Posterolateral Lumbar Fusion Research Articles

Complications of degenerative lumbar spondylolisthesis and stenosis surgery in patients over 80\xa0s: comparative study with over 60\xa0s and 70\xa0s. Experience with 678 cases

PurposeDegenerative spondylolisthesis (DS) is a debilitating condition that carries a high economic burden. As the global population ages, the number of patients over 80 years old demanding spinal fusion is constantly rising. Therefore, neurosurgeons often face the important decision as to whether to perform surgery or not in this age group, commonly perceived at high risk for complications.MethodsSix hundred seventy-eight elder patients, who underwent posterolateral lumbar fusion for DS (performed in three different centers) from 2012 to 2020, were screened for medical, early and late surgical complications and for the presence of potential preoperative risk factors. Patients were divided in three categories based on their age: (1) 60–69 years, (2) 70–79 years, (3) 80 and over. Multiple logistic regression was used to determine the predictive power of age and of other risk factors (i.e., ASA score; BMI; sex; presence or absence of insulin-dependent and -independent diabetes, use of anticoagulants, use of antiaggregants and osteoporosis) for the development of postoperative complications.ResultsIn univariate analysis, age was significantly and positively correlated with medical complications. However, when controls for other risk factors were added in the regressions, age never reached significance, with the only noticeable exception of cerebrovascular accidents. ASA score and BMI were the two risk factors that significantly correlated with the higher numbers of complication rates (especially medical).ConclusionPatients of different age but with comparable preoperative risk factors share similar postoperative morbidity rates. When considering octogenarians for lumbar arthrodesis, the importance of biological age overrides that of chronological.

Bone union-promoting effect of romosozumab in a rat posterolateral lumbar fusion model.

This study investigated the effect of romosozumab on bone union in a rat posterolateral lumbar fixation model. Posterolateral lumbar fixation was performed on 8-week-old male Sprague Dawley rats (n = 20). For bone grafting, autogenous bone (40 mg) was harvested from the spinous processes of the 10th thoracic vertebra until the 2nd lumbar vertebra and implanted between the intervertebral joints and transverse processes of the 4th and 5th lumbar vertebrae on both sides. Rats were matched by body weight and equally divided into two groups: R group (Evenity®, 25 mg/kg) and control (C) group (saline). Subcutaneous injections were administered twice a week until 8 weeks after surgery. Computed tomography was performed at surgery and week 8 after surgery. The area and percentage of bone trabeculae in the total area of bone fusion were calculated. Statistical analysis was performed using an unpaired t test (p < 0.05). We found that the R group rats had significantly higher mean bone union rate and volume than did the C group rats at all time courses starting week 4 after surgery. The R group had significantly higher increase rates than did the C group at weeks 4 and 6 after surgery. The percentage of bone trabeculae area in the R group was approximately 1.7 times larger than that in the C group. Thus, we demonstrated that romosozumab administration has stimulatory effects on bony outgrowth at bone graft sites. We attribute this to the modeling effect of romosozumab.

Transforaminal Lumbar Interbody Fusion versus Posterolateral Fusion for Surgical Treatment of Segmental Lumbar Spinal Instability

Background Data: The rationale behind lumbar fusion surgery is to eliminate pathologic segmental motion and its accompanying symptoms, especially low back pain.Posterolateral fusion (PLF) using pedicle screw fixation (PSF) has been one of the most popular procedures among the posterior lumbar reconstruction techniques.Lumbar interbody fusion is a recognized surgical technique in treating chronic low back pain in segmental instability. Purpose: The purpose of this study was to compare the clinical and radiological outcomes of stabilizing the lumbar spine using TLIF versus PLF for lumbar segmental instability. Study Design: A prospective, nonrandomized clinical controlled trial. Patients and Methods: Forty patients with segmental lumbar instability were divided into two groups: TLIF and PLF groups, with twenty patients each. Top loaded pedicle screw construct was used with both groups. The mean age of the patients was 48.35 years in the TLIF group and 45.3 years in the PLF group. Sex distribution was 6 males and 14 females in the TLIF group and 7 males and 13 females in the PLF group. Mechanical low back pain was the chief complaint in all patients. Sciatica was a complaint in 12 patients (60%) of the TLIF group and 13 (65%) patients of the PLF group. Patients were evaluated pre- and postoperatively by visual analogue scale (VAS), Oswestry disability index (ODI), and radiographs. Results: The average operative time was 214.5 minutes in the TLIF group and 192.5 minutes in the PLF group. The mean estimated blood loss was 278 ml in the TLIF group and 259 ml in the PLF group. The average length of hospital stay was 3.85 days in the TLIF group and 3.8 days in the PLF group. Patients progressively improved regarding VAS and ODI in both groups with no statistically significant difference except for VAS for back pain, where the TLIF group gave better results. However, TLIF group gave better results in patients with postlaminectomy instability than the PLF group. Solid fusion occurred in 17 patients (85%) of the TLIF group and 16 patients (80%) of the PLF group with no statistical difference. Conclusion: Both transforaminal lumbar interbody fusion and posterolateral fusion are effective and safe options for treating segmental lumbar instability. However, interbody fusion yield superior results in patients with postlaminectomy instability. (2021ESJ253)

