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Background The anterior cage at L5-S1 segment is more vulnerable to anterior migration because of the sacral slope, the greater disc angle (DA), the higher shear force, and the weaker pedicle screw fixation at S1. We hypothesized that a supplemental screw (SS) fixation is effective for the prevention of anterior cage migration in oblique lateral interbody fusion (OLIF) at L5-S1. Methods This study involved 61 consecutive patients who underwent OLIF at L5-S1 and had more than 1-year regular follow-up. In the first 35 cases, the anterior cage was fixed with pedicle screws only (non-SS group). In the remaining 26 cases, the anterior cage was fixed with a SS and pedicle screws (SS group). Radiological parameters including anterior disc height (ADH), posterior disc height (PDH), DA, cage migration, cage subsidence, and fusion rate at L5-S1 were compared between the two groups. Result Of the total 61 patients, fifteen (24.6%) patients had an anterior cage migration of >2 mm and six (9.8%) patients had an anterior cage migration of >5 mm. Baseline demographic characteristics were similar between the two groups. The mean cage migration was 2.0 ± 3.1 mm in the non-SS group and 0.9 ± 0.9 mm in the SS group (P = 0.038). Thirteen (37.1%) patients had a cage migration of >2 mm in the non-SS group, while only two (7.7%) had a cage migration of >2 mm in the SS group (P = 0.002). There were no significant differences in the ADH, PDH, DA, cage subsidence, and fusion rate between the two groups (all P > 0.05). There was no SS-related complication in the SS group. Conclusions SS fixation in front of the anterior L5-S1 cage is simple, safe, and effective for the prevention of anterior cage migration in OLIF at L5-S1.

Introduction and objectives Most of the studies evaluating the effect of cross links on spinal stability are performed in vitro on porcine or human spine segments and there is limited data regarding clinical benefits of cross link augmentation in traumatic injuries. In this study we aimed to evaluate the effects of cross-links insertion between rods on the fusion rates and post-surgical patients’ satisfaction among patients with traumatic thoracolumbar fractures who underwent posterior spinal fixation with pedicle screws. Materials and methods This study was conducted as a randomized clinical trial on 60 patients suffering from traumatic thoracolumbar vertebrae fractures. Patients were randomized into three groups: A (without any cross-link), B (One cross-link insertion) and C (two cross-links insertion). Six months after surgery outcomes were evaluated: fusion rates (plain X-ray and CT scan), Back pain (Visual Analog Scale) and patient satisfaction (fair, good, excellent). Results In group A 13 (65%) patients had structured bone fusion, but in 7 (35%) patients bone fusion was not observed. In both groups B and C, 19 patients (95%) had bone fusion, but only in 1 patient (5%) fusion failed (p = 0.009). In group A, fair satisfaction has the highest rate (8 patients (40%)) compared to the other groups. The highest reported severity of back pain was observed in group A while the lowest reported intensity of back pain was related to group B (p = 0.001). Conclusions Adding cross link to posterior spinal fixations of patients with traumatic thoracolumbar fractures can be associated with better final fusion results and patients’ satisfaction. However it is necessary to design studies with greater sample sizes to confirm this theory. Trial registration number: IRCT20120527009878N3.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is a common surgery to treat cervical degenerative disc disease. Use of an anterior spacer and plate system (ASPS) results in increased disc height, higher fusion rate, lower subsidence rate, and lower complication rate than a spacer alone.1,2 However, anterior cervical plating is associated with complications, such as dysphagia, plate-screw dislodgment, soft tissue injury, neural injury, and esophageal perforation.3–9 To potentially reduce these drawbacks, integrated spacer and plate (ISP) systems have gained popularity. METHODS: From November 2009 to October 2013, a total of 84 consecutive patients who underwent 2-level ACDF using ISP or ASPS were reviewed for clinical and radiographic outcomes. Patient-reported visual analog scale (VAS) and Neck Disability Index (NDI) scores, fusion rates, and hardware failure were determined at 1, 3, 6, 12, and 24 months after surgery. RESULTS: Forty-three patients received ISP and 41 patients received ASPS. There were no significant differences in patient demographics between the 2 groups. Perioperative characteristics were similar, except for operative time. Postoperatively, no significant differences in VAS or NDI scores or fusion status were found. At the proximal surgical level only, there was a trend toward an earlier observed radiographic fusion rate in ASPS vs ISP, but this finding was not statistically significant (P = 0.092). One case of long-term dysphagia was reported in each group. Neither group had implant failures up to 2 years. CONCLUSIONS: The ISP system for 2-level ACDF compared to traditional ASPS has comparable clinical and radiographic outcomes up to 2 years postoperatively. There may be a trend toward an earlier observed radiographic fusion in the ASPS group, but there was no difference in long-term dysphagia rate. CLINICAL RELAVANCE: Integrated spacer and traditional anterior spacer for 2-level ACDF has similar clinical and radiographical outcome. LEVEL OF EVIDENCE: 4.

Study designRetrospective cohort study.ObjectiveTo compare the outcomes of patients with adult spinal deformity (ASD) following spinal fusion with the lowest instrumented vertebra (LIV) at L4/L5 versus S1/ilium.MethodsA multicenter ASD database was evaluated. Patients were categorized into 2 groups based on LIV levels-groups L (fusion to L4/L5) and S (fusion to S1/ilium). Both groups were propensity matched by age and preoperative radiographic alignments. Patient demographics, operative details, radiographic parameters, revision rates, and health-related quality of life (HRQOL) scores were compared.ResultsOverall, 349 patients had complete data, with a mean follow-up of 46 months. Patients in group S (n = 311) were older and had larger sagittal and coronal plane deformities than those in group L (n = 38). After matching, 28 patients were allocated to each group with similar demographic, radiographic, and clinical parameters. Sagittal alignment restoration at postoperative week 6 was significantly better in group S than in group L, but it was similar in both groups at the 2-year follow-up. Fusion to S1/ilium involved a longer operating time, higher PJK rates, and greater PJK angles than that to L4/L5. There were no significant differences in the complication and revision rates between the groups. Both groups showed significant improvements in HRQOL scores.ConclusionsFusion to S1/ilium had better sagittal alignment restoration at postoperative week 6 and involved higher PJK rates and greater PJK angles than that to L4/L5. The clinical outcomes and rates of revision surgery and complications were similar between the groups.

Interbody cages are currently being used to address diseases of the vertebra requiring surgical stabilization. Titanium cages were first introduced in 1988. Polyetheretherketone (PEEK) cages are used frequently as one of the alternatives to titanium cages in current practice. This study aimed to compare available cage materials by reviewing the surgical and radiographic outcomes following anterior cervical discectomy and fusion.A comprehensive search of several electronic databases was conducted following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Baseline characteristics, operative outcomes, arthrodesis rates, subsidence rates, and complications were collected from included studies. Collected outcomes were further stratified according to the procedure type, the number of levels operated, and graft used to compare cage materials.Following the screening for inclusion criteria, a total of 37 studies with 2363 patients were included. The median age was 49.5 years and the median follow-up was 26 months. Overall, no significant differences were found between PEEK and titanium cages regarding fusion, neurologic deficit, subsidence rates, or "good and excellent" outcome according to Odom criteria. However, the standalone comparison between PEEK, titanium, and poly-methyl-methacrylate (PMMA) cages showed a significantly lower fusion rate for PMMA (PEEK: 94%, PMMA: 56%, titanium: 95%, P0.01).In the present systematic review and meta-analysis, a comparison of the long-term patient-reported and the radiographic outcomes associated with the use of titanium and PEEK, intervertebral body cages showed similar findings. However, there were significantly lower fusion rates for PMMA cages when using a standalone cage without graft material.

