What Is the Clinical Relevance of Radiographic Nonunion After Single-Level Lumbar Interbody Arthrodesis in Degenerative Disc Disease?: A Meta-Analysis of the YODA Project Database

Adjunctive Use of Bone Growth Stimulation Increases Cervical Spine Fusion Rates in Patients at Risk for Pseudarthrosis

STUDY DESIGN

A prospective multicenter clinical trial (NCT03177473) was conducted with a retrospective cohort used as a control arm.

OBJECTIVE

The purpose of this study was to evaluate cervical spine fusion rates in subjects with risk factors for pseudarthrosis who received pulsed electromagnetic field (PEMF) treatment.

SUMMARY OF BACKGROUND DATA

Certain risk factors predispose patients to pseudarthrosis, which is associated with prolonged pain, reduced function, and decreased quality of life.

METHODS

Subjects in the PEMF group were treated with PEMF for 6 months postoperatively. The primary outcome measure was fusion status at the 12-month follow-up period. Fusion status was determined using anterior/posterior, lateral, and flexion/extension radiographs and computed tomography (without contrast).

RESULTS

A total of 213 patients were evaluated (PEMF, n=160; Control, n=53). At baseline, the PEMF group had a higher percentage of subjects who used nicotine ( P =0.01), had osteoporosis ( P <0.05), multi-level disease ( P <0.0001), and were >65 years of age ( P =0.01). The PEMF group showed over two-fold higher percentage of subjects that had ≥3 risk factors (n=92/160, 57.5%) compared with the control group (n=14/53, 26.4%). At the 12-month follow-up, the PEMF group demonstrated significantly higher fusion rates compared with the control (90.0% vs. 60.4%, P <0.05). A statistically significant improvement in fusion rate was observed in PEMF subjects with multi-level surgery ( P <0.0001) and high BMI (>30 kg/m 2 ; P =0.0021) when compared with the control group. No significant safety concerns were observed.

CONCLUSIONS

Adjunctive use of PEMF stimulation provides significant improvements in cervical spine fusion rates in subjects having risk factors for pseudarthrosis. When compared with control subjects that did not use PEMF stimulation, treated subjects showed improved fusion outcomes despite being older, having more risk factors for pseudarthrosis, and undergoing more complex surgeries.

Risk factors for nonunion in oblique lateral interbody fusion

BACKGROUND

Compared with posterior interbody fusion techniques, oblique lateral interbody fusion (OLIF) offers a larger fusion bed with greater intervertebral space access, use of larger cages, more sufficient discectomy, and better end-plate preparation. However, the fusion rate of OLIF is similar to that of other interbody fusions. This study aimed to examine the factors associated with nonunion in OLIF.

METHODS

This study examined 201 disc levels from 124 consecutive patients who underwent OLIF for lumbar degenerative diseases with 1-year regular follow-up. Demographic and surgical factors were reviewed from the medical records. Radiological factors measured were sagittal parameters, intervertebral disc angle (DA) before surgery and at the final follow-up, presence of vertebral end-plate lesions, and cage subsidence. Multivariable logistic regression analysis was performed to identify the factors associated with nonunion.

RESULTS

Among the 201 discs, 185 (92.0%) achieved union at 1-year followed up. Smoking, surgery at the L5-S1 level, not performing laminectomy, and a large intervertebral DA were factors associated with nonunion in OLIF (all P < 0.05). Multivariable logistic regression analysis showed two independent variables (surgery at L5-S1 level and not performing laminectomy) as risk factors for nonunion in OLIF.

CONCLUSIONS

Not performing laminectomy and surgery at the L5-S1 level were risk factors for nonunion in OLIF. To reduce the nonunion rate, surgeons should consider additional stabilization strategies for the L5-S1 OLIF and perform laminectomy.

Bioactive glass grants equivalent fusion compared to autologous iliac crest bone for ALIF: a within-patient comparative study

Purpose

To determine within-patient fusion rates of chambers filled with bioactive glass versus autologous iliac crest bone on computed tomography (CT) following anterior lumbar interbody fusion (ALIF).

Methods

A consecutive series of 40 patients (58 levels) that underwent single-level (L5-S1 only) or two-level (L5-S1 and L4-L5) ALIF were assessed. Indications for fusion were one or more of the following: degenerative disc disease with or without Modic changes, spondylolisthesis, and stenosis. Each intervertebral cage had a middle beam delimiting two chambers, one of which was filled with bioactive glass and the other with autologous iliac crest bone. CT scans were graded using the Bridwell classification (grade I, best; grade IV, worst). Patients were evaluated using the Oswestry Disability Index (ODI), and by rating pain in the lower back and legs on a Visual Analog Scale (pVAS); complications and reoperations were noted.

Results

At 15 ± 5 months follow-up, there were no significant differences in fusion across chambers filled with bioactive glass versus chambers filled with autologous bone (p = 0.416). Two patients with Bridwell grade III at both chambers of the L4-L5 cages required reoperation using posterior instrumentation. Clinical assessment of the 38 remaining patients (54 levels) at 25 ± 2 months, revealed ODI of 15 ± 12, lower back pVAS of 1.4 ± 1.5 and legs pVAS of 1.9 ± 1.6.

