Instrumented Versus Noninstrumented Spinal Fusion for Degenerative Lumbar Spondylolisthesis: A Systematic Review

Biomechanical Comparison of Corticopedicular Spine Fixation versus Pedicle Screw Fixation in a Lumbar Degenerative Spondylolisthesis Finite Element Analysis Model

OBJECTIVE

To compare the stability of a corticopedicular posterior fixation (CPPF) device with traditional pedicle screws for decompression and fusion in adult degenerative lumbar spondylolisthesis.

METHODS

Finite element analysis (FEA) was used in a validated model of grade 1 L4-L5 spondylolisthesis to compare segmental stability after laminectomy alone, laminectomy with pedicle screw fixation, or laminectomy with CPPF device fixation. A 500-N follower load was applied to the model and different functional movements were simulated by applying a 7.5-Nm force in different directions. Outcomes included degrees of motion, tensile forces experienced in the CPPF device, and stresses in surrounding cortical bone.

RESULTS

At maximum loading, laminectomy alone demonstrated a 1° increase in flexion range of motion, from 6.35° to 7.39°. Laminectomy with pedicle screw fixation and CPPF device fixation both reduced spinal segmental motion to ≤1° at maximum loading in all ranges of motion, including flexion (0.94° and 1.09°), extension (-0.85° and -1.08°), lateral bending (-0.56° and -0.96°), and torsion (0.63° and 0.91°), respectively. There was no significant difference in segmental stability between pedicle screw fixation and CPPF device fixation during maximum loading, with a difference of ≤0.4° in any range of motion. Tensile forces in the CPPF device remained ≤51% the ultimate load to failure (487 N) and stress in surrounding cortical bone remained ≤84% the ultimate stress of cortical bone (125.4 MPa) during maximum loading.

CONCLUSIONS

CPFF fixation demonstrated similar segmental stability to traditional pedicle screw fixation whereas tensile forces and stress in surrounding cortical bone remained below the load to failure.

Efficacy and Outcome Measurement of iFactor/ABM/P-15 in Lumbar Spine Surgery: A Systematic Review

STUDY DESIGN

Systematic Review.

OBJECTIVES

To determine the efficacy and overall outcomes of iFactor/ABM/P-15 following lumbar spine surgery.

METHODS

We performed a search of the Cochrane Library, Medline Ovid, PubMed, and SCOPUS databases from inception until August 2023. Eligible studies included outcomes of patients receiving iFactor following lumbar spine surgery. The primary outcomes of interest were fusion rates and iFactor efficacy after lumbar surgery in patients who received iFactor. Secondary outcomes included patient-reported outcomes and complication rates.

RESULTS

A total of 766 titles were initially screened. After inclusion criteria were applied, 5 studies (388 patients) were included, which measured overall outcomes of iFactor/ABM/P-15 following lumbar spine surgery. These studies showed acceptable reliability for inclusion based on the Methodical Index for Non-Randomized studies and Critical Appraisal Skills Programme assessment tools. iFactor/ABM/P-15 facilitated significantly faster bone development in various procedures while maintaining favorable clinical outcomes compared to traditional grafts.

CONCLUSIONS

This systematic review found that iFactor/ABM/P-15 use for lumbar spine surgery maintains similar managing patient-reported outcomes relative to other grafting methods. In regard to rates of fusion, iFactor/ABM/P-15 showed a significantly faster rate of fusion when compared to traditional grafts including allograft, autograft, demineralized bone matrix (DBM), and recombinant human bone morphogenetic protein-2 (rhBMP-2). Future multicenter randomized control trials with larger sample sizes are recommended to further assess iFactor/ABM/P-15 efficacy in lumbar spine surgery.

Variations in surgical practice and short-term outcomes for degenerative lumbar scoliosis and spondylolisthesis: do surgeon training and experience matter?