The aim of this meta-analysis was to investigate the effects of retropharyngeal steroid use during operation on bony fusion and dysphagia rate after ACDF. We searched the electronic literature database of PubMed, Embase and the Cochrane Library published from January 1990 to February 2020. The size of each group, mean age, proportion of female patients, dysphagia events and fusion rate at one-year follow-up were extracted. RevMan 5.3 was used for the meta-analysis. A total of eight studies including six RCTs and two case–control studies met the inclusion criteria. This meta-analysis showed that retropharyngeal steroids could achieve significantly lower dysphagia rates (p

Background Autologous bone has been used for posterior lumbar intervertebral fusion (PLIF). However, harvesting autologous bone graft is associated with donor site complications. We previously developed a hydroxyapatite/collagen (HAp/Col) composite as an osteoconductive artificial bone, characterized by having a highly porous structure with sponge‐like elasticity. This study aims to investigate the effectiveness of HAp/Col composite with bone marrow aspirate (BMA) as a graft substitute in PLIF for the treatment of lumbar spinal diseases. Methods This study prospectively investigated patients who received one-level PLIF. For the interbody fusion, two titanium cages were inserted. On the one side of interbody space, HAp/Col composite incorporated with BMA filling the titanium cage was grafted. On the other side, local bone graft (LBG) harvested during decompressive laminotomy was grafted and then one-level instrumentation using pedicle screws was performed. The target levels were at L2/3 in 2 cases, L3/4 in 3 cases, L4/5 in 36 cases, and L5/S in 5 cases. We evaluated clinical symptoms and radiological outcomes of 46 patients and compared the fusion status of HAp/Col composite with that of LBG. Results The 1-year postoperative CT evaluation demonstrated that, in the HAp/Col, a complete fusion was observed in 38 patients (82.6%), whereas in the LBG, a complete fusion was observed in 35 patients (76.1%). There were no statistical differences between the HAp/Col and LBG. In the HAp/Col, incomplete fusion was observed in five patients (10.9%) and non-fusion in two patients (4.3%), and in the LBG, incomplete fusion was observed in nine patients (19.6%) and non-fusion in two patients (4.3%). At 2 years after the surgery, complete fusion increased to 44 patients (95.7%) in the HAp/Col and 41 patients (89.1%) in the LBG. There were no significant differences in the clinical scores for lumbar spine between patients with fusion and non-fusion. Conclusions The HAp/Col composite with BMA in the titanium cage can be effectively used as an alternative to conventional autologous LBG for intervertebral spinal fusion. Trial registration University hospital Medical Information Network, UMIN000045010, July 30th, 2021, Retrospectively registered, https://www.umin.ac.jp/english/.

Background Reduction of lumbar spondylolisthesis during spinal fusion surgery is important for improving the fusion rate and restoring the sagittal alignment. Despite the variety of reduction methods, the fundamental mechanics of lumbar spondylolisthesis reduction remain unclear. This study aimed to investigate the biomechanical behavior while performing spondylolisthesis reduction with the anterior and posterior lever reduction method. Methods We developed an L4–L5 spondylolisthesis model using sawbones. Two spine surgeons performed the simulated reduction with a customized Cobb elevator. The following data were collected: the torque and angular motion of Cobb, displacement of vertebral bodies, change of lordotic angle between L4 and L5, total axial force and torque applied on the model, and force received by adjacent disc. Results Less torque value (116 N-cm vs. 155 N-cm) and greater angular motion (53o vs. 38o) of Cobb elevator were observed in anterior lever reduction. Moreover, the total axial force received by the entire model was greater in the posterior lever method than that in the anterior lever method (40.8 N vs. 16.38 N). Besides, the displacement of both vertebral bodies was greater in the anterior lever method. Conclusions The anterior lever reduction is a more effort-saving method than the posterior lever reduction method. The existing evidence supports the biomechanical advantage of the anterior reduction method, which might be one of the contributing factors to successfully treating high-grade lumbar spondylolisthesis with short-segment instrumentation.

Background: A prospective comparative study between fusion and non-fusion techniques in anterior cervical discec-tomy (ACD) evaluating the results achieved using polymeth-ylmethacrylate (PMMA) as a non-fusion and cervical cage (PEEK) as a fusion following single level ACD. Patients and Methods: A total of 40 patients, divided in to two groups of 20 patients each, group (A); having PMMA used for disc replacement and group (B) cervical (PEEK) cage placement after ACD. Results: Of both groups are evaluated regarding: (1) Clinical outcome according to Odom's criteria (2) Radiological outcome and inter body fusion, (3) Simplicity and postoperative morbidity of each procedure and (4) Complications related to each technique. Patients were followed up for a mean period of 10 months. Group (A) presented excellent and good clinical outcome in 85% at 6 months and 90% at 12 months. Radio-logical none fusion was noticed in 80% of patients and partial fusion occurred in 20% of cases at 12 months postoperative interval cage migration in 5% (one patient) into adjacent vertebral bodies which needed surgical removal and replaced by cage after causing partial collapse of the disc space height. No other graft related complications, progressive deformity or instability were reported. Group (B) achieved 90% excellent and good clinical outcome at 6 and 12 months respectively. Fusion rate of 85% at 6 months and increased to 95% at 12 months. No other cage related complications were reported. Conclusion: Clinical outcome in both group is related to the surgical decompression technique and preoperative neu-rological status of the patients e.g. cervical spondylotic myelopathy (CSM), cervical spondylotic radiculopathy (CSR) or both than to the use of either disc replacement by fusion (PEEK) cage or non fusion by bone cement (PMMA). The use of interbody fusion cage is preferred owing to their ability to function as load-sharing devices and to adequately fix the spine and increase segmental stiffness thus achieve acceptable fusion rate and low complication when compared with PMMA graft.

Objective Midline lumbar interbody fusion is performed for treatment of various lumbar degenerative diseases, with good clinical outcomes and few complications. However, there are no large-scale or long-term studies regarding midline lumbar interbody fusion. Therefore, the purpose of this study was to evaluate the clinical results of midline lumbar interbody fusion and to compare the results according to surgical level. Methods Between January 2013 and December 2015, 200 patients with lumbar degenerative disease undergoing midline lumbar interbody fusion surgery were enrolled. The mean patient age was 69.9 ± 15.8 years (range, 40-85 years). The patients were divided into groups according to surgical level: (1) level 1 operation (136 patients), (2) level 2 operation (43 patients), (3) level 3 operation (12 patients), and (4) level 4 or higher (9 patients). Clinical outcomes, fusion rates, and complications were compared among the 4 groups. Results All clinical outcomes significantly improved after surgery (measured at 3 years postoperatively) in all groups. Mean fusion rate was 90.5% ± 5.21%. Fusion rate was highest in group I (95.8%) and lowest in group IV (85.2%). There were complications in 17 cases (8.5%). Adjacent segment disease occurred in 16 cases, 5 of which required surgery. Group 1 had 1 case, and group 4 had 4 cases. Screw loosening occurred in 1 case in group 4. There were no cases of infection or mechanical complications. Conclusion This large, single-institution, retrospective study demonstrates favorable clinical outcomes after midline lumbar interbody fusion for lumbar degenerative disease regardless of surgical level.

Background The effects of postoperative intervertebral height (IH) changes on the clinical and radiological outcomes after anterior cervical decompression and fusion (ACDF) surgery using a zero-profile device remain unclear. Methods We retrospectively reviewed patients who had undergone ACDF using a zero-profile device from March 2012 to February 2016 at our institution. Based on the postoperative IH variation, the patients were divided into group A with postoperative IH 0 to 2 mm, group B with postoperative IH 2 to 4 mm, and group C with postoperative IH greater than 4 mm. Clinical efficacy was evaluated using JOA, VAS, and NDI scores in the groups. Imaging parameters including the IH, cervical lordosis, fusion rate, intervertebral foramen (IVF) diameter and complications such as subsidence, dysphagia, and ASD were also compared across the three groups. Results The average IH increased significantly from 6.72 mm preoperatively to 10.46 mm 1 week after surgery, and then gradually decreased to 7.48 mm at the final follow-up. The fusion rate was 61.90% in group A, 63.23% in group B, 53.57% in group C at 3 months, 73.81% in group A, 79.41% in group B, 67.86% in group C at 6 months, 90.48% in group A, 95.59% in group B, 92.86% in group C 1 year after surgery, and at the last follow-up, the fusion rate of three groups was all 100%. The IVF diameter was 6.52 ± 1.80 mm in group A, 9.55 ± 2.36 mm in group B, and 9.34 ± 1.62 mm in group C. ASD at the superior and inferior levels affected 11.90 and 16.67% patients in group A, 5.88 and 7.38% in group B, and 14.28 and 10.71% in group C. Regarding the 3 groups, the subsidence rates were 7.14, 4.41, and 14.29%, respectively. Conclusions No clear correlation was found between IH changes and clinical efficacy within a year of surgery. However, the IH may affect various complications after ACDF. If postoperative IH changes are maintained at 2 to 4 mm after a year, a satisfactory imaging parameters and relatively low complications may be achieved after ACDF surgery using a zero-profile device.