Conclusions

For ALIF at L5-S1 or L4-L5, within-patient fusion rates were equivalent for bioactive glass compared to autologous iliac crest bone; thus, bioactive glass can substitute autologous bone, avoiding increased operative time and blood loss, as well as donor site morbidity.

Cost-effectiveness of 4 mg dibotermin alfa/absorbable collagen sponge versus iliac crest bone graft for lumbar degenerative disc disease in the United Kingdom

AIMS

To develop a model to evaluate the cost-effectiveness of 4 mg dibotermin alfa/absorbable collagen sponge (ACS) versus iliac crest bone graft (ICBG) in patients with lumbar degenerative disc disease in the United Kingdom.

MATERIALS & METHODS

A Markov decision-analytic model was constructed to calculate costs and quality-adjusted life-years over a 4-year time horizon in each treatment group, from a United Kingdom National Health Service perspective. An individual patient data meta-analysis was undertaken to synthesize data from four randomized controlled trials and two single-arm studies concerning health-related quality of life and procedural resource use. Current cost data from the United Kingdom were then applied to determine the overall mean cost per patient in each group. One-way and probabilistic sensitivity analyses were undertaken to explore the impact of parameter uncertainty.

RESULTS

The model predicted 4-year discounted cost savings of £192 per patient treated with dibotermin alfa/ACS, compared with ICBG, and a gain of 0.0114 QALYs per patient over the same time period. Sensitivity analyses indicated that the results were most sensitive to variability in the differences in health-related quality of life and secondary surgery rate, with dibotermin alfa/ACS having a 60% probability of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY gained.

LIMITATIONS

There is uncertainty in the difference in cost and QALYs between the two groups. However, comprehensive sensitivity analyses were undertaken to explore this and present the results in a transparent manner.

CONCLUSIONS

Our results provide an economic case for the use of 4 mg dibotermin alfa/ACS versus iliac crest bone graft, with additional health benefits predicted at reduced overall cost.

Clinical and radiological outcomes in patients who underwent posterior lumbar interbody fusion: comparisons between unilateral and bilateral cage insertion

BACKGROUND

Although the original technique involves inserting two cages bilaterally, there could be situations that only allow for insertion of one cage unilaterally. However, only a few studies have compared the outcomes between unilateral and bilateral cage insertion. The purpose of this study was to compare the clinical and radiological outcomes in patients who underwent posterior lumbar interbody fusion (PLIF) between unilaterally and bilaterally inserted cages.

METHODS

Among 206 eligible patients who underwent 1- or 2-level PLIF, 78 patients were 1:3 cohort-matched by age, sex, and operation level (group U, 19 patients with unilateral cages; and group B, 57 patients with bilateral cages). Fusion status was evaluated by computed tomography (CT) scans at postoperative 1 year. Clinical outcomes were measured by visual analog scale (VAS), Oswestry Disability Index (ODI), and EQ-5D. Radiological and clinical parameters were compared between the two groups. Risk factors for pseudarthrosis were also analyzed by multivariate analysis.

RESULTS

The demographic data were not significantly different between the two groups. However, previous laminectomy, asymmetric disc collapse, and fusion at L5-S1 level were more frequently found in group U (P = 0.003, P = 0.014, and P = 0.014, respectively). Furthermore, pseudarthrosis was more frequently observed in group U (36.8%) than in group B (7.0%) (P = 0.004). Back pain VAS was higher in group U at postoperative 1 year (P = 0.033). Lower general activity function of EQ-5D was observed in group U at postoperative 1 year (P = 0.035). Older age (P = 0.028), unilateral cage (P = 0.007), and higher bone mineral density (P = 0.033) were positively correlated with pseudarthrosis.

CONCLUSIONS

Unilaterally inserted cage might be a possible risk factor for pseudarthrosis when performing PLIF, which could be related with the difficult working conditions such as scars due to previous laminectomy or asymmetric disc collapse. Furthermore, suboptimal clinical outcomes are expected following PLIF with unilateral cage insertion at postoperative 1 year regardless of similar clinical outcomes at postoperative 2 year. Therefore, caution is advised when inserting cages unilaterally, especially under above-mentioned conditions in terms of its possible relationship with symptomatic pseudarthrosis.

Low-Intensity Pulsed Ultrasound as a Potential Adjuvant Therapy to Promote Spinal Fusion: Systematic Review and Meta-analysis of the Available Data

Despite extensive research, nonunion continues to affect a nontrivial proportion of patients undergoing spinal fusion. Recently, preclinical studies have suggested that low-intensity pulsed ultrasound (LIPUS) may increase rates of spinal fusion. In this study, we summarized the available in vivo literature evaluating the effect of LIPUS on spinal fusion and performed a meta-analysis of the available data to estimate the degree to which LIPUS may mediate higher fusion rates. Across 13 preclinical studies, LIPUS was associated with a 9-fold increase in the odds of successful spinal fusion. Future studies are necessary to establish the benefit of LIPUS on spinal fusion in clinical populations.

