Derek T Cawley

• MMedSc MCh FRCS Orth
• Consultant at Mater Private Hospital

Objective Intra-Discal Vacuum phenomenon (IDVP) is associated with advanced disc degeneration, representing persistent intra-segmental movement. Our objective is to further characterise IDVP patterns from both MRI and CT thus informing on an otherwise poorly understood phenomenon. Methods An observational analysis was performed, including an over-...

Cement discoplasty (CD) was initially described in 2015. This novel treatment involves injecting polymethylmethacrylate (PMMA) into the degenerate disc cavity. This is particularly applicable to elderly patients with disc degeneration and collapse, where restoration of disc height improves lordosis and sagittal balance, treating symptoms of degener...

Study Design Systematic literature review and meta-analysis. Objectives Predicting patient risk of intraoperative neuromonitoring (IONM) alerts preoperatively can aid patient counselling and surgical planning. Sielatycki et al established an axial-MRI-based spinal cord classification system to predict risk of IONM alerts in scoliosis correction su...

Purpose Intra-Discal Vacuum phenomenon (IDVP) is well-recognised, yet poorly visualised and poorly understood radiological finding in disc degeneration, particularly with regard to its role in spinal alignment. CT analysis of the lumbar spine in an aging population aims to identify patterns associated with IDVP including lumbopelvic morphology and...

Study Design Observational serial CT analysis of the lumbar spine in a normal-aging population. Objective Assess the natural history of IntraDiscal Vacuum Phenomenon and its role in disc degeneration. Summary of Background Data: The natural history of disc degeneration is well described but our understanding of the end stage of pathogenesis remain...

Intra-Discal Vacuum Phenomenon (IDVP) represents an intradiscal nitrogen gas accumulation where a cavity opens in a supine position, lowering intra-discal pressure and generating a bubble. IDVP has been observed in up to 20% of elderly patients and reported in almost 50% of chronic LBP patients. With a highly accurate detection on CT, its significa...

Purpose: Coronal balance is a major factor impacting the surgical outcomes in adult spinal deformity (ASD). The Obeid coronal malalignment (O-CM) classification has been proposed to improve the coronal alignment in ASD surgery. Aim of this study was to investigate whether a postoperative CM < 20 mm and adherence to the O-CM classification could im...

OBJECTIVE The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5-10 years, 10-20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery). M...

Study Design. Global cross-sectional survey. Objective. To determine the classification accuracy, interob-server reliability, and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on an international group of AO Spine members. Summary of Background Data. Previous upper cervical spine injury classificati...

Intoduction: Mechanical complications from spinal fusion including implant loosening or junctional failure result in poor outcomes, particularly in osteoporotic patients. While the use of percutaneous vertebral augmentation with polymethylmethacrylate (PMMA) has been studied for augmentation of junctional levels to offset against kyphosis and fail...

Highlights •Key anterior approaches differences in LSTV include vascular (aortic bifurcation/iliocaval confluence), muscular (psoas) and osseus anatomy (inter-crestal tangent/pubic symphysis), when compared to non-LSTV. •There are increased surgical deviations but not significantly greater complications for anterior approaches in LSTV. •Vascular aw...

Purpose To validate the AO Spine Subaxial Injury Classification System with participants of various experience levels, subspecialties, and geographic regions. Methods A live webinar was organized in 2020 for validation of the AO Spine Subaxial Injury Classification System. The validation consisted of 41 unique subaxial cervical spine injuries with...

Study design: Narrative literature review. Objective: The aim of this study was to review published literature discussing sustainable healthcare and identify aspects that pertain to spine surgery. Summary of background data: In recent years research has investigated the contribution of surgical specialties to climate change. To our knowledge n...

Background The objective of this study was to determine the effect of obesity on the functional outcomes and complication rates of patients with adult spinal deformity (ASD) undergoing multi-level thoracolumbar fusion. Methods An age and sex matched comparison of functional outcomes [Numeric Rating Scale (NRS) back and leg scores, Core Outcome Mea...

Study Design Global Survey Objective To determine the accuracy, interobserver reliability, and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeons’ AO Spine region of practice (Africa, Asia, Central/South America, Europe, Middle East, and North America). Methods A total of 275 AO Spine membe...

OBJECTIVE The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5–10 years, 10–20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and “other” surgery). M...

