Assessing the predictive capability of machine learning models in determining clinical outcomes for patients with cervical spondylotic myelopathy treated with laminectomy and posterior spinal fusion.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is a prevalent degenerative condition resulting from spinal cord compression and injury. Laminectomy with posterior spinal fusion (LPSF) is a commonly employed treatment approach for CSM patients. This study aimed to assess the effectiveness of machine learning models (MLMs) in predicting clinical outcomes in CSM patients undergoing LPSF. METHODS: A retrospective analysis was conducted on 329 CSM patients who underwent LPSF at our institution from Jul 2017 to Jul 2023. Neurological outcomes were evaluated using the modified Japanese Orthopaedic Association (mJOA) scale preoperatively and at the final follow-up. Patients were categorized into two groups based on clinical outcomes: the favorable group (recovery rates ≥ 52.8%) and the unfavorable group (recovery rates < 52.8%). Potential predictors for poor clinical outcomes were compared between the groups. Four MLMs-random forest (RF), logistic regression (LR), support vector machine (SVM), and k-nearest neighborhood (k-NN)-were utilized to predict clinical outcome. RF model was also employed to identify factors associated with poor clinical outcome. RESULTS: Out of the 329 patients, 185 were male (56.2%) and 144 were female (43.4%), with an average follow-up period of 17.86 ± 1.74 months. Among them, 267 patients (81.2%) had favorable clinical outcomes, while 62 patients (18.8%) did not achieve favorable results. Analysis using binary logistic regression indicated that age, preoperative mJOA scale, and symptom duration (p < 0.05) were independent predictors of unfavorable clinical outcomes. All models performed satisfactorily, with RF achieving the highest accuracy of 0.922. RF also displayed superior sensitivity and specificity (sensitivity = 0.851, specificity = 0.944). The Area under the Curve (AUC) values for RF, Logistic LR, SVM, and k-NN were 0.905, 0.827, 0.851, and 0.883, respectively. The RF model identified preoperative mJOA scale, age, symptom duration, and MRI signal changes as the most significant variables associated with poor clinical outcomes in descending order. CONCLUSIONS: This study highlighted the effectiveness of machine learning models in predicting the clinical outcomes of CSM patients undergoing LPSF. These models have the potential to forecast clinical outcomes in this patient population, providing valuable prognostic insights for preoperative counseling and postoperative management.

Return to Sporting Activities Following Long Fusions to the Pelvis in Adult Spinal Deformity.

BACKGROUND CONTEXT: Returning to recreational sporting activities after adult spinal deformity (ASD) correction may significantly impact the patient's perceived quality of life. PURPOSE: This study sought to characterize participation in sporting activities before and after ASD surgery, and to identify factors associated with impaired return to sports. STUDY DESIGN: Cross-sectional survey and retrospective review of prospectively collected data. PATIENT SAMPLE: Patients who underwent posterior-only thoracolumbar ASD surgery between 2016-2021 with ≥1 year follow-up and ≥3 levels of fusion to the pelvis were included. OUTCOME MEASURES: Preoperative and postoperative participation in sports, timing of return to these activities, and reasons for limited sports participation postoperatively were assessed. METHODS: A survey was used to evaluate outcome measures. Differences in demographic, surgical, and perioperative variables between patients who reported improved, unchanged, or worsened activity tolerance were evaluated. RESULTS: Ninety-five patients were included (mean age: 64.3±10.1 years; BMI: 27.3±6.1 kg/m2; median levels fused: 7). The survey was completed at an average of 43.5 ± 15.9 months after surgery. Sixty-eight (72%) patients participated in sports preoperatively. The most common sports were swimming (n=33, 34.7%), yoga (n=23, 24.2%), weightlifting (n=20, 21.1%), elliptical (n=19, 20.0%), and golf (n=11, 11.6%). Fifty-seven (83.8%) returned to at least one sport postoperatively, most commonly 6-12 months after surgery (45%). Elliptical had the highest rate of equal or improved participation (53%). Patients generally returned below their preoperative level to all other sports. Reasons for reduced sporting activities included physical limitation (51.4%), fear (20.0%), pain (17.1%), and surgeon advice (8.6%). There were no differences in the demographic, surgical, or perioperative characteristics between those who returned to sports at the same or better level compared with those who returned at a lower level. CONCLUSIONS: 84% of patients successfully resumed sporting activities after undergoing fusion to the sacrum/pelvis for ASD. However, this return is typically at a lower level of participation than their preoperative participation, particularly in higher demand sports. Understanding trends in sporting activity may be valuable for counseling patients and setting expectations.