Prognosis of Symptomatic Pseudarthrosis Observed at 1 Year After Lateral Lumbar Interbody Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to investigate the prognosis of symptomatic pseudarthrosis observed at 1 year after lateral lumbar interbody fusion (LLIF) surgery and to analyze the risk factors for persistent pseudarthrosis for 2 years postoperatively.

SUMMARY OF BACKGROUND DATA

Few articles have evaluated the prognosis of symptomatic pseudarthrosis following LLIF surgery.

METHODS

One hundred fifty-two patients with a minimum follow-up of 2 years were screened. Fusion status was assessed at 1 year postoperatively, and unfused segments were reevaluated at 2 years postoperatively. Dynamic x-rays and computed tomography images were acquired to evaluate the fusion status. Demographic data were evaluated to identify the risk factors associated with persistent pseudarthrosis. Clinical outcomes, including the visual analog scale (VAS) for back/leg pain and the Oswestry disability index (ODI), were evaluated preoperatively and at 1 and 2 years postoperatively.

RESULTS

Symptomatic pseudarthrosis was detected in 42 patients at 1 year postoperatively. Among them, 23 patients (54.8%) exhibited solid bony fusion 2 years postoperatively without further intervention. Fourteen patients (33.3%) showed asymptomatic pseudarthrosis, and the remaining five patients (11.9%) showed symptomatic pseudarthrosis. Multivariable analysis showed that diabetes (adjusted odds ratio [OR]: 2.817, P = 0.007), smoking (adjusted OR: 6.497, P = 0.008), and fusion at more than three levels (adjusted OR: 2.525, P = 0.031) were risk factors for persistent pseudarthrosis. Improvements in the VAS scores for back pain and ODI scores were significantly lower in the persistent pseudarthrosis group than in the final solid fusion group at 2 years postoperatively.

CONCLUSION

It is not necessary to intervene for all patients in whom symptomatic pseudarthrosis is detected at 1 year postoperatively because only 11.9% of them will show persistent symptomatic pseudarthrosis. However, early revision surgery should be considered when severe symptomatic pseudarthrosis associated with diabetes, smoking, and fusion at more than three levels is present.Level of Evidence: 4.

The Efficacy of Lumbar Hybrid Fusion for the Prevention of Adjacent Segment Disease: Fact or Artifact? A Meta-analysis

STUDY DESIGN

A systematic literature review and meta-analysis.

OBJECTIVE

The aim of this study is to compare hybrid constructs with traditional fusion-only constructs for the incidence of adjacent segment degeneration (ASDeg) and clinical outcomes in patients with degenerative lumbar diseases.

SUMMARY OF BACKGROUND DATA

Spinal fusion is a standard surgery for various pathologies of the lumbar spine, which results in changes to the biomechanics of the spine, potentially leading to ASDeg. Although ASDeg can occur slowly as a natural course, early-onset ASDeg is regarded to be related to fusion surgery.

MATERIALS AND METHODS

A systematic search was conducted to identify studies that match the purpose. Included studies were compared using the incidence of ASDeg, Oswestry Disability Index, Visual Analog Score, and perioperative outcomes. We calculated the Peto odds ratio and mean difference (MD) for the continuous variables, respectively. In the hybrid group, subgroup analysis was also performed among devices.

RESULTS

Among 10 papers involving 767 patients, 372 patients underwent hybrid fusion and 395 patients underwent fusion-only. ASDeg occurred in 10.2% in the hybrid and 21.5% in the fusion-only group [Peto odds ratio, 0.39; 95% confidence interval (CI), 0.23-0.64]. The MD for Visual Analog Score were 0.45 (95% CI, 0.05-0.85) between 2 groups, which was statistically significant but was too small to have clinical significance. The MD for Oswestry Disability Index was 0.93 (95% CI, -1.016 to 2.872), which was not statistically different between 2 groups. The hybrid is superior for 18 minutes (95% CI, 5.78-30.72) shorter than typical surgery.

CONCLUSIONS

Hybrid lumbar surgery decreased the incidence of early-onset ASDeg for about 2 years of follow-up. Among the hybrid constructs, the interspinous devices group accomplished favorable results with a lower risk. Adjacent segment disease was not as statistically significant as ASDeg, but adjacent segment disease may show a substantial difference for >2-year follow-up.

Robot-assisted minimally invasive transforaminal lumbar interbody fusion versus open transforaminal lumbar interbody fusion: a retrospective matched-control analysis for clinical and quality-of-life outcomes

Aim: To compare the screw accuracy and clinical outcomes between robot-assisted minimally invasive transforaminal lumbar interbody fusion (RA MIS-TLIF) and open TLIF in the treatment of one-level lumbar degenerative disease. Materials & methods: From May 2018 to December 2019, a consecutive series of patients undergoing robot-assisted minimally invasive one-level lumbar fusion procedures were retrospectively compared with matched controls who underwent one-level open TLIF procedures for clinical and quality-of-life outcomes. Results: A total of 52 patients underwent RA MIS-TLIF procedures (robot-assisted [RA] group) and 52 matched controls received freehand open TLIF procedures (open [OP] group). The RA group had more grade A screws with 96.2% one-time success rate of screw placement (p < 0.05). Besides, the RA group experienced less intraoperative blood loss and shorter length of hospital stay, while the OP group had shorter operative duration and cumulative radiation time (p < 0.001). What is more, the average VAS score for low back pain and ODI score in the RA group were lower than that in the OP group 1 month after operation (p < 0.05). Conclusion: The use of real-time, image-guided robot system may further expand the advantages of MIS-TLIF technique in terms of accuracy and safety.