Odontoid fractures are considered a frequent pathology within elderly patients in relationship with degenerative bone changes in context of aging. Its management depends on the type of fracture according to Anderson and D’Alonzo classification. Type I and III fractures are susceptible of conservative management due to its high fusion rate. Treatment of type II fractures is controversial due to its high mortality and morbidity rates associated with the type of patients affected. We present the case of an octogenarian patient with a C1-C2 anterior spinal epidural hematoma due to type II odontoid fracture managed with urgent odontoidectomy and hematoma removal.

STUDY DESIGN Biomechanical study of range of motion (ROM) at the vertebral levels adjacent to the construct of posterior pedicle screw-rod fixation with different types of lumbar interbody fusion techniques (LIF). OBJECTIVE To investigate the differences in adjacent segment mobility among three types of LIF: lateral lumbar interbody fusion (LLIF), transforaminal lumbar interbody fusion (TLIF), and posterior lumbar interbody fusion (PLIF). SUMMARY OF BACKGROUND DATA Previous studies have concluded that LLIF, TLIF, and PLIF with posterior pedicle screw-rod fixation (PSR) provide equivalent stability in cadaveric specimens and are comparable in fusion rate and functional outcome. However, long-term complications, such as adjacent segment degeneration associated with each type of interbody device, are currently unclear. Little is known about the biomechanical effects of interbody fusion technique on the mobility of adjacent segments. METHODS Normalized ROM data at the levels adjacent to L3-L4 PSR fixation with three different types of lumbar interbody fusion approaches (LLIF, TLIF, and PLIF) were analyzed. Intact (n = 21) and instrumented (n = 7 per group) L2-L5 cadaveric specimens were tested multidirectionally under pure moment loading (7.5 Nm). Analysis of variance of adjacent segment ROM among the groups was performed. Statistical significance was set at P

Study Design: Retrospective case-control study. Objectives: This study aims to present the clinical and radiographical outcomes of the titanium-polyetheretherketone (Ti/PEEK) composite cage compared to those of the standard PEEK cage in patients receiving minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). Methods: Patients receiving 1 level MI-TLIF between October 2015 and October 2017 were included with a minimum of 2-year follow-up. The patients were segregated into 2 groups; Ti/PEEK group and PEEK group. Each patient was propensity-matched using preoperative age, sex, and body mass index. Early fusion rate was evaluated by computed tomography at postoperative 6 months. Clinical outcomes were assessed using the visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. Results: After matching, there were 27 patients included in each group. The demographics, diagnosis, and surgical details were not significantly different between the 2 groups. The 6-month rate was 88.9% in Ti/PEEK group. The fusion rate and cage subsidence rate had no difference between the 2 groups. The complication rate in the Ti/PEEK group was comparable to that in the PEEK group. There was no difference in VAS and ODI scores during a 2-year follow-up period. Conclusions: The use of Ti/PEEK composite cage was as safe and effective as the use of PEEK cage in MI-TLIF. The 6-month fusion rate was 88.9%. Our finding revealed comparable clinical results for surgeons using Ti/PEEK composite cages in MI-TLIF compared to those using the PEEK cage.

Introduction Successful ALIF surgery depends upon achieving solid fusion, whilst avoiding significant complications. Herein, we present the ‘Northumbria Technique’ of combining allograft with autograft in order to achieve solid interbody fusion. Materials and Methods A single-surgeon series of 100 consecutive patients undergoing stand-alone ALIF from 2016 to 2019 was studied. All had percutaneously harvested iliac crest bone graft (ICBG) dowels inserted into blocks of fresh frozen femoral head (FFFH) allograft, which were then inserted into the ALIF cages. Patients had dynamic radiographs at 4 months, CT at 6 months, and patient reported outcome measure scores (PROMS) throughout. Results One hundred patients (average age 44.8 years) were followed-up for an average of 29.1 months. Ninety-four (94%) patients were assessed as having fused on both CT and radiographs by an independent Radiologist. Three (3%) patients had abolition of movement on radiographs, but either lacked a CT scan or failed to meet Williams criteria for fusion. Two patients failed to attend for any imaging, so were considered not fused, and one patient had no evidence of fusion in either modality. There was a significant improvement in all PROMS. There were no intra-operative complications, and one patient had transient donor-site pain. Conclusions The newly described ‘Northumbria Technique’ utilises the osteoconductive characteristics of the FFFH allograft, as well as the osteoinductive and osteogenic properties of the ICBG autograft. It gives high fusion rates (94–97%) and statistically significant improvements in PROMS, whilst avoiding the complications of harvesting a large amount of autograft and the huge costs of using synthetic agents.

Background Lumbar spine fusion surgery is traditionally performed with rigid fixation. Because the rigidity is often supraphysiologic, semirigid rods were developed. To the best of our knowledge, a comprehensive evaluation of rod material type on surgical outcomes has yet to be conducted. Methods A systematic review based on PRISMA guidelines was conducted across 3 electronic databases. After examination for inclusion and exclusion criteria, data were extracted from the studies. Results Seventeen studies, including 1399 patients, were included in this review. The mean rigid rod fusion rate is 92.2% and 95.5% for semirigid rods (P = 0.129). The mean improvement in back pain was 60.6% in rigid rods and 71.6% in semirigid rods. The improvement in leg pain was 81.9% and 77.2%, respectively. There were no differences in visual analog scale back pain score (P = 0.098), visual analog scale leg pain score (P = 0.136), or in functional improvement between rigid and semirigid rods (P = 0.143). There was no difference (P = 0.209) in the reoperation rate between rigid rods (13.1%) and semirigid rods (6.5%). There was a comparable incidence of adjacent segment disease (3%), screw fracture (1.7%), and wound infection (1.9%) between rod material types. Conclusions There is a moderate level of evidence supporting that surgical intervention results in high fusion rates regardless of rod material type. Surgical intervention improves back pain, leg pain, and function, with neither material type showing clear superiority. There are comparable rates of reoperation, development of adjacent segment disease, development of mechanical complications, and incidence of infection in both rigid and semirigid rods. Further studies regarding rod material type are warranted.

Pseudarthrosis is a well-recognized complication following multi-level ACDF. We aim to characterize the fusion order and level-specific rates of arthrodesis across four time points following 3-level ACDF. Patients who underwent 3-level ACDF by three UCSF spine surgeons from August 2012 to December 2019 were identified. Fusion status at each level was determined by measuring the interspinous motion on flexion and extension radiographs and assessing for evidence of bridging bone. Measurements were performed post-operatively at 6 weeks, 6 months, 12 months, and 18–24 months. A total of 77 patients with 3-level ACDF were identified and included in this study. Specific ACDF levels include C3-C6 (17 patients), C4-C7 (57 patients), and C5-T1 (3 patients). At 6 months, the cranial, middle, and caudal level fusion rates were 17.0%, 34.0%, and 3.8%, respectively. By 24 months, fusion rates were 61.1%, 88.9%, and 27.8% at the cranial, middle, and caudal level, respectively. PEEK cages were associated with lower odds of multi-level arthrodesis. Arthrodesis occurred the quickest at the middle level with an 88.9% fusion rate by 24 months after surgery. The caudal level had the slowest rate of arthrodesis with only a 27.8% fusion rate at 24 months, likely due to increased biomechanical stress at the most caudal level. Allograft was associated with higher odds of multi-level arthrodesis compared to PEEK cages.

