Iliac crest bone graft versus cell-based grafts to augment spinal fusion: a systematic review and meta-analysis.

INTRODUCTION: Despite successful fusion rates with iliac crest bone graft (ICBG), donor-site morbidity and increased operating time remain a considerable limitation and drive the search for alternatives. In this systematic review, grafts with additional cellular supplementation were compared with ICBG for spinal arthrodesis. We compared safety, efficacy and long-term outcomes, thus providing the current and relevant evidence for orthopaedic surgeons to make informed choices regarding this rapidly developing field. METHODS: An electronic literature search was conducted according to the PRISMA guidelines by two independent reviewers for articles published up to 1st March 2023 using PubMed, EMBASE and the Cochrane Central Register of Controlled Trial. Cellular allografts were not included. The following data were extracted: Number of patients, type of graft, fusion assessment method, follow-up duration, fusion rates, clinical outcomes and complications. The methodological quality of evidence (MQOE) was assessed using the Risk of Bias 2 (RoB-2) tool and Risk of Bias In Non-Randomised Studies (ROBINS) tool developed by Cochrane for evaluating bias in randomised and non-randomised studies. RESULTS: Ten studies fulfiled the inclusion criteria, including 465 patients. The mean number of patients per study was 43.8 (std dev. 28.81, range 12-100). Two studies demonstrated cell-based therapy to be significantly more successful in terms of fusion rates compared to ICBG. However, the remaining eight demonstrated equivocal results. No study found that cell-based therapy was inferior. No difference was seen between the two groups in three studies who focused on degenerative cohorts. No difference in functional outcome scores was seen between the groups. A number of different preparation techniques for cell-based grafts were used throughout the studies. CONCLUSION: Cell-based therapy offers a promising alternative to ICBG in spinal fusion surgery, which could help reduce the associated morbidity to patients. This review found that cell-based therapy is non-inferior to iliac crest bone graft and may offer patients an alternative treatment option with fewer complications and reduced post-operative pain. However, the literature to date is limited by heterogeneity of the cell preparation and grafting process. Future research with a unified approach to the cell preparation process is required to fully delineate the potential advantages of this technology.

Outcomes following spinal instrumented fusions in patients with parkinson's disease: a systematic review and meta-analysis.

BACKGROUND: Parkinson's Disease (PD) patients represent challenging spinal surgery candidates due to associated frailty and deformity. This study consolidates the literature concerning spinal surgery outcomes in PD versus non-PD patients, to evaluate if PD predisposes patients to worse post-operative outcomes, so that treatment protocols can be optimised. METHODS: A systematic review and meta-analysis was conducted of PubMed/Medline, Embase, and Google Scholar databases per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies of interest included comparative (PD versus non-PD) cohorts undergoing spinal instrumented fusions. Post-operative clinical outcomes were collated and compared for significance between cohorts. Further analysis was made on outcomes based on the different surgical procedures performed (Anterior Cervical Discectomy and Fusion (ACDF), Thoracolumbar or Lumbar fusions, Thoracolumbar or Lumbar fusions without Osteoporotic Vertebral Compression fracture (OVCF) patients). All statistical analysis was performed using The R Project for Statistical Computing (version 4.1.2), with a p-value of < 0.05 deemed statistically significant. RESULTS: In total, 2,323,650 patients were included across 16 studies. Of those, 2,308,949 (99.37%) were patients without PD (non-PD), while 14,701 (0.63%) patients had PD at time of surgery. The collective mean age was 68.23 years (PD: 70.14 years vs non-PD: 64.86 years). Comparatively, there were 844,641 males (PD: 4,574; non-PD: 840,067) and 959,908 females (PD: 3,213; non-PD: 956,695). Overall, there were more post-operative complications in the PD cohort. Specifically, PD patients experienced significantly more surgical site infections (p = 0.01), increased rates of revision surgeries (p = 0.04) and increased venous thromboembolic events (p = 0.02) versus the non-PD cohort. In thoracolumbar/lumbar spinal fusions without OVCF patients, the PD cohort had increased rates of revision surgeries (p < 0.01) in comparison to the non-PD cohort. However, when including OVCF patients in thoracolumbar/lumbar spinal fusions, the PD cohort had significantly higher amounts of postoperative complications (p = 0.01), pneumonia (p = 0.02), and revision surgeries (p < 0.01) when compared to the non-PD cohort. CONCLUSION: Although more robust prospective studies are needed, the results of this study highlight the need for advanced wound care management in the postoperative period, both in-hospital and in the community, in addition to comprehensive multidisciplinary care from allied health professionals, with potential for the use of Enhanced Recovery After Surgery (ERAS) protocols in PD patients undergoing spinal instrumented fusions.