The effect of local steroid application on bony fusion in a rat posterolateral spinal arthrodesis model.

IntroductionLocal steroid administration during anterior cervical spine surgery has been shown to improve postoperative dysphagia. However, concerns over potential complications remain. This study aims to evaluate the effect of local steroid administration on bone regeneration and spine fusion in a preclinical model, as well as the impact on osteogenic differentiation of human bone marrow‐derived mesenchymal stem cells (hBM‐MSCs) in a 3D culture system.Materials and methodsForty‐five rats underwent bilateral L4‐L5 posterolateral lumbar fusion (PLF) utilizing local delivery of low‐dose recombinant human bone morphogenetic protein‐2 (rhBMP‐2; 0.5 μg/implant). Rats were divided into three groups: no steroid (control), low dose (0.5 mg/kg), and high dose (2.5 mg/kg) of triamcinolone. Bone growth and fusion were assessed using radiography, blinded manual palpation, and micro‐CT analysis and were visualized by histology. The impact of triamcinolone exposure on osteogenic differentiation of hBM‐MSCs was evaluated by gene expression analysis, alkaline phosphatase activity assay, and alizarin red staining.ResultsNo significant differences in fusion scores or rates were seen in the low‐ or high‐dose steroid treatment groups relative to untreated controls. Quantification of new bone formation via micro‐CT imaging revealed no significant between‐group differences in the volume of newly regenerated bone. Triamcinolone also had no negative impact on pro‐osteogenic gene transcript levels, and ALP activity was enhanced in the presence of triamcinolone. Mineral deposition appeared comparable in cultures grown with and without triamcinolone.ConclusionsLocal steroid application does not seem to inhibit rhBMP‐2‐mediated spine fusion in rats, though our study may not be adequately powered to detect differences in fusion as measured by manual palpation or bone volume as measured by micro‐CT. These findings suggest that local triamcinolone may not increase pseudarthrosis in spine fusion procedures. Further large animal and clinical studies to verify its safety and efficacy are warranted.

Spinal anesthesia in awake surgical procedures of the lumbar spine: a systematic review and meta-analysis of 3709 patients

Awake surgery has previously been found to improve patient outcomes postoperatively in a variety of procedures. Recently, multiple groups have investigated the utility of this modality for use in spine surgery. However, few current meta-analyses exist comparing patient outcomes in awake spinal anesthesia with those in general anesthesia. Therefore, the authors sought to present an updated systematic review and meta-analysis investigating the utility of spinal anesthesia relative to general anesthesia in lumbar procedures. Following a comprehensive literature search of the PubMed and Cochrane databases, 14 clinical studies were included in our final qualitative and quantitative analyses. Of these studies, 5 investigated spinal anesthesia in lumbar discectomy, 4 discussed lumbar laminectomy, and 2 examined interbody fusion procedures. One study investigated combined lumbar decompression and fusion or decompression alone. Two studies investigated patients who underwent discectomy and laminectomy, and 1 study investigated a series of patients who underwent transforaminal lumbar interbody fusion, posterolateral fusion, or decompression. Odds ratios, mean differences (MDs), and 95% confidence intervals were calculated where appropriate. A meta-analysis of the total anesthesia time showed that time was significantly less in patients who received spinal anesthesia for both lumbar discectomies (MD -26.53, 95% CI -38.16 to -14.89; p = 0.00001) and lumbar laminectomies (MD -11.21, 95% CI -19.66 to -2.75; p = 0.009). Additionally, the operative time was significantly shorter in patients who underwent spinal anesthesia (MD -14.94, 95% CI -20.43 to -9.45; p < 0.00001). Similarly, when analyzing overall postoperative complication rates, patients who received spinal anesthesia were significantly less likely to experience postoperative complications (OR 0.29, 95% CI 0.16-0.53; p < 0.0001). Furthermore, patients who received spinal anesthesia had significantly lower postoperative pain scores (MD -2.80, 95% CI -4.55 to -1.06; p = 0.002). An identical trend was seen when patients were stratified by lumbar procedures. Patients who received spinal anesthesia were significantly less likely to require postoperative analgesia (OR 0.06, 95% CI 0.02-0.25; p < 0.0001) and had a significantly shorter hospital length of stay (MD -0.16, 95% CI -0.29 to -0.03; p = 0.02) and intraoperative blood loss (MD -52.36, 95% CI -81.55 to -23.17; p = 0.0004). Finally, the analysis showed that spinal anesthesia cost significantly less than general anesthesia (MD -226.14, 95% CI -324.73 to -127.55; p < 0.00001). This review has demonstrated the varying benefits of spinal anesthesia in awake spine surgery relative to general anesthesia in patients who underwent various lumbar procedures. The analysis has shown that spinal anesthesia may offer some benefits when compared with general anesthesia, including reduction in the duration of anesthesia, operative time, total cost, and postoperative complications. Large prospective trials will elucidate the true role of this modality in spine surgery.

