Understanding spinopelvic mechanics is important for the success of total hip arthroplasty (THA). Despite significant advancements in appreciating spinopelvic balance, numerous challenges remain. It is crucial to recognize the individual variability and postoperative changes in spinopelvic parameters and their consequential impact on prosthetic component positioning to mitigate the risk of dislocation and enhance postoperative outcomes. This review describes the integration of advanced diagnostic approaches, enhanced technology, implant considerations, and surgical planning, all tailored to the unique anatomy and biomechanics of each patient. It underscores the importance of accurately predicting postoperative spinopelvic mechanics, selecting suitable imaging techniques, establishing a consistent nomenclature for spinopelvic stiffness, and considering implant-specific strategies. Furthermore, it highlights the potential of artificial intelligence to personalize care.

Cite this article: Bone Joint J 2024;106-B(11):1206–1215.

The October 2024 Spine Roundup³⁶⁰ looks at: Analysis of risk factors for non-fusion of bone graft in anterior cervical discectomy and fusion: a clinical retrospective study; Does paraspinal muscle mass predict lumbar lordosis before and after decompression for degenerative spinal stenosis?; Return to work after surgery for lumbar disk herniation: a nationwide registry-based study; Can the six-minute walking test assess ambulatory function impairment in patients with cervical spondylotic myelopathy?; Complications after adult deformity surgery: losing more than sleep; Frailty limits how good we can get in adult spine deformity surgery.

Aims. The escalating demand for medical resources to address spinal diseases as society ages is an issue that requires careful evaluation. However, few studies have examined trends in spinal surgery, especially unscheduled hospitalizations or surgeries performed after hours, through large databases. Our study aimed to determine national trends in the number of spine surgeries in Japan. We also aimed to identify trends in after-hours surgeries and unscheduled hospitalizations and their impact on complications and costs. Methods. We retrospectively investigated data extracted from the Diagnosis Procedure Combination database, a representative inpatient database in Japan. The data from April 2010 to March 2020 were used for this study. We included all patients who had undergone any combination of laminectomy, laminoplasty, discectomy, and/or spinal arthrodesis. Results. This investigation included 739,474 spinal surgeries and 739,215 hospitalizations in Japan. There was an average annual increase of 4.6% in the number of spinal surgeries. Scheduled hospitalizations increased by 3.7% per year while unscheduled hospitalizations increased by 11.8% per year. In-hours surgeries increased by 4.5% per year while after-hours surgeries increased by 9.9% per year. Complication rates and costs increased for both after-hours surgery and unscheduled hospitalizations, in comparison to their respective counterparts of in-hours surgery and scheduled hospitalizations. Conclusion. This study provides important insights for those interested in improving spine care in an ageing society. The swift surge in after-hours spinal surgeries and unscheduled hospitalizations highlights that the medical needs of an increasing number of patients due to an ageing society are outpacing the capacity of existing medical resources. Cite this article: Bone Jt Open 2024;5(8):662–670

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Implant-related postoperative spondylodiscitis (IPOS) is a severe complication in spine surgery and is associated with high morbidity and mortality. With growing knowledge in the field of periprosthetic joint infection (PJI), equivalent investigations towards the management of implant-related infections of the spine are indispensable. To our knowledge, this study provides the largest description of cases of IPOS to date.

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This study aimed to investigate the risk of postoperative complications in COVID-19-positive patients undergoing common orthopaedic procedures.

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Traumatic central cord syndrome (CCS) typically follows a hyperextension injury and results in motor impairment affecting the upper limbs more than the lower, with occasional sensory impairment and urinary retention. Current evidence on mortality and long-term outcomes is limited. The primary aim of this study was to assess the five-year mortality of CCS, and to determine any difference in mortality between management groups or age.

The April 2023 Spine Roundup. 360. looks at: Percutaneous transforaminal endoscopic discectomy versus microendoscopic discectomy; Spine surgical site infections: a single debridement is not enough; Lenke type 5, anterior, or posterior: systematic review and meta-analysis; Epidural steroid injections and postoperative infection in lumbar decompression or fusion; Noninferiority of posterior cervical foraminotomy versus anterior cervical discectomy; Identifying delays to surgical treatment for metastatic disease; Cervical disc replacement and adjacent segment disease: the NECK trial; Predicting complication in adult spine deformity surgery

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Repeated lumbar spine surgery has been associated with inferior clinical outcomes. This study aimed to examine and quantify the impact of this association in a national clinical register cohort.

