Trends in spinal cancers: Primary & metastatic. An Irish epidemiological perspective

Background

The incidence and histological type of spinal cancer is diverse. It is our role as physicians to explore the epidemiology of spinal cancers so that several projections can be made. Resource allocation, cost analyses, and the requirement of rehabilitation facilities all need to be considered.The objective of this paper is to provide an account of the acute spinal oncological admissions to the National Spinal Injuries Unit (NSIU) in both 2010 and 2020 with the hypothesis that upward trends will be noted. Only by exemplifying this trend, will it highlight the need to give spinal cancer the attention it deserves in the Republic of Ireland.

Methods

All patients who were to undergo spinal surgery for primary or metastatic spinal cancer in the Mater Misericordiae University Hospital (MMUH) in 2010 and 2020 were included in this retrospective cohort study. A list of medical record numbers (MRNs) for all patients who underwent spinal surgery in the MMUH were included. Data pertaining to patient demographics were noted.

Results

90 patients were included in this retrospective cohort study. 37 patients in 2010, had increased to 53 by 2020. Metastatic disease to the spine was still the most prominent reason for referral. The most common spinal region affected was the thoracic spine. Breast cancer was the most prevalent metastatic cancer to the spine in 2010. Lung cancer became the most prevalent by 2020. Posterior spinal fusion was the most frequent surgical procedure performed. The length of stay in higher care facilities decreased from 5.4 days in 2010, to 4 days in 2020. Decreased were also seen in the mean length of hospital stay, plummeting from 23.6 days in 2010, to 7.6 days in 2020. The same could not be said for the 30-day mortality rate, increasing from 5.4% in 2010, to 9.4% in 2020.

Conclusion

The results of this study show a substantial rise in the incidence and prevalence of both primary and metastatic spinal disease here in Ireland. One can see clear improvements in operative technique, with less patients proceeding to higher levels of post-operative care, and earlier discharge times. This data can be used for future planning. The paper highlights the economic cost of spinal oncological care, but it also identifies key areas where preventative campaigns can be targeted.

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 ​= ​0.31), length of operation (217.9mins vs 175.3mins; p ​= ​0.07), overall length-of-stay (12 days vs 21.9 days; p ​= ​0.16), patients requiring HDU (3/14 vs 5/15; p ​= ​0.09) or ICU (5/14 vs 9/15; p ​= ​0.10), postoperative neurological improvement (1/14 vs 1/15; p ​= ​0.48) or deterioration (1/14 vs 0/15; p ​= ​0.15), intraoperative complications (2/14 vs 3/15; p ​= ​0.34), postoperative complications 4/14 vs 4/15; p ​= ​0.46), revision surgeries (3/14 vs 1/15; p ​= ​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.

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 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.

An evaluation of the effectiveness of an advanced practice physiotherapist in the emergency department setting in Ireland

BACKGROUND

One of the means of easing increased pressure on emergency care worldwide has been the development of advanced musculoskeletal physiotherapy practice in the emergency department setting. This model of care is in its infancy in Ireland.

AIMS

To evaluate the effectiveness of an advanced practice physiotherapist working as a primary contact clinician in the emergency department at St. James's Hospital, Dublin.

METHODS

A three-month retrospective chart review was undertaken for patients assigned the advanced practice physiotherapist as their primary clinician during their emergency department attendance. Three widely accepted measures of quality in emergency medicine were used to evaluate effectiveness, namely, time from attendance to discharge, time from triage to assessment, and unplanned reattendance within seven days.

RESULTS

A total of 129 patients were included in this study. Time from attendance to discharge was significantly less in the APP group (mean 208.5 min, standard deviation 122.4 min) than in the ED group (mean 377.1 min, standard deviation 314.7 min) (mean difference - 168.61 (95% C.I - 191.24- - 145.98)) (p < 0.001). Time from triage to assessment was significantly less in the APP group (mean 72.1 min, standard deviation 51.9 min) than in the ED group (mean 94.1 min, standard deviation 96.5 min) (mean difference - 22.08 (95% C.I - 31.28- - 12.89)) (p < 0.001). The unplanned reattendance rate was 3.9%. No adverse events were identified.

CONCLUSIONS

The findings of this study indicate that an advanced practice physiotherapist can provide a timely, effective, and safe service for patients attending the emergency department with musculoskeletal complaints in Ireland.

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.

The Incidence, Characteristics and Outcomes of Vertebral Artery Injury Associated with Cervical Spine Trauma: A Systematic Review

STUDY DESIGN

Systematic Review.