Accuracy of augmented reality-assisted pedicle screw placement: a systematic review.

OBJECTIVE: Conventional freehand methods of pedicle screw placement are associated with significant complications due to close proximity to neural and vascular structures. Recent advances in augmented reality surgical navigation (ARSN) have led to its adoption into spine surgery. However, little is known regarding its overall accuracy. The purpose of this study is to delineate the overall accuracy of ARSN pedicle screw placement across various models. METHODS: A systematic review was conducted of Medline/PubMed, Cochrane and Embase Library databases according to the PRISMA guidelines. Relevant data extracted included reports of pedicle screw placement accuracy and breaches, as defined by the Gertzbein-Robbins classification, in addition to deviation from pre-planned trajectory and entry point. Accuracy was defined as the summation of grade 0 and grade 1 events per the Gertzbein-Robbins classification. RESULTS: Twenty studies reported clinically accurate placed screws. The range of clinically accurate placed screws was 26.3-100%, with 2095 screws (93.1%) being deemed clinically accurate. Furthermore, 5.4% (112/2088) of screws were reported as grade two breaches, 1.6% (33/2088) grade 3 breaches, 3.1% (29/926) medial breaches and 2.3% (21/926) lateral breaches. Mean linear deviation ranged from 1.3 to 5.99 mm, while mean angular/trajectory deviation ranged 1.6°-5.88°. CONCLUSION: The results of this study highlight the overall accuracy of ARSN pedicle screw placement. However, further robust prospective studies are needed to accurately compare to conventional methods of pedicle screw placement.

The correlation between altmetric score and traditional measures of article impact for studies published within the Surgeon Journal.

Alternative metrics, or altmetrics, have emerged as a promising tool for measuring the social impact of research, which is increasingly important in today's digital and social media-driven world. Altmetric Attention Score (AAS) is a weighted count of all the online attention garnered by a study, and it is currently unclear whether a relationship with traditional bibliometrics exists. The purpose of this article was to retrospectively review articles published in the Surgeon Journal from 2003 to 2020 to compare AAS with bibliometric parameters using an Independent t-test and Pearson's correlation analysis. There were statistically significant weakly positive relationships between AAS and sample size, number of reads, and number of citations. There was no statistically significant relationship between AAS and number of authors, H-index, or level of evidence. This study highlights the potential value of altmetrics by measuring the social impact of research as altmetrics can provide valuable information not captured by traditional metrics. It is currently unclear what the optimal balance of social and academic impact is in evaluating research impact and how altmetrics can be integrated into existing research frameworks.

Comparative surgical outcomes of navigated vs non-navigated posterior spinal fusions in ankylosing spondylitis patients.

INTRODUCTION: Ankylosing Spondylitis (AS) patients with acute spinal fractures represent a challenge for practicing spine surgeons due to difficult operative anatomy and susceptibility to complications. RESEARCH QUESTION: Does intraoperative CT-navigation improve outcomes in patients with ankylosing spondylitis undergoing surgery? METHODS: A retrospective review was carried out at our centre from 05/2016-06/2021 to identify AS patients presenting with a traumatic spinal fracture, managed surgically with posterior spinal fusion (PSF). Cohorts were categorised and compared for outcomes based on those who underwent PSF with intraoperative CT-navigation versus those surgically managed with traditional intraoperative fluoroscopy. RESULTS: 37 AS patients were identified. 29/37 (78.4%) underwent PSF. Intraoperative navigation was used in 14 (48.3%) cases. Mean age of the entire cohort was 67.6 years. No difference existed between the navigated and non-navigated groups for mean levels fused (5.35 vs 5.07; p â€‹= â€‹0.31), length of operation (217.9mins vs 175.3mins; p â€‹= â€‹0.07), overall length-of-stay (12 days vs 21.9 days; p â€‹= â€‹0.16), patients requiring HDU (3/14 vs 5/15; p â€‹= â€‹0.09) or ICU (5/14 vs 9/15; p â€‹= â€‹0.10), postoperative neurological improvement (1/14 vs 1/15; p â€‹= â€‹0.48) or deterioration (1/14 vs 0/15; p â€‹= â€‹0.15), intraoperative complications (2/14 vs 3/15; p â€‹= â€‹0.34), postoperative complications 4/14 vs 4/15; p â€‹= â€‹0.46), revision surgeries (3/14 vs 1/15; p â€‹= â€‹0.16) and 30-day mortality (0/14 vs 0/15). CONCLUSION: This is the first study that compares surgical outcomes of navigated vs non-navigated PSFs for AS patients with an acute spinal fracture. Although limited by its retrospective design and sample size, this study highlights the non-inferiority of intraoperative navigation as a surgical aid in a challenging cohort.