For diverse procedures, sizable geographic variation exists in rates and outcomes of surgery, including for degenerative lumbar spine conditions. Little is known about how surgeon training and experience are associated with surgeon-level variations in spine surgery practice and short-term outcomes. This retrospective observational analysis characterized variations in surgical operations for degenerative lumbar scoliosis or spondylolisthesis, two common age-related conditions. The study setting was two large spine surgery centers in one region during 2017-19. Using data (International Classification of Diseases-10th edition and current procedural terminology codes) extracted from electronic health record systems, we characterized surgeon-level variations in practice (use of instrumented fusion - a more extensive procedure that involves device-related risks) and short-term postoperative outcomes (major in-hospital complications and readmissions). Next, we tested for associations between surgeon training (specialty and spine fellowship) and experience (career stage and operative volume) and use of instrumented fusion as well as outcomes. Eighty-nine surgeons performed 2481 eligible operations. For the study diagnoses, spine surgeons exhibited substantial variation in operative volume, use of instrumented fusion, and postoperative outcomes. Among surgeons above the median operative volume, use of instrumented fusion ranged from 0% to >90% for scoliosis and 9% to 100% for spondylolisthesis, while rates of major in-hospital complications ranged from 0% to 25% for scoliosis and from 0% to 14% for spondylolisthesis. For scoliosis, orthopedic surgeons were more likely than neurosurgeons to perform instrumented fusion for scoliosis [49% vs. 33%, odds ratio (OR) = 2.3, 95% confidence interval (95% CI) 1.3-4.2, P-value = .006] as were fellowship-trained surgeons (49% vs. 25%, OR = 3.0, 95% CI 1.6-5.8; P = .001). Fellowship-trained surgeons had lower readmission rates. Surgeons with higher operative volumes used instrumented fusion more often (OR = 1.1, 95% CI 1.0-1.2, P < .05 for both diagnoses) and had lower rates of major in-hospital complications (OR = 0.91, 95% CI 0.85-0.97; P = .006). Surgical practice can vary greatly for degenerative spine conditions, even within the same region and among colleagues at the same institution. Surgical specialty and subspecialty, in addition to recent operative volume, can be linked to variations in spine surgeons' practice patterns and outcomes. These findings reinforce the notion that residency and fellowship training may contribute to variation and present important opportunities to optimize surgical practice over the course of surgeons' careers. Future efforts to reduce unexplained variation in surgical practice could test interventions focused on graduate medical education. Graphical Abstract.

Instrumented Versus Uninstrumented Posterolateral Fusion for Lumbar Spondylolisthesis: A Randomized Controlled Trial

BACKGROUND

In Scandinavia, spinal fusion is frequently performed without instrumentation, as use of instrumentation in the elderly can be complicated by poor bone quality and the risk of screw pull-out. However, uninstrumented fusion carries the risk of nonunion. We performed a randomized controlled trial in an attempt to determine if use of instrumentation leads to better outcomes and fusion rates when spinal fusion is performed for degenerative spondylolisthesis in the elderly.

METHODS

This was a randomized, single-center, open-label trial of patients with symptomatic single-level degenerative spondylolisthesis who were assigned 1:1 to decompression and fusion with or without instrumentation after at least 12 weeks of nonoperative treatment had failed. The primary outcome was the change in the Oswestry Disability Index (ODI), and secondary outcomes included fusion rates within 1 year, reoperation rates within 2 years, and changes in the EuroQol-5 Dimension-3 Level (EQ-5D) score.

RESULTS

Fifty-four subjects were randomized to each of the 2 groups, which had similar preoperative demographic and surgical characteristics. We found similar improvements in the ODI (p = 0.791), back pain, leg pain, and quality of life between groups at 1 and 2 years of follow-up. Solid fusion on computed tomography (CT) scans was noted in 94% of the patients in the instrumented group and 31% in the uninstrumented group (p < 0.001). One patient (2%) in the instrumented group and 7 (13%) in the uninstrumented group (p = 0.031) had a reoperation within 2 years after the index surgery.

CONCLUSIONS

We found no difference in patient-reported outcomes when we compared instrumented with uninstrumented fusion in patients with degenerative spondylolisthesis. The uninstrumented group had a significantly higher rate of nonunion and reoperations at 2 years.

LEVEL OF EVIDENCE

Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Combination of percutaneous endoscopic lumbar discectomy and platelet-rich plasma hydrogel injection for the treatment of lumbar disc herniation

OBJECTIVE

To determine the safety and efficacy of percutaneous endoscopic lumbar discectomy (PELD) combined with platelet-rich plasma (PRP) hydrogel injection in patients with lumbar disc herniation (LDH).

METHODS

A total of 98 consecutive patients with LDH who underwent either PELD combined with PRP hydrogel injection or PELD alone were reviewed. This retrospective study was performed between January 2019 and January 2021. Clinical outcomes were compared in the visual analog scale (VAS) for low back pain and leg pain, Oswestry disability index (ODI), Japanese Orthopaedic Association (JOA) scores, and Macnab criteria. Intervertebral disc height on MRI was measured, and the Pfirrmann grade classification was used pre-operatively and post-operatively.