Assessing the Outcome of Transforminal Lumbar Interbody Fusion and Posterolateral Lumbar Fusion with Instrumentation in Treatment of Degenerative Lumbar Disorders

Abstract Background Degenerative lumbar disorders are relatively common condition that typically affects persons over the age of 50 and are more common in females. Patients typically present with a constellation of symptoms that include back pain, radiculopathy, and/or neurogenic claudication. Aim of the Work to assess the clinical and radiological outcome of Transforaminal Lumbar Interbody Fusion (TLIF) and posterolateral fusion (PLF) in the treatment of degenerative lumbar disorders. Patients and Methods a prospective study was conducted on patients with degenerative lumbar spondylolisthesis and degenerative lumbar spine stenosis who were admitted to Neurosurgical department at Ain Shams University hospital and Arab contractors medical center and underwent lumbar spine fixation with either transforaminal interbody fusion or posterolateral fusion from February 2017 to February 2019. The patients were divided into two groups according to the operative procedure done for each group. Group A (20 patients) included patients who underwent transforaminal lumbar interbody fusion. Group B (20 patients) included patients who underwent posterolateral fusion. Results We found that both TLIF and PLF provide improvement of disability and pain in patients with degenerative lumbar disorders. TLIF is superior to PLF with regard to achieving radiographic fusion. There is no strong evidence to support the use of TLIF over traditional PLF in treatment of degenerative lumbar disorders, especially with the increased material costs associated with interbody fusion. Conclusion both TLIF and PLF provide improvement of disability and pain in patients with degenerative lumbar disorders. TLIF is superior to PLF with regard to achieving radiographic fusion.

The Impact of Nurse Navigator-Led Preoperative Education on Hospital Outcomes Following Posterolateral Lumbar Fusion Surgery

Beyond the spine-specific pathology, patient factors such as associated medical and psychosocial conditions, understanding of the treatment process, and the degree of patient activation-defined as the ability of the individual to utilize the available information and actively engage in making their healthcare decisions-can influence outcomes after posterolateral lumbar fusion (PLF) surgery. A retrospective observational cohort study of 177 patients undergoing PLF at a single institution was conducted. Patient demographics, medical and psychosocial risk factors, and outcomes were compared between patients who attended a nurse navigator-led group preoperative education course and those who did not. Patients attending the course were younger, more likely to undergo one-level fusion, less likely to undergo 5- or more-level fusion, and had less comorbidity burden as measured by the hierarchical condition categories score. No differences in psychosocial risk factors were observed between groups. Course attendees had a significantly shorter length of stay (2.12 vs. 2.60 days, p = .042) and decreased average hospital cost (U.S. $10,149 vs. U.S. $14,792, p < .001) than those who did not attend; no differences in other outcomes were observed. After controlling for differences in risk factors, patients enrolled in a preoperative education course demonstrated a statistically significant reduction in hospital cost (β=-4,143, p < .001). Preoperative education prior to PLF surgery may reduce hospital cost, possibly through increased patient activation. Given the relatively high prevalence of psychosocial risk factors in this and similar patient populations, optimizing patient activation and engagement is important to achieve high value care. Based on our findings, nurse navigator-led preoperative education appears to be valuable in this patient population and should be included in enhanced recovery protocols.