Biomimetic Inspired Hydrogels for Regenerative Vertebral Body Stenting.

PURPOSE OF REVIEW: This review aims to explore the potential of biomimetic hydrogels as an alternative to bone cement in vertebral body stenting (VBS), a minimally invasive treatment for vertebral compression fractures. RECENT FINDINGS: The use of bone cement in VBS procedures can lead to complications such as incomplete fracture reduction and cement leakage. Biomimetic hydrogels have gained significant attention as potential biomaterial alternatives for VBS due to their unique properties, including tuneable therapeutic and mechanical properties. Over the past decade, there has been significant advancements in the development of biomimetic hydrogels for bone regeneration, employing a wide range of approaches to enhance the structural and functional properties of hydrogels. Biomimetic hydrogels hold significant promise as safer and reparative alternatives to bone cement for VBS procedures. However, further research and development in this field are necessary to explore the full potential of hydrogel-based systems for vertebral bone repair.

Risk factors for distal junctional failure in long-construct instrumentation for adult spinal deformity.

PURPOSE: The aim of this study is to identify risk factors associated with postoperative DJF in long constructs for ASD. METHODS: A retrospective review was performed at a tertiary referral spine centre from 01/01/2007 to 31/12/2016. Demographic, clinical and radiographic parameters were collated for patients with DJF in the postoperative period and compared to those without DJF. Survival analyses were performed using univariate logistic regression to identify variables with a p value < 0.05 for inclusion in multivariate analysis. Spearman's correlations were performed where applicable. RESULTS: One hundred two patients were identified. 41 (40.2%) suffered DJF in the postoperative period, with rod fracture being the most common sign of DJF (13/65; 20.0%). Mean time to failure was 32.4 months. On univariate analysis, pedicle subtraction osteotomy (p = 0.03), transforaminal lumbar interbody fusion (p < 0.001), pre-op LL (p < 0.01), pre-op SVA (p < 0.01), pre-op SS (p = 0.02), postop LL (p = 0.03), postop SVA (p = 0.01), postop PI/LL (p < 0.001), LL correction (p < 0.001), SVA correction (p < 0.001), PT correction (p = 0.03), PI/LL correction (p < 0.001), SS correction (p = 0.03) all proved significant. On multivariate analysis, pedicle subtraction osteotomy (OR 27.3; p = 0.03), postop SVA (p < 0.01) and LL correction (p = 0.02) remained statistically significant as independent risk factors for DJF. CONCLUSION: Recently, DJF has received recognition as its own entity due to a notable postoperative incidence. Few studies to date have evaluated risk factors for DJF. The results of our study highlight that pedicle subtraction osteotomy, poor correction of lumbar lordosis, and sagittal vertical axis are significantly associated with postoperative occurrence of DJF.

Changing Demographic Trends in spine trauma: The presentation and outcome of Major Spine Trauma in the elderly.