A Meta-analysis of the Impact of Bariatric Surgery on Back Pain

BACKGROUND

The functional aspects of obesity are increasingly recognised as a significant clinical and public health concern. Whilst there is substantial evidence for the beneficial impact of bariatric surgery on metabolic and cardiovascular disease, there is less understanding of the quantitative effect of bariatric surgery on back pain. The aim of this meta-analysis was to assess the impact of bariatric surgery on back pain in reported studies.

METHODS

Medline, Embase, conference proceedings and reference lists were searched for studies assessing quantitative back pain scores both before and after bariatric surgery. The primary outcome was visual analogue score for back pain pre- and post-bariatric surgery. Secondary outcomes were change in BMI, SF-36 quality of life scores and Oswestry Disability Index (ODI) scores. Weighted mean differences (MD) were calculated for continuous outcomes.

RESULTS

Seven studies were included in the analysis of 246 patients undergoing bariatric surgery. Mean study follow-up was between 3 and 24 months. There was a statistically significant reduction in visual analogue score for back pain following bariatric surgery (MD - 3.01; 95% CI - 4.19 to - 1.89; p < 0.001). Bariatric surgery also resulted in statistically significant improvements in BMI, SF-36 score and ODI score.

CONCLUSIONS

Bariatric surgery produces significant and quantifiable reductions in back pain. This may be commuted through reductions in axial load or improved quality of life, but further studies will improve understanding and aid preoperative counselling.

Three- and 4-Level Lumbar Arthrodesis Using Adjunctive Pulsed Electromagnetic Field Stimulation: A Multicenter Retrospective Evaluation of Fusion Rates and a Review of the Literature

BACKGROUND

The incidence of 3- and 4-level lumbar arthrodesis is rising due to an aging population, and fusion rates affect clinical success in this population. Pulsed electromagnetic field (PEMF) stimulation is used as an adjunct to increase fusion rates following multilevel arthrodesis. The purpose of the study was to evaluate the fusion rates for subjects who underwent 3- and 4-level lumbar interbody arthrodesis following PEMF treatment.

METHODS

In this retrospective, multicenter study, patient charts that listed 3- or 4-level lumbar arthrodesis with adjunctive use of a PEMF device were evaluated. Inclusion criteria included patients who were diagnosed with lumbar degenerative disease, spinal stenosis, and/or spondylolisthesis (grade 1 or 2). A radiographic evaluation of fusion status was performed at 12 months by the treating physicians. Fusion rates were stratified by graft material, surgical interbody approach, and certain clinical risk factors for pseudoarthrosis.

RESULTS

A total of 55 patients were identified who had a 12-month follow-up. The radiographic fusion rate was 92.7% (51 patients) at 12 months. There were no significant differences in fusion rates for patients treated with allograft or autograft, for patients with different interbody approaches, or for those with or without certain clinical risk factors.

CONCLUSIONS

With modern fusion techniques and PEMF, the overall fusion rate was high following 3- and 4-level lumbar arthrodesis.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

PEMF may be a useful adjunct for treatment of patients with surgical risk factors, such as multilevel arthrodesis, and clinical risk factors.

Good clinical outcomes in nonunion cases after facet fusion with a percutaneous pedicle screw system for degenerative lumbar spondylolisthesis

There are many satisfactory long-term outcomes after posterolateral fusion (PLF) for degenerative lumbar spondylolisthesis (DLS); nonunion cases have also achieved good clinical outcomes. Facet fusion (FF), a minimally invasive evolution of PLF, also resulted in good clinical outcomes. We aimed to assess the course of nonunion cases after FF and determine whether the nonunion cases achieved good clinical outcomes. We retrospectively reviewed the records of 136 patients who underwent FF for DLS. Range of motion (ROM) at the fused level was measured using a flexion-extension lateral radiograph preoperatively and 1 year postoperatively. Patients were classified into the Fusion or Unconfirmed Fusion group by computed tomography (CT) 1 year postoperatively. Furthermore, patients in the Unconfirmed Fusion group were classified into the Delayed Union or Nonunion group depending on the confirmation status of FF upon the following CT. The average preoperative ROM and clinical outcomes were compared between the three groups. The Fusion, Delayed Union, and Nonunion groups had 109, 14, and 13 patients, respectively. In the Nonunion group, the average ROM significantly decreased from 13.0° preoperatively to 4.9° postoperatively. There was a significant difference in the average preoperative ROM between the groups. The larger the preoperative ROM, the fewer facets fused. There was no significant difference in clinical outcomes between the groups. Five patients (3.7%) required revision surgery for adjacent segment disease 1-5.5 years after FF. Even nonunion cases after FF achieved good clinical outcomes, likely because the unstable spondylolisthesis was stabilized. FF did not require revision surgery for nonunion itself.