Cervical kyphosis after posterior cervical laminectomy with and without fusion.

BACKGROUND: Cervical posterior instrumentation and fusion is often performed to avoid post-laminectomy kyphosis. However, larger comparative analyses of cervical laminectomy with or without fusion are sparse. METHODS: A retrospective, two-center, comparative cohort study included patients after stand-alone dorsal laminectomy with (n = 91) or without (n = 46) additional fusion for degenerative cervical myelopathy with a median follow-up of 59 (interquartile range (IQR) 52) months. The primary outcome was the C2-7 Cobb angle and secondary outcomes were Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, revision rates, T1 slope and C2-7 sagittal vertical axis (C2-7 SVA) at final follow-up. Logistic regression analysis adjusted for potential confounders (i.e. age, operated levels, and follow-up). RESULTS: Preoperative C2-7 Cobb angle and T1 slope were higher in the laminectomy group, while the C2-7 SVA was similar. The decrease in C2-7 Cobb angle from pre- to postoperatively was more pronounced in the laminectomy group (- 6° (IQR 20) versus -1° (IQR 7), p = 0.002). When adjusting for confounders, the decrease in C2-7 Cobb angle remained higher in the laminectomy group (coefficient - 12 (95% confidence interval (CI) -18 to -5), p = 0.001). However, there were no adjusted differences for postoperative NDI (- 11 (- 23 to 2), p = 0.10), mJOA, revision rates, T1 slope and C2-7 SVA. CONCLUSION: Posterior cervical laminectomy without fusion is associated with mild loss of cervical lordosis of around 6° in the mid-term after approximately five years, however without any clinical relevance regarding NDI or mJOA in well-selected patients (particularly in shorter segment laminectomies of < 3 levels).

Topping-Off a Long Thoracic Stabilization With Semi-Rigid Constructs May Have Favorable Biomechanical Effects to Prevent Proximal Junctional Kyphosis: A Biomechanical Comparison.

STUDY DESIGN: In-vitro cadaveric biomechanical study. OBJECTIVES: Long posterior spinal fusion is a standard treatment for adult spinal deformity. However, these rigid constructs are known to alter motion and stress to the adjacent non-instrumented vertebrae, increasing the risk of proximal junctional kyphosis (PJK). This study aimed to biomechanically compare a standard rigid construct vs constructs "topped off" with a semi-rigid construct. By understanding semi-rigid constructs' effect on motion and overall construct stiffness, surgeons and researchers could better optimize fusion constructs to potentially decrease the risk of PJK and the need for revision surgery. METHODS: Nine human cadaveric spines (T1-T12) underwent non-destructive biomechanical range of motion tests in pure bending or torsion and were instrumented with an all-pedicle-screw (APS) construct from T6-T9. The specimens were sequentially instrumented with semi-rigid constructs at T5: (i) APS plus sublaminar bands; (ii) APS plus supralaminar hooks; (iii) APS plus transverse process hooks; and (iv) APS plus short pedicle screws. RESULTS: APS plus transverse process hooks had a range of motion (ie, relative angle) for T4-T5 and T5-T6, as well as an overall mechanical stiffness for T1-T12, that was more favourable, as it reduced motion at adjacent levels without a stark increase in stiffness. Moreover, APS plus transverse process hooks had the most linear change for range of motion across the entire T3-T7 range. CONCLUSIONS: Present findings suggest that APS plus transverse process hooks has a favourable biomechanical effect that may reduce PJK for long spinal fusions compared to the other constructs examined.

Optimising operating theatre (OT) efficiency while maintaining the standardised patient care in adolescent idiopathic scoliosis (AIS) surgery with the dedicated spine team approach: a specialised spine unit experience.