INTRODUCTION: Major trauma has seen a demographic shift in recent years and it is expected that the elderly population will comprise a greater burden on the major trauma service in the near future. However, whether a similar trend exists in those undergoing operative intervention for spinal trauma remains to be elucidated. AIMS: To compare the presentation and outcomes of patients ≥65 years of age sustaining spine trauma to those <65 years at a national tertiary referral spine centre. METHODS: The local Trauma Audit Research Network (TARN) database was analysed to identify spinal patients referred to our institution, a national tertiary referral centre, between 01/2016 and 05/2019. Patients were divided into a young cohort (16-64 years old) and an elderly cohort (> 64 years old). No explicit distinction was made between major and minor spine trauma cases. Variables analysed included patient demographics, injury severity, mortality, interventions, mechanism of injury and length of hospital stay. RESULTS: A total of 669 patients were admitted of which 480 patients underwent operative intervention for spinal trauma. Within the elderly cohort, this represented 75.3% of cases. Among the younger population, road traffic collisions were the most common mechanism of injury (37.1%), while low falls (<2 m) (57.4%) were the most common mechanism among the older population. Patients ≥65 years old had significantly longer length of stay (21 days [1-194] v 14 days [1-183]) and suffered higher 30-day mortality rates (4.6% [0-12] v 0.97% [0-4]). CONCLUSION: Orthopaedic spinal trauma in older people is associated with a significantly higher mortality rate as well as a longer duration of hospitalization. Even though severity of injury is similar for both young and old patients, the mechanism of injury for the older population is of typically much lower energy compared to the high energy trauma affecting younger patients.

Timing of surgical fixation in traumatic spinal fractures: A systematic review.

BACKGROUND: The optimal timing of fracture fixation following spinal injury is controversial. Many spinal fractures occur as part of polytrauma requiring a complex management strategy. Whilst the decision to stabilize unstable spinal column injuries is without debate, the duration between injury and definitive fixation can impact on the incidence of post-operative complications. This study was designed to systemically summarize and compare the complication profile of early vs late stabilization of spinal injuries, in an attempt to unveil an appropriate treatment protocol for traumatic spinal fractures. METHODS: A comprehensive search strategy was performed on the PubMed, Cochrane, and Google Scholar databases using key words. The search strategy provided 1120 results. Forty-six articles were reviewed for full-text. Reference lists were analysed for potential additional texts. RESULTS: Sixteen articles met the inclusion criteria and were included for systematic review. Studies were controversial and the overall result was inconclusive. Several studies favour early stabilisation to reduce post-surgical complication rates, especially in cases of patients with high Injury Severity Scale (ISS) scores. However, this is challenged by a small number of studies reporting a higher mortality rate in the early-stabilisation cohort. CONCLUSION: Due to limited studies and a small overall cohort, the authors would cautiously recommend the early surgical fixation of unstable spine fractures in the stable trauma patient. For severely injured patients, the discordance among literature warrants the need for further investigation.

A systematic review of the presentation of scan-negative suspected cauda equina syndrome.

BACKGROUND: A significant proportion of patients presenting with suspected cauda equina syndrome (CES) do not have associated radiological evidence to support the diagnosis, often termed 'scan-negative'. Due to the limited number of studies regarding the matter, there is no clear understanding for this presentation. As a result, no treatment protocol exists for the scan-negative group. The purpose of this review is to assess the potential contributing factors leading to the presentation of suspected CES with normal imaging. METHODS: A systematic review was conducted on PubMed and Cochrane databases. Bibliographies of key articles and Google Scholar were searched for additional results. The search strategy provided 204 results. Of those, 8 had no identifiable causation for suspected CES and were included for systematic review. RESULTS: 6 of 8 studies investigated for a difference in clinical presentation between cohorts that may indicate a normal scan. Studies were either inconclusive and contradictory. Two studies suggest a functional somatic disorder as reasoning for negative MRI, with positive provisional findings. CONCLUSION: A psychogenic hypothesis is plausible and warrants further investigation. The need for additional studies is essential to scheming a potential treatment protocol for the scan-negative population, which currently does not exist.

Managing the cervical spine in multiple myeloma patients.

Discuss the relevant literature on surgical and nonsurgical treatments for multiple myeloma (MM) and their complementary effects on overall treatment. Existing surgical algorithms designed for neoplasia of the spine may not suit the management of spinal myeloma. Less than a fifth of metastatic, including myelomatous lesions, occur in the cervical spine but have a poorer prognosis and surgery in this area carries a higher morbidity. With the advances of chemotherapy, early access to radiotherapy, early orthosis management, and high definition imaging, including CT and MRI, surgical indications in MM have changed. Medical decompression (or oncolysis), including in the presence of neurological deficit and orthotic stabilization, are proving viable nonsurgical options to manage MM. A key to decision making is the assessment and monitoring of biomechanical spinal stability as part of a multidisciplinary approach.

