Ashish Diwan

• MBBS MS PhD FRACS FAOrthA
• UNSW Sydney

Medical implants, being biomaterials with increasing global use, continue to attract researchers focused on enhancing clinical performance. In situations requiring bone substitutes, there is a search for advancements in synthetic graft biomaterials, with polymer-based implants being one of the potential materials. Thus, this study aims to develop v...

Aims Previous research on knee kinematics has demonstrated that achieving a tibial joint line angle (TJLA) parallel to the floor in the single-leg stance phase of gait may restore native knee kinematics and optimize compartmental compressive loads in total knee arthroplasty (TKA). However, it is currently unclear which surgical alignment strategy b...

Introduction Low back pain (LBP), a global disability leader, is often linked to intervertebral disc (IVD) degeneration. Traditional diagnostics like T2‐weighted MRI provide qualitative but imprecise evaluations. A novel post‐processing MRI technique, Decay Variance (DeVa), has shown promise in differentiating degenerate from healthy discs in anima...

Study design Scoping Review. Objective Degenerative cervical myelopathy (DCM) is a leading cause of chronic spinal cord dysfunction, with diverse clinical presentations that complicate diagnosis. Therefore, it is important to identify the signs and symptoms of DCM that demonstrate high diagnostic accuracy. This review aims to evaluate the sensitiv...

Study Design Cross-sectional study. Objectives To assess global practices and preferences in the use of osteobiologics for anterior cervical discectomy and fusion (ACDF) and identify factors influencing the choice of specific osteobiologics. Methods An online survey developed by AO Spine was distributed to spine surgeons worldwide. The survey cap...

Introduction Intervertebral disc degeneration (IVD) is a leading cause of low back pain, a prevalent musculoskeletal condition. IVD degeneration is characterized by the degradation of nucleus pulposus (NP), annulus fibrosus (AF), and cartilage endplates (EP). Growth Differentiation Factor 6 (GDF6), part of the bone morphogenetic protein family, has...

Introduction Knowledge translation from research to clinical practice can often be challenging, and practice modification patterns among surgeons may stem from a variety of sources, including personal experience, peer influence, ongoing education, and evolving research findings. Research question This study aimed to investigate the adoption patter...

Background Chronic low back pain (LBP) is a significant global health concern, often linked to vertebral bone marrow lesions (BML), particularly fatty replacement (FR). This study aims to explore the relationship between the gut microbiome, serum metabolome, and FR in chronic LBP patients. Methods Serum metabolomic profiling and gut microbiome ana...

Background Pain of a chronic nature remains the foremost concern in tertiary spine clinics, yet its elusive nature and quantification challenges persist. Despite extensive research and education on low back pain (LBP), the realm of diagnostic practices lacks a unified approach. Clinically, LBP exhibits a multifaceted character, encompassing convent...

Background Degenerative Cervical Myelopathy (DCM) is the most common cause of non‐traumatic, chronic spinal cord dysfunction worldwide, causing debilitating disability with a diminishing quality of life. The natural history of DCM is poorly understood. This is a preliminary report of the first 60 patients recruited to the MYelopathy NAtural History...

Study Design Cross-sectional survey. Objective Surgical treatment of degenerative lumbar spondylolisthesis is remarkably varied due to heterogeneity of clinical-radiological presentations. This study aimed to assess which spinopelvic radiological parameters were considered for decision-making. Methods Survey distributed to International AO Spine...

Intervertebral disc degeneration, which leads to low back pain, is the most prevalent musculoskeletal condition worldwide, significantly impairing quality of life and imposing substantial socioeconomic burdens on affected individuals. A major impediment to the development of any prospective cell-driven recovery of functional properties in degenerat...

Degenerative Cervical Myelopathy (DCM) is a chronic progressive condition of the cervical spine that leads to compression of the spinal cord. It is the most common cause of spinal cord dysfunction in adults, and it occurs due to age-related changes or genetically associated pathologies. DCM is a clinical and radiological diagnosis and presents with...

Chronic low back disorders are the leading cause of direct and indirect healthcare burden globally. Exercise training improves pain intensity, mental health and physical function. However, the optimal prescription variables are unknown. We aim to compare the efficacy of various exercise dosages for chronic low back disorders to identify the optimal...

Study Design Prospective cohort study. Objective Understanding the complex nature of low back pain (LBP) is crucial for effective management. The PainDETECT questionnaire is a tool that distinguishes between neuropathic (NeP) and nociceptive (NoP) low back pain. Traditionally NeP and NoP have been primarily attributed to patho-anatomical abnormali...