Radiographic and clinical outcomes of silicate-substituted calcium phosphate (SiCaP) bone grafts in spinal fusion: Systematic review and meta-analysis

Pseudarthrosis continues to affect a nontrivial proportion of spine fusion patients. Given its ties to poorer patient outcomes and high reoperation rates, there remains great interest in interventions aimed at reducing the rates of nonunion. Recently, silicate-substituted calcium phosphate (SiCaP) bone grafts have been suggested to improve fusion rates, yet there exists no systematic review of the body of evidence for SiCaP grafts. Here, we present the first such review along with a meta-analysis of the effect of SiCaP bone grafts on fusion rates. Using the PubMed, Embase, and Web of Science databases, we queried the English-language literature for all studies examining the effect of SiCaPs on spinal fusion. Primary endpoints were: 1) radiographic fusion rate at last follow-up and 2) postoperative improvements in Visual Analog Scale (VAS) pain scores and Oswestry Disability Index (ODI) at last follow-up. Meta-analyses were performed for each endpoint using random effects. Ten articles (694 patients treated with SiCaP bone grafts) were included. Among SiCaP-treated patients, 93% achieved radiographic fusion (range: 79-100%), with comparable rates across subgroups. Meta-analysis of the three randomized controlled trials demonstrated no difference in fusion rates between SiCaP-treated patients and patients receiving grafts with recombinant human bone morphogenetic protein-2 (rhBMP-2) (OR: 1.11; p = 0.83). Patients treated with SiCaP bone grafts experienced significant improvements in VAS back pain (-3.3 points), VAS leg pain (-4.8 points), and ODI (-31.6 points) by last follow-up (p < 0.001 for each). Additional high-quality research is needed to evaluate the relative cost-effectiveness of SiCaP bone grafts in spinal fusion.

The effect of bioactive glasses on spinal fusion: A cross-disciplinary systematic review and meta-analysis of the preclinical and clinical data

Pseudarthrosis following spinal fusion is correlated with poorer patient outcomes and consequently is an area of continued interest within spinal research. Recently, bioactive glasses have been proposed as a means of augmenting fusion rates. Here, we present the first systematic review and meta-analysis of the existing preclinical and clinical literature on the effect of bioactive glasses on spinal fusion. Using the MEDLINE, Embase, and Web of Science databases, we queried all publications in the English-language literature examining the effect of bioactive glasses on spinal fusion. The primary endpoint was fusion rate at last follow-up and the secondary endpoint for clinical studies was the rate of deep wound infection. Random-effects meta-analyses were performed independently for the preclinical and clinical data. Twelve preclinical studies (267 animals) and 12 clinical studies (396 patients) evaluating a total of twelve unique bioactive glass formulations were included. Across clinical studies, fusion was seen in 84% treated with bioactive glass. On sub-analysis, fusion rates were similar for standalone autograft (91.6%) and bioactive glass-local autograft mixtures (89.6%). Standalone bioactive glass substrates produced inferior fusion rates relative to autograft alone (33.6% vs. 98.8%; OR 0.01, p < 0.02). Rates of deep wound infection did not differ between the bioactive glass and autograft groups (3.1%). The preclinical data similarly showed comparable rates of fusion between autograft and bioactive glass-treated animals. The available data suggest that bioactive glass-autograft mixtures confer similar rates of spinal fusion relative to standalone autograft without altering the risk of deep wound infection.

Postoperative Low Back Pain after Posterior Lumbar Interbody Fusion Surgery Using Cortical Bone Trajectory Screws

Study Design

Retrospective analysis of a case series of prospectively collected data.

Purpose

To compare clinical and radiological outcomes between two posterior lumbar interbody fusion techniques: cortical bone trajectory (CBT) and traditional pedicle screw (PS).

Overview of Literature

Biomechanical studies have revealed the benefits of the CBT technique. However, clinical evidence obtained from the direct comparison of outcomes between CBT and PS is limited.

Methods

We retrospectively investigated 104 patients who had undergone posterior lumbar interbody fusion using CBT or PS. Clinical symptoms were evaluated and compared between CBT and PS using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Visual Analog Scale (VAS) before and 1 year after surgery. Spinal fusion status was assessed by multiplanar reconstruction computed tomography at 1 year after surgery.

Results

The CBT and PS techniques were performed on 36 and 68 patients, respectively. Both CBT- and PS-treated patients exhibited improvement in each subdomain of the JOABPEQ and in the VAS. With regard to postoperative improvement of low back pain, the treatment effect, as assessed by the JOABPEQ, was greater for PS than for CBT. The spinal fusion rate was slightly lower for CBT than for PS, although the difference between them was not significant. The effect of treatment on postoperative low back pain was smaller for CBT than for PS, regardless of whether rigid spinal fusion was achieved.