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This study was performed to explore the effect of melatonin on pyroptosis in nucleus pulposus cells (NPCs) and the underlying mechanism of that effect.

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CRP is an acute-phase protein that is used as a biomarker to follow severity and progression in infectious and inflammatory diseases. Its pathophysiological mechanisms of action are still poorly defined. CRP in its pentameric form exhibits weak anti-inflammatory activity. The monomeric isoform (mCRP) exerts potent proinflammatory properties in chondrocytes, endothelial cells, and leucocytes. No data exist regarding mCRP effects in human intervertebral disc (IVD) cells. This work aimed to verify the pathophysiological relevance of mCRP in the aetiology and/or progression of IVD degeneration.

Anterior cervical discectomy and fusion (ACDF) is a well-established spinal operation for cervical disc degeneration disease with neurological compromise. The procedure involves an anterior approach to the cervical spine with discectomy to relieve the pressure on the impinged spinal cord to slow disease progression. The prosthetic cage replaces the disc and can be inserted stand-alone or with an anterior plate that provides additional stability. The literature demonstrates that the cage-alone (CA) is given preference over the cage-plate (CP) technique due to better clinical outcomes, reduced operation time and resultant morbidity. This retrospective case-controlled study compared CA versus CP fixation used in single and multilevel anterior cervical discectomy and fusion for myelopathy in a tertiary centre in Wales. A retrospective clinico-radiological analysis was undertaken, following ACDF procedures over seven years in a single tertiary centre. Inclusion criteria were patients over 18 years of age with cervical myelopathy who had at least six-month follow-up data. SPSS was used to identify any statistically significant difference between both groups. The data were analysed to evaluate the consistency of our findings in comparison to published literature. Eighty-six patients formed the study cohort; 28 [33%] underwent ACDF with CA and 58 [67%] with CP. The patient demographics were similar in both groups, and fusion was observed in all individuals. There was no statistical difference between the two constructs when assessing subsidence, clinical complication (dysphagia, dysphonia, infection), radiological parameters and reoperations. However, a more significant percentage [43% v 61%] of patients improved their cervical lordosis angle with CP treatment. Furthermore, the study yielded that surgery to upper cervical levels results in a higher incidence of dysphagia [65% v 35%]. Finally, bony growth across the cage was observed on X-ray in 12[43%] patients, a unique finding not mentioned in the literature previously. Our study demonstrates no overall difference between the two groups, and we recommend careful consideration of individual patient factors when deciding what construct to choose

Aims. To identify the incidence and risk factors for five-year same-site recurrent disc herniation (sRDH) after primary single-level lumbar discectomy. Secondary outcome was the incidence and risk factors for five-year sRDH reoperation. Methods. A retrospective study was conducted using prospectively collected data and patient-reported outcome measures, including the Oswestry Disability Index (ODI), between 2008 and 2019. Postoperative sRDH was identified from clinical notes and the centre’s MRI database, with all imaging providers in the region checked for missing events. The Kaplan-Meier method was used to calculate five-year sRDH incidence. Cox proportional hazards model was used to identify independent variables predictive of sRDH, with any variable not significant at the p < 0.1 level removed. Hazard ratios (HRs) were calculated with 95% confidence intervals (CIs). Results. Complete baseline data capture was available for 733 of 754 (97.2%) consecutive patients. Median follow-up time for censored patients was 2.2 years (interquartile range (IQR) 1.0 to 5.0). sRDH occurred in 63 patients at a median 0.8 years (IQR 0.5 to 1.7) after surgery. The five-year Kaplan-Meier estimate for sRDH was 12.1% (95% CI 9.5 to 15.4), sRDH reoperation was 7.5% (95% CI 5.5 to 10.2), and any-procedure reoperation was 14.1% (95% CI 11.1 to 17.5). Current smoker (HR 2.12 (95% CI 1.26 to 3.56)) and higher preoperative ODI (HR 1.02 (95% CI 1.00 to 1.03)) were independent risk factors associated with sRDH. Current smoker (HR 2.15 (95% CI 1.12 to 4.09)) was an independent risk factor for sRDH reoperation. Conclusion. This is one of the largest series to date which has identified current smoker and higher preoperative disability as independent risk factors for sRDH. Current smoker was an independent risk factor for sRDH reoperation. These findings are important for spinal surgeons and rehabilitation specialists in risk assessment, consenting patients, and perioperative management. Cite this article: Bone Joint J 2023;105-B(3):315–322

