Jean Albert Ouellet

Background: Tranexamic acid (TXA) is increasingly used to reduce perioperative blood loss during scoliosis surgery; however, its effectiveness in pediatric patients with non-idiopathic scoliosis remains underexplored. Unlike adolescent idiopathic scoliosis, non-idiopathic scoliosis is frequently associated with neuromuscular, syndromic, or other underlying disorders that increase surgical complexity and may limit the generalizability of evidence from idiopathic populations. This systematic review and meta-analysis evaluated the impact of TXA on surgical outcomes in pediatric patients undergoing posterior spinal fusion for non-idiopathic scoliosis. Methods: This analysis encompassed five studies (comprising one randomized controlled trial and four observational studies) involving a total of 230 patients (TXA group: 98; control group: 132). The primary outcomes were estimated blood loss and the volume of packed red blood cells (PRBCs) transfused. Secondary outcomes included total transfusion amount, operation duration, complications, cell salvage application, preoperative hematocrit levels and blood loss percentage. A random-effects model was used. Mean difference (MD) was used for continuous outcomes, and odds ratio (OR) for dichotomous variables, both with 95% confidence intervals (CIs). Results: The use of TXA during posterior fusion surgery showed to be of benefit and was associated with significantly less estimated blood loss (p < 0.0001) and cell salvage volume transfusion (p < 0.0001). The remaining secondary outcomes did not show significant differences when compared with the control. Conclusion: Current evidence suggests that TXA is an effective blood conservation strategy in pediatric patients undergoing posterior spinal fusion for non-idiopathic scoliosis. However, the available evidence remains limited, particularly regarding perioperative complications, and further high-quality prospective studies are required to strengthen the evidence base. Clinical relevance: Exploring the use of TXA in scoliosis surgery has the potential to influence the standard of care, especially if associated with significantly more desirable post-operative and long-term outcomes.

Purpose Early-onset scoliosis (EOS) is a challenging condition for spinal surgeons. Growing rods represent the standard treatment for patients requiring surgery, and magnetically controlled growing rods (MCGR) are increasingly adopted. Many patients ultimately transition to posterior spinal fusion (PSF), although the necessity of definitive fusion remains debated. This systematic review and single-arm meta-analysis aimed to evaluate radiographic and surgical outcomes of PSF following MCGR treatment. Methods A systematic literature search was conducted in PubMed, Google Scholar, Medline, Scopus, Embase, and the Cochrane Library up to April 2025, following PRISMA guidelines. Eligible studies were identified using a PIO (Population, Intervention, Outcome) framework. Extracted data included demographic, radiographic, and surgical outcomes, including complications. A single-arm meta-analysis compared pre- and post-PSF radiographic parameters (main curve magnitude, thoracic kyphosis (TK), T1–T12 and T1–S1 lengths). Risk of bias was assessed using the MINORS tool. Results Eight retrospective studies were included (370 patients), of which six were eligible for quantitative synthesis. The meta-analysis demonstrated significant improvements in all radiographic parameters (main curve magnitude, TK, T1–T12 and T1–S1 lengths, p < 0.05). The pooled overall postoperative complication rate after PSF was 17.2%. Conclusions PSF appears to be a viable treatment option following MCGR, providing significant deformity correction with a relatively acceptable complication rate. Nevertheless, the current evidence is limited by small, retrospective cohorts. Larger, prospective studies with standardized reporting of surgical variables and clinical outcomes are needed to better define the role of final fusion and to optimize treatment protocols.

Pain is common in adolescents with idiopathic scoliosis (AIS), yet its distribution is heterogeneous and mechanisms remain incompletely understood. Beyond structural factors, emerging evidence suggests a psychosocial component with links to mental health. This study examined the relationship between preoperative pain and its distribution with mental health in Lenke type 1-2 AIS patients undergoing posterior spinal fusion. In this prospective single-center cohort study (July 2023-July 2025), Lenke type 1-2 AIS patients completed the revised SRS-22 (SRS-22r) questionnaire and a standardized 10-region pain diagram prior to corrective surgery. Concurrently, coronal and sagittal parameters were measured on EOS imaging. Group comparisons of SRS-22r domain scores between patients with and without pain were performed using the Mann-Whitney U test. An a priori power analysis (80% power, medium effect size 0.3, α = 0.05) indicated that a minimum of 10 patients per parameter was required to detect the intended effect. Univariable linear regressions were conducted to examine the associations between SRS-22r mental health scores, pain regions, and radiographic variables; models were run both unadjusted and adjusted for age, sex, and primary Cobb angle (α < .05). Sixty patients (47 female; mean age 16.1 ± 2.3 years) were included and divided into a pain group (N = 42) and a no-pain group (N = 18). Patients without preoperative pain demonstrated significantly higher SRS-22r scores across all domains, with the most pronounced difference in mental health (p < 0.001). Within the pain group, neck region pain (R1) was reported by 21.4% of patients and was independently associated with lower mental health scores (β = -0.54, p = .029). No other pain regions or radiographic parameters were significantly associated with mental health outcomes. In this study cohort, preoperative axial neck pain was associated with poorer mental health scores, whereas patients without pain consistently reported higher SRS-22r outcomes across all domains. No associations were found with radiographic parameters, underscoring the role of psychosocial factors in AIS and the need for further multicenter studies.