Purpose To compare the radiological outcomes and complications of adult spinal deformity patients who underwent a pedicle subtraction osteotomy (PSO) below L2 but categorized according to their construct where either a domino connector was applied for osteotomy correction or not. Methods Retrospective review of a prospective, multicenter adult spi...

Purpose To determine if responses given to each question of the Scoliosis Research Society-22 (SRS22), Oswestry disability index (ODI) and Short Form-36 (SF-36) questionnaires are influenced by the radiological parameters. Methods Patients enrolled in a multi-centre prospectively collected adult spinal deformity database who had complete SRS22, OD...

Objective: To evaluate Obeid-coronal malalignment (O-CM) modifiers according to age, sagittal alignment, and patient-reported outcome measures (PROMs), in the mobile spine. Methods: Retrospective review of a prospective multicenter adult spinal deformity (ASD) database with 1,243 (402 nonoperative, 841 operative) patients with no prior fusion su...

Purpose Objectives in scoliosis corrective surgery include restoration of normal sagittal and coronal parameters to achieve patient satisfaction. HRQLs improvements remain limited after corrective surgery. The aim of this study was to evaluate the HRQL subclass variability specific to the sagittal and coronal correction in adult scoliosis surgery....

PurposeA normal sagittal vertical axis (SVA) after spinal deformity correction can yield mechanical complications of up to 30%. Post-operative compensatory pelvic orientation can produce a normal SVA. We assess relative pelvic version (RPV), an individualised measure, for persistent post-operative compensatory measures.Methods Adult spinal deformit...

Purpose: To evaluate the pain and functional effect of the COVID-19 pandemic on patients with ASD reflected by their response to SRS-22, ODI, and SF-36 questionnaires. Methods: Patients who had stable pain and functional outcome scores over the preceding 2 years were enrolled in a local prospectively collected adult spinal deformity (ASD) databa...

PurposeThe management of cervical facet dislocation injuries remains controversial. The main purpose of this investigation was to identify whether a surgeon’s geographic location or years in practice influences their preferred management of traumatic cervical facet dislocation injuries.MethodsA survey was sent to 272 AO Spine members across all geo...

Study design: Global cross-sectional survey. Objective: To validate the AO Spine Subaxial Cervical Spine Injury Classification by examining the perceived injury severity by surgeon across AO geographical regions and practice experience. Summary of background data: Previous subaxial cervical spine injury classifications have been limited by sub...

Study Design Global cross-sectional survey. Objective To develop an injury score for the AO Spine Subaxial Cervical Spine Injury Classification System. Methods Respondents numerically graded each variable within the classification system for severity. Based on the results, and with input from the AO Spine Trauma Knowledge Forum, the Subaxial Cerv...

PurposeCoronal malalignment (CM) causes pain, impairment of function and cosmetic problems for adult spinal deformity (ASD) patients in addition to sagittal malalignment. Certain types of CM are at risk of insufficient re-alignment after correction. However, CM has received minimal attention in the literature compared to sagittal malalignment. The...

Purpose The management of cervical facet dislocation injuries remains controversial. The main purpose of this investigation was to identify whether a surgeon's geographic location or years in practice influences their preferred management of traumatic cervical facet dislocation injuries. Methods A survey was sent to 272 AO Spine members across all...

Background transarticular screw (TAS) fixation without a supplementary posterior construct, even in rheumatoid arthritis (RA) patients, provides sufficient stability with acceptable clinical results. Here, we present our experience with 15 RA patients who underwent atlantoaxial (AA) TAS fixation without utilizing a supplementary posterior fusion....

With the identification of literature shortfalls on the techniques employed in intraoperative navigated (ION) spinal surgery, we outline a number of measures which have been synthesised into a coherent operative technique. These include positioning, dissection, management of the reference frame, the grip, the angle of attack, the drill, the templat...

Study design: Multicenter, retrospective study. Objective: The aim of this study was to examine the performance and concurrent validity of the adult spinal deformity surgical decision-making (ASD-SDM) score compared to decision-making factors in the ASD population. Summary of background data: The ASD-SDM score, which has been recently proposed...

Purpose We aimed to develop and internally validate a scoring system, the adult spinal deformity surgical decision-making (ASD-SDM) score, to guide the decision-making process for ASD patients aged above 40 years. Methods A multicentre prospective ASD database was retrospectively reviewed. The scoring system was developed using data from a derivat...

