BACKGROUND CONTEXT:Autologous bone graft remains the clinical standard in spinal fusion due to its reliable performance. Characterization of the biological mechanism underlying the clinical superiority of autologous bone graft in spinal fusion remains incomplete. The field is divided between "creeping substitution," which posits the graft as a passive scaffold whose cells perish, and the "cellular hypothesis," which argues for an active contribution from viable donor cells. PURPOSE:This study aimed to build upon prior work by further characterizing graft-derived cell survival after transplantation and identify the biological mechanisms by which these cells may contribute to spinal fusion. STUDY DESIGN:We employed an immunocompetent "sibling-pair" murine posterolateral fusion model (L3-L4) of Iliac bone grafting for this study. METHODS:Autologous Iliac bone grafts from fluorescent reporter mice were transplanted into nonfluorescent siblings. A panel of inducible Cre-lox reporter lines (CAG, Col1a1, Sox9, and Aggrecan) was used to trace the fate of specific graft-derived cell populations. A pregrafting induction strategy was used to label mature cells at harvest, while a postgrafting induction strategy identified donor progenitor cells that survived and differentiated in vivo. Fusion masses were analyzed at 2 and 6 weeks following grafting via microcomputed tomography, histology, and fluorescence microscopy. RESULTS:Pan-cellular (CAG-Cre) tracing suggests robust donor cell survival and integration into the 2 and 6-week fusion masses. In contrast, prelabeled grafted mature osteoblasts and osteocytes (Col1a1-Cre) were largely absent at all time points, suggesting this population does not meaningfully survive transplantation. Postgrafting induction of Col1a1-Cre mice revealed the emergence of numerous new, donor-derived osteoblasts at 2 and 6 weeks, suggesting their origin from an unlabeled progenitor pool. Additionally, postgrafting induction of chondrocyte-lineage reporters (Sox9-Cre, Aggrecan-Cre) demonstrated the appearance of donor-derived chondrocytes at 2 weeks, which subsequently transitioned into osteocytes within the mature bone by 6 weeks, suggesting endochondral ossification. CONCLUSIONS:These findings builds on prior work supporting the "cellular hypothesis," which argues that autologous bone grafts contribute viable cells. Furthermore, our findings suggest a model of "Skeletal Stem and Progenitor Cells (SSPC)-driven Adaptation," where the iliac crest bone graft serves as a vehicle for resilient SSPCs. These progenitors, rather than mature osteoblasts, appear to survive transplantation and adapt to the avascular fusion bed by initiating endochondral ossification to form the fusion mass. CLINICAL SIGNIFICANCE:This suggests that the clinical focus on mature "osteogenic" cells may be complemented by consideration of SSPC populations. Autograft quality may be defined, in part, by its SSPC content. This provides an additional potential benchmark for evaluating autograft quality and developing cell-based biologics. Furthermore, these findings have potential implications for intraoperative decisions regarding graft handling and harvesting to preserve SSPC-rich regions such as periosteum.