PURPOSE: To report the efficiency of OT utilisation and perioperative outcomes with a dedicated spine team approach in AIS patients who underwent posterior spinal fusion (PSF) surgeries in a consecutive case operation list. METHODS: Three AIS patients operated in a day (8:00 AM-8:00 PM) by a dedicated spine team were recruited between 2021 and 2022. The dedicated team comprised of three senior spine consultants who operated using a dual attending surgeon strategy, an anaesthetic consultant, dedicated surgical scrub nurses, anaesthesiology nurses, radiographers, and neuromonitoring technicians. Patients were categorised according to the sequence of operation list of the day (Case 1, Case 2, and Case 3). OT efficiency was represented by OT time in five stages (preoperative time, operative time, postoperative time, total OT time, and turnover time). OT time and perioperative outcomes were compared. RESULTS: 102 cases were analysed. On average, Case 1 began at 8:38 AM whereas Case 3 ended by 5:54 PM. OT efficiency was consistent throughout the day of operation with comparable OT time in all five stages between groups (p > 0.05). The mean turnover time was 15.1 ± 13.5 min and the mean operative time was 123.0 ± 28.1 min. Intraoperative arterial blood gas (ABG) parameters were maintained in an optimal range. The complication rate was 2.0% (N = 2/102). CONCLUSION: Consistent OT efficiency was demonstrated with a dedicated spine team approach. Despite performing three AIS cases in a consecutive case operation list, patients' safety was not compromised as perioperative outcomes between groups were comparable.

Pseudarthrosis risk factors in lumbar fusion: a systematic review and meta-analysis.

This study presents a systematic literature review and meta-analysis of pseudarthrosis risk factors following lumbar fusion procedures. The odds ratio (OR) and 95% confidence interval (95% CI) were used for outcome measurements. The objective of this study was to identify the independent risk factors for pseudarthrosis after lumbar spinal fusion, which is crucial for mitigating morbidity and reoperation. Systematic searches in PubMed, Embase, and Scopus (1990-July 2021) were conducted using specific terms. The inclusion criteria included prospective and retrospective cohorts and case‒control series reporting ORs with 95% CIs from multivariate analysis. The quality assessment utilized the Newcastle-Ottawa scale. Meta-analysis, employing OR and 95% CI, assessed pseudarthrosis risk factors in lumbar fusion surgery, depicted in a forest plot. Of the 568 abstracts identified, 12 met the inclusion criteria (9 retrospective, 2006-2021). The 17 risk factors were categorized into clinical, radiographic, surgical, and bone turnover marker factors. The meta-analysis highlighted two significant clinical risk factors: age (95% CI 1.02-1.11; p = 0.005) and smoking (95% CI 1.68-5.44; p = 0.0002). The sole significant surgical risk factor was the number of fused levels (pooled OR 1.35; 95% CI 1.17-1.55; p < 0.0001). This study identified 17 risk factors for pseudarthrosis after lumbar fusion surgery, emphasizing age, smoking status, and the number of fusion levels. Prospective studies are warranted to explore additional risk factors and assess the impact of surgery and graft type.

Posterior spinal fusion for adolescent idiopathic scoliosis and the impact of postoperative intravenous dexamethasone supplementation.

Postoperative care pathways for adolescent idiopathic scoliosis patients undergoing posterior spinal fusion have demonstrated decreases in postoperative opioid consumption, improved pain control, and lead to decreased lengths of stay. Our objective was to implement postoperative steroids to reduce acute postoperative opioid consumption, pain scores, and length of stay. Dosing consisted of intravenous dexamethasone 0.1 mg/kg up to 4 mg per dose for a total of three doses at 8, 16, and 24 h postoperatively. As part of a quality initiative, we compared three cohorts of patients. The initial retrospective epidural cohort (EPI) (n = 59) had surgeon placed epidural catheters with infusion of ropivacaine 0.1% postoperatively for 18-24 h. Following an institutional change in postoperative care, epidural use was discontinued. A second cohort (n = 149), with prospectively collected data, received a surgeon placed erector spinae plane block and wound infiltration with a combination of liposomal and plain bupivacaine (LB). A third cohort (n = 168) was evaluated prospectively. This cohort received a surgeon placed erector spinae plane block and wound infiltration with liposomal and plain bupivacaine and additionally received postoperative dexamethasone for three doses (LB + D). Compared to the LB cohort, the LB + D cohort demonstrated statistically significant decreases in oral milligram morphine equivalents per kilogram at 0-24, 24-48, and 48-72 h. There was a statistically significant difference in median pain scores at 24-48 and 48-72 h in LB + D versus LB. The LB + D cohort's median length of stay in hours was significantly less compared to the LB cohort (52 h vs. 70 h, p < 0.0001). Postoperative intravenous dexamethasone was added to an established postoperative care pathway for patients undergoing posterior spinal fusion for idiopathic scoliosis resulting in decreased VAS pain scores, opioid consumption, and shorter length of stay.