NCPD Tests: The Impact of Nurse Navigator-Led Preoperative Education on Hospital Outcomes Following Posterolateral Lumbar Fusion Surgery.

NCPD Tests: The Impact of Nurse Navigator-Led Preoperative Education on Hospital Outcomes Following Posterolateral Lumbar Fusion Surgery.

Use of Vancomycin Mixed Bone Graft and Vancomycin Mixed Saline Wash Before Wound Closure Reduces the Rate of Infection in Lumbar Spine Fusion Surgery.

This study aims to evaluate whether surgical site vancomycin mixed in bone grafts and local vancomycin mixed in normal saline wash before wound closure decrease the infection rates in patients undergoing lumbar spinal instrumentation and posterolateral fusion. A retrospective study was performed on cases between 2017 and 2019, who underwent lumbar spine instrumentation and posterolateral fusion for lumbar canal stenosis or listhesis. The routine prophylactic procedures were performed in all patients as per institutional protocol. Patients' records were analysed and categorised into two groups, the vancomycin group (VG), where vancomycin mixed in bone graft and normal saline wash was used at the surgical site, and the control group (CG), where vancomycin was not used. The study included 63 patients, 31 in VG and 32 in CG. There is no statistical difference in age, sex, and diabetes mellitus in both groups. A total of seven cases were infected, six in CG (6/32) and one in VG (1/31). Out of six infections in CG, three patients had diabetes and four infected cases underwent surgery for debridement. In VG, the only single case got infected and treated with intravenous antibiotics. We found that the use of vancomycin added to the bone graft and normal saline in posterior lumbar spinal instrumentation and posterolateral fusion is associated with significantly lower rates of infection (p value=0.049).

P1. Efficacy of a calcium phosphate collagen matrix bone graft with needle-shaped submicron surface topography in a rabbit posterolateral lumbar spine fusion model

<h3>BACKGROUND CONTEXT</h3> Synthetic bone grafts are a promising alternative for the treatment of degenerative spine conditions and are available without the added drawbacks associated autografts including limited availability and donor-site morbidity. Of these synthetic materials, calcium phosphate (CaP) with a characteristic needle-shaped submicron surface topography (BCP<µm) has attracted much attention due to its unique bone-forming ability which is essential for repairing critical-size bone defects such as those found in the posterolateral spine [1,2]. Previous in vitro and ex-vivo data presented by van Dijk LA [3] and Yuan H [4] at NASS, 2020 demonstrated that these specific surface characteristics drive a favorable response from the innate immune system. <h3>PURPOSE</h3> This study was to evaluate the efficacy of a novel synthetic bone graft using a clinically-relevant "Boden" rabbit posterolateral spine fusion model. The synthetic bone graft comprised of CaP granules with a needle-shaped submicron surface structure (BCP<µm) embedded in a highly porous and fibrillar bovine type I collagen matrix (col-BCP<µm). The fibrillar collagen was introduced as a carrier, designed to facilitate admixing of the graft with biological fluids perioperatively and to minimize graft migration postoperatively. <h3>STUDY DESIGN/SETTING</h3> The novel synthetic bone graft was first mixed in a 1:1 volume ratio with autologous bone (ABG). Subsequently, grafts were implanted in the rabbit posterolateral spine environment for 3 days, 6, 9 and 12 weeks. An autologous bone graft group was used as a positive control in this study. Outcomes for the test article were additionally compared to historical data for the same material (BCP<µm) implanted alone, without the fibrillar collagen carrier. <h3>OUTCOME MEASURES</h3> Spinal fusion was determined by manual palpation (MP), X-ray and µCT imaging (based on the Lenke scale), mechanical testing (range of motion testing at 12 weeks only) and histology (decalcified and undecalcified). <h3>METHODS</h3> Forty skeletally mature New Zealand white rabbits were divided into two groups and underwent single-level bilateral posterolateral intertransverse process spine arthrodesis at L4-5. Animals were euthanized after 3 days, 6, 9 and 12 weeks. <h3>RESULTS</h3> Based on all endpoints, the test group and positive control group showed an equivalent and gradual progression in bone formation and implant resorption over time, leading to mature fusion masses at 12 weeks. No adverse reactions were observed in any of the groups. Bilateral fusion rates by MP were consistent with the literature (0-40% at 6 weeks; 60-70% at 12 weeks) and similar trends were seen by histological and radiographic assessment (both X-ray and µCT). Flexion-extension and lateral bending results at 12 weeks demonstrated fusion of the treated level consistent with the MP results. The results observed for the test group were consistent with those seen historically for the same material implanted without the fibrillar collagen carrier. <h3>CONCLUSIONS</h3> These results show that BCP with needle-shaped submicron-scale surface topography (BCP<µm) combined with a fibrillar collagen matrix (col-BCP<µm) could achieve equivalent fusion rates to ABG when used as a bone graft extender in a clinically relevant single level rabbit intertransverse process posterolateral lumbar fusion model. Over time, a progression in bone healing, graft resorption and remodeling were seen with all experimental endpoints, with equivalency between the groups. The results for col-BCP<µm were consistent with those previously seen for BCP<µm alone, confirming that the fibrillar collagen carrier improved handling properties but was not detrimental to the bone-forming capacity of the BCP<µm. <h3>FDA DEVICE/DRUG STATUS</h3> Col-BCP<µm (Investigational/Not approved)