OBJECTIVES

Vertebral Artery Injury (VAI) is a potentially serious complication of cervical spine fractures. As many patients can be asymptomatic at the time of injury, the identification and diagnosis of VAI can often prove difficult. Due to the high rates of morbidity and mortality associated with VAI, high clinical suspicion is paramount. The purpose of this review is to elucidate incidence, diagnosis, treatment and outcomes of VAI associated with cervical spine injuries.

METHODS

A systematic search of electronic databases was performed using 'PUBMED', 'EMBASE','Medline (OVID)', and 'Web of Science, for articles pertaining to traumatic cervical fractures with associated VAI.

RESULTS

24 studies were included in this systematic review. Data was included from 48 744 patients. In regards to the demographics of the focus groups that highlighted information on VAI, the mean average age was 46.6 (32.1-62.6). 75.1% (169/225) were male and 24.9% (56/225) were female. Overall incidence of VAI was 596/11 479 (5.19%). 190/420 (45.2%) of patients with VAI had fractures involving the transverse foramina. The right vertebral artery was the most commonly injured 114/234 (48.7%). V3 was the most common section injured (16/36 (44.4%)). Grade I was the most common (103/218 (47.2%)) injury noted. Collective acute hospital mortality rate was 32/226 (14.2%), ranging from 0-26.2% across studies.

CONCLUSION

VAI secondary to cervical spine trauma has a notable incidence and high associated mortality rates. The current available literature is limited by a low quality of evidence. In order to optimise diagnostic protocols and treatment strategies, in addition to reducing mortality rates associated with VAI, robust quantitative and qualitative studies are needed.

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.

The relationship between radiological paraspinal lumbar measures and clinical measures of sarcopenia in older patients with chronic lower back pain

Objectives

Sarcopenia is postulated to be an influential factor in chronic low back pain. The aim of this study is to evaluate the relationship between traditional clinical measures of sarcopenia and novel radiographic methods which evaluate overall muscle status, such as adjusted psoas cross-sectional area (APCSA) and degree of fat infiltration (%FI) in paraspinal muscles, in patients with chronic low back pain.

Methods

Prospective study performed at our institution from 01/01/19-01/04/19. Inclusion criteria were patients ≥65 years old not requiring surgical intervention presenting to a low back pain assessment clinic.

Results

25 patients were identified (mean age: 73 years, 62% male). On spearman's analyses, %FI shared a significant relationship with hand grip strength (r = -0.37; p=0.03), chair rise (r=0.38; p=0.03), SC (r=0.64; p<0.01), and visual analogue scale scores (r=-0.14; p=0.02). Comparably, a statistically significant correlation was evident between APCSA and %FI (r=-0.40; p=0.02) on analysis.

Conclusion

The results of our study demonstrate a statistically significant relationship between APCSA and %FI in the multifidus and erector spinae muscles. Further significant associations of relatability were depicted with traditional clinical measures of sarcopenia. Thus, %FI may be a supplemental indicator of the sarcopenic status of patients presenting with chronic low back pain.

The diagnostic and prognostic value of artificial intelligence and artificial neural networks in spinal surgery : a narrative review

In recent years, machine learning (ML) and artificial neural networks (ANNs), a particular subset of ML, have been adopted by various areas of healthcare. A number of diagnostic and prognostic algorithms have been designed and implemented across a range of orthopaedic sub-specialties to date, with many positive results. However, the methodology of many of these studies is flawed, and few compare the use of ML with the current approach in clinical practice. Spinal surgery has advanced rapidly over the past three decades, particularly in the areas of implant technology, advanced surgical techniques, biologics, and enhanced recovery protocols. It is therefore regarded an innovative field. Inevitably, spinal surgeons will wish to incorporate ML into their practice should models prove effective in diagnostic or prognostic terms. The purpose of this article is to review published studies that describe the application of neural networks to spinal surgery and which actively compare ANN models to contemporary clinical standards allowing evaluation of their efficacy, accuracy, and relatability. It also explores some of the limitations of the technology, which act to constrain the widespread adoption of neural networks for diagnostic and prognostic use in spinal care. Finally, it describes the necessary considerations should institutions wish to incorporate ANNs into their practices. In doing so, the aim of this review is to provide a practical approach for spinal surgeons to understand the relevant aspects of neural networks. Cite this article: Bone Joint J 2021;103-B(9):1442-1448.