Impact of Depression on Postoperative Medical and Surgical Outcomes in Spine Surgeries: A Systematic Review and Meta-Analysis.

Introduction: The relationship between psychiatric disorders, including depression, and invasive interventions has been a topic of debate in recent literature. While these conditions can impact the quality of life and subjective perceptions of surgical outcomes, the literature lacks consensus regarding the association between depression and objective perioperative medical and surgical complications, especially in the neurosurgical domain. Methods: MEDLINE (PubMed), EMBASE, PsycINFO, and the Cochrane Library were queried in a comprehensive manner from inception until 10 November 2023, with no language restrictions, for citations investigating the association between depression and length of hospitalization, medical and surgical complications, and objective postoperative outcomes including readmission, reoperation, and non-routine discharge in patients undergoing spine surgery. Results: A total of 26 articles were considered in this systematic review. Upon pooled analysis of the primary outcome, statistically significantly higher rates were observed for several complications, including delirium (OR:1.92), deep vein thrombosis (OR:3.72), fever (OR:6.34), hematoma formation (OR:4.7), hypotension (OR:4.32), pulmonary embolism (OR:3.79), neurological injury (OR:6.02), surgical site infection (OR:1.36), urinary retention (OR:4.63), and urinary tract infection (OR:1.72). While readmission (OR:1.35) and reoperation (OR:2.22) rates, as well as non-routine discharge (OR:1.72) rates, were significantly higher in depressed patients, hospitalization length was comparable to non-depressed controls. Conclusions: The results of this review emphasize the significant increase in complications and suboptimal outcomes noted in patients with depression undergoing spinal surgery. Although a direct causal relationship may not be established, addressing psychiatric aspects in patient care is crucial for providing comprehensive medical attention.

Socioeconomic differences in access to scoliosis care in the pediatric population.

PURPOSE: Adolescent idiopathic scoliosis (AIS) is a common spinal deformity affecting pediatric patients, with up to 10% requiring surgical intervention. Studies have shown disparities in these patients associated with race, ethnicity, and insurance type, but there is limited information on disparities that exist based on geographical parameters. In this study, we aim to explore the disparities in the care for AIS by looking at differences in the rates of readmission, infection, and revision between patients residing in rural and urban environments. METHODS: This is a retrospective cohort study utilizing the Pediatric Health Information System. Pediatric patients that underwent posterior spinal fusion (PSF) for AIS from October 2015 to July 2022 were included. Diagnoses and procedures were identified based on ICD-10 codes and internal tools built into the database. Descriptive statistics were used to summarize the data, including demographics, infection rates, readmission rates, and revision rates. T tests, Chi-squared tests, and logistic regression were used to assess differences between the rural and urban populations. We utilized STATA/SE 15.1 for all data analysis. RESULTS: 15,318 patients were included in the final cohort. Demographics and baseline characteristics were similar between the rural and urban patients, although more rural patients used Medicaid over commercial insurance (41.5% vs. 32.7%, p < 0.01), median household income was lower in rural patients (p < 0.01), and there was a higher proportion of Hispanic patients in the urban patient cohort (13.9% vs. 6.4%, p < 0.01). Complication rates were not significantly different between the urban and rural patient cohorts, although rural patients did have a significantly higher 90-day readmission rate (7.3% vs. 6.1%, p = 0.03) and higher rates of instrumentation removal (7.7% vs. 4.9%, p = 0.01). CONCLUSIONS: The surgical outcomes between rural and urban pediatric AIS patients undergoing PSF are comparable, although 90-day readmission rates and rates of instrumentation removal were higher in rural patients. Insurance status is likely a significant driver for the differences observed in this study. Future research is needed to better understand the reasons for these differences and to develop strategies to improve outcomes. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

The attainment of a patient acceptable symptom state in patients undergoing revision spine fusion.