Background:Plate fixation in skeletally immature children can cause angular deformity with longitudinal growth even when the plate does not overlie the adjacent physis. While this phenomenon has been described for the distal femur, angular deformity has not been reported following plating in other long bones. The aim of the study was to characterize whether sagittal-plane deformity occurs following volar plating of radius fractures in skeletally immature children and to determine associated risk factors. Methods:A retrospective review of volar plating of acute radius fractures in children with an open distal radius physis at a single institution was completed. In patients with at least 4 months of follow-up, the first radiograph and the last follow-up radiograph were evaluated for any change in sagittal angulation distal to the plate. Demographic information was obtained from the electronic medical record. Linear regression analysis was used to determine if distance from the plate to the physis, follow-up time, age, or coexisting ulnar fracture was predictive of any observed changes in angulation. Results:Sixty-one acute radius fractures treated with volar plating at a mean age of 12.1 years (67% male, 70.5% White, 90.2% non-Hispanic) were included. When analyzing by fracture location, 78% (21/27) of the distal-third radius fractures with appropriate follow-up developed at least 10° of apex volar angular deformity, with 44% (12/27) exhibiting greater than 20°. Middle-third and proximal-third fractures did not exhibit similar degrees of angulation (only 13% [4/30] and 0% [0/4] of included patients developed more than 10° of deformity, respectively). Linear regression analysis revealed distance of the plate to the physis and follow-up time to be strong predictors of angulation (both p < 0.0001). Conclusions:Children with radius fractures, particularly those in the distal-third, treated with a volar plate may develop apex volar angular deformity. While the exact rate of this phenomenon is unclear, these findings underscore the importance of strict surgical indications and vigilant postoperative monitoring beyond fracture healing, and represent a paradigm shift in understanding growth modulation following plating. Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background:Avascular necrosis (AVN) is a devastating complication of pediatric septic arthritis (SA). While traditionally attributed to increased intra-articular pressure, emerging evidence suggests that the host's systemic response to infection may contribute to ischemic injury. We hypothesized that an immunocoagulopathic phenotype characterized by extreme inflammation and platelet consumption would identify children at the highest risk of developing AVN. Methods:Following institutional review board approval, children aged younger than 18 years diagnosed with SA between 2010 and 2016 were retrospectively identified from a multicenter database. The primary outcome was the development of AVN. Demographic, clinical, microbiologic, and early laboratory variables were collected. Multivariable logistic regression using Firth's penalized likelihood method was used to account for rare events. Subgroup-level predicted risks of AVN were calculated based on combinations of dichotomized laboratory markers. Results:Among 616 children with SA, 23 developed AVN (incidence, 3.7%). Patients with AVN demonstrated greater early inflammatory burden, including higher C-reactive protein (CRP) levels, lower platelet counts, and more frequent positive blood and tissue cultures. In multivariable analysis, extreme CRP elevation (>160 mg/L) and relative thrombocytopenia (<245 × 103/µL) were each associated with nearly 7-fold increased odds of AVN, while elevated admission white blood cell count (>9.3×103/µL) and erythrocyte sedimentation rate (>60 mm/h) were associated with approximately threefold increased odds. A prediction model using these markers demonstrated excellent discrimination (area under the curve, 0.85), with an estimated AVN risk of 43% in the highest-risk group. Conclusions:In this multicenter cohort, AVN occurred in 3.7% of children with SA. The development of AVN was strongly associated with an immunocoagulopathic phenotype, defined by extreme inflammation (CRP >160 mg/L) and coagulopathy (relative thrombocytopenia <245 × 103/µL). These findings support the hypothesis that pathological immunothrombosis, rather than mechanical pressure alone, drives ischemic injury in SA. Early recognition of this profile identifies patients who may benefit from heightened surveillance and aggressive perfusion-sparing management. Level of Evidence:Level IV, prognostic. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND CONTEXT:The common surgical approach in posterior spinal fusion (PSF) conflicts with basic principles of bone repair and may lead to high failure rates. In recent years, experimental data has shown that the periosteum plays an indispensable role in fracture bone repair both for skeletal stem/progenitor cells (SSPCs) and for angiogenesis promotion. However, the role of the periosteum in spinal fusion remains experimentally poorly defined. Furthermore, current surgical approach often involves electrocautery to achieve subperiosteal dissection. However, the impact of this electrocautery remains not fully defined. We hypothesize that the periosteum is a potent driver of spinal fusion, and that its excessive ablation through electrocautery can be a significant iatrogenic contributor to reduced bone formation. PURPOSE:This study investigates the periosteum's contribution to spinal fusion and how electrocautery, commonly used for subperiosteal dissection, impacts this contribution. STUDY DESIGN:A nondecorticated murine PSF model compared bone formation after sharp dissection with electrocautery (Caut) versus sharp dissection without electrocautery (Sharp). A nondecorticated model was utilized to isolate the contributions of the periosteum without decortication as a confounding variable. METHODS:Bone formation and integration were evaluated using microCT and histology. Pulse-chase lineage tracing in Aggrecan CreERT2+/Ai9+ mice tracked skeletal stem/progenitor cell (SSPC) source and differentiation pathway. This model identifies mostly cells committed to the chondrogenic lineage during regeneration. Angiogenesis was assessed with Microfil, including 2D and 3D reconstructions. RESULTS:Bone formation was significantly lower on the cauterized side (p=.0002; p<.0001) 6 weeks after surgery. Sharp dissection without electrocautery triggered a periosteum-driven regenerative process similar to fracture repair, involving both endochondral and intramembranous ossification. Electrocautery abolished this response and significantly decreased periosteum-derived chondrogenesis (p=.0009). Angiogenesis was also reduced on the cauterized side (p=.0367). Without surgical decortication, new bone integrated into the native cortex through biological remodeling, indicating that surgical decortication may not be necessary. CONCLUSION:The periosteum is a potent driver of PSF bone formation through combined endochondral and intramembranous ossification, achieving integration without surgical decortication. CLINICAL SIGNIFICANCE:Monopolar electrocautery can destroy key regenerative contributions of the periosteum in PSF, cautioning the excessive use of monopolar electrocautery in surgical practices. More research is needed to determine the impact of alternate means of achieving hemostasis such as bipolar on bone formation, as these may better preserve periosteal tissue.

Necrotizing soft-tissue infections (NSTIs) are rapidly progressive and highly lethal, with diagnostic uncertainty contributing to treatment delays and mortality rates approaching 30%. To address this challenge, a multi-center clinical trial has been initiated to evaluate dynamic contrast-enhanced fluorescence imaging (DCE-FI) with indocyanine green as a rapid diagnostic tool. This technology enables visualization of microvascular thrombi characteristic of NSTIs, distinguishing them from less severe infections. The trial engages seven tertiary centers within a collaborative NSTI study group. This presentation will focus on the execution and implementation of this complex, multi-institutional study, including processes for protocol harmonization, regulatory coordination, and standardized imaging workflows. A key element of implementation was the development of real-time, smartphone-accessible didactic materials to ensure consistent imaging technique, data acquisition, and troubleshooting across all participating sites. Emphasis will be placed on the strategies used to maintain study fidelity and ensure successful completion across centers, enabling validation of DCE-FI as a transformative diagnostic adjunct in NSTI care.