Purpose To assess pain, health-related quality of life (HRQOL) scores and sagittal parameters of adult spinal deformity (ASD)-operated patients in the context of their analgesic consumption especially opioids (narcotics) over the first year postoperative period. Methods In total, 372 patients from a multicenter database were stratified into 3 grou...

The reserve of hip extension can be defined as the amplitude of maximum extension of the coxo-femoral articulation relative to the vertical neutral position.

This richly illustrated and comprehensive book covers a broad range of normal and pathologic conditions of the vertebral column, from its embryology to its development, its pathology, its dynamism and its degeneration. The dynamic anatomy of the living subject is viewed using the latest technologies, opening new perspectives to elucidate the pathol...

Aims: Intraoperative 3D navigation (ION) allows high accuracy to be achieved in spinal surgery, but poor workflow has prevented its widespread uptake. The technical demands on ION when used in patients with adolescent idiopathic scoliosis (AIS) are higher than for other more established indications. Lean principles have been applied to industry an...

This chapter describes details of the craniovertebral junction that pertain to alignment of the spine. Foremost in our understanding is the discovery of how and why Hominidae came to this evolutionary point. The relationship of the craniovertebral junction to the subaxial spine is dynamic and displays a “fine tuning” contribution to sagittal balanc...

Background: Both adult spinal deformity (ASD) and obesity are growing concerns internationally. This study therefore aims to determine the effect of increasing body mass index (BMI) on the pain and function of patients with ASD. Methods: A retrospective review of prospectively collected data from a multicentre European database was undertaken. I...

Wound closure after wide, local excision of an appendicular soft‐tissue sarcoma (STS) can be challenging. This study evaluates the value of magnetic resonance imaging (MRI)‐based tumour parameters in planning wound closure. A total of 71 patients with a primary limb‐based STS, excluding vascular or osseous involvement, excluding the shoulder or han...

Background: Mid-term clinical and radiological evaluation of a carbon-fiber cage in multilevel cervical spondylosis (MCS). Anterior cervical corpectomy and fusion (ACCF) using titanium mesh cages (TMC) has shown satisfactory outcomes, but with subsidence of up to 20%. Conventional long-fiber carbon fiber cages have shown a safe profile in discecto...

Purpose We aimed to develop and internally validate a simple scoring system: the adult spinal deformity (ASD) surgical decision-making (ASD-SDM) score, which is specific to the decision-making process for ASD patients aged below 40 years. Methods A multicentre prospective ASD database was retrospectively reviewed. The scoring system was developed...

Purpose: Firstly, to describe two cases of cerebral ischaemia complicating anterior upper thoracic spinal surgery and define the likely cause of this complication. Secondly, to describe preventative measures and the effect these have had in reducing this complication within our institution. Methods: Firstly, a review of two cases of cerebral isc...

Study design: Retrospective, longitudinal observational study. Purpose: To describe the natural history of anterior bone loss (ABL) in cervical disc arthroplasty (CDA) and introduce a classification system for its assessment. Overview of literature: ABL has recently been recognized as a complication of CDA, but its cause and clinical effects r...

Discuss the relevant literature on surgical and non‐surgical 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 s...

Purpose: We aimed to elucidate the factors for the decision-making process in the treatment of adult spinal deformity (ASD), including sagittal parameters, that impact health-related quality of life (HRQOL). Methods: A multicenter prospective ASD database was retrospectively reviewed. The demographic data, HRQOL, and radiographic measures were a...

Background: Pelvic incidence (PI) is an anatomical parameter that is considered invariable in a given individual. Although changes in posture influence the mobile lumbar spine, lumbar lordosis (LL) and the pelvis are typically evaluated only in the standing position. Thus, whether other positions commonly used during daily activities influence the...

Purpose: To understand whether a spondylolisthesis in the sub-axial spine cranial to a cervical disc arthroplasty (CDA) construes a risk of adjacent level disease (ALD). Methods: A retrospective review of 164 patients with a minimum 5-year follow-up of a cervical disc arthroplasty was performed. Multi-level surgeries, including hybrid procedures...

Decompression of lumbar spinal stenosis is the most common spinal surgery in those over 60 years of age. While this procedure has shown immediate and durable benefits, improvements in outcome have not changed significantly. Technical aspects of surgical decompression have evolved significantly. The recently introduced ultrasonic bone cutter allows...