The February 2023 Spine Roundup. 360. looks at: S2AI screws: At what cost?; Just how good is spinal deformity surgery?; Is 80 years of age too late in the day for spine surgery?; Factors affecting the accuracy of pedicle screw placement in robot-assisted surgery; Factors causing delay in discharge in patients eligible for ambulatory lumbar fusion surgery; Anterior cervical discectomy or fusion and selective laminoplasty for cervical spondylotic myelopathy; Surgery for cervical radiculopathy: what is the complication burden?; Hypercholesterolemia and neck pain; Return to work after surgery for cervical radiculopathy: a nationwide registry-based observational study

Aims

Degenerative cervical spondylosis (DCS) is a common musculoskeletal disease that encompasses a wide range of progressive degenerative changes and affects all components of the cervical spine. DCS imposes very large social and economic burdens. However, its genetic basis remains elusive.

Symptomatic lumbar spinal stenosis is a common entity and increasing in prevalence. Limited evidence is available regarding patient reported outcomes comparing primary vs revision surgery for those undergoing lumbar decompression, with or without fusion. Evidence available suggest a lower rate of improvement in the revision group. The aim of this study was to assess patient reported outcomes in patients undergoing revision decompression, with or without fusion, when compared to primary surgery. Patient data was collected from the Canadian Spine Outcomes Research Network (CSORN) database. Patients undergoing lumbar decompression without or without fusion were included. Patients under 18, undergoing discectomy, greater than two level decompressions, concomitant cervical or thoracic spine surgery were excluded. Demographic data, smoking status, narcotic use, number of comorbidities as well as individual comorbidities were included in our propensity scores. Patients undergoing primary vs revision decompression were matched in a four:one ratio according to their scores, whilst a separate matched cohort was created for those undergoing primary vs revision decompression and fusion. Continuous data was compared using a two-tailed t-test, whilst categorical variables were assessed using chi-square test. A total of 555 patients were included, with 444 primary patients matched to 111 revision surgery patients, of which 373 (67%) did not have fusion. Patients undergoing primary decompression with fusion compared to revision patients were more likely to answer yes to “feel better after surgery” (87.8% vs 73.8%, p=0.023), “undergo surgery again” (90.1% vs 76.2%, P=0.021) and “improvement in mental health” (47.7% vs 28.6%, p=0.03) at six months. There was no difference in either of these outcomes at 12 or 24 months. There was no difference between the groups ODI, EQ-5D, SF 12 scores at any time point. Patients undergoing primary vs revision decompression alone showed no difference in PROMs at any time point. In a matched cohort, there appears to be no difference in improvement in PROMS between patients undergoing primary vs revision decompression, with or without fusion, at two year follow-up. This would suggest similar outcomes can be obtained in revision cases

Intervertebral disc degeneration (IDD) affects more than 80% of the population all over the world. Current strategies for the treatment of IDD are based on conservative or surgical procedures with the aim of relieving pain. Mesenchymal stem cell (MSC) transplantation has emerged as a promising therapy in recent decades, but studies showed that the particularly hostile microenvironment in the intervertebral disc (IVD) can compromise cells survival rate. The use of exosomes, extracellular vesicles released by various cell types, possess considerable economic advantages including low immunogenicity and toxicity. Exosomes allow intercellular communication by conveying functional proteins, RNA, miRNA and lipids between cells. The purpose of this study is to assess the therapeutic effects of exosomes derived from Wharton Jelly mesenchymal stromal cells (WJ-MSC) on human nucleuspulposus cells (hNPC) in an in vitro 3D culture model. Exosomes (exos) were isolated by tangential flow filtration of WJ-MSC conditioned media and characterized by: quantification with BCA test; morphological observation with TEM, surface marker expression by WB and size evaluation by NTA. Confocal microscopy has been used to identify exosomes marked with PKH26 and monitor fusion and/or incorporation in hNPC. hNPC were isolated from waste surgical material from patients undergoing discectomy (n = 5), expanded, encapsulated in alginate beads and treated with: culture medium (control group); WJ-MSC exos (WJ-exos) at different concentrations (10 μg/ml, 50 μg/ml and 100 μg/ml). They were then analysed for: cell proliferation (Trypan Blu); viability (Live/Dead Assay); quantification of nitrites (Griess) and glycosaminoglycans, GAG (DMBB). The hNPC in alginate beads treated for 7 days were included in paraffin and histologically analysed to determine the presence of extracellular matrix (ECM) components. Finally, the expression levels of catabolic and anabolic genes were evaluated through real-time polymerase chain reaction (qPCR). All concentrations of WJ-exos under exam were capable to induce a significant increase in cell proliferation after 10 and 14 days of treatment (p < 0.01 and p < 0.001, respectively). Live/Dead assay showed a decrease in cell death at 50 μg/ml of WJ-exos (p < 0.05). While cellular oxidative stress indicator, nitrite production, was reduced in a dose-dependent way and statistically significant only with 100 μg/ml of WJ-exos (p < 0.05). WJ-exos at 10 and 100 μg/ml induced a significant increase in GAG content (p < 0.05; p < 0.01, respectively) confirmed by Alcian Blu staining. Exos derived from WJ-MSC modulated gene expression levels by increasing expression of ACAN and SOX-9 genes and reducing significantly of IL-6, MMP-1, MMP-13 and ADAMTS-5 levels (p < 0.05; p < 0.01) compared to the control group. Our results supported the potential use of exosomes from WJ-MSC for the treatment of IDD. Exosomes improved hNPC growth, attenuated ECM degradation and reduced oxidative stress and inflammation. This study offers a new scenario in IVD regeneration, promoting the potential use of extracellular vesicles as an alternative strategy to cell therapy