BACKGROUND : Lateral lumbar interbody fusion (LLIF) is used to treat multiple conditions, including spondylolisthesis, degenerative disc disorders (DDD), adjacent segment disease (ASD), and degenerative scoliosis. While many advocate for posterior fixation with LLIF, stand-alone LLIF is increasingly being performed. Yet the fusion rate for stand-alone LLIF is unknown. PURPOSE : Determine the fusion rate for stand-alone LLIF. STUDY DESIGN : Systematic Review. METHODS : We queried MEDLINE, COCHRANE, and EMBASE for literature on stand-alone LLIF fusion rate with a publication cutoff of April 2020. LLIF surgery was considered stand-alone when not paired with supplemental posterior fixation. Cohort fusion rate differences were calculated and tested for significance (p RESULTS : A total of 2,735 publications were assessed. Nineteen studies met inclusion criteria, including 736 patients and 1,103 vertebral levels. Mean age was 61.7 years with BMI 26.5 kg/m2. Mean fusion rate was 85.6% (range, 53.0%-100.0%), which did not different significant by number of levels fused (1-level, 2-level, and ≥3-level). Use of rhBMP-2 was reported in 39.3% of subjects, with no difference in fusion rates between studies using rhBMP-2 (87.7%) and those in which rhBMP-2 was not used (83.9%, OR=1.37, p=0.448). Fusion rate did not differ with the addition of a lateral plate, or by underlying diagnosis. All-complication rate was 42.2% and mean reoperation rate was 11.1%, with 2.3% reoperation due to pseudarthrosis. Of the studies comparing stand-alone to circumferential fusion, pooled fusion rate was found to be 80.4% vs. 91.0% (p=0.637). CONCLUSIONS Stand-alone LLIF yields high fusion rates overall. The wide range of reported fusion rates and lower fusion rates in studies involving subsequent surgical reoperation highlights the importance of being well-trained in this technique and employing a rigorous algorithm when indicating patients for stand-alone LLIF. Future research should focus on examining risk factors and patient-reported outcomes in stand-alone LLIF.

Background CaO-SiO2-P2O5-B2O3 bioactive glass ceramic (BGC) is known to chemically bond with bones by forming a hydroxyapatite layer and inducing osteoblastic differentiation. This study was conducted to compare the clinical outcomes, radiographic outcomes, and safety of a CaO-SiO2-P2O5-B2O3 BGC cage in anterior cervical diskectomy and fusion (ACDF) with those of an allograft interbody spacer. Methods A total of 63 patients who underwent 2-level ACDF to treat degenerative cervical radiculopathy/myelopathy were reviewed. Results from 26 patients who were recruited prospectively using CaO-SiO2-P2O5-B2O3 BGC as a cage material (BGC group) were compared with a historical control group of 37 patients who underwent surgery using an allograft (allograft group). Fusion rates, subsidence, and adjacent segment degeneration were compared between the groups. Demographic data, fusion rates, visual analog scale (VAS) scores for neck or arm pain, Neck Disability Index (NDI) scores, and complications were also compared. Results Fusion rates were 88.5% when assessed by interspinous motion and 92.3% when assessed by intragraft bone bridging in the BGC group at 12-month follow-up. The neck pain or arm pain VAS scores and NDI scores significantly improved in both groups. No material-related complications were observed in the BGC group, such as graft resorption and breakage. Fusion rates, subsidence, neck pain or arm pain VAS scores, and NDI scores did not significantly differ between the BGC and allograft groups. Conclusions CaO-SiO2-P2O5-B2O3 BGC cage was effective and safe when used in ACDF, conferring a high fusion rate and favorable clinical outcomes similar to those of the allograft.

Background: Low back agony is a significant reason for social and money related worry since it is related with impeded personal satisfaction. Degenerative lumbar circle problems are considered answerable for low back agony. This is an aystematic survey to evaluate the clinical and radiographic results and difficulties OF transforaminal lumbar interbody combination (TLIF).. Subjects and strategies: A precise pursuit of different clinical reference information bases was led for transforaminal lumbar interbody combination. Qualified examinations remembered reads for which patient went through TLIF. Results: The pursuit yielded 12 examinations adding up to 494patients . Study Fusion rate is 89.26 %. ODI improvement of study is 26.75. VAS improvement of study is 4.3 . the pace of Neurological inconveniences of the investigation is 5.9% . the pace of Infection of the examination is 4.97 % . the pace of Dural injury of the investigation is 2.54 . the pace of Blood vessel injury of the examination is 0.0% . the pace of Adjacent section degeneration of the examination is 7.5% Conclusion: study results exhibit that TLIF viably decrease the clinical VAS and ODI scores and reestablish the radiologic discoveries.

OBJECTIVEIn this study the authors aimed to evaluate the rate of malposition, including pedicle breach and superior facet violation, after percutaneous insertion of pedicle screws using the coaxial fluoroscopic view of the pedicle, and to assess the risk factors for pedicle breach.METHODSIn total, 394 percutaneous screws placed in 85 patients using the coaxial fluoroscopic view of the pedicle between January 2014 and September 2017 were assessed, and 445 pedicle screws inserted in 116 patients using conventional open procedures were used for reference. Pedicle breach and superior facet violation were evaluated by postoperative 0.4-mm slice CT.RESULTSSuperior facet violation was observed in 0.5% of the percutaneous screws and 1.8% of the conventionally inserted screws. Pedicle breach occurred more frequently with percutaneous screws (28.9%) than with conventionally inserted screws (11.9%). The breaches in percutaneous screws were minor and did not reduce the interbody fusion rate. The angle difference between the percutaneous and conventionally inserted screws was comparable. Insertion at the L3 or L4 level, right-sided insertion, placement around a trefoil canal, smaller pedicle angle, and a small difference between the screw and pedicle diameters were found to be risk factors for pedicle breach by percutaneous pedicle screws.CONCLUSIONSPercutaneous pedicle screw placement using the coaxial fluoroscopic view of the pedicle carries a low risk of superior facet violation. The screws should be placed carefully considering the level and side of insertion, canal shape, and pedicle angle.

Spinal fusion surgery can now be performed through the endoscopic approach. Adequate endplate preparation and sufficient contact between bone graft or bone graft substitutes with the surfaces of the vertebral endplates are main factors to achieve successful arthrodesis. The purpose of this study are to compare the bone graft area, ratio of allograft-bonegraft (allo-bone) to total disc area, fusion rate, functional and radiographic outcomes between Endoscopic and Mini-open TLIF and to introduce the endoscopic technique of endplate preparation and implantation.

Supplemental Digital Content is available in the text, Study Design. Two-year clinical and radiographic follow-up of a double-blind, multicenter, randomized, intra-patient controlled, non-inferiority trial comparing a bone graft substitute (AttraX® Putty) with autograft in instrumented posterolateral fusion (PLF) surgery. Objectives. The aim of this study was to compare PLF rates between 1 and 2 years of follow-up and between graft types, and to explore the role of bone grafting based on the location of the PLF mass. Summary of Background Data. There are indications that bony fusion proceeds over time, but it is unknown to what extent this can be related to bone grafting. Methods. A total of 100 adult patients underwent a primary, single- or multilevel, thoracolumbar PLF. After instrumentation and preparation for grafting, the randomized allocation side of AttraX® Putty was disclosed. The contralateral posterolateral gutters were grafted with autograft. At 1-year follow-up, and in case of no fusion at 2 years, the fusion status of both sides of each segment was blindly assessed on CT scans. Intertransverse and facet fusion were scored separately. Difference in fusion rates after 1 and 2 years and between grafts were analyzed with a Generalized Estimating Equations (GEE) model (P