OBJECTIVE The objective of this study was to identify the risk factors of anterior bone loss (ABL) in cervical disc arthroplasty (CDA) and the subsequent effect of this phenomenon. METHODS The authors performed a retrospective radiological review of 185 patients with a minimum 5-year follow-up after CDA (using Bryan, Discocerv, Mobi-C, or Baguera...

Purpose: To assess the efficacy of bisphosphonate therapy in the management of spinal aneurysmal bone cysts (ABCs). Methods: A prospective study of six consecutive patients aged between 7 and 22 years with spinal ABCs treated with pamidronate (1 mg/kg) or zoledronate (4 mg). A visual analogue scale (VAS) for pain and radiological (contrast-enhan...

Purpose: To evaluate the radiographic, functional outcomes, complications and surgical specificities of L5 pedicle subtraction osteotomy for fixed sagittal and coronal malalignment. Methods: A retrospective cohort of consecutive patients with prospectively collected data. Ten patients who underwent PSO at L5 were eligible for a 2-year minimum fo...

Purpose: Pedicle Subtraction Osteotomy (PSO) is an effective surgical technique for the correction of fixed sagittal malalignment of the spine. It is a demanding technique that requires a long learning curve. The aim of this study is to analyze a surgeon's learning curve for lumbar PSO in relation to the preoperative, perioperative, and postoperat...

Study design: Multicenter, prospective study of consecutive adult spinal deformity (ASD) patients. Objective: To evaluate back and leg pain as a combined score in ASD and compare their relative and cumulative correlations with HRQOL and sagittal parameters. Summary of background data: Pain and disability are commonly reported in patients with...

Introduction We report a rare case of cervical spine trauma through a cervical disc replacement and adjacent multilevel disc fusions. Cervical disc replacement (CDR) is a viable option for the surgical treatment of degenerative disc disease however long term follow up data regarding this operative technique is poor specifically relating to traumati...

Unfortunately, two author names were missed out in author group of the original publication.

Background The CTDR is a technique that treats cervical disc degenerative disease. Initial shorter-term studies showed good clinical and radiological results. PurposeTo assess the clinical and radiological results of Bryan cervical disc replacement (Medtronic Sofamor Danek Inc., Memphis, TN) at 15-year follow-up. ResultsThis prospective study inclu...

Background: Identifying the gluteal vessels during a posterior sacrectomy can be challenging. This study defines anatomical landmarks that can be used to approximate the location of the superior and inferior gluteal arteries (SGA and IGA) during a posterior sacrectomy. Methods: Cadaveric dissection of six fresh adult pelvises to determine the lo...

Introduction L’Échelle d’Évaluation Numérique (EEN) lombaire et radiculaire est effectuée en routine clinique. L’évolution des symptômes, notamment après une chirurgie de déformation rachidienne, peut rendre difficile l’interprétation des résultats cliniques et de l’impact réel d’une chirurgie rachidienne. L’objectif de cette étude est d’évaluer l’...

Introduction La prise de morphiniques avant une chirurgie rachidienne augmente le risque de dépendance aux morphiniques en postopératoire. L’évaluation postopératoire de prise d’antalgiques après une chirurgie de déformation rachidienne de l’adulte n’est pas bien évaluée. L’objectif de cette étude est d’évaluer cette prise d’antalgique avant et apr...

Introduction La classification SRS-Schwab est une classification validée mais complexe, offrant 27 catégories pour l’analyse de l’équilibre sagittal. Une simplification de cette classification a été proposée en additionnant le nombre de « + » obtenu après mesure de la version pelvienne (VP), de la SVA et de la soustraction de l’incidence pelvienne...

Introduction Le remplacement total de disque cervical (CTDR) est une technique qui traite les maladies dégénératives du disque cervical. Les premières études à court terme ont montré de bons résultats cliniques et radiologiques. L’objectif était d’évaluer les résultats clinique et radiologique de la prothèse cervicale discale Bryan (Medtronic Sofam...

Introduction L’indication chirurgicale dans les déformations de l’adulte est difficile à poser, car elle concerne une population très hétérogène. L’âge est un paramètre reconnu, mais aucune étude exhaustive incluant l’ensemble des paramètres radioclinique n’est décrite. L’objectif est d’évaluer l’impact des paramètres radio-clinique sur l’indicatio...