Single level discectomy (SLD) is one of the most commonly performed spinal surgery procedures. Two key drivers of their cost-of-care are duration of surgery (DOS) and postoperative length of stay (LOS). Therefore, the ability to preoperatively predict SLD DOS and LOS has substantial implications for both hospital and healthcare system finances, scheduling and resource allocation. As such, the goal of this study was to predict DOS and LOS for SLD using machine learning models (MLMs) constructed on preoperative factors using a large North American database. The American College of Surgeons (ACS) National Surgical and Quality Improvement (NSQIP) database was queried for SLD procedures from 2014-2019. The dataset was split in a 60/20/20 ratio of training/validation/testing based on year. Various MLMs (traditional regression models, tree-based models, and multilayer perceptron neural networks) were used and evaluated according to 1) mean squared error (MSE), 2) buffer accuracy (the number of times the predicted target was within a predesignated buffer), and 3) classification accuracy (the number of times the correct class was predicted by the models). To ensure real world applicability, the results of the models were compared to a mean regressor model. A total of 11,525 patients were included in this study. During validation, the neural network model (NNM) had the best MSEs for DOS (0.99) and LOS (0.67). During testing, the NNM had the best MSEs for DOS (0.89) and LOS (0.65). The NNM yielded the best 30-minute buffer accuracy for DOS (70.9%) and ≤120 min, >120 min classification accuracy (86.8%). The NNM had the best 1-day buffer accuracy for LOS (84.5%) and ≤2 days, >2 days classification accuracy (94.6%). All models were more accurate than the mean regressors for both DOS and LOS predictions. We successfully demonstrated that MLMs can be used to accurately predict the DOS and LOS of SLD based on preoperative factors. This big-data application has significant practical implications with respect to surgical scheduling and inpatient bedflow, as well as major implications for both private and publicly funded healthcare systems. Incorporating this artificial intelligence technique in real-time hospital operations would be enhanced by including institution-specific operational factors such as surgical team and operating room workflow

The December 2022 Spine Roundup³⁶⁰ looks at: Deep venous thrombosis prophylaxis protocol on a Level 1 trauma centre patient database; Non-specific spondylodiscitis: a new perspective for surgical treatment; Disc degeneration could be recovered after chemonucleolysis; Three-level anterior cervical discectomy and fusion versus corpectomy- anterior cervical discectomy and fusion “hybrid” procedures: how does the alignment look?; Rivaroxaban or enoxaparin for venous thromboembolism prophylaxis; Surgical site infection: when do we have to remove the implants?; Determination of a neurologic safe zone for bicortical S1 pedicle placement; Do you need to operate on unstable spine fractures in the elderly: outcomes and mortality; Degeneration to deformity: when does the patient need both?

