroplasty versus fusion-a prospective, single-blinded, randomized, controlled multicenter study

PURPOSE

Standard surgical treatment for symptomatic cervical disc disease has been discectomy and fusion, but the use of arthroplasty, designed to preserve motion, has increased, and most studies report clinical outcome in its favor. Few of these trials, however, blinded the patients. We, therefore, conducted the Norwegian Cervical Arthroplasty Trial, and present 2-year clinical outcome after arthroplasty or fusion.

METHODS

This multicenter trial included 136 patients with single-level cervical disc disease. The patients were randomized to arthroplasty or fusion, and blinded to the treatment modality. The surgical team was blinded to randomization until nerve root decompression was completed. Primary outcome was the self-rated Neck Disability Index. Secondary outcomes were the numeric rating scale for pain and quality of life questionnaires Short Form-36 and EuroQol-5Dimension-3 Level.

RESULTS

There was a significant improvement in the primary and all secondary outcomes from baseline to 2-year follow-up for both arthroplasty and fusion (P < 0.001), and no observed significant between-group differences at any follow-up times. However, linear mixed model analyses, correcting for baseline values, dropouts and missing data, revealed a difference in Neck Disability Index (P = 0.049), and arm pain (P = 0.027) in favor of fusion at 2 years. The duration of surgery was longer (P < 0.001), and the frequency of reoperations higher (P = 0.029) with arthroplasty.

CONCLUSION

The present study showed excellent clinical results and no significant difference between treatments at any scheduled follow-up. However, the rate of index level reoperations was higher and the duration of surgery longer with arthroplasty.

TRIAL REGISTRATION

http://www.clinicaltrials.gov NCT 00735176.19.

[Registries of the German Society for Orthopaedics and Trauma : Overview and perspectives of the DGU and DGOOC registries]

The register network of the German Society for Orthopaedics and Trauma (DGOU) consists of 14 registries that cover the various fields of traumatology and elective orthopedics. In addition to registries that focus on implants and types of diseases without age limitations, there are also registries dealing with special diseases in children and adolescents as well as the special needs of elderly patients with fractures. The registries serve as instruments for outcome research and quality assurance and can be used to develop treatment recommendations on a high level of evidence. The objective of the network is to exchange experience that facilitates the establishment of new registers, to pool expertise and to conserve resources.