Conclusions

Clinical symptoms and spinal fusion efficiency were not significantly different between CBT and PS except for postoperative improvement in low back pain. The treatment effect on postoperative low back pain was smaller for CBT than for PS.

Randomized Controlled Trial of Posterior Lumbar Interbody Fusion With Ti- and CaP-Nanocoated Polyetheretherketone Cages: Comparative Study of the 1-Year Radiological and Clinical Outcome

Background

Polyetheretherketone (PEEK) is a popular material for posterior lumbar interbody fusion (PLIF) cages, although osseointegration remains limited. To optimize PEEK cage characteristics, titanium (Ti) and calcium phosphate (CaP) nanocoatings have been developed with proven mechanical safety. This multicenter randomized controlled trial compared the clinical and radiological outcome parameters of nanocoated and uncoated PEEK cages, up to 1 year after surgery.

Methods

Standard open PLIF surgery was performed on 127 patients, randomized in 3 groups: Ti-nanocoated (n = 44), CaP-nanocoated (n = 46), and uncoated PEEK cages (n = 37). Clinical assessments up to 1 year after surgery included visual analogue scales (VASs), Oswestry Disability Index (ODI), and 36-Item Short Form Survey (SF-36). Primary radiological outcome parameters were implant stability and fusion status, assessed by x-ray and computed tomography (CT) scans. Patients, surgeons, and postsurgery analysts were blinded.

Results

PLIF surgery with all cage types resulted in significant improvements of clinical outcome parameters, exceeding the minimum clinically important differences. No significant differences in VAS, ODI, or SF-36 scores were found among the 3 groups. One year after the surgery, 65.6% of patients with uncoated PEEK cages achieved definite fusion. Significantly more patients with nanocoated PEEK cages achieved definite fusion: 93.9% for Ti nanocoating (P = .0034) and 88.0% for CaP nanocoating (P = .032). No significant differences in fusion were found between the nanocoated cage types (P = .4318).

Conclusions

The similar clinical outcome improvements after 1 year suggest that nanocoated PEEK cages have the same safety and efficacy as the clinically accepted uncoated PEEK cages. Furthermore, nanocoated PEEK cages achieved a better fusion rate than uncoated PEEK cages at the 1-year follow-up. A 5-year follow-up study is warranted to revisit the findings.

Clinical Relevance

The safety, efficacy, and enhanced osseointegration of nanocoated PEEK cages were demonstrated. Osseointegration is a significant predictor of positive long-term clinical outcomes and improved implant longevity, implying a clinical added value of nanocoatings. Enhanced osseointegration becomes even more important in minimally invasive spine surgery and in patients at risk for incomplete fusion.

The Clinical Implications and Complications of Anterior Versus Posterior Surgery for Multilevel Cervical Ossification of the Posterior Longitudinal Ligament; An Updated Systematic Review and Meta-Analysis

OBJECTIVE

Theoretically, the optimal approach is determined by the status of ossification of the posterior longitudinal ligament (OPLL) and sagittal alignment. However, there have long been disputes about the optimum surgical approach of OPLL. This study is to compare risk-effectiveness between anterior decompression and fusion (ADF) and laminoplasty and laminectomy with fusion (LP/LF) for the patient with cervical myelopathy due to multilevel cervical OPLL.

METHODS

We searched core databases, and compared complication and outcomes between ADF and LP/LF for patients with multiple OPLL for the cervical spine. The incidence of complications such as neurologic deterioration, C5 palsy, and dura tear was assessed. Changes in JOA score between baseline and final evaluations were assessed for 2 groups. The minimal clinically important difference (MCID) was utilized for evaluating clinical significance. We calculated Peto odds ratio (POR) and mean difference for the incidence and continuous variables, respectively.

RESULTS

We included data from 21 articles involving 3,872 patients with cervical myelopathy with OPLL. Major neurologic deficits such as paraplegia, quadriplegia developed 2.17% in the ADF group and 1.11% in the LP/LF group, and POR was 2.16. Mean difference of JOA score improvement of 2 groups was 1.30, and the mean difference showed a statistical significance. However, 1.3 points of JOA improvement cannot reach 2.5 points of the MCID.

CONCLUSION

Anterior surgery often led to rare but critical complications, and the difference of neurological improvement between 2 groups was below a clinically meaningful level. Posterior surgeries may be appropriate in the treatment of multilevel cervical myelopathy with OPLL.

Efficacy and Safety of Full-endoscopic Decompression via Interlaminar Approach for Central or Lateral Recess Spinal Stenosis of the Lumbar Spine: A Meta-analysis

STUDY DESIGN

A meta-analysis of five retrospective cohort studies.

OBJECTIVE

The aim of the study was to delineate the efficacy and safety of full-endoscopic decompression via the interlaminar approach for central or lateral recess spinal stenosis of the lumbar spine using a meta-analysis.