Introduction: The incidence of pneumocephalus and pneumorrhachis after spinal surgery is unknown, with a paucity of literature on this complication. Materials and methods: We present the first published case of delayed onset tension pneumocephalus and pneumorrhachis associated with spinal surgery. Results: This complication occurred from a cer...

BACKGROUND: Thoracic hyperkyphosis can display pathological deterioration, resulting in either hyperlordotic cervical compensation or sagittal malalignment. Various techniques have been described to treat fixed malalignment. Pedicle subtraction osteotomy (PSO) is commonly used in the lumbar spine and frequently limited to the distal thoracic spine....

Total hip arthroplasty (THA) is an effective and durable treatment option for hip osteoarthritis (OA). As life expectancy continues to increase, so too will the demand for joint arthroplasty in the 10th decade of life, frequently in cases involving osteoarthritis of both hips. Simultaneous bilateral total hip arthroplasty (SBTHA) is a valuable ther...

The farming and agricultural sector remains one of Ireland’s primary industries. Fatality rates remain higher than the European average. The aim of this study was to analyze the national trend in hospital in-patient admissions for farmyard related fractures and related fatalities in Ireland from 2005 to 2014. Relevant socioeconomic trends were used...

Background: Standard positioning for percutaneous balloon kyphoplasty requires placing a patient prone with supports under the iliac crests and upper thorax. The authors believe that hip hyperextension maximises pelvic anteversion creating anterior longitudinal ligamentotaxis, thus facilitating restoration of vertebral height. Methods: Radiograp...

A 30-year-old man fell from his cabin bed while asleep aboard an overnight bus, suffering a direct impact injury to his coccygeal area. Initial symptoms included perianal and right buttock pain, nausea, and persistent headache, which ceased after 1 week. There was significant bruising cen- trally with a large fluctuant swelling in the right buttock...

Correction of scoliotic deformity in Duchenne's muscular dystrophy (DMD) is performed to maintain adequate seating posture and facilitate comfort. The surgery carries a high morbidity and is not well tolerated as patients develop progressive cardiorespiratory compromise. Early limited instrumentation may provide a solution to optimize patients with...

We present a case of a patient with a bisphosphonate-related atypical femoral fracture. Her surgical management was complicated by obliteration of the medullary canal, which prohibited the passage of an intramedullary nail. The relevant literature is discussed. 2015 BMJ Publishing Group Ltd.

Hip arthroplasty registries, encompassing all-cause end-stage hip degeneration, have shown that slightly more right hip replacements are performed than left. Given that greater than 85% of individuals are right-handed, we sought to investigate the association between side of hand dominance and side of hip osteoarthritis. This Level III observationa...

Background & aim Intraoperative epidural corticosteroids have been used to decrease post-operative pain post-discectomy. The objective of this study is to assess the efficacy of epidural corticosteroids on post-operative pain and length of post-operative hospital stay in patients undergoing unilateral lumbar microdiscectomy. Methods 150 consecutiv...

Assessment of the integrity of the multifidus muscles and corresponding nerve roots, post-open (OSS) versus minimally invasive spinal surgery (MISS) for lumbar spine fractures. We investigated the first six patients undergoing MISS in our institution and age- and sex-matched them with 6 random patients who previously had OSS. All had a similar lumb...

The stress distribution and plastic deformation of peri-prosthetic trabecular bone during press-fit tibial component implantation in total knee arthroplasty is investigated using experimental and finite element techniques. It is revealed that the computed stress distribution, implantation force and plastic deformation in the trabecular bone is high...

The optimum cementing technique for the tibial component in cemented primary total knee replacement (TKR) remains controversial. The technique of cementing, the volume of cement and the penetration are largely dependent on the operator, and hence large variations can occur. Clinical, experimental and computational studies have been performed, with...

Aseptic tibial component loosening remains a major cause of total knee arthroplasty failure. The cementation technique used to achieve fixation may play a major role in loosening. Despite this, the optimum technique remains unanswered. This study aims to investigate stress and strain distributions in the proximal tibia for full cementation and surf...

Study design: Case report.We present the case of a 55-year-old woman with cauda equina syndrome, and hypokalaemic paralysis secondary to thiazide diuretic abuse.