Background: Low back pain is a global health problem directly related to intervertebral disc (IVD) degeneration. Senolytic drugs (RG-7112 and o-Vanillin) target and remove senescent cells from IVDs in vitro, improving tissue homeostasis. One drawback of using a single senolytic agent is the failure to target multiple senescent antiapoptotic pathways. This study aimed to determine if combining the two senolytic drugs, o-Vanillin and RG-7112, could more efficiently remove senescent cells and reduce the release of inflammatory factors and pain mediators in cells from degenerating human IVDs than either drug alone. Methods: Preliminary data evaluating multiple concentrations of o-Vanillin and RG-7112 led to the selection of four treatment groups. Monolayer and pellet cultures of cells from painful degenerate IVDs were exposed to TLR-2/6 agonist. They were then treated with the senolytics o-Vanillin and RG7112 alone or combined. p16^ink4a, Ki-67, caspase-3, inflammatory mediators, and neuronal sprouting were assessed. Results: Compared to the single treatments, the combination of o-Vanillin and RG-7112 significantly reduced the amount of senescent IVD cells, proinflammatory cytokines, and neurotrophic factors. Moreover, both single and combination treatments significantly reduced neuronal sprouting in rat adrenal pheochromocytoma (PC-12 cells). Conclusions: Combining o-Vanillin and RG-7112 greatly enhanced the effect of either senolytic alone. Together, these results support the potential of senolytics as a promising treatment for IVD-related low back pain.

Adolescent idiopathic scoliosis (AIS) is a poorly understood deformity of the thoracolumbar spine which affects the intervertebral discs (IVDs) and the articular facet joints. The knowledge concerning facet joints in this context is very limited, although facet joint degeneration is a known contributor of back pain. In this study, a comprehensive investigation was performed to characterize the facet joint chondrocytes and extracellular matrix within the scoliotic spine. Surgically removed articular facet joint tissues were collected from patients undergoing spinal corrective surgery for AIS deformities, while non‐scoliotic articular facet joint tissues were obtained from cadaveric organ donors. Alterations in cartilage tissue structure were evaluated histologically with safranin‐O fast green and a modified OARSI grading scale. Pro‐inflammatory cytokines, matrix‐degrading proteases, and fragmented matrix molecules associated with cartilage degradation were analyzed by immunohistochemistry and western blotting. Safranin‐O fast green staining revealed that young scoliotic facet joints show clear signs of degeneration with substantial proteoglycan loss, similar to osteoarthritis (OA). The proteoglycan levels were significantly lower than in healthy asymptomatic non‐scoliotic control individuals. In comparison to controls, scoliotic articular facets showed increased cell density, increased expression of the proliferation marker Ki‐67, and higher expression of MMP‐3, MMP‐13, and IL‐1β. Expression and fragmentation of the small leucine‐rich proteins (SLRPs) chondroadherin, decorin, biglycan, lumican, and fibromodulin were analyzed with western blot. Chondroadherin and decorin were fragmented in cartilage from patients with a curve greater than 70°, whereas biglycan and fibromodulin did not show curve‐related fragmentation. AIS facet joint cartilage shows hallmarks of OA including proteoglycan loss, overexpression of pro‐inflammatory mediators, increased synthesis of matrix‐degrading proteases and fragmentation of SLRPs. As with patients with age‐related OA, the premature joint degeneration seen in scoliotic patients is likely to contribute to the pain perceived in some individuals.