RESULTS

No severe adverse events were reported during an 18-month follow-up period. VAS scores for back pain were decreased at 1 month, 3 months, and 18 months in the treatment group than that in the control group. JOA score and ODI in the treatment group at 3-month and 18-month follow-up was lower than that in the control group (P < 0.05). The excellent and good rate of the Macnab criteria was 92.0% (46/50) in the treatment group and 89.6% (43/48) in the control group (P > 0.05). The comparison of Pfirrmann grading and disc height at 18-month follow-up showed significant difference in two groups (P < 0.05). The recurrence of LDH in the treatment group was lower than that in the control group (P < 0.05).

CONCLUSIONS

We suggest that PELD combined with PRP hydrogel injection to treat patients with LDH is a safe and promising method. PRP injection was beneficial for disc remodelling after PELD.

Decompression alone versus decompression with instrumented fusion in the treatment of lumbar degenerative spondylolisthesis: a systematic review and meta-analysis of randomised trials

OBJECTIVE

To determine the efficacy of adding instrumented spinal fusion to decompression to treat degenerative spondylolisthesis (DS).

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

MEDLINE, Embase, Emcare, Cochrane Library, CINAHL, Scopus, ProQuest Dissertations & Theses Global, ClinicalTrials.gov and WHO International Clinical Trials Registry Platform from inception to May 2022.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Randomised controlled trials (RCTs) comparing decompression with instrumented fusion to decompression alone in patients with DS. Two reviewers independently screened the studies, assessed the risk of bias and extracted data. We provide the Grading of Recommendations, Assessment, Development and Evaluation assessment of the certainty of evidence (COE).

RESULTS

We identified 4514 records and included four trials with 523 participants. At a 2-year follow-up, adding fusion to decompression likely results in trivial difference in the Oswestry Disability Index (range 0-100, with higher values indicating greater impairment) with mean difference (MD) 0.86 (95% CI -4.53 to 6.26; moderate COE). Similar results were observed for back and leg pain measured on a scale of 0 to 100, with higher values indicating more severe pain. There was a slightly increased improvement in back pain (2-year follow-up) in the group without fusion shown by MD -5·92 points (95% CI -11.00 to -0.84; moderate COE). There was a trivial difference in leg pain between the groups, slightly favouring the one without fusion, with MD -1.25 points (95% CI -6.71 to 4.21; moderate COE). Our findings at 2-year follow-up suggest that omitting fusion may increase the reoperation rate slightly (OR 1.23; 0.70 to 2.17; low COE).

CONCLUSIONS

Evidence suggests no benefits of adding instrumented fusion to decompression for treating DS. Isolated decompression seems sufficient for most patients. Further RCTs assessing spondylolisthesis stability are needed to determine which patients would benefit from fusion.

PROSPERO REGISTRATION NUMBER

CRD42022308267.

Decompression with or without Fusion for Lumbar Synovial Cysts—A Systematic Review and Meta-Analysis

The management of symptomatic lumbar synovial cysts (LSC) is still a matter of debate. Previous systematic reviews did not stratify data according to different treatment techniques or incompletely reported comparative data on patients treated with lumbar posterior decompression (LPD) and lumbar decompression and fusion (LDF). The aim of our study was to compare LPD and LDF via a systematic review and meta-analysis of the existing literature. The design of this study was in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The review questions were as follows: among patients suffering from symptomatic lumbar synovial cysts (population) and treated with either posterior lumbar decompression or posterior decompression with fusion (intervention), who gets the best results (outcome), in terms of cyst recurrence, reoperation rates, and improvement of postoperative symptoms (comparison)? The search of the literature yielded a total of 1218 results. Duplicate records were then removed (n = 589). A total of 598 articles were screened, and 587 records were excluded via title and abstract screening; 11 studies were found to be relevant to our research question and were assessed for eligibility. Upon full-text review, 5 were excluded because they failed to report any parameter separately for both LPD and LDF. Finally, 6 studies for a total of 657 patients meeting the criteria stated above were included in the present investigation. Our analysis showed that LDF is associated with better results in terms of lower postoperative back pain and cyst recurrence compared with LPD. No differences were found in reoperation rates and complication rates between the two techniques. The impact of minimally invasive decompression techniques on the different outcomes in LSC should be assessed in the future and compared with instrumentation techniques.