STUDY DESIGN A retrospective study. OBJECTIVE To assess the long-term results of zero-profile spacer for 3-level anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA Although widely used, there are still controversies about the long-term results of zero-profile spacer, especially in multilevel cases. METHODS Cases received 3-level ACDF for cervical spondylotic myelopathy (CSM) using either zero-profile spacer (n = 27) (ZP Group), or plate and cages (n = 34) (PC Group), and with 5-year follow-up were reviewed. Neurological function and life quality were assessed by modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and Short-Form 36 (SF-36) score. Disc height, cervical lordosis, fusion rate, and surgical complications were observed. RESULTS Neurological recovery and life quality improvement were similar in both groups. Disc height and cervical lordosis (C2-7 Cobb angle) were well restored after operations, but lost in both groups during follow-up. Loss of correction (LOC) in disc height was larger in ZP Group (11.38% vs 5.71%, P

Using capabilities of the gamma-ray spectrometry, fusion born alpha-particles were studied in recent D-3He plasma experiments on JET. A substantial population of the alpha-particles was generated in the 3He-rich plasma due to the 3He(D, p)4He reaction. Fast deuterium ions of the neutral beam injection (NBI) heating were accelerated to MeV energies with three-ion scenario D-(DNBI)-3He using radio frequency waves in the ion cyclotron range of frequencies (ICRF). A high reaction rate allowed to measure the alpha-particle production rate and their spatial distribution in the plasma by detecting 16.7-MeV gamma-rays from the 3He(D, ?)5 Li reaction, which is a weak branch of 3He(D, p)4He reaction. A branching ratio of gamma-ray transitions to the ground and the first excited states of 5Li was obtained. Due to the beryllium is a main impurity of JET plasmas, intensive gamma-rays from the 9Be(D, n?) 10B, 9Be(D, p?) 10Be and 9Be(?, n?) 12C reactions were observed. Exploitation of the reaction cross-sections and the Doppler shape analysis (DSA) of gamma-lines in the recorded spectra provided the possibility to reconstruct distribution functions of the confined D-ions and the fusion-born alpha-particles.

Using capabilities of the gamma-ray spectrometry, fusion born alpha-particles were studied in recent D-3He plasma experiments on JET. A substantial population of the alpha-particles was generated in the He-3-rich plasma due to the He-3(D, p)He-4 reaction. Fast deuterium ions of the neutral beam injection (NBI) heating were accelerated to MeV energies with three-ion scenario D-(DNBI)-He-3 using radio frequency waves in the ion cyclotron range of frequencies (ICRF). A high reaction rate allowed to measure the alpha-particle production rate and their spatial distribution in the plasma by detecting 16.7-MeV gamma-rays from the He-3(D, y)Li-5 reaction, which is a weak branch of He-3(D, p)He-4 reaction. A branching ratio of gamma-ray transitions to the ground and the first excited states of Li-5 was obtained. Due to the beryllium is a main impurity of JET plasmas, intensive gamma-rays from the Be-9(D, ny)10B, Be-9(D, py)Be-10 and Be-9(a, ny)C-12 reactions were observed. Exploitation of the reaction cross-sections and the Doppler shape analysis (DSA) of gamma-lines in the recorded spectra provided the possibility to reconstruct distribution functions of the confined D-ions and the fusion-born alpha-particles.

Background: The use of expandable cages in cervical spine has gained popularity over the last decade. They have been used in dorsal spine since long but were rarely used in cervical spine due to their high cost. Now, with more insight into their mechanics, many advantages have been noted over the fixed cages along with similar efficacy and with no added complications. Aims and Objectives: To study the benefits of expandable cage with incorporated anterior cervical plate over non expandable cage in cervical spine corpectomies. Materials and Methods: Ten cases of two level corpectomy were operated in each group and compared for intraoperative time, postoperative fusion rates and complications. Results: Intraoperative time was less in the expandable cage group. Fusion rates were comparable at 6 month follow up. No reported long term complication in both groups. Conclusion: Expandable cages are less frequently used in cervical spine due to their significantly higher cost but there are advantages such as decreased intraoperative manipulation and operative time, less damage to end plates and also useful in cases of poor bone quality.

External fixator knee arthrodesis is a salvage procedure used primarily in cases of end-stage infected total knee replacement (iTKR). Stable fixation combined with bone-end compression is essential to achieve knee fusion, but providing sufficient stability can be challenging in the presence of severe bone loss. Our hypothesis is that using an external fixation biplanar configuration would bring about a fusion rate superior to that of a monolateral frame. This study compares outcomes of biplanar external fixator knee fusion due to non-revisable iTKR with those of a historical cohort control study with patients managed with a monoplanar configuration. Primary endpoints were fusion rate, time to achieve bone fusion and infection eradication rate. Limb-length discrepancy, pain level, patient satisfaction and health-related quality of life were evaluated. A total of 29 knee fusion cases were included. In the biplanar group, infection was eradicated in 100% of the patients and fusion was achieved in all cases within an average of 5.24 months. In comparison, in the monolateral group, infection was eradicated in 86% of the cases and fusion was achieved in 81% of the patients after a mean of 10.3 months (p

Whilst rigid fixation for craniovertebral instability is the gold standard, in very young, small children conventional management may have to be modified. We present a single-centre experience of craniocervical fixation in children under 5 years. A retrospective review of cases that had undergone atlantoaxial (AA) or occipitocervical (OC) fixation aged under 5 years. Fusion was assessed using computerised tomography or flexion extension X-rays. Twenty-six children (median age 2.3, range 0.8–4.9 years, 19 under the age of 3) underwent OC (n = 19) or AA (n = 7) fusion between 1999 and 2016. Pathology comprised 17 congenital, five trauma, two tumour and two post-infection cases. Twenty-one patients underwent sublaminar cable fixation with calvarial, autologous bone graft and halo-body orthosis immobilisation. An occipital plate and rods to sublaminar wire construct were used in four cases. A rigid instrumented fixation with occipital plate and C2 pedicle screws was utilised in one case. Follow-up was for a median of 2.8 years (range 0.03–16.3 years). Initial fusion rate was 91%, reaching 100% following two re-operations. Ninety-two per cent of patients were neurologically stable or improved following surgery. Twenty-one patients had a good overall outcome. Two patients had post-operative neurological deteriorations, and four died due to non-procedure related causes. Pin site morbidity secondary to halo use occurred in five cases. High fusion rates with good outcomes are achievable using semi-rigid fixation in the under 5-year-olds. Full thickness, autologous calvarial bone graft secured with wire cables and halo external orthosis offers a safe and effective alternative technique when traditional screw instrumentation is not feasible. These slides can be retrieved under Electronic Supplementary Material.

The aim of this meta-analysis and systematic review is to summarize and critically analyze the influence of surgery-related factors in lumbar interbody fusion for degenerative spine diseases. A systematic review of the literature was carried out with a primary search being performed on Medline through PubMed. The 2009 PRISMA flowchart and checklist were taken into account. Sixty-seven articles were included in the analysis: 48 studies were level IV of evidence, whereas 19 were level III. All interbody fusion techniques analyzed have proved to reach a good fusion rate. An overall mean fusion rate of 93% (95% CI 92–95%, p

To examine the clinical results of different minimally invasive techniques for the therapy of far lateral disc herniation in middle-aged and elderly patients. An endoscopic approach (percutaneous endoscopic lumbar discectomy; PELD), MIS-TLIF combined with contralateral translaminar screw (MIS-TLIF CTS), and MIS-TLIF combined with bilateral pedicle screws (MIS-TLIF BPS) were evaluated via a retrospective chart review. Data from 74 consecutive middle-aged and elderly patients with far lateral disc herniation were analyzed. All patients underwent surgery; 19 with PELD, 24 with MIS-TLIF CTS, and 31 with MIS-TLIF BPS. Clinical data included the length of the incision, duration of the operation, estimated blood loss, hospitalization time, operation cost, recurrence rate, and fusion rate. Preoperative and postoperative patient outcomes including the VAS, ODI scores and MacNab criteria were assessed and recorded. The mean follow-up time was 26.4 months (range from 14 to 46 months). Compared with the internal fixation groups, the length of the incision, duration of operation, estimated blood loss, and hospitalization time were obviously lower in the PELD group. The difference in operation cost among the three methods was statistically significant. The postoperative VAS scores for LBP and LP decreased significantly as compared with those recorded preoperatively. The postoperative ODI scores were lower than those recorded preoperatively. MacNab criteria rating excellent, good and fair results were in 27, 37 and 10 patients, respectively. Conclusion: PELD, MIS-TLIF CTS, and MIS-TLIF BPS are all effective minimally invasive techniques for the therapy of single segment far lateral lumbar disc herniation in middle-aged and elderly patients. PELD had a shorter operation time and less surgical trauma, being a less invasive and more economical method; however, there was no recurrence of disc herniation after fixation. Compared with MIS-TLIF BPS, MIS-TLIF CTS obtained a similar clinical effect and certain costs were saved.