INTRODUCTION: Revision lumbar fusion is most commonly due to nonunion, adjacent segment disease (ASD), or recurrent stenosis, but it is unclear if diagnosis affects patient outcomes. The primary aim of this study was to assess whether patients achieved the patient acceptable symptom state (PASS) or minimal clinically important difference (MCID) after revision lumbar fusion and assess whether this was influenced by the indication for revision. METHODS: We retrospectively identified all 1-3 level revision lumbar fusions at a single institution. Oswestry Disability Index (ODI) was collected at preoperative, three-month postoperative, and one-year postoperative time points. The MCID was calculated using a distribution-based method at each postoperative time point. PASS was set at the threshold of ≤ 22. RESULTS: We identified 197 patients: 56% with ASD, 28% with recurrent stenosis, and 15% with pseudarthrosis. The MCID for ODI was 10.05 and 10.23 at three months and one year, respectively. In total, 61% of patients with ASD, 52% of patients with nonunion, and 65% of patients with recurrent stenosis achieved our cohort-specific MCID at one year postoperatively with ASD (p = 0.78). At one year postoperatively, 33.8% of ASD patients, 47.8% of nonunion patients, and 37% of patients with recurrent stenosis achieved PASS without any difference between indication (p = 0.47). CONCLUSIONS: The majority of patients undergoing revision spine fusion experience significant postoperative improvements regardless of the indication for revision. However, a large proportion of these patients do not achieve the patient acceptable symptom state. While revision spine surgery may offer substantial benefits, these results underscore the need to manage patient expectations.

Successful Surgical Intervention and Remarkable Recovery in a Child With Traumatic Spondyloptosis.

More than 100% of the traumatic subluxation of one vertebral body over another in the coronal or sagittal plane is known as traumatic spondyloptosis, which typically results in the contusion of the spinal cord. It is an uncommon yet severe spinal column injury. Here, we present traumatic lumbosacral spondyloptosis at the L5 and S1 levels with complete spinal cord compression with paraplegia and bowel and bladder involvement. The patient underwent posterior spinal fusion (delta fixation) and decompression. The patient improved his motor and sensory deficits at one-month follow-up. By the eighth-month follow-up, the patient had recovered entirely from his motor and sensory deficits and was stable for the entire year.

Can zoledronic acid reduce the risk of cage subsidence after oblique lumbar interbody fusion combined with bilateral pedicle screw fixation in the elderly population? A retrospective study.

BACKGROUND: The objective of this study was to evaluate the potential of zoledronic acid for reducing the incidence of cage subsidence and enhancing interbody fusion rates following oblique lumbar interbody fusion (OLIF) surgery, particularly as the first reported evidence of the role of zoledronic acid combined with OLIF. METHODS: A retrospective analysis was conducted on data from 108 elderly patients treated for degenerative lumbar diseases using OLIF combined with bilateral pedicle screw fixation from January 2018 to December 2021. Patients were divided into the zoledronic acid (ZOL) group (43 patients, 67 surgical segments) and the control group (65 patients, 86 surgical segments). A comparative analysis of the radiographic and clinical outcomes between the groups was performed, employing univariate and multivariate regression analyses to explore the relationships between cage subsidence and the independent variables. RESULTS: Radiographic outcomes, including anterior height, posterior height, disc height, coronal disc angle, foraminal height, and lumbar lordosis, were not significantly different between the two groups. Similarly, no statistically significant differences were noted in the back visual analog scale (VAS) scores and Oswestry Disability Index (ODI) scores between the groups. However, at the 1-year follow-up, the leg VAS score was lower in the ZOL group than in the control group (P = 0.028). The ZOL group demonstrated a notably lower cage subsidence rate (20.9%) than did the control group (43.0%) (P < 0.001). There was no significant difference in the interbody fusion rate between the ZOL group (93.0%) and the control group (90.8%). Non-use of zoledronic acid emerged as an independent risk factor for cage subsidence (OR = 6.047, P = 0.003), along with lower bone mineral density, lower postoperative anterior height, and concave endplate morphology. The model exhibited robust discriminative performance, with an area under the curve (AUC) of 0.872. CONCLUSION: The administration of zoledronic acid mitigates the risk of cage subsidence following OLIF combined with bilateral pedicle screw fixation in elderly patients; however, it does not improve the interbody fusion rate.