Study DesignRetrospective cohort study.PurposeThe purpose of this study was to assess the rate of blood transfusion after cervical fusion surgery, and its effect on complication rates.Overview of LiteratureCervical spine fusions have gained interest in the literature since these procedures are now ever more frequently being performed in an outpatient setting with few complications.MethodsThe American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent cervical fusion from 2010 to 2013. Multivariate regression analysis was used to determine postoperative complications associated with transfusion and cervical fusion.ResultsWe identified 11,588 patients who had cervical fusion between 2010 and 2013. The rate of blood transfusion following cervical fusion found to be 1.47%. All transfused patients were found to have increased risk of venous thromboembolism (TBE) (odds ratio [OR], 3.19; 95% confidence interval [95% CI], 1.16–8.77), myocardial infarction (MI) (OR, 9.12; 95% CI, 2.53–32.8), increased length of stay (LOS) (OR, 28.03; 95% CI, 14.28–55.01) and mortality (OR, 4.14; 95% CI, 1.44–11.93). Single level fusion had increased risk of TBE (OR, 3.37; 95% CI, 1.01–11.33), MI (OR, 10.5; 95% CI, 1.88–59.89), and LOS (OR, 14.79; 95% CI, 8.2–26.67). Multilevel fusion had increased risk of TBE (OR, 5.64; 95% CI, 1.15–27.6), surgical site infection (OR, 16.29; 95% CI, 3.34–79.49), MI (OR, 10.84; 95% CI, 2.01–58.55), LOS (OR, 26.56; 95% CI, 11.8–59.78), and mortality (OR, 10.24; 95% CI, 2.45–42.71). Patients who had anterior cervical discectomy and fusion surgery and received a transfusion had an increased risk of TBE (OR, 4.87; 95% CI, 1.04–22.82), surgical site infection (OR, 9.73; 95% CI, 2.14–44.1), MI (OR, 9.88; 95% CI, 1.87–52.2), increased LOS of more than 2 days (OR, 28.34; 95% CI, 13.79–58.21) and increase in mortality (OR, 6.3; 95% CI, 1.76–22.48). While, transfused patients who had posterior fusion surgery had increased risk of MI (OR, 10.45; 95% CI, 1.42–77.12) and increased LOS of more than 6 days (OR, 4.42; 95% CI, 2.68–7.29).ConclusionsOur results demonstrate that although cervical fusions can be done as outpatient procedures special precautions and investigations should be done for patients who receive transfusion after cervical fusion. These patients are demonstrated to have higher rate of MI, TBE, wound infection and mortality when compared to those who do not receive transfusion.

Retrospective cohort study. Several studies have shown that the accuracy of pedicle screw placement significantly improves with use of computer-assisted surgery (CAS). Yet few studies have compared the incidence of postoperative complications between CAS and conventional techniques. The objective of this study is to determine the difference in postoperative complication rates between CAS and conventional techniques in spine surgery. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients who underwent posterior lumbar fusion from 2011 to 2013. Multivariate analysis was conducted to demonstrate the difference in postoperative complication rates between CAS and conventional techniques in spine surgery. Out of 15 222 patients, 14 382 (95.1%) were operated with conventional techniques and 740 (4.90%) were operated with CAS. Multivariate analysis showed that patients in the CAS group had fewer odds to experience adverse events postoperatively (odds ratio [OR] = 0.57, P < .001). Minor adverse events occurred in 2905 (20.2%) patients in the conventional group and in 98 (13.2%) patients in the CAS group (OR = 0.57, P < .001). Blood transfusion was present in 2488 (17.3%) of the patients in the conventional group compared to 81 (11.0%) of the patients in the CAS group (OR = 0.56, P < .001). The mean operative time in the conventional group was 205.2 ± 106.1 minutes, and it was 227.0 ± 111.9 minutes in the CAS group. This difference was statistically significant (r = 20.14, P < .001). This article examined the complications in lumbar spinal surgery with or without the use of CAS. These results suggest that CAS may provide a safer technique for implant placement in lumbar fusion surgeries.

Introduction: Excessive mechanical loading of intervertebral discs (IVDs) is thought to alter matrix properties and influence disc cell metabolism, contributing to degenerative disc disease and development of discogenic pain. However, little is known about how mechanical strain induces these changes. This study investigated the cellular and molecular changes as well as which inflammatory receptors and cytokines were upregulated in human intervertebral disc cells exposed to high mechanical strain (HMS) at low frequency. The impact of these metabolic changes on neuronal differentiation was also explored to determine a role in the development of disc degeneration and discogenic pain. Methods: Isolated human annulus fibrosus (AF) and nucleus pulposus (NP) cells were exposed to HMS (20% cyclical stretch at 0.001 Hz) on high-extension silicone rubber dishes coupled to a mechanical stretching apparatus and compared to static control cultures. Gene expression of Toll-like receptors (TLRs), neuronal growth factor (NGF) and tumour necrosis factor α (TNFα) was assessed. Collected conditioned media were analysed for cytokine content and applied to rat pheocromocytoma PC12 cells for neuronal differentiation assessment. Results: HMS caused upregulation of TLR2, TLR4, NGF and TNFα gene expression in IVD cells. Medium from HMS cultures contained elevated levels of growth-related oncogene, interleukin 6 (IL-6), IL-8, IL-15, monocyte chemoattractant protein 1 (MCP-1), MCP-3, monokine induced by γ interferon, transforming growth factor β1, TNFα and NGF. Exposure of PC12 cells to HMS-conditioned media resulted in both increased neurite sprouting and cell death. Conclusions: HMS culture of IVD cells in vitro drives cytokine and inflammatory responses associated with degenerative disc disease and low-back pain. This study provides evidence for a direct link between cellular strain, secretory factors, neoinnervation and potential degeneration and discogenic pain in vivo.