Background: Low back pain (LBP) is a debilitating phenomenon that significantly impacts quality-of-life (QoL). The PainDETECT questionnaire (PD-Q) is a screening tool aimed at distinguishing nociceptive pain (NoP) and neuropathic pain (NeP) classifications. Associations between these classifications and patient-reported outcome measures (PROMs) an...

Background The shoulder microbiome is an emerging field in orthopedic research. Large synovial joints which were typically considered to be sterile now have strong evidence demonstrating the presence of native organisms colonizing the joint. Many of the conditions that surgeons see and treat in the shoulder, including osteoarthritis, rotator cuff t...

Introduction: Surgical approaches when clinically required for lumbar degenerative spondylolisthesis in the real world is not consistent with randomized controlled trials and big data registries that indicate the superiority of decompression over fusion in controlled setting. This study analyzes the fusion preference-profile among the AO spine memb...

Introduction: Lumbar degenerative spondylolisthesis is a common condition addressed by spine surgeons across the globe. Compared to the open laminectomy, evolution in the minimally invasive (MIS) decompression surgery techniques using endoscopes and tubular/bladed retractors has changed the practice pattern for decompression for degenerative spondy...

Introduction: Surgical treatment of lumbar spondylolisthesis remains highly varied (from direct decompression, indirect decompressions, to various fusion methods) due to the high heterogeneity of the clinical and radiographical presentations. The underlying concern amongst surgeons is to minimize risks of iatrogenic spinal deformities. In recent ye...

Introduction: Lumbar degenerative spondylolisthesis is a common clinical condition that spine surgeons across the globe treat routinely. Patients with symptomatic lumbar spondylolisthesis may present with significant variations of clinical presentation and radiographic findings that impact surgeons’ treatment decisions. Age-related and other medica...

Introduction: Degenerative lumbar spondylolisthesis (DLS) is one of the most common causes of chronic low back pain and mainly occurs at the L4-L5 level. In severely symptomatic cases and in the presence of neurological deficits, surgical treatment is often indicated to decompress the neural structures and stabilize the slipped segment. To date, al...

Introduction: Low back disorder (LBD) is a major cause of disability worldwide. Inflammation results in proliferation of cytokines or consequent degradation products (collectively known as inflammatory biomarkers) that activate pain pathways which can result in non-specific LBD. This systematic review and meta-analysis aim to evaluate the relation...

(1) Background: Intervertebral disc degeneration has been linked to obesity; its potential mechanical effects on the intervertebral disc remain unknown. This study aimed to develop and validate a patient-specific model of L3–L4 vertebrae and then use the model to estimate the impact of increasing body weight on disc degeneration. (2) Methods: A thr...

Purpose High intensity zones (HIZ) in the lumbar intervertebral disk (IVD) can be associated with degenerative changes which may ultimately manifest as low back pain (LBP). However, the relationship between the prevalence of HIZ and lumbar degenerative parameters is still unclear. The purpose of this study was to determine the prevalence of HIZ in...

Aims While mechanical alignment (MA) is the traditional technique in total knee arthroplasty (TKA), its potential for altering constitutional alignment remains poorly understood. This study aimed to quantify unintentional changes to constitutional coronal alignment and joint line obliquity (JLO) resulting from MA. Methods A retrospective cohort st...

Introduction The pharmacological management of chronic low back pain (LBP) is complex. The World Health Organisation recommends a laddered approach to pain medication usage. The PainDETECT questionnaire distinguishes between neuropathic pain (NeP), nociceptive pain (NoP), and ambiguous pain. By elucidating the difference in medication efficacy betw...

Introduction Understanding the complex nature of low back pain (LBP) is crucial for effective management. The PainDETECT questionnaire is a tool that distinguishes between neuropathic (NeP), nociceptive (NoP), and ambiguous pain. This study aimed to investigate the relationship between pain classification and lumbar intervertebral degenerative para...

Background: The substantial burden of low back pain on patients and healthcare systems is exacerbated by unclear pathology and ineffective diagnostic methods, hindering effective management. The painDETECT questionnaire (PD-Q) has been used to facilitate the evaluation and categorization of low back pain. While preliminary validation and translati...

Purpose To compare the clinical effectiveness of reduction and fusion with in situ fusion in the management of patients with degenerative lumbar spondylolisthesis (DLS). Methods The systematic review was conducted following the PRISMA guidelines. Relevant studies were identified from PubMed, Embase, Scopus, Cochrane Library, ClinicalTrials.gov, an...