Does fusion status following posterolateral lumbar fusion in the treatment for stable lumbar degenerative spondylolisthesis affect the long-term surgical outcomes? A propensity score-weighted analysis of consecutive patients

BackgroundThe surgical strategy of lumbar degenerative spondylolisthesis (LDS) is controversial, especially regarding whether or not fusion should be used. Although some reports have indicated that decompression combined with fusion may be better than decompression alone in the treatment of LDS, the effect of fusion status after uninstrumented posterolateral lumbar fusion (PLF) on the outcomes of patients with stable LDS remains unknown. This study aimed to evaluate the surgical outcomes of uninstrumented PLF for stable LDS and clarify whether radiographic fusion status could affect surgical outcomes. MethodsA total of 93 consecutive patients who had undergone single-level uninstrumented PLF for Meyerding grade I LDS without preoperative dynamic instability with a minimum follow-up period of 5 years were retrospectively studied. Patients were divided into two groups: nonunion (52 patients) and union (41 patients). The primary outcomes were the 5-year percent recovery of postoperative Japanese Orthopaedic Association (JOA) scores, Oswestry Disability Index (ODI), Visual analog scale (VAS) scores, and reoperation rate. The outcome scores were compared between the groups using the inverse probability weighting method using propensity scores. ResultsThe union and nonunion groups had comparable weighted means of the 5-year postoperative clinical score for the percent recovery of the JOA score (70.2% vs. 71.1%, P = 0.86), ODI (14.5 vs.14.6, P = 0.98), VAS of low back pain (20.3 vs. 18.7 mm, P = 0.72), and VAS of leg pain (24.0 vs. 19.4 mm, P = 0.43). The reoperation rate was 2.4% (one case of adjacent segment pathology) in the union group and 0% in the nonunion group (P = 0.44). ConclusionThe fusion status following uninstrumented PLF had no significant effect on the 5-year postoperative clinical outcomes and reoperation rate in patients with Meyerding grade I LDS without dynamic instability.

Posterior Lumbar Fixation Surgeries, Indications and Approaches (Posterolateral Fixation, PLIF and TLIF) Clinical Perspective

Background: Posterior lumbar fixation surgery is common procedure associated with lumbar fusion with different technique. The most frequent type of spine fusion is lumbar spine fusion, which can be done for a variety of reasons. There are two main techniques for lumbar spine fusion, posterolateral fusion and lumbar interbody fusion. This review aims to summarise, evaluate systematic reviews and analyze the therapeutic efficacy and outcome of posterior lumbar fixation surgeries and lumbar fusion including posterolateral fusion, PLIF and TLIF for most common diagnoses. In cases of recurrent lumbar disc herniation, there is no evidence that spine fusion has therapeutic advantage over repeated discectomy. There was no difference in the rates of re-operation between the two surgical procedures. According to lumbar fracture, we found no superiority in clinical benefit, system failure rate and other radiological parameters of arthrodesis over fixation only, in thoracolumbar burst fracture. The no-fusion group had much less surgical time and blood loss. Results of review for patients receiving fusion surgery for spondylolisthesis show that, In terms of attaining radiographic fusion, TLIF is superior to PLF without any observable increased risk for infection. However, There is very little evidence, that TLIF is better than PLF for attaining clinical improvement. If surgical intervention for spondylodiscitis is needed, less invasive surgical approaches (single-stage anterior or posterior fusion techniques) are strongly recommended, since they can have a better therapeutic outcome than more complex mixed anterior–posterior procedures. For more accurate evaluation of the efficacy of spinal fusion surgery on all indications, more evidence is required.