SUMMARY OF BACKGROUND DATA

The paradigm of spinal endoscopy is shifting from treatment of soft disc herniation to that of lumbar spinal stenosis. Technical advancements have enabled full-endoscopic decompression in spinal stenosis surgery. There is few strong evidence supporting this surgical technique, and clinicians usually rely on their own opinions and experiences.

METHODS

A systematic search of electronic databases, including PubMed, EMBASE, Cochrane Library, Web of science, and KoreaMed, up to August 2017 was performed to identify studies concerning full-endoscopic decompression via the interlaminar approach for lumbar spinal stenosis. Changes in clinical outcomes [Oswestry Disability Index (ODI) and Visual Analog Scales (VAS) for back and leg pain] were compared with the minimal clinically important difference (MCID) for each item. We then calculated the mean differences and 95% confidence intervals (95% CIs) using random-effects models.

RESULTS

We included data from five studies involving 156 patients at 6- and 12-month follow-ups. The majority of enrolled papers included patients with neurogenic claudication due to central stenosis refractory to conservative management and excluded patients with significant instability or previous surgery. The overall mean difference of patients with ODI and VAS scores for leg and back pain exceeded the criteria for MCID. ODI scores improved by 41.71 (95% CI, 39.80-43.62) after the surgery, which was twice the MCID. The VAS leg and back pain scores improved by 5.95 (95% CI, 5.70-6.21) and 4.22 (95% CI, 3.88-4.56), respectively, indicating statistically significant improvement over the MCID.

CONCLUSION

Successful clinical outcomes can be achieved with full-endoscopic decompression via the interlaminar approach for lumbar central spinal stenosis in patients for the defined indications.

LEVEL OF EVIDENCE

2.

Overview and experience of the YODA Project with clinical trial data sharing after 5 years

The Yale University Open Data Access (YODA) Project has facilitated access to clinical trial data since 2013. The purpose of this article is to provide an overview of the Project, describe key decisions that were made when establishing data sharing policies, and suggest how our experience and the experiences of our first two data generator partners, Medtronic, Inc. and Johnson & Johnson, can be used to enhance other ongoing or future initiatives.

The efficacy of conventional radiofrequency denervation in patients with chronic low back pain originating from the facet joints: a meta-analysis of randomized controlled trials

BACKGROUND CONTEXT

Radiofrequency denervation is commonly used for the treatment of chronic facet joint pain that has been refractory to more conservative treatments, although the evidence supporting this treatment has been controversial.

PURPOSE

We aimed to elucidate the precise effects of radiofrequency denervation in patients with low back pain originating from the facet joints relative to those obtained using control treatments, with particular attention to consistency in the denervation protocol.

STUDY DESIGN/SETTING

A meta-analysis of randomized controlled trials was carried out.

PATIENT SAMPLE

Adult patients undergoing radiofrequency denervation or control treatments (sham or epidural block) for facet joint disease of the lumbar spine comprised the patient sample.

OUTCOME MEASURES

Visual analog scale (VAS) pain scores were measured and stratified by response of diagnostic block procedures.

METHOD

We searched PubMed, Embase, Web of Science, and the Cochrane Database for randomized controlled trials regarding radiofrequency denervation and control treatments for back pain. Changes in VAS pain scores of the radiofrequency group were compared with those of the control group as well as the minimal clinically important difference (MCID) for back pain VAS. Meta-regression model was developed to evaluate the effect of radiofrequency treatment according to responses of diagnostic block while controlling for other variables. We then calculated mean differences and 95% confidence intervals (CIs) using random-effects models.

RESULTS

We included data from seven trials involving 454 patients who had undergone radiofrequency denervation (231 patients) and control treatments such as sham or epidural block procedures (223 patients). The radiofrequency group exhibited significantly greater improvements in back pain score when compared with the control group for 1-year follow-up. Although the average improvement in VAS scores exceeded the MCID, the lower limit of the 95% CI encompassed the MCID. A subgroup of patients who responded very well to diagnostic block procedures demonstrated significant improvements in back pain relative to the control group at all times. When placed into our meta-regression model, the response to diagnostic block procedure was responsible for a statistically significant portion of treatment effect. Studies published over the last two decades revealed that radiofrequency denervation reduced back pain significantly in patients with facet joint disease compared with the MCID and control treatments.

CONCLUSIONS

Conventional radiofrequency denervation resulted in significant reductions in low back pain originating from the facet joints in patients showing the best response to diagnostic block over the first 12 months when compared with sham procedures or epidural nerve blocks.

Clinical and Radiographic Outcomes in Patients Undergoing Single-level Anterior Cervical Arthrodesis: A Prospective Trial Comparing Allograft to a Reduced Dose of rhBMP-2

STUDY DESIGN

A prospective study with historical controls.

OBJECTIVES

To evaluate and compare the safety and effectiveness of recombinant human bone morphogenetic protein-2 (rhBMP-2) with allograft for anterior cervical discectomy and fusion (ACDF) in patients with symptomatic single-level cervical degenerative disk disease.

SUMMARY OF BACKGROUND DATA

rhBMP-2 is an osteoinductive protein that has been shown to induce fusion when used as an implant with a suitable carrier in spine surgery. However, some previous studies have shown rhBMP-2 use to be associated with a higher complication rate.