Surgical vs ultrasound-guided lumbar erector spinae plane block for pain management following lumbar spinal fusion surgery.

PURPOSE: Spinal surgery is associated with severe diffuse pain in the postoperative period. Effective pain management plays an essential role in reducing morbidity and mortality. This study is designed to compare the ultrasound-guided erector spinae plane (ESP) block and surgical infiltrative ESP block for postoperative analgesia management after lumbar spinal fusion surgery. METHODS: The patients who underwent two or three levels of posterior lumbar spinal fusion surgery were randomly allocated into one of three groups with 30 patients each (Group SE = Surgical ESP block; Group UE = ultrasound-guided ESP block; Group C = Controls). The primary aim was to compare postoperative opioid consumption, and the secondary aim was to evaluate postoperative dynamic and static pain scores and the incidence of opioid-related adverse effects. RESULTS: There was a significant difference in terms of opioid consumption, rescue analgesia on demand, and both static and dynamic pain scores between groups at all time periods (p < 0.05). Group SE and Group UE had lower pain scores and consumed fewer opioids than the controls (p < 0.05). However, the Group UE had lower pain scores and opioid consumption than the Group SE. The sedation level of patients was significantly higher in the control group than in the other two groups. Also, nausea was more common in controls than in the other groups. CONCLUSION: While both surgical and ultrasound-guided ESP blocks reduced opioid consumption compared to the controls, the patients who received ultrasound-guided ESP blocks experienced better postsurgical pain relief than those in the other groups (surgical ESP and controls).

Lower Limb Deep Venous Thrombosis After Posterior Spinal Fusion as an Initial Manifestation of Factor V Leiden Mutation in a Pediatric Patient: A Case Report.

Deep venous thrombosis (DVT) is a serious condition in which a blood clot forms in a deep vein, usually of the lower extremity. In pediatric orthopedic surgery, the incidence of thrombotic events is rare. This is a case presentation of a 12-year-old female patient without previous events or a family history of thrombotic events who underwent a posterior spinal fusion due to severe adolescent idiopathic scoliosis. The patient developed a DVT due to an underlying Factor V Leiden mutation. The purpose of this case report is to create awareness, facilitate the diagnosis and management, and aid in future interventions and clinical outcomes.

Pre-operative carbohydrate drink in pediatric spine fusion: randomized control trial.

PURPOSE: As rapid discharge protocols for pediatric spine fusion shorten stays, gastrointestinal (GI) complications are uncovered and cause delays in discharge. A pre-operative carbohydrate (CHO) drink has been shown to improve perioperative GI symptoms and functional return but has not been examined in pediatric spine patients. We aimed to determine if a preoperative CHO drink is safe in pediatric spine fusion patients, and if it improves their comfort scores and return of bowel function. METHODS: We prospectively randomized ASA-1 and -2 pediatric spine fusion patients to either a pre-anesthesia carbohydrate drink 2 h prior to surgery or to a control group (standard 8 h NPO), blinded to surgical team. We documented time to return to flatus, bowel movement, GI symptoms, and comfort scores for 72 h post-operatively or until discharge. RESULTS: 62 patients were randomized. There was no significant differences between the groups' pre-operative characteristics, surgical details, nor post-operative morphine dose equivalents, except for EBL (405 cc control, 340 cc CHO drink, p = 0.044). There were no perioperative complications related to ingestion of the CHO drink. CHO group had a positive trend for earlier return of flatus (21% vs. 3% return at 12 h), and comfort scores for anxiety and abdominal pain, but no statistically significant differences. There was no difference in length of stay or time to first bowel movement. CONCLUSION: There were no complications related to ingestion of a CHO drink 2 h prior to pediatric spinal fusion surgery. Further studies are needed to develop a study blinded to the participants with larger sample size. Level of evidence I.