Objective To compare the surgical trauma and outcomes between oblique lateral interbody fusion (OLIF) and posterior fixation and posterior lumbar interbody fusion (PLIF) with fixation for adult degenerative scoliosis (ADS). Methods We included ADS patients who underwent OLIF with fixation or PLIF with fixation treatment from June 2020 to December...

Purpose Increased intramedullary signal intensity (IISI) on T2 weighted MRI scan (T2WI) in patients with Degenerative Cervical Myelopathy (DCM) can be a radiological feature of spinal cord damage. However, the association of IISI to degeneration of the spinal column remains unclear in literature. The purpose of this study was to determine the preva...

Importance: Adolescent idiopathic scoliosis (AIS) is the most common pediatric spinal disorder. Routine physical examinations by trained personnel are critical to diagnose severity and monitor curve progression in AIS. In the presence of concerning malformation, radiographs are necessary for diagnosis or follow-up, guiding further management, such...

Introduction & importance Atlanto-occipital assimilation is a rare congenital abnormality which can cause atlantoaxial instability. Basilar invagination and instability can lead to cord compression and myelopathy in young individuals. Case report & discussion A 37-year-old male presented with gradually worsening axial neck pain for four years dura...

Introduction: Cranio-cervical instability (CCI) is a condition commonly found in patients with connective tissue disorders such as Ehlers-Danlos Syndrome (EDS), leading to various symptoms. Assessing patients for surgical fusion as a treatment for CCI is challenging due to the complex nature of EDS-related symptoms. This study aimed to evaluate the...

Background Recent signs of fraudulent behaviour in spine RCTs have queried the integrity of trials in the field. RCTs are particularly important due to the weight they are accorded in guiding treatment decisions, and thus, ensuring RCTs’ reliability is crucial. This study investigates the presence of non-random baseline frequency data in purported...

Although cigarette smoke (CS) and low back pain (LBP) are common worldwide, their correlations and the mechanisms of action remain unclear. We had shown that excessive activation of Mast Cells (MCs) and their proteases play key roles in CS associated diseases, like asthma, chronic obstructive pulmonary disease (COPD), blood coagulation and lung can...

Study Design A prospective case-control study. Objective To analyze global coronal malalignment (GCM) in degenerative lumbar scoliosis (DLS) and to prospectively investigate the performance of priority-matching correction technique on preventing postoperative coronal imbalance. Methods A total of 444 DLS inpatients and outpatients were recruited....

Introduction & Aim: Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has secured a prominent role in the operative management of degenerative spinal conditions. Compared to open TLIF, minimal tissue dissection with minimal neural tissue handling and adequate decompression can be achieved with this surgery. It remains partially k...

Introduction & Aim: Any revision surgeries have poorer outcomes when compared to primary surgeries. Indications for minimally invasive transforaminal lumbar interbody fusion (MAS-TLIF) are spondylolisthesis, recurrent herniation of lumbar discs, and degenerative lumbar deformities with or without canal stenosis. The outcome of the MAS-TLIF (Nuvasi...

Current in vitro intervertebral disc (IVD) models do not fully recapitulate the complex mechanobiology of native tissue, and so far there is no strategy to effectively evaluate IVD regeneration. The development of a modular microfluidic on-chip model is expected to enhance the physiological relevance of experimental data leading to successful clini...

Most diseases of the spine disproportionately impact older persons, with the modal (i.e., commonest) patient a female in their 8th decade of life. We examined the corpus of spinal RCTs to determine how many included "average" spine patients. We searched PubMed for randomized clinical trials published in the top 7 spine journals over a period of 5 y...

Many factors may trigger intervertebral disc (IVD) structural failure (intervertebral disc degeneration (IDD) and endplate changes), including inflammation, infection, dysbiosis, and the downstream effects of chemical factors. Of these, microbial diversity in the IVD and elsewhere in the body has been considered as one of the potential reasons for...

Objective: Whilst microdiscectomy is an excellent reliever of pain for recalcitrant lumbar disc herniation (LDH), it has a high failure rate over time due to the ensuing reduction in mechanical stabilization and support of the spine. One option is to clear the disc and replace it with a nonhygroscopic elastomer. Here, we present the evaluation of...

Animal models have been invaluable in the identification of molecular events occurring in and contributing to intervertebral disc (IVD) degeneration and important therapeutic targets have been identified. Some outstanding animal models (murine, ovine, chondrodystrophoid canine) have been identified with their own strengths and weaknesses. The llama...