Comparing the efficacy of adipose-derived and bone marrow-derived cells in a rat model of posterolateral lumbar fusion.

Although bone marrow-derived mesenchymal stem cells (BMCs) have been widely used in spinal fusion procedures, adipose-derived stem cells (ASCs) offer a number of advantages as an alternative clinical cell source. This study directly compares the efficacy of ASCs and BMCs from the same donor animals to achieve successful fusion when combined with a clinical-grade bone graft substitute in a rat lumbar fusion model. ASCs and BMCs were isolated from the same Lewis donor rats and grown to passage 2 (P2). Single-level bilateral posterolateral intertransverse process lumbar fusion surgery was performed on syngeneic rats divided into three experimental groups: clinical-grade bone graft substitute alone (CBGS); CBGS+ rat ASCs (rASC); and, CBGS+ rat BMCs (rBMC). Eight weeks postoperatively, fusion was evaluated via micro-CT, manual palpation and histology. In vitro analysis of the osteogenic capacity of rBMCs and rASCs was also performed. Results indicated that the average fusion volume in the rASC group was the largest and was significantly larger than the CBGS group. Although the rASC group displayed the highest fusion rates via micro-CT and manual palpation, this difference was not statistically significant. Cell-seeded grafts showed more histological bone formation than cell-free grafts. P2 rASCs and rBMCs displayed similar in vitro osteogenic differentiation capacities. Overall, this study showed that, when combined with a clinical-grade bone graft substitute in a rat model, rASCs cells yielded the largest fusion masses and comparable fusion results to rBMCs. These results add to growing evidence that ASCs provide an attractive alternative to BMCs for spinal fusion procedures.

The utility of intraoperative neuromonitoring on simple posterior lumbar fusions—analysis of the National Inpatient Sample

Several studies have demonstrated the utility of intraoperative neuromonitoring (IOM) including somatosensory evoked potentials (SSEPs), motor-evoked potentials (MEPs), and electromyography (EMG), in decreasing the risk of neurologic injury in spinal deformity procedures. However, there is limited evidence supporting the routine use of IOM in elective posterolateral lumbar fusion (PLF). The National Inpatient Sample (NIS) was analyzed for the years 2012-2015 to identify patients undergoing elective PLF with (n=22,404) or without (n=111,168) IOM use. Statistical analyses were conducted to assess the impact of IOM on length of stay, total charges, and development of neurologic complications. These analyses controlled for age, gender, race, income percentile, primary expected payer, number of reported comorbidities, hospital teaching status, and hospital size. The overall use of IOM in elective PLFs was found to have increased from 14.6% in the year 2012 to 19.3% in 2015. The total charge in hospitalization cost for all patients who received IOM increased from $129,384.72 in 2012 to $146,427.79 in 2015. Overall, the total charge of hospitalization was 11% greater in the IOM group when compared to those patients that did not have IOM (P<0.001). IOM did not have a statistically significant impact on the likelihood of developing a neurological complication. While there may conceivably be benefits to the use of this technology in complex revision fusions or pathologies, we found no meaningful benefit of its application to single-level index PLF for degenerative spine disease.

Adjacent segment degeneration after posterolateral lumbar fusion: results and complications of posterior revision surgery.

Lumbar fusion is an important technique for the treatment of degenerative pathologies. Adjacent segment degeneration is a known complication after lumbar fusion that causes significant morbidity. Our objective was to evaluate the demographics, risk factors, type of surgery, and surgical complications in patients who underwent reoperation through a posterior route due to adjacent segment degeneration. We performed a retrospective analysis of all patients who underwent instrumented posterolateral fusion in the lumbar spine for the treatment of degenerative diseases from January 2000 to December 2015 at a single institution. Patients who developed symptomatic adjacent segment degeneration requiring a second surgery were noted and compared with patients who did not develop adjacent segment degeneration. A total of 750 patients with degenerative pathologies who underwent fusion with instrumentation were identified. Forty-five patients (6%) required a second surgery for symptomatic adjacent segment degeneration. The average onset of adjacent segment degeneration symptoms after fusion was 5.89 years. Adjacent segment degeneration occurred above the level of fusion in 40 cases and below in 5 cases. The risk factor identified in our series was L5-S1 fusion. The main complication seen after the second surgery was infection in 5 cases (11%). This study identifies the L5-S1 fusion as a possible risk factor for adjacent segment degeneration. Reoperation through a posterior route is a therapeutic option but is associated with considerable morbidity. Further studies are necessary to elucidate this pathology and the best options for its management.