Synthesis and evaluation of a novel vancomycin-infused, biomimetic bone graft using a rat model of spinal implant-associated infection.

Background: Postoperative infection is a complication of spinal fusion surgery resulting in increased patient morbidity. Strategies including intraoperative application of powdered vancomycin have been proposed to reduce the incidence of infection; however, such antimicrobial effects are short-lived. Methods: Instrumentation of the L4-L5 vertebrae was performed mimicking pedicle screw and rod fixation in 30 rats. Titanium instrumentation inoculated with either PBS or 1×105 CFU bioluminescent MRSA, along with biomimetic bone grafts infused with varying concentrations of vancomycin and 125 µg of rhBMP-2 (BioMim-rhBMP-2-VCM) were implanted prior to closure. Infection was quantified during the six-week postoperative period using bioluminescent imaging. Arthrodesis was evaluated using micro-CT. Results: Infected animals receiving a bone graft infused with low-dose (0.18 mg/g) or high-dose vancomycin (0.89 mg/g) both exhibited significantly lower bioluminescent signal over the six-week postoperative period than control animals inoculated with MRSA and implanted with bone grafts lacking vancomycin (p=.019 and p=.007, respectively). Both low and high-dose vancomycin-infused grafts also resulted in a statistically significant reduction in average bioluminescence when compared to control animals (p=.027 and p=.047, respectively), independent of time. MicroCT analysis of animals from each group revealed pseudoarthrosis only in the control group, suggesting a correlation between infection and pseudoarthrosis. MRSA-inoculated control animals also had significantly less bone volume formation on micro-CT than the PBS-inoculated control cohort (p<.001), the MRSA+low-dose vancomycin-infused bone graft cohort (p<.001), and the MRSA+high-dose vancomycin-infused bone graft cohort (p<.001). Conclusion: BioMim-rhBMP-2-VCM presents a novel tissue engineering approach to simultaneously promoting arthrodesis and antimicrobial prophylaxis in spinal fusion. Despite mixed evidence of potential osteotoxicity of vancomycin reported in literature, BioMim-rhBMP-2-VCM preserved arthrodesis and osteogenesis with increasing vancomycin loading doses due to the graft's osteoinductive composition.

Logistic regression model predicts early surgical site infection after spinal fusion: a retrospective cohort study.

OBJECTIVE: This study aimed to develop a diagnostic model for predicting early surgical site infection (SSI) based on postoperative inflammatory markers after spinal fusion surgery. METHODS: In this retrospective study, we analysed the trends of inflammatory markers between SSI and non-SSI groups. The data were randomly divided into training cohort and validation cohort (ratio 7:3). The variables for SSI were analysed using stepwise logistic regression to develop the prediction model. To evaluate the model, we analysed its sensitivity, specificity, positive predictive value, negative predictive value, as well as the area under the curve in the validation cohort. Calibration plots and decision curve analysis were employed to assess the calibration and clinical usefulness of the model. FINDINGS: We observed significant changes in inflammatory markers on the seventh day after surgery. The prediction model included four variables on the seventh day after surgery: body temperature, C-reactive protein, erythrocyte sedimentation rate and neutrophil counts. After binary processing of these data, the simplified model achieved an area under the curve of 0.86 (95% confidence interval (CI): 0.81-0.92) in the training cohort and 0.9 (95% CI: 0.82-0.98) in the validation cohort. Calibration plots and decision curve analysis demonstrated that the proposed model was effective for the diagnosis of SSI. CONCLUSION: We developed and validated a prediction model for diagnosing early infection after spinal fusion.

Mesenchymal Stem Cell Exosomes Enhance Posterolateral Spinal Fusion in a Rat Model.