Spinal disease in myeloma: cohort analysis at a specialist spinal surgery centre indicates benefit of early surgical augmentation or bracing.

BACKGROUND: Multiple myeloma osteolytic disease affecting the spine results in vertebral compression fractures. These are painful, result in kyphosis, and impact respiratory function and quality of life. We explore the impact of time to presentation on the efficacy of spinal treatment modalities. METHODS: We retrospectively reviewed 183 patients with spinal myeloma presenting to our service over a 2 year period. RESULTS: Median time from multiple myeloma diagnosis to presentation at our centre was 195 days. Eighty-four patients (45.9 %) were treated with balloon kyphoplasty and the remainder with a thoracolumbar-sacral orthosis as per our published protocol. Patients presenting earlier than 195 days from diagnosis had significant improvements in patient reported outcome measures: EuroQol 5-Dimensions (p < 0.001), Oswestry Disability Index (p < 0.001), and Visual Analogue Pain Score (p < 0.001) at follow-up, regardless of treatment. Patients presenting after 195 days, however, only experienced benefit following balloon kyphoplasty, with no significant benefit from non-operative management. CONCLUSION: Vertebral augmentation and thoracolumbar bracing improve patient reported outcome scores in patients with spinal myeloma. However, delay in treatment negatively impacts clinical outcome, particularly if managed non-operatively. It is important to screen and treat patients with MM and back pain early to prevent deformity and improve quality of life.

Presentation and outcome of patients treated non-operatively or operatively for Copenhagen Disease: a 30-year experience.

PURPOSE: Our purpose was to analyse the presentation, management and clinical outcome of patients treated operatively and non-operatively for Copenhagen Disease (CD). METHODS: We performed a retrospective analysis of 10 patients (n = 10) with CD, with a mean follow-up time of 14.7 years. Seven patients underwent non-operative treatment and three patients were treated operatively. Clinical presentation and radiological findings were analysed. Health-related quality of life (HRQOL) outcome measures utilized included Oswestry Disability Index (ODI), Short Form 12 Health Survey (SF-12) and visual analogue scale (VAS). RESULTS: Patients tended to present with back pain. No significant difference was detected in functional scores at time of diagnosis and when compared to last follow-up. ODI improved from 20.0 to 18.4 (p = 0.839), PCS component of SF-12 from 44.5 to 45.9 (p = 0.719), MCS component of SF-12 from 45.7 to 46.9 (p = 0.840) and VAS score remained at 2.8 (p = 1.000). There was no significant difference in functional scores when comparing operative and non-operative treatment groups. CONCLUSION: CD is likely to remain stable with time or slightly improve after treatment according to functional outcomes tests. Progression of the kyphosis can be halted at different degrees with operative and non-operative treatments although it does not correlate with changes in symptomatology.

Learning curve analyses in spine surgery: a systematic simulation-based critique of methodologies.

BACKGROUND CONTEXT: Various statistical approaches exist to delineate learning curves in spine surgery. Techniques range from dividing cases into intervals for metric comparison, to employing regression and cumulative summation (CUSUM) analyses. However, their inherent inconsistencies and methodological flaws limit their comparability and reliability. PURPOSE: To critically evaluate the methodologies used in existing literature for studying learning curves in spine surgery and to provide recommendations for future research. STUDY DESIGN: Systematic literature review. METHODS: A comprehensive literature search was conducted using PubMed, Embase, and Scopus databases, covering articles from January 2010 to September 2023. For inclusion, articles had to evaluate the change in a metric of performance during human spine surgery across time/a case series. Results had to be reported in sufficient detail to allow for evaluation of individual performance rather than group/institutional performance. Articles were excluded if they included cadaveric/nonhuman subjects, aggregated performance data or no way to infer change across a number of cases. Risk of bias was assessed using the Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tool. Surgical data were simulated using Python 3 and then examined via multiple commonly used analytic approaches including division into consecutive intervals, regression and CUSUM techniques. Results were qualitatively assessed to determine the effectiveness and limitations of each approach in depicting a learning curve. RESULTS: About 113 studies met inclusion criteria. The majority of the studies were retrospective and evaluated a single-surgeon's experience. Methods varied considerably, with 66 studies using a single proficiency metric and 47 using more than 1. Operating time was the most commonly used metric. Interval division was the simplest and most commonly used method yet inherent limitations prevent collective synthesis. Regression may accurately describe the learning curve but in practice is hampered by sample size and model choice. CUSUM analyses are of widely varying quality with some being fundamentally flawed and widely misinterpreted however, others provide a reliable view of the learning process. CONCLUSION: There is considerable variation in the quality of existing studies on learning curves in spine surgery. CUSUM analyses, when correctly applied, offer the most reliable estimates. To improve the validity and comparability of future studies, adherence to methodological guidelines is crucial. Multiple or composite performance metrics are necessary for a holistic understanding of the learning process.