Introduction:. Exercise has showed to reduce pain and improve function in patients with discogenic low back pain (LBP). Although there is currently no biologic evidence that the intervertebral disc (IVD) can respond to physical exercise in humans, a recent study has shown that chronic running exercise is associated with increased IVD hydration and hypertrophy1. Irisin, a myokine released upon muscle contraction, has demonstrated to yield anabolic effects on different cell types, including chondrocytes2. This study aimed to investigate the effect of irisin on human nucleus pulposus cells (hNPCs). Our hypothesis is that irisin may improve hNPCs metabolism and proliferation. METHODS:. The hNPCs, isolated from discectomy surgical waste material (n = 5), were expanded and encapsulated in alginate beads. The hNPCs were treated with: i) only growth medium (control); ii) medium with recombinant irisin (r-IR) at different concentrations (5, 10 and 25 ng / mL); iii) medium with Interleukin-1β (IL1β); iv) medium with IL1β for 24 h and then with IL1β and r-IR; v) medium with r-IR for 24 h and then with r-IR and IL1 β. We evaluated proliferation (trypan blue and PicoGreen), metabolic activity (MTT), nitrite concentration (Griess), and expression levels of catabolic and anabolic genes via real-time polymerase chain reaction (qPCR). Each analysis was performed in triplicate for each donor and each experiment was performed three times. Data were expressed as mean ± S.D. One-way ANOVA was used for the groups under exam. RESULTS:. Irisin increased hNPCs proliferation (p < 0.001), metabolic activity at 10 ng/mL (p < 0.05), and GAG content at concentration of 10 ng/mL and 25 ng/mL (p < 0.01; p < 0.001, respectively). The production of nitrites, used as an indicator of cellular oxidative stress, was significantly decreased (p < 0.01). Gene expression levels compared to the control group increased for COL2A1 (p < 0.01), ACAN (p < 0.05), TIMP-1 and −3 (p < 0.01), while a decrease in mRNA levels of MMP-13 (p < 0.05) and IL1β (p < 0.001) was noticed. r-IR pretreatment of hNPCs cultured in pro-inflammatory conditions resulted in a rescue of metabolic activity (p < 0.001), as well as a decrease of IL-1β (p < 0.05) levels. Similarly, incubation of hNPCs with IL-1β and subsequent exposure to r-IR led to an increment of hNPC metabolic activity (p < 0.001), COL2A1 gene expression (p < 0.05) and a reduction of IL-1β (p < 0.05) and ADAMTS-5 gene levels (p < 0.01). CONCLUSIONS:. The present study suggested that irisin may stimulate hNPCs proliferation, metabolic activity, and anabolism by reducing the expression of IL-1β and catabolic enzymes while promoting the synthesis of extracellular matrix components. Furthermore, this myokine was able to blunt the catabolic effect of in vitro inflammation. Our results indicate that irisin may be one of the mediators by which physical exercise and muscle tissues modulate IVD metabolism, thus suggesting the existence of a biological cross-talk mechanism between the muscle and the IVD

Prolonged length of stay (LOS) is a significant contributor to the variation in surgical health care costs and resource utilization after elective spine surgery. The primary goal of this study was to identify patient, surgical and institutional variables that influence LOS. The secondary objective is to examine variability in institutional practices among participating centers. This is a retrospective study of a prospectively multicentric followed cohort of patients enrolled in the CSORN between January 2015 and October 2020. A logistic regression model and bootstrapping method was used. A survey was sent to participating centers to assessed institutional level interventions in place to decrease LOS. Centers with LOS shorter than the median were compared to centers with LOS longer than the median. A total of 3734 patients were included (979 discectomies, 1102 laminectomies, 1653 fusions). The median LOS for discectomy, laminectomy and fusion were respectively 0.0 day (IQR 1.0), 1.0 day (IQR 2.0) and 4.0 days (IQR 2.0). Laminectomy group had the largest variability (SD=4.4, Range 0-133 days). For discectomy, predictors of LOS longer than 0 days were having less leg pain, higher ODI, symptoms duration over 2 years, open procedure, and AE (p< 0.05). Predictors of longer LOS than median of 1 day for laminectomy were increasing age, living alone, higher ODI, open procedures, longer operative time, and AEs (p< 0.05). For posterior instrumented fusion, predictors of longer LOS than median of 4 days were older age, living alone, more comorbidities, less back pain, higher ODI, using narcotics, longer operative time, open procedures, and AEs (p< 0.05). Ten centers (53%) had either ERAS or a standardized protocol aimed at reducing LOS. In this study stratifying individual patient and institutional level factors across Canada, several independent predictors were identified to enhance the understanding of LOS variability in common elective lumbar spine surgery. The current study provides an updated detailed analysis of the ongoing Canadian efforts in the implementation of multimodal ERAS care pathways. Future studies should explore multivariate analysis in institutional factors and the influence of preoperative patient education on LOS