Study Design: Systematic literature review. Objective: Our primary objective was to compare reported fusion rates after anterior cervical discectomy and fusion (ACDF) using structural allograft versus polyetheretherketone (PEEK) interbody devices in patients with cervical spine degeneration. Our secondary objectives were to compare differences in rates of subsidence and reoperation and in patient-reported outcomes between the 2 groups. Methods: Through a systematic review of the English-language literature using various databases, we identified 4702 articles. After we applied inclusion and exclusion criteria, 14 articles (7 randomized controlled trials, 4 prospective studies, and 3 retrospective studies) reporting fusion rates of structural allograft or PEEK interbody devices were eligible for our analysis. No randomized controlled trials compared outcomes of structural allograft versus PEEK interbody devices. Extracted data included authors, study years, study designs, sample sizes, patient ages, duration of follow-up, types of interbody devices used, fusion rates, definition of fusion, reoperation rates, subsidence rates, and patient-reported outcomes. Results: Fusion rates were 82% to 100% for allograft and 88% to 98% for PEEK interbody devices. The reported data were insufficient to perform meta-analysis. Structural allograft had the highest reported rate of reoperation (14%), and PEEK interbody devices had the highest reported subsidence rate (18%). Patient-reported outcomes improved in both groups. There was insufficient high-quality evidence to compare the associations of various PEEK modifications with fusion rates. Conclusion: Fusion rates were similar between structural allograft and PEEK interbody devices when used for ACDF for cervical spine degeneration. Currently, there is insufficient high-quality evidence to assess associations of PEEK modifications with fusion rates. Level of Evidence: II.

Total ankle arthroplasty (TAA) has the objective to maintain the range of motion of the tibiotarsal joint and to preserve the nearby joints. However, the complication rate and failures remain quite high after TAA. The main objective of the study was to evaluate the improvement in the functional scores of the tibiotarsal arthrodesis after TAA failure. The secondary objective was to assess the specific complications. This monocentric retrospective series includes 12 patients (nine men, three women, average age 52.5 years) operated between 2003 and 2018. An iliac graft was used in all cases. The arthrodesis was stabilized either by screws or by retrograde nailing. The reoperation was due to painful malleolar conflicts or loosening. The AOFAS score increased from 38/100 to 67/100 (51–86) post-operatively. The fusion was acquired at 3.7 months (3–6) except in two cases. The 83% primary fusion rate is in the low average of the literature and 92% fusion rate in the high average after reoperation. All patients were improved even in two non-unions. The results of this study confirm that the arthrodesis after TAA failure is a reliable alternative to the TAA replacement. However, they are lower than those after a first-line arthrodesis.

Lumbar spinal stenosis dengan instabilitas, salah satu pilihan pengobatannya dengan laminektomi dekompresi, stabilisasi posterior dan PLIF (Posterior Lumbar Interbody Fusion). Derajat fusi dapat ditentukan dengan pemeriksaan CT-scan post operatif. Sedangkan untuk menilai disabilitas dan skor fungsional pada pasien LSS menggunakan skor Oswestry Disability Index (ODI). Penelitian ini merupakan penelitian analisis observasional pada 18 pasien LSS yang telah dilakukan operasi instrumentasi PLIF. Pasien diminta mengisi kuesioner ODI dan dilakukan evaluasi CT Scan, kemudian dilakukan uji korelasi data yang didapat. Penelitian ini menunjukkan adanya korelasi yang signifikan antara derajat fusi dengan ODI. Koefisien korelasi antara derajat fusi dengan ODI didapatkan 0,904 dengan nilai signifikansi 0,00 (p

Objective: Unipolar pulses have been used in cell electrofusion over the last decades. However, the problem of high mortality with unipolar pulses has not been solved effectively. The cell fusion rate is restricted by cell mortality. By using the advantages of bipolar pulses which cause less cell damage, this paper attempts to use bipolar pulses to increase the cell fusion rate. Methods : the transmembrane voltage and pore density of cells subjected to unipolar/bipolar pulses were simulated in COMSOL software. In an experiment, two 40 μs unipolar and two 20–20 μs bipolar pulses with electric fields of 2, 2.5, and 3 kV/cm were applied to SP2/0 murine myeloma cells. To determine the cell fusion rate and cell mortality, cells were stained with Hoechst 33342 and propidium iodide. Results: the simulation in this paper showed that a high transmembrane voltage and a high pores density were concentrated only at the contact area of cells when bipolar pulses were used. The results of the cell staining experiment verified the simulation analysis. When bipolar pulses were applied, the cell mortality was significantly reduced. In addition, the cell fusion rate with bipolar pulses was almost two times higher than that with unipolar pulses. Conclusion: for cell electrofusion, compared with unipolar pulses, bipolar pulses can not only reduce the cell mortality remarkably but also improve the cell fusion rate obviously. Significance: this paper introduces a novel way to increase the fusion rate of cells.

The aim of this study was to compare the clinical efficacy and radiological outcomes of skip corpectomy and fusion (SCF) with anterior controllable antedisplacement and fusion (ACAF) for treating multilevel ossification of the posterior longitudinal ligament (OPLL). 62 patients with multilevel OPLL who had undergone SCF or ACAF were analyzed retrospectively. Types of OPLL, occupying ratio (OR), Japanese Orthopaedic Association (JOA) score, Recovery Rate (RR), Neck Disability Index (NDI) score, Cobb’s angles of C2–C7, operation time, blood loss, hospital stay, ratings for fusion assessment and complications were recorded and assessed. Postoperative C2–C7 Cobb’s angle (11.1 ± 3.2° vs. 13.7 ± 2.5°; P

Study Design A retrospective review of patients who underwent 2-level anterior cervical discectomy and fusion (ACDF) with standalone polyetheretherketone (PEEK) cages for cervical spondylotic myelopathy (CSM). Purpose To evaluate the efficacy of stand-alone PEEK cage in 2-level cervical interbody fusion for CSM. Overview of Literature ACDF is a standard surgical procedure to treat degenerative disc disease. However, the use of additional anterior plating for 2-level ACDF remains controversial. Methods We reviewed outcomes of patients who underwent 2-level ACDF with stand-alone PEEK cages for CSM over a 7-year period (2007–2015) in a regional hospital. Japanese Orthopaedic Association (JOA) score, fusion rate, subsidence rate, cage migration, and cervical alignment by the C2–7 angle as well as the local segmental angle (LSA) of the cervical spine were assessed. Results In total, 31 patients (mean age, 59 years; range, 36–87 years) underwent 2-level ACDF with a cage-only construct procedure between 2007 and 2015. The minimum follow-up was 24 months; mean follow-up was 51 months. C3–5 fusion was performed in 45%, C4–6 fusion in 32%, and C5–7 fusion in 23%. Mean JOA score improved from 10.1±2.2 to 13.9±2.1 (p

Background The aim of this study was to assess the relationship between the atlantodental interval (ADI) on dynamic flexion/extension cervical radiographs and functional outcomes of posterior spinal fixation by the Harms technique for atlantoaxial subluxation (AAS).Dynamic flexion/extension on cervical radiographs is a standard assessment for evaluation of C1/2 instability in AAS patients. Most studies focused on postoperative ADI and functional outcome, including pain and fusion rate; only few studies compared dynamic ADI change pre- to post-operatively. Material and methods Retrospectively, we reviewed the medical records of 16 patients who underwent posterior spinal fixation in our center from 2018 to 2019. We used dynamic cervical flexion/extension radiographs to assess the pre- to postoperative change at 12 months in ADI of flexion (ADIf), ADI of extension (ADIe), ADI between flexion/extension (ADIΔ), C1/2 fusion rate and functional outcomes measured by the modified Japanese Orthopaedic Association scale (mJOA scale). Postoperative CT at 3∼12 months assessed screw positioning on the Gertzbein and Robbins classification. Results In the 16 patients included in this study, ADIf, ADIe and ADIΔ were significantly reduced, from respectively 8.0mm, 5.0mm and 3.0mm preoperatively to 4.6mm, 3.8mm and 0.8mm at 12 months' follow-up. The fusion rate was 81% and the mJOA score recovery rate was 34.9±14.7%. Although the screw malposition rate was higher than in other studies in C1(10%) and C2(20%), there were no new neurologic deficits or worsening of symptoms at follow-up. Conclusions The ADIΔ showed significant reduction, showing that the Harms technique of posterior spinal fixation can effective in maintaining the stability of the atlantoaxial joint and improving functional outcome.