3D printing of fibre-reinforced cartilaginous templates for the regeneration of osteochondral defects

Successful osteochondral defect repair requires regenerating the subchondral bone whilst simultaneously promoting the development of an overlying layer of articular cartilage that is resistant to vascularization and endochondral ossification. During skeletal development articular cartilage also functions as a surface growth plate, which postnatally is replaced by a more spatially complex bone-cartilage interface. Motivated by this developmental process, the hypothesis of this study is that bi-phasic, fibre-reinforced cartilaginous templates can regenerate both the articular cartilage and subchondral bone within osteochondral defects created in caprine joints. To engineer mechanically competent implants, we first compared a range of 3D printed fibre networks (PCL, PLA and PLGA) for their capacity to mechanically reinforce alginate hydrogels whilst simultaneously supporting mesenchymal stem cell (MSC) chondrogenesis in vitro. These mechanically reinforced, MSC-laden alginate hydrogels were then used to engineer the endochondral bone forming phase of bi-phasic osteochondral constructs, with the overlying chondral phase consisting of cartilage tissue engineered using a co-culture of infrapatellar fat pad derived stem/stromal cells (FPSCs) and chondrocytes. Following chondrogenic priming and subcutaneous implantation in nude mice, these bi-phasic cartilaginous constructs were found to support the development of vascularised endochondral bone overlaid by phenotypically stable cartilage. These fibre-reinforced, bi-phasic cartilaginous templates were then evaluated in clinically relevant, large animal (caprine) model of osteochondral defect repair. Although the quality of repair was variable from animal-to-animal, in general more hyaline-like cartilage repair was observed after 6 months in animals treated with bi-phasic constructs compared to animals treated with commercial control scaffolds. This variability in the quality of repair points to the need for further improvements in the design of 3D bioprinted implants for joint regeneration. STATEMENT OF SIGNIFICANCE: Successful osteochondral defect repair requires regenerating the subchondral bone whilst simultaneously promoting the development of an overlying layer of articular cartilage. In this study, we hypothesised that bi-phasic, fibre-reinforced cartilaginous templates could be leveraged to regenerate both the articular cartilage and subchondral bone within osteochondral defects. To this end we used 3D printed fibre networks to mechanically reinforce engineered transient cartilage, which also contained an overlying layer of phenotypically stable cartilage engineered using a co-culture of chondrocytes and stem cells. When chondrogenically primed and implanted into caprine osteochondral defects, these fibre-reinforced bi-phasic cartilaginous grafts were shown to spatially direct tissue development during joint repair. Such developmentally inspired tissue engineering strategies, enabled by advances in biofabrication and 3D printing, could form the basis of new classes of regenerative implants in orthopaedic medicine.

Regeneration of Osteochondral Defects Using Developmentally Inspired Cartilaginous Templates

IMPACT STATEMENT

Successfully treating osteochondral defects involves regenerating both the damaged articular cartilage and the underlying subchondral bone, in addition to the complex interface that separates these tissues. In this study, we demonstrate that a cartilage template, engineered using bone marrow-derived mesenchymal stem cells, can enhance the regeneration of such defects and promote the development of a more mechanically functional repair tissue. We also use a computational mechanobiological model to understand how joint-specific environmental factors, specifically oxygen levels and tissue strains, regulate the conversion of the engineered template into cartilage and bone in vivo.

Optic neuritis secondary to antiandrogen therapy

BACKGROUND

Optic neuropathy is a disorder characterised by dysfunction or destruction of the optic nerve tissues. Acquired causes include interruption in the blood supply, nutritional deficiency, compression by a tumour or aneurysm, trauma, and toxic types (Ambizas and Patel In US Pharm 36(4):HS2-HS6, 1). Drug-induced optic neuropathy is of the toxic type and can be defined as a clinical syndrome characterised by papillomacular bundle damage, central, or cecocentral scotoma, and reduced colour vision (Ambizas and Patel In US Pharm 36(4):HS2-HS6, 2011; Sharma and Sharma In Indian J Ophthalmol 59(2):137-141, 2).

AIM

To report a case unilateral optic neuritis, secondary to the use of the antiandrogen, cyproterone acetate.

CASE REPORT

A 21-year-old female presented with a 4-day history of right brow pain exacerbated by eye movement, and blurring of the right temporal field of vision. She had been taking desogestrel 75 mg and cyproterone acetate 50 mg for the previous 2 months for hormone imbalance. Unaided right visual acuity measured 6/9 and unaided left visual acuity measured 6/6 on Snellen chart. Right red desaturation was present. Goldmann perimetry showed a right enlarged blind spot with predominantly temporal visual field loss. Visually evoked potential (VEP) testing of the right eye showed slightly increased latency, but normal amplitude. Three weeks after discontinuation of the antiandrogen therapy, her symptoms resolved. Repeat Goldmann visual fields showed expansion.

CONCLUSION

Known side-effects of cyproterone acetate include retinal vascular disorder and retinal vein thrombosis, but an association with optic neuritis had not been described to date. There was a temporal relationship between cessation of the medication and improvement in visual symptoms. This implies that discontinuation of the offending drug constitutes the basis of treatment in drug-induced optic neuropathy.