An Assessment of the World's Contribution to Spine Trauma Care: A Bibliometric Analysis of Classifications and Surgical Management; An AO Spine Knowledge Forum Trauma Initiative.

STUDY DESIGN: Bibliometric analysis. OBJECTIVES: An analysis of the literature related to the assessment and management of spinal trauma was undertaken to allow the identification of top contributors, collaborations and research trends. METHODS: A search to identify original articles published in English between 2011 and 2020 was done using specific keywords in the Web of Science database. After screening, the top 300 most cited articles were analyzed using Biblioshiny R software. RESULTS: The highest number of contributions were from the Thomas Jefferson University, USA, University of Toronto and University of British Columbia, Canada. The top 3 most prolific authors were Vaccaro AR, Arabi B, and Oner FC. The USA and Canada were among the top contributing countries; Switzerland and Brazil had most multiple country co-authored articles. The most relevant journals were the European Spine Journal, Spine and Spine Journal. Three of the 5 most cited articles were about classification systems of fractures. The keyword analysis included clusters for different spinal regions, spinal cord injury, classification agreement and reliability studies, imaging related studies, surgical techniques and outcomes. CONCLUSIONS: The study identified the most impactful authors and affiliations, and determined the journals where most impactful research is published in the field. Study also compared the productivity and collaborations across countries. The study highlighted the impact of development of new classification systems, and identified research trends including instrumentation, fixation and decompression techniques, epidemiology and recovery after spinal trauma.

Mechanical Vertebral Body Augmentation Versus Conventional Balloon Kyphoplasty for Osteoporotic Thoracolumbar Compression Fractures: A Systematic Review and Meta-Analysis of Outcomes.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: Surgical management of osteoporotic vertebral compression fractures (OVCFs) has traditionally consisted of vertebroplasty or kyphoplasty procedures. Mechanical percutaneous vertebral body augmentation (MPVA) systems have recently been introduced as alternatives to traditional methods. However, the effectiveness of MPVA systems vs conventional augmentation techniques for OVCFs remains unclear. This serves as the premise for this study. METHODS: A systematic review and meta-analysis was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies of interest included randomized controlled trials (RCTs) which directly compared patient outcomes following kyphoplasty to patients treated with MPVA systems. Clinical and radiological findings were collated and compared for significance between cohorts. RESULTS: 6 RCTs were identified with 1024 patients total. The mean age of all patients was 73.5 years. 17% of the cohort were male, 83% were female. 515 patients underwent kyphoplasty and 509 underwent mechanical vertebral body augmentation using MPVA systems. MPVAs showed similar efficacy for restoration of vertebral body height (P = .18), total complications (P = .36), cement extravasation (P = .58) and device-related complications (P = .06). MPVAs also showed reduced rates of all new fractures (16.4% vs 22.2%; P = .17) and adjacent fractures (14.7% vs 18.9%; P = .23), with improved visual analogue scale (VAS) scores at 6-month (P = .13). CONCLUSION: The results of this meta-analysis highlight no significant improvement in clinical or radiological outcomes for MPVA systems when compared to balloon kyphoplasty for vertebral body augmentation. Further research is needed to establish a true benefit over traditional operative methods.

The efficacy of anchored stand-alone spacers in comparison to conventional cage and plate in anterior cervical discectomy and fusion surgery: A meta-analysis of randomised controlled trials for clinical and radiological outcomes.