Denosumab alleviates intervertebral disc degeneration adjacent to lumbar fusion by inhibiting endplate osteochondral remodeling and vertebral osteoporosis in ovariectomized rats

BackgroundAlthough adjacent segmental intervertebral disc degeneration (ASDD) is one of the most common complications after lumbar fusion, its exact mechanism remains unclear. As an antibody to RANKL, denosumab (Dmab) effectively reduces bone resorption and stimulates bone formation, which can increase bone mineral density (BMD) and improve osteoporosis. However, it has not been confirmed whether Dmab has a reversing or retarding effect on ASDD.MethodsThree-month-old female Sprague-Dawley rats that underwent L4–L5 posterolateral lumbar fusion (PLF) with spinous-process wire fixation 4 weeks after bilateral ovariectomy (OVX) surgery were given Dmab 4 weeks after PLF surgery (OVX+PLF+Dmab group). In addition, the following control groups were defined: Sham, OVX, PLF, and OVX+PLF (n=12 each). Next, manual palpation and X-ray were used to evaluate the state of lumbar fusion. The bone microstructure in the lumbar vertebra and endplate as well as the disc height index (DHI) of L5/6 was evaluated by microcomputed tomography (μCT). The characteristic alterations of ASDD were identified via Safranin-O green staining. Osteoclasts were detected using tartrate-resistant acid phosphatase (TRAP) staining, and the biomechanical properties of vertebrae were evaluated. Aggrecan (Agg), metalloproteinase-13 (MMP-13), and a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4) expression in the intervertebral disc were detected by immunohistochemistry and real-time polymerase chain reaction (RT-PCR) analysis. In addition, the expression of CD24 and Sox-9 was assessed by immunohistochemistry.ResultsManual palpation showed clear evidence of the fused segment’s immobility. Compared to the OVX+PLF group, more new bone formation was observed by X-ray examination in the OVX+PLF+Dmab group. Dmab significantly alleviated ASDD by retaining disc height index (DHI), decreasing endplate porosity, and increasing vertebral biomechanical properties and BMD. TRAP staining results showed a significantly decreased number of active osteoclasts after Dmab treatment, especially in subchondral bone and cartilaginous endplates. Moreover, the protein and mRNA expression results in discs (IVDs) showed that Dmab not only inhibited matrix degradation by decreasing MMP-13 and ADAMTS-4 but also promoted matrix synthesis by increasing Agg. Dmab maintained the number of notochord cells by increasing CD24 but reducing Sox-9.ConclusionsThese results suggest that Dmab may be a novel therapeutic target for ASDD treatment.

Comparison of Functional and Radiological Outcomes of Transforaminal Lumbar Interbody Fusion and Posterolateral Fusion Techniques in the Treatment of Lumbar Spinal Stenosis.

This study aimed to compare posterolateral fusion with transforaminal lumbar interbody fusion (PLF + TLIF) and PLF only in terms of revision surgery rates and complications, as well as functional and radiological outcomes in lumbar spinal stenosis (LSS) patients. Seventy-one patients (37 patients in the PLF + TLIF group and 34 patients in the PLF only group) who underwent surgery due to LSS between January 2013 and December 2016 were retrospectively investigated. Functional evaluation was performed by using the McGill-Melzack Pain Questionnaire (MPQ), Roland Morris Disability Questionnaire (RMDQ), and Oswestry Disability Index (ODI) scales pre-and postoperatively. Radiological evaluation was made by examining adjacent vertebrae, posterior ligamentous complex (PLC) morphology, and sagittal balance on magnetic resonance imaging (MRI). Postoperative MPQ, RMDQ, and ODI scores were significantly better in the PLF + TLIF group (p < 0.001, p < 0.001, and p = 0.001, respectively). The complication rate was significantly higher in the PLF only group (p = 0.026). In the PLF + TLIF group, postoperative functional scores showed significant improvement in terms of the instrumented segment and level of interbody fusion. Postoperative functional scores showed significant improvement in PLF + TLIF patients with no complications, no revision surgery, no postoperative MRI findings, and neutral sagittal balance compared to the preoperative functional scores (p < 0.001). PLF + TLIF is significantly superior in terms of functional scores and complications, despite the statistical similarity in terms of postoperative MRI findings and sagittal balance between the groups. Surgeons should prefer PLF + TLIF for the surgical treatment of LSS for better results.