PURPOSE A variety of different lumbar spinal fusion techniques have been developed. In this study, we review published medical literature highlighting the differences between lumbar interbody fusion techniques with regard to their surgical technique, clinical outcomes, and complications. MATERIALS AND METHODS PubMed, ScienceDirect, and Google Scholar searches were performed for studies published between January 1990 to April 2018 reporting spinal fusion surgery clinical outcomes of at least one fusion technique. Clinical outcomes were extracted and pooled by surgical technique. Chi-squared analyses and Fisher Exact Tests were used to determine differences in rates between groups. RESULTS PLIF had the highest rate of successful fusion (97% [155/159]) and the lowest rate of complications (4% [6/131]). A chi square analysis revealed a significant difference in fusion success in PLIF compared to PLF (84% [278/330], p

Teriparatide belongs to osteo-anabolic compounds and has been used in recent years to treat patients with osteoporosis, with the benefits of increased bone density. Its osteo-anabolic action has led to the investigation of the use of teriparatide for the improvement of bone quality. Apart from the enhancement of fracture union, teriparatide has been extensively studied in the promotion of fusion rate after spinal fusion. This study summarizes the preclinical and clinical results of the off-label use of teriparatide in the spine, and specifically its intermittent administration after instrumented spinal arthrodesis along with its impact on the spinal bone quality and spinal bone mineral density.

Displaced nonunited type II odontoid fracture can result in atlantoaxial instability, causing delayed cervical myelopathy. Both Magerl’s C1-C2 transarticular screw fixation technique and Harms-Goel C1-C2 screw-rod segmental fixation technique are effective techniques to provide stability. This study aimed to demonstrate the results of two surgical fixation techniques for the treatment of reducible nonunited type II odontoid fracture with atlantoaxial instability. Medical records of patients with reducible nonunited type II odontoid fracture hospitalized for spinal fusion between April 2007 and April 2018 were reviewed. For each patient, specific surgical fixation, either Magerl’s C1-C2 transarticular screw fixation technique augmented with supplemental wiring or Harms-Goel C1-C2 screw-rod fixation technique, was performed according to our management protocol. We reported the fusion rate, fusion period, and complications for each technique. Of 21 patients, 10 patients were treated with Magerl’s C1-C2 transarticular screw fixation technique augmented with supplemental wiring, and 11 were treated with Harms-Goel C1-C2 screw-rod fixation technique. The bony fusion rate was 100% in both groups. The mean time to fusion was 69.7 (95%CI 53.1, 86.3) days in Magerl’s C1-C2 transarticular screw fixation technique and 75.2 (95%CI 51.8, 98.6) days in Harms-Goel C1-C2 screw-rod fixation technique. No severe complications were observed in either group. Displaced reducible, nonunited type II odontoid fracture with cervical myelopathy should be treated by surgery. Both fixation techniques promote bony fusion and provide substantial construct stability.

Objective High grade spondylolisthesis (HGS) is a quite rare entity and many techniques are available to address this condition. In 1994 Abdu et al. proposed a transdiscal fixation approach that achieved a good clinical outcome. We analyse outcome and fusion achieved in patients treated by transdiscal fixation after 1-year follow-up. Methods We reviewed patients operated through transdiscal fixation since 2014 with a follow-up of at least 1 year, and compared preoperative and postoperative clinical measures (ODI, VAS and EQ-5D) and postoperative complications. Also, we analyzed the degree of fusion on CT scan with Lenke and Birdwell criteria. Results Twelve patients were included in the study with a mean follow-up of 49.4 months (range 12.8–84.1 months). Three cases presented a Meyerding grade IV spondylolisthesis and 9 cases grade III. At 1-year follow-up mean postoperative ODI, VAS and EQ5D scores improved (ODI 13.2 (range 0–30) vs 49.83 (range 15–71.1); p = .005). Equally this improvement was seen in the last follow-up (ODI 9.28 (range 0–35) vs 49.83 (range 15–71.1); p = .005). CT scan showed fusion grade A in 5 patients (41.6%), another 5 as grade B (41.6%) in Lenke classification. According to the Birdwell criteria 4 patients were classified as grade I (33.3%), 7 patients grade II (58.3%). None showed complications postoperatively or radiolucency in follow-up. Conclusions Transdiscal fixation shows a good clinical outcome that is maintained throughout a long time period and provides a reliable and suitable fusion.

The purpose of this meta-analysis was to compare the fusion rate and outcomes directly between patients who underwent stand-alone lateral lumbar interbody fusion (LLIF) and LLIF with supplemental posterior instrumentation. A comprehensive literature search was performed for relevant studies using PubMed, EMBASE, Web of Science, and Cochrane Library. The stand-alone and instrumented LLIF were compared by the fusion rate, the radiographic parameters, the cage subsidence rate, the clinical outcomes, the complication rate, and the reoperation rate. A total of 13 studies comprising 1090 patients with lumbar degenerative disease (LDD) were included. There was no significant statistical difference in the complication rate, and there was no significant clinical difference in the improvement of clinical outcomes at the last follow-up between patients who underwent stand-alone and instrumented LLIF. Nevertheless, lower fusion rate (RR, 0.92; 95% CI 0.87 to 0.98, P = 0.006), inferior restoration of disk height (WMD, -0.68; 95% CI -1.04 to -0.32, P 0.001) and segmental lordosis (WMD, -1.28; 95% CI -2.30 to -0.27, P = 0.013), higher cage subsidence rate (RR, 1.68; 95% CI 1.36 to 2.07, P 0.001), and higher reoperation rate (RR, 2.12; 95% CI 1.02 to 4.43, P = 0.045) were observed in the stand-alone group. Both stand-alone and instrumented LLIF were effective in improving the clinical outcomes of patients with LDD. However, the stand-alone LLIF was associated with lower fusion rate, inferior maintenance of indirect decompression, and higher reoperation rate due to high-grade cage subsidence. For patients with risk factors of high-grade cage subsidence, the LLIF with posterior instrumentation may be the better choice.

Background The variance in clinical responses to polyetheretherketone (PEEK) cages with titanium (Ti) and hydroxyapatite (HA) coatings (PEEK-Ti-HA cages) is still not clear. In this study, we aimed to evaluate the radiographic and clinical outcomes of patients undergoing TLIF using PEEK-Ti-HA cages with a particular focus on fusion rate. Methods A prospective and nonrandomized study was conducted to compare the outcomes of PEEK-Ti-HA cages (group A, n = 32) and uncoated PEEK cages (group B, n = 32). The follow up time was at least 2 years. The radiographic assessments included the regional lordosis (RL), disc height (DH), and fusion rate. The clinical indexes included the Japanese Orthopedic Association (JOA) scores and visual analog scale (VAS) scores (back and leg). Results No significant differences were found in the pre- and postoperative RL and DH between Group A and Group B. And RL and DH, even if there were any variance initially, were restored not long after surgery in both groups. Though Group A had a significantly higher fusion rate than group B at 3 months post-surgery (93.7% vs. 75.0%), the fusion rates for the two groups reached the same level (100%) when it comes to the final follow-up. Additionally, differences of VAS and JOA scores for the two groups in general approximate. Conclusions PEEK-Ti-HA cages, in contrast with uncoated PEEK cages, produced a better fusion rate at 3 months after single-level TLIF. The fusion rates of both groups could get 100% at the final follow-up. PEEK-Ti-HA cages could achieve similar RL, DH, JOA scores and VAS scores in comparison with uncoated PEEK cages post-surgery.