Spinal fusion, a common surgery performed for degenerative lumbar conditions, often uses recombinant human bone morphogenetic protein 2 (rhBMP-2) that is associated with adverse effects. Mesenchymal stromal/stem cells (MSCs) and their extracellular vesicles (EVs), particularly exosomes, have demonstrated efficacy in bone and cartilage repair. However, the efficacy of MSC exosomes in spinal fusion remains to be ascertained. This study investigates the fusion efficacy of MSC exosomes delivered via an absorbable collagen sponge packed in a poly Ɛ-caprolactone tricalcium phosphate (PCL-TCP) scaffold in a rat posterolateral spinal fusion model. Herein, it is shown that a single implantation of exosome-supplemented collagen sponge packed in PCL-TCP scaffold enhanced spinal fusion and improved mechanical stability by inducing bone formation and bridging between the transverse processes, as evidenced by significant improvements in fusion score and rate, bone structural parameters, histology, stiffness, and range of motion. This study demonstrates for the first time that MSC exosomes promote bone formation to enhance spinal fusion and mechanical stability in a rat model, supporting its translational potential for application in spinal fusion.

3D CT modeling demonstrates the anatomic feasibility of S1AI screw trajectory for spinopelvic fixation in neuromuscular scoliosis.

PURPOSE: In patients with neuromuscular scoliosis undergoing posterior spinal fusion, the S2 alar iliac (S2AI) screw trajectory is a safe and effective method of lumbopelvic fixation but can lead to implant prominence. Here we use 3D CT modeling to demonstrate the anatomic feasibility of the S1 alar iliac screw (S1AI) compared to the S2AI trajectory in patients with neuromuscular scoliosis. METHODS: This retrospective study used CT scans of 14 patients with spinal deformity to create 3D spinal reconstructions and model the insertional anatomy, max length, screw diameter, and potential for implant prominence between 28 S2AI and 28 S1AI screw trajectories. RESULTS: Patients had a mean age of 14.42 (range 8-21), coronal cobb angle of 85° (range 54-141), and pelvic obliquity of 28° (range 4-51). The maximum length and diameter of both screw trajectories were similar. S1AI screws were, on average, 6.3 ± 5 mm less prominent than S2AI screws relative to the iliac crests. S2AI screws were feasible in all patients, while in two patients, posterior elements of the lumbar spine would interfere with S1AI screw insertion. CONCLUSION: In this cohort of patients with neuromuscular scoliosis, we demonstrate that the S1AI trajectory offers comparable screw length and diameter to an S2AI screw with less implant prominence. An S1AI screw, however, may not be feasible in some patients due to interference from the posterior elements of the lumbar spine.

Revision Lumbar Spine Surgeries: An Early Career Neurosurgery Experience.

BACKGROUND: The aims and ambitions of a surgeon in the early years of his professional career are to make a good reputation by providing excellent patient outcomes and avoiding complex and difficult surgeries. Revision lumbar spine surgeries (RLSSs) pose a significant challenge in terms of surgical management, as the moribund anatomy increases the risk of complications, adding to an unlikely outcome. OBJECTIVE: We conducted this study to determine the clinical indications and outcomes of RLSSs performed by an early career neurosurgeon. MATERIALS AND METHODS: This cross-sectional study was conducted after approval from the hospital's ethical committee, and data was collected in late December of 2022 and early January 2023, from retrospective records for a single early career neurosurgeon. A form was filled with each patient's data, such as age, gender, time since surgery, indication for surgery, operative findings, types of surgery performed, etc. All variables were noted for the patient and were further categorized, based on the clinical records, into many sub-categories. RESULTS: Almost 400 lumbar spine surgeries were performed by the surgeon, and about 45 (11.25%) were revision surgeries, and the full record was available for 42 surgeries. These patients' ages ranged from 22 to 70 years, and the mean age was about 46.74±13.29 SD. The common symptoms leading to revision surgeries were numbness and pain in 17 (40.5%) patients each; common per-operative findings were recurrent disc in eight patients (19%), infection in nine patients (21.4%), and fibrosis/adhesions in 16 (38.1%); most common surgeries performed were diskectomy in 11 (26.2%) and diskectomy plus release of adhesions in 12 (28.6%); complications occurred in 14 (33%), and good to excellent outcomes was recorded in 29 (69%) cases.  Conclusion: RLSSs are difficult compared to first-time lumbar spine surgeries, and the moribund anatomy predisposes to complications, and better shall be dealt with great care and, at the minimum, shall be embarked upon as a team.