Preoperative Fluoroscopically Guided Regional Erector Spinae Plane Blocks Reduce Opioid Use, Increase Mobilization, and Reduce Length of Stay Following Lumbar Spine Fusion.

Retrospective review. To determine the effectiveness of erector spinae plane (ESP) blocks at improving perioperative pain control and function following lumbar spine fusions. A retrospective analysis was performed on patients undergoing < 3 level posterolateral lumbar fusions. Data was stratified into a control group and a block group. We collected postop MED (morphine equivalent dosages), physical therapy ambulation, and length of stay. PROMIS pain interference (PI) and physical function (PF) scores, ODI, and VAS were collected preop and at the first postop visit. Chi-square and student's t-test (P = .05) were used for analysis. We also validated a novel fluoroscopic technique for ESP block delivery. There were 37 in the block group and 39 in the control group. There was no difference in preoperative opioid use (P = .22). On postop day 1, MED was reduced in the block group (32 vs 51, P < .05), and more patients in the block group did not utilize any opioids (22% vs 5%, P < .05). The block group ambulated further on postop day 1 (312 ft vs 204 ft, P < .05), and had reduced length of stay (2.4 vs 3.2 days, P < .05). The block group showed better PROMIS PI scores postoperatively (58 vs 63, P < .05). The novel delivery technique was validated and successful in targeting the correct level and plane. ESP blocks significantly reduced postop opioid use following lumbar fusion. Block patients ambulated further with PT, had reduced length of stay, and had improved PROMIS PI postoperatively. Validation of the block demonstrated the effectiveness of a novel fluoroscopic delivery technique. ESP blocks represent an underutilized method of reducing opioid consumption, improving postoperative mobilization and reducing length of stay following lumbar spine fusion.

Efficacy and safety of Escherichia coli-derived recombinant human bone morphogenetic protein-2 in additional lumbar posterolateral fusion: minimum 1-year follow-up

Recombinant human bone morphogenetic protein-2 (BMP-2) is the growth factor with the most striking osteoinductive performance in orthopedic operations; it is also able to induce heterotopic bone formation. However, there has been little clinical research on Escherichia coli-derived BMP-2 (E.BMP-2). To confirm the efficacy and safety of E.BMP-2 with a hydroxyapatite carrier when applied to one-sided posterolateral fusion (PLF) in addition to lumbar interbody fusion (LIF), and to measure the lower dose of E.BMP-2 ever reported achieving solid fusion. Retrospective case-control study PATIENT SAMPLE: A total of 121 patients who received surgery for 1 or 2 levels of fusion for lumbar degenerative spinal stenosis or spondylolisthesis from January 2009 to December 2019 were included. Clinical and functional outcomes were evaluated using preoperative and final follow-up visual analogue scales for back pain (VAS-BP) and leg pain (VAS-LP), and Korean Oswestry disability index (K-ODI) scores. Fusion rates were evaluated by computed tomography at six months and one year after surgery. In addition, a subgroup analysis of group E according to number of fusion levels was conducted, and the fusion rates in the one-level and two-level fusion groups were compared. LIF and additional one-sided PLF was performed in all patients. They received autogenous iliac bone grafts (Group C, n=69) or 1mg of E.BMP-2 (Group E, n=52). There were no significant differences between preoperative and final VAS-BP, VAS-LP and K-ODI. The PLF rate was 79.7% for Group C and 82.7% for Group E at postoperative six months, and 94.2% for Group C and 100% for Group E at postoperative one year (P = 0.679, 0.134, respectively). The LIF rate was 71.0% in Group C and 71.2% in Group E at six months after surgery, and 97.1% in Group C and 100% in Group E at one year (P = 0.987, 0.506, respectively). In terms of numbers of fusion levels in Group E, PLF rates at six months (P = 0.486) and one year after surgery were similar in the two groups, as were LIF rates at six months (P = 0.822) and one year after surgery. There were no cases of malignancy or radiculopathy in Group E during one-year of follow-up. One milligram of E.BMP-2 is a safe and effective osteoinductive material in short-level lumbar PLF surgery.

Chemical composition of ceramics affects the longevity of CRM in posterolateral lumbar fusion achieved by rhBMP6 in autologous blood coagulum with ceramic particles in rabbits

Chemical composition of ceramics affects the longevity of CRM in posterolateral lumbar fusion achieved by rhBMP6 in autologous blood coagulum with ceramic particles in rabbits