The primary objective of this study was to compare the radiological and clinical results of anterograde and retrograde screwing in subtalar arthrodesis using a single compression screw. The secondary objective was to evaluate the subjective results and consolidation of this procedure. The hypotheses were that isolated screw fixation was sufficient to achieve good consolidation and that there was no difference between the two techniques with a similar rate of bone fusion. This is a monocentric, retrospective, radio-clinical study based on 99 patients (101 feet), 58 males and 41 females, with an average age of 64 years. The main aetiology was post-traumatic osteoarthritis, which represented 51% of cases. Two groups were formed: group A (52 feet) consisting of fixed arthrodesis with ascending (retrograde) screwing and group D (49 feet) consisting of fixed arthrodesis with descending (anterograde) screwing. The two groups were statistically comparable in terms of demographic data as well as aetiologies and comorbidities. Arthrodeses which were not fused at 6 months were reassessed at one year and in the event of any radio-clinical doubt regarding consolidation, an additional CT scan was prescribed. Average post-operative follow-up was 11 ± 5 years (2–27 years). Ninety-two arthrodeses (93%) were fused at one year and 9 were considered to be in non-union, 5 (9.8%) in group A, and 4 (8.3%) in group D. We recorded 30 complications, 22 of which were due to a conflict with the screw head, 18 (34.5%) in group A and 4 (8.3%) in group D (p = 0.03). Conflict between the screw head and the heel led to the removal of the screw after consolidation of the arthrodesis. The clinical results were evaluated using Odom’s criteria. Nine per cent of patients described their results as excellent, 29% as good, 51% as satisfactory and 11% found the result to be poor. The fusion rate for isolated compression screw arthrodesis is good, and there is no difference between anterograde and retrograde screws. However, the discomfort caused by the screw head being insufficiently embedded in the retrograde group led to a non-negligible number of additional surgeries to remove the screw.

Objectives: This retrospective comparative study aimed to compare the efficacy of selective caudal fixed screw constructs with all variable screw constructs in anterior cervical discectomy and fusion (ACDF). Methods: Thirty-five patients who underwent surgery using selective caudal fixed screw construct (SF group) were compared with 44 patients who underwent surgery using all variable constructs (AV group). The fusion rate, subsidence, adjacent level ossification development (ALOD), adjacent segmental disease (ASD), and plate-adjacent disc space distance were assessed.Results: The one-year fusion rates assessed by computed tomography bone bridging and interspinous motion as well as the significant subsidence rate did not differ significantly between the AV and SF groups. The ALOD and ASD rates and plate-adjacent disc space distances did not significantly differ between the two groups at both the cranial and caudal adjacent levels. The number of operated levels was significantly associated with pseudarthrosis in the logistic regression analysis.Conclusion: The stability provided by the locking mechanism of the fixed screw did not lead to an increased fusion rate at the caudal level. Therefore, the screw type should be selected based on individual patient’s anatomy and surgeon’s experience without concern for increased complications caused by screw type.

Study Design: Retrospective cohort study. Objective: To compare the outcomes of patients with adult spinal deformity (ASD) following spinal fusion with the lowest instrumented vertebra (LIV) at L4/L5 versus S1/ilium. Methods: A multicenter ASD database was evaluated. Patients were categorized into 2 groups based on LIV levels—groups L (fusion to L4/L5) and S (fusion to S1/ilium). Both groups were propensity matched by age and preoperative radiographic alignments. Patient demographics, operative details, radiographic parameters, revision rates, and health-related quality of life (HRQOL) scores were compared. Results: Overall, 349 patients had complete data, with a mean follow-up of 46 months. Patients in group S (n = 311) were older and had larger sagittal and coronal plane deformities than those in group L (n = 38). After matching, 28 patients were allocated to each group with similar demographic, radiographic, and clinical parameters. Sagittal alignment restoration at postoperative week 6 was significantly better in group S than in group L, but it was similar in both groups at the 2-year follow-up. Fusion to S1/ilium involved a longer operating time, higher PJK rates, and greater PJK angles than that to L4/L5. There were no significant differences in the complication and revision rates between the groups. Both groups showed significant improvements in HRQOL scores. Conclusions: Fusion to S1/ilium had better sagittal alignment restoration at postoperative week 6 and involved higher PJK rates and greater PJK angles than that to L4/L5. The clinical outcomes and rates of revision surgery and complications were similar between the groups.

Purpose To evaluate the accuracy of screw placement and fusion rate after the minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) technique under O-arm navigation. Methods In 475 consecutive patients at a single-center, the accuracy of screw placement was evaluated on intraoperative O-arm imaging. Misplaced screws were investigated to identify the direction of deviation and associated clinical outcomes. The fusion rate was evaluated on postoperative computed tomography scan at 1 and 2 year(s). The assessment of screw placement and fusion level was analyzed for inter-rater reliability and reported as a kappa value. Accuracy of screw placement (Gertzbein-Robbins Classification), extent of fusion (Bridwell Interbody Fusion Grading System), and complications were considered as outcome measures. Results A retrospective data analysis from 2,098 pedicle screws in 475 patients. The mean age of participants was 56.61 ± 12.30 years, and 45.26% were female. Their ethnicities were as follows: Asian (58.74%), Caucasian (20.21%), Middle-eastern (14.32%), and African (6.74%). The final fusion levels were single (80.63%), two (18.11%), three (1.05%), and four (0.21%). There were L4/L5 as the most prevalent placement (55.35%), followed by L5/S1 (36.29%), L3/L4 (5.22%), L2/L3 (2.35%), L1/L2 (0.52%), and S1/S2 (0.26%). Seven out of 2,098 screws were breaches. None of screw needed immediate revision. In total, 99.66% of the screws were grade A (no breach), 0.19% were grade B (breach

Study design A retrospective analysis of prospectively collected data. Objective The aim was to examine whether posterior lumbar interbody fusion with cortical bone trajectory screw fixation (CBT-PLIF) is inferior to PLIF using traditional trajectory screw fixation (TT-PLIF) regarding early fusion status and whether the titanium-coated polyetheretherketone (PEEK) cage (TP cage) improves early fusion status compared with the same shape pure PEEK cage (P cage). Summary of background data We recently reported that the fusion rate was relatively lower after CBT-PLIF than after TT-PLIF, although no significant difference was found and that compared with the carbon PEEK cage, the TP cage significantly reduced the incidence of vertebral endplate cysts (cyst signs) and slightly improved the early fusion rate at 1 year after CBT-PLIF. Materials and methods The subjects were 37 patients undergoing TT-PLIF using P cages (TT-P group), 24 patients undergoing CBT-PLIF using P cages (CBT-P group), 32 patients undergoing TT-PLIF using TP cages (TT-TP group), and 20 patients undergoing CBT-PLIF using TP cages (CBT-TP group). On multiplanar reconstruction computed tomography at 6 months after surgery, cyst signs were evaluated and classified into diffuse or local cysts. Early fusion status was assessed using both dynamic plain radiographs and multiplanar reconstruction computed tomography at 1-year postoperatively. Results The incidence of the diffuse cyst was 27.0% in the TT-P group, 29.2% in the CBT-P group, 25.0% in the TT-TP group and 25.0% in the CBT-TP group (P>0.05). The early fusion rate was 75.7% in the TT-P group, 75.0% in the CBT-P group, 71.9% in the TT-TP group and 75.0% in the CBT-TP group (P>0.05). Conclusions These results indicate that CBT-PLIF resulted in the equivalent early fusion status to TT-PLIF and that compared with the same shape P cage, the TP cage did not improve early fusion status after both TT-PLIF and CBT-PLIF.