Extreme lateral interbody fusion (XLIF) may be performed with a standalone interbody cage, or with the addition of unilateral or bilateral pedicle screws; however, decisions regarding supplemental fixation are predominantly based on clinical indicators. This study examines the impact of posterior supplemental fixation on facet micromotions, cage lo...

There are several complications associated with lumbar interbody fusion surgery however, pseudarthrosis (non-union) presents a multifaceted challenge in the postoperative management of the patient. Rates of pseudarthrosis range from 3-20% in patients with healthy bone and 20-30% in patients with osteoporosis. The current methods in post-operative f...

BACKGROUND Routine check-ups for adolescent idiopathic scoliosis are critical to monitor progression and prescribe interventions. AIS is primarily screened via physical examination. If there are features of deformity, radiographs are necessary for diagnosis or follow-up, guiding further management, i.e., bracing corrections for moderate deformities...

The purpose of this review was to evaluate data generated by animal models of intervertebral disc (IVD) degeneration published in the last decade and show how this has made invaluable contributions to the identification of molecular events occurring in and contributing to pain generation. IVD degeneration and associated spinal pain is a complex mul...

Degenerative cervical myelopathy (DCM) manifests as the primary cause of spinal cord dysfunction and is non-traumatic, chronic and progressive in nature. Decompressive surgery is typically utilised to halt further disability and neurological dysfunction and as such, early diagnosis and assessment is a vital means of slowing the disease process. Cur...

Background: Degenerative cervical myelopathy (DCM) manifests as the primary cause of spinal cord dysfunction and is non-traumatic, chronic and progressive in nature. Decompressive surgery is typically utilised to halt further disability and neurological dysfunction. The limitations of current diagnostic options surrounding assessment and prognosti...

Background: The anterior approach to the cervical spine is the most commonly used surgery with effective decompression and less surgical trauma. Anterior plate construct (APC) is considered a standard technique. However, it appears to cause implant failure and postoperative dysphagia. Due to these reasons, locking stand-alone cages (LSCs) without...

Purpose Examine the effectiveness of interventions to approach guideline-adherent surgical referrals for low back pain assessed via systematic review and meta-analysis. Methods Five databases (10 September 2021), Google Scholar, reference lists of relevant systematic reviews were searched and forward and backward citation tracking of included stud...

A Comparison Review of fusion methods (Open Vs Minimal invasive) of sacroiliac dysfunction

Purpose To evaluate intra- and inter-rater agreement and reliability of seven reported disc height index (DHI) measurement methods on standing lateral X-ray of lumbar spine. Methods The adult patients who had standing lateral X-ray of lumbar spine were recruited. Seven methods were used to measure DHI of each lumbar intervertebral disc level, incl...

Routine check-ups for adolescent idiopathic scoliosis are critical to monitor progression and prescribe interventions. AIS is primarily screened via physical examination. If there are features of deformity, radiographs are necessary for diagnosis or follow-up, guiding further management, i.e., bracing for moderate deformity and surgery for severe....

Aims Intraoperative pressure sensors allow surgeons to quantify soft-tissue balance during total knee arthroplasty (TKA). The aim of this study was to determine whether using sensors to achieve soft-tissue balance was more effective than manual balancing in improving outcomes in TKA. Methods A multicentre randomized trial compared the outcomes of...

Purpose Low back pain (LBP), a widely prevalent and costly disease around the world, is mainly caused by intervertebral disc (IVD) degeneration (IDD). Although numerous factors may trigger this degenerative process, microbiome dysbiosis has recently been implicated as one of the likely causes. However, the exact relationship between the microbiome...

Intervertebral disc degeneration (IDD) is the main cause of low back pain, and little is known about its molecular and pathological mechanisms. According to reports, excessive compression is a high-risk factor for IDD; compressive stress can induce oxidative stress in nucleus pulposus (NP) cells during IDD progression that, in turn, promotes cell a...

Intervertebral Disc Degeneration Ancient Chinese astronomers divided the sky into four quarters. Each of the four directions contains seven of the twenty‐eight constellations. The four directions, collectively known as the Four Symbols, each assigned a mysterious animal. They are Azure Dragon on the east, Black Tortoise on the north, White Tiger on...

The blood-spinal cord barrier (BSCB) has been long thought of as a functional equivalent to the blood-brain barrier (BBB), restricting blood flow into the spinal cord. The spinal cord is supported by various disc tissues that provide agility and has different local immune responses compared to the brain. Though physiologically, structural component...