METHODS

Investigational patients (224) with single-level cervical degenerative disk disease underwent ACDF with rhBMP-2 at a dose of 0.6 or 1.05 mg and were compared with historical control patients (486) treated with allograft spacer and cervical plate.

RESULTS

At 24 months, improvement was significantly greater in the investigational group (37.1 points) than in the control group for Neck Disability Index (P=0.002) and arm pain (P=0.031). The overall neurological success rate was higher in the investigational group (P<0.001). Neck pain and general health status (SF-36 PCS and MCS) were similar. Fusion rate in the investigational group was higher than in the control group (99.4% vs. 87.2%, P=0.002).Cumulative adverse event rates at 24 months were similar; however, higher rates of dysphagia (P=0.001), local swelling (P=0.024), oropharyngeal pain (P=0.013), neck pain (P=0.019), and foraminal stenosis (P=0.002) were observed in the investigational group. Heterotopic ossification was also higher in the investigational group.

CONCLUSIONS

At doses of 0.6 or 1.05 mg in a PEEK interbody cage, rhBMP-2 was effective in inducing fusion and improving Neck Disability Index and arm pain in single-level ACDF patients; however, higher rates of certain adverse events were observed in the investigational group.

LEVEL OF EVIDENCE

Level 2.

Effectiveness of deformity-correction surgery for primary degenerative sagittal imbalance: a meta-analysis

OBJECTIVE

As life expectancy continues to increase, primary degenerative sagittal imbalance (PDSI) is diagnosed in an increasing number of elderly people. Although corrective surgery for this sagittal deformity is becoming more popular, the effectiveness of the procedure remains unclear. The authors aimed to collate the available evidence on the effectiveness and complications of deformity-correction surgery in patients with PDSI.

METHODS

The authors carried out a meta-analysis of clinical studies regarding deformity correction in patients with PDSI. The studies were identified through searches of the PubMed, Embase, Web of Science, and Cochrane databases. Surgery outcomes were evaluated and overall treatment effectiveness was assessed in terms of the minimum clinically important difference (MCID) in Oswestry Disability Index (ODI) values and pain levels according to visual analog scale (VAS) scores and in terms of restoration of spinopelvic parameters to within a normal range. Data are expressed as mean differences with 95% CIs.

RESULTS

Ten studies comprising 327 patients were included. The VAS and ODI values improved after deformity-correction surgery. The smallest treatment effect exceeded the MCID for VAS values (4.15 [95% CI 3.48–4.82]) but not for ODI values (18.11 [95% CI 10.99–25.23]). At the final follow-up visit, the mean lumbar lordosis angle (−38.60° [95% CI −44.19° to −33.01°]), thoracic kyphosis angle (31.10° [95% CI 24.67°–37.53°]), C-7 sagittal vertical axis (65.00 mm [95% CI 35.27–94.72 mm]), and pelvic tilt angle (30.82° [95% CI 24.41°–37.23°]) remained outside their normal ranges. Meta-regression analyses revealed a significant effect of ODI change in relation to lumbar lordosis change (p = 0.004). After a mean of 2 years after deformity correction, the mean lumbar lordosis angle and C-7 sagittal vertical axis decreased by 5.82° and 38.91 mm, respectively, and the mean thoracic kyphosis angle increased by 4.7°. The incidences of proximal junctional kyphosis and pseudarthrosis were 23.7% and 12.8%, respectively.

CONCLUSIONS

Deformity correction substantially relieves back pain for about 2 years in adult patients with PDSI. Sufficient surgical restoration of lumbar lordosis can lead to substantial improvement in patient disability and reduced decompensation. Deformity correction represents a viable therapeutic option for patients with PDSI, but further technical advancements are necessary to achieve sufficient lumbar lordosis and reduce complication rates.

Publishing descriptions of non-public clinical datasets: proposed guidance for researchers, repositories, editors and funding organisations

Sharing of experimental clinical research data usually happens between individuals or research groups rather than via public repositories, in part due to the need to protect research participant privacy. This approach to data sharing makes it difficult to connect journal articles with their underlying datasets and is often insufficient for ensuring access to data in the long term. Voluntary data sharing services such as the Yale Open Data Access (YODA) and Clinical Study Data Request (CSDR) projects have increased accessibility to clinical datasets for secondary uses while protecting patient privacy and the legitimacy of secondary analyses but these resources are generally disconnected from journal articles-where researchers typically search for reliable information to inform future research. New scholarly journal and article types dedicated to increasing accessibility of research data have emerged in recent years and, in general, journals are developing stronger links with data repositories. There is a need for increased collaboration between journals, data repositories, researchers, funders, and voluntary data sharing services to increase the visibility and reliability of clinical research. Using the journal Scientific Data as a case study, we propose and show examples of changes to the format and peer-review process for journal articles to more robustly link them to data that are only available on request. We also propose additional features for data repositories to better accommodate non-public clinical datasets, including Data Use Agreements (DUAs).