Introduction: Anterior cervical discectomy and fusion (ACDF) is commonly performed with cage and plate constructs to stabilise diseased or injured cervical segments. Despite it being a commonly performed procedure, there are notable rates of associated morbidity reported in the literature. Stand-alone spacers represent a novel form of instrumentation to conventional cage and plate constructs. Research question: Do stand-alone spacers have improved operative characteristics and postoperative outcomes in ACDF cohorts when compared to cage and plate constructs? Methods: A systematic review and meta-analysis was conducted of PubMed/Medline, Embase and Google Scholar databases per the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes guidelines. Studies of interest included cage and plate instrumentation versus anchored stand-alone spacers for patients undergoing ACDF. Pre- and post-operative clinical and radiological outcomes were collated and compared for significance between cohorts. Results: 10 RCTs were identified and included with 779 patients total. Mean age of the entire cohort was 50.1 years. 62% (483/779) of the cohort were male. 384 patients underwent ACDF with stand-alone cage, while 395 had ACDF with conventional cage and plate. Stand-alone spacers significantly outperformed conventional instrumentation in terms of estimated blood loss (p < 0.01), total postoperative complications (p < 0.01), dysphagia rates (p = 0.04) and adjacent segment disease (p = 0.04). Non-inferiority was evident in both patient reported outcome measures and radiological outcomes. Conclusion: This meta-analysis highlights the efficacy of stand-alone spacers for the management of primarily cervical spondylitic disease for both single-level and multi-level pathology, and thus presents an attractive alternative to conventional instrumentation for patients undergoing ACDF surgery.

Comparison of serum Dkk1 (Dickkopf-1) and bone mineral density in patients on bisphosphonate treatment vs no treatment.

Complex pathways affect bone metabolism at the cellular level, and a balance between osteoblast and osteoclast activity is critical to bone remodeling. One of the major pathways affecting bone metabolism is Wnt/ß-catenin signaling, and its disturbances lead to a wide range of bone abnormalities. An important antagonist of this pathway is Dickkopf-1 (Dkk1). Higher Dkk1 levels have been associated with increased bone loss due to inhibition of Wnt pathway. Currently, bisphosphonates are the most commonly used agents to treat primary osteoporotic patients. This study demonstrates the effect of bisphosphonates on Dkk1 levels and its correlation with bone mineral density (BMD). Eighty patients with low BMD were recruited and divided into 2 groups of 40 each (bisphosphonate treatment group and control group). The mean Dkk1 level in the treatment group was significantly reduced to 2358.18 vs 3749.80 pg/mL in the control group (p<0.001). Pearson correlation coefficient showed negative correlation between Dkk1 and BMD at lumbar spine (r=-0.55) and femoral neck in the control group; however, no such correlation was found in the treatment group (r=-0.05). Hence, bisphosphonate therapy leads to reduction in Dkk1 levels, but it does not correlate with BMD in such patients.

Pharmacogenetic profiling and individualised therapy in the treatment of degenerative spinal conditions.

Patients presenting with degenerative spinal changes are often poor surgical candidates due to associated co-morbidities, frailty, or sarcopenia. Additionally, surgeries of a degenerative spine can prove difficult due to the distortion of normal surgical anatomy. Therefore, many patients are managed conservatively with a variety of modalities, including over-the-counter and prescription medications. Nevertheless, several patients do not experience adequate relief from pain with analgesic medications, precipitating multiple hospital visits, and usage of resources. As a result, back pain is regarded as a major economic burden, with total costs of associated treatment exceeding $100 billion annually. Pharmacogenetics is a relatively novel method of evaluating an individual's response to analgesic medications, through analysis of germline polymorphisms. It entails obtaining a genetic sample, often via buccal swab or peripheral blood sample, and genetic analysis achieved through either polymerase chain reaction +/- Sanger sequencing, microassays, restriction length fragment polymorphism analysis, or genetic library preparation and next generation sequencing. The potential efficacy of pharmacogenetic analysis has been highlighted across several specialities to date. However, a paucity of evidence exists regarding spine surgery populations. Nevertheless, regular prospective pharmacogenetic analysis may ultimately prove beneficial when concerning degenerative spinal cohorts due to aforementioned surgical and economic considerations. The purpose of this narrative review is to outline how metaboliser profile variants affect the pharmacokinetics of specific analgesia used to treat back pain, and to discuss the current potential and limitations of employing regular pharmacogenetic analysis for spine surgery populations with degenerative conditions.