Purpose: To evaluate intra- and inter-rater agreement and reliability of seven reported disc height index (DHI) measurement methods on standing lateral X-ray of lumbar spine. Methods: The adult patients who had standing lateral X-ray of lumbar spine were recruited. Seven methods were used to measure DHI of each lumbar intervertebral disc level. Bla...

Although degeneration of the nucleus pulposus (NP) is a major contributor to intervertebral disc degeneration (IVDD) and low back pain, the underlying molecular complexity and cellular heterogeneity remain poorly understood. Here, a comprehensive single-cell resolution transcript landscape of human NP is reported. Six novel human NP cells (NPCs) po...

Introduction Chronic low back pain disorders (CLBDs) present a substantial societal burden; however, optimal treatment remains debated. To date, pairwise and network meta-analyses have evaluated individual treatment modes, yet a comparison of a wide range of common treatments is required to evaluate their relative effectiveness. Using network meta-...

PurposeTo evaluate the impact of discectomy on disc height (DH) in lumbar disc herniation (LDH) patients following discectomy surgery and address the association of DH change with pain score change.Methods We searched three online databases for randomized controlled trials (RCTs) and observational studies. In LDH patients, eligible for discectomy s...

Aim To assist surgeons to determine a potential approach to reduce incidences of recurrent lumbar disc herniation and assess the current devices regarding their outcomes and complications. Method Four electronic full-text databases were systematically searched through September 2017. All results were pooled utilising meta-analysis with weighted me...

With lower back pain increasingly becoming a highly prevalent economic, clinical and social burden among the global population, the demand for a reliable clinical approach for the quantification of the mechanical properties of the human intervertebral disc (IVD) to detect premature degeneration or identify the underlying pathophysiology that is ess...

Extreme lateral interbody fusion allows for the insertion of a large-footprint interbody cage while maintaining the presence of natural stabilising ligaments and the facets. It is unclear how the load-distribution mechanisms through these structures alters with temporal changes in the bone graft. The aim of this research was to examine the effects...

Introduction Understanding practice-based differences in treatment of lumbar disc herniations (LDHs) is vital for reducing unwarranted variation in the delivery of spine surgical health care. Identifying factors that influence surgeons’ decision-making will offer useful insights for developing the most cost-effective and safest surgical strategy as...

Degeneration of the nucleus pulposus (NP) is a major contributor to intervertebral disc degeneration (IVDD) and low back pain. However, the underlying molecular complexity and cellular heterogeneity remain poorly understood. Here, we first reported a comprehensive single-cell resolution transcriptional landscape of human NP. Six novel human nucleus...

Study design: Translational review encompassing basic science and clinical evidence. Objectives: Multiple components of the lumbar spine interact during its normal and pathological function. Bony stress in the lumbar spine is recognized as a factor in the development of pars interarticularis defect and stress fractures, but its relationship with...

Cigarette smoke (CS) has been consistently demonstrated to be an environmental risk factor for amyotrophic lateral sclerosis (ALS), although the molecular pathogenic mechanisms involved are yet to be elucidated. Here, we propose different mechanisms by which CS exposure can cause sporadic ALS pathogenesis. Oxidative stress and neuroinflammation are...

PurposeRecent animal studies have discovered dysregulation of local inflammatory activity as a novel mechanism to explain fat and connective tissue accumulation in the multifidus muscle in association with intervertebral disc (IVD) degeneration/injury. This study aimed to test whether similar mechanisms are active in humans by investigation of whet...

A previous version of this editorial lacked hyperlink to the articles published for the supplement. The hyperlink to the articles has been enabled and given below. Further, Havey et al. is now updated to Patwardhan and Havey.

Bariatric surgery produces significant and quantifiable reductions in back pain. However, there is a lack of information on the association of weight changes after bariatric surgery with changes in pain score. We aim to evaluate the impact of bariatric surgery on back pain in obese patients and to address the association between changes in body mas...

Degenerative cervical myelopathy (DCM), earlier referred to as cervical spondylotic myelopathy (CSM), is the most common and serious neurological disorder in the elderly population caused by chronic progressive compression or irritation of the spinal cord in the neck. The clinical features of DCM include localised neck pain and functional impairmen...

Study design: Observational study. Objective: To evaluate whether inflammatory and/or muscle regeneration markers in paraspinal tissues (multifidus muscle/fat) during microdiscectomy surgery in patients with lumbar disc herniation (LDH) with radiculopathy, differ between individuals with good or poor outcome. Summary of background data: Struct...