Background: There is no validated system for classifying and treating traumatic subaxial cervical spine injuries in children. The subaxial cervical spine injury classification (SLIC) system is widely used in adults, but its applicability in children is uncertain. This study evaluated the validity of the SLIC system in predicting operative versus non-operative treatment in pediatric patients with traumatic subaxial cervical spine injuries. Methods: Patients younger than 18 years with acute, traumatic, subaxial cervical spine injuries (without concomitant occipitocervical injury) were identified at a single pediatric level I trauma center from 2006 to 2020. Classification scores were determined from initial imaging and neurological examinations. Patients were grouped according to adult SLIC thresholds (<4 nonoperative, =4 indeterminate, >4 operative), and recommended treatment was compared with the treatment received. Validity was assessed using sensitivity, specificity, positive and negative predictive values, receiver-operating-characteristic area under the curve, and F1 score. Subgroup analyses were performed for children younger than 10 years and those 10 years or older. Results: Forty-seven patients met the inclusion criteria (7 operative, 40 nonoperative). No patient with SLIC<4 (recommended nonoperative treatment) required surgery. All patients with SLIC=4 (indeterminate) were successfully treated without surgery, as were 4/11 patients with SLIC>4 (recommended surgery). Overall area under the curve and F1 scores were 0.968 and 0.78, respectively. Performance decreased in children younger than 10 years, but was excellent in older children. Conclusions: The subaxial cervical spine injury classification system can be helpful in pediatric patients, though this study identifies key differences from its performance in adults. SLIC remains highly sensitive at identifying severe injury; however, it recommended surgery for multiple patients who were ultimately treated non-operatively in this cohort. All patients with SLIC >4 (recommended operative treatment) who were treated without surgery were younger than 10 years. While SLIC demonstrates modest validity in children, our findings suggest that younger patients may be recommended for unnecessary surgery. These results support the selective use of SLIC in pediatric patients, though larger studies are imperative for further age-specific validation. Level of Evidence: Level III—retrospective cohort study.

BACKGROUND AND OBJECTIVES:While tranexamic acid (TXA) reduces blood loss in orthopedic surgery, thromboembolic concerns in cancer patients have limited adoption in orthopedic oncology. This study evaluated TXA efficacy and safety in patients undergoing endoprosthetic reconstruction for oncologic indications. METHODS:This retrospective single-center study included 617 patients who underwent lower extremity endoprosthetic reconstruction for oncologic indications between 2000 and 2024. Patients were stratified by perioperative TXA administration (n = 166) versus no TXA (n = 451). The primary outcome was perioperative blood loss calculated using the Mercuriali method. Secondary outcomes included perioperative packed red blood cells (pRBC) transfusion, hospital length of stay, and 90-day venous thromboembolic (VTE) complications. RESULTS:TXA was associated with a 429 mL reduction in calculated perioperative blood loss (1878 ± 1168 mL vs. 2307 ± 1442 mL; p = 0.003). TXA was not associated with reduced intraoperative pRBC transfusion rates (31% vs. 33%; RR 0.96 [95% CI: 0.74-1.25], p = 0.752) but was associated with significantly reduced postoperative transfusion requirements (17% vs. 30%; RR 0.56 [95% CI: 0.39-0.81], p = 0.003). No significant differences existed in 90-day VTE complications, reoperation rates, or mortality. CONCLUSIONS:Perioperative TXA use was associated with reduced blood loss and postoperative transfusion requirements without a detectable increase in thromboembolic complications, supporting TXA as a beneficial adjunct in musculoskeletal oncology limb salvage procedures.

Background: Femoral version (FV) is often assessed clinically on physical examination using prone hip range of motion (ROM) and quantified anatomically with advanced imaging measurements. Uncertainty exists over the relationship between the two, as well as which modality represents the benchmark. The purpose of this study is to assess the association between prone ROM and measured FV in pediatric and adolescent patients. Methods: This was a retrospective cohort study identifying all patients ≤18 years of age presenting to the study institution with hip pain. Patients were included if they had both documented prone ROM and hip magnetic resonance imaging (MRI) and/or CT scan with axial cuts through the distal femoral condyles done within 6 months of their clinical examination. Total hip arc of motion was calculated by adding prone internal (IR) and external (ER) rotation. Patients lacking advanced imaging studies or with neuromuscular disorders, altered femoral head anatomy, or history of surgical procedures to the hip before imaging were excluded. Pearson correlation coefficient was calculated to assess the strength of the relationship between prone hip ROM and FV as measured on CT and MRI. Results: One hundred forty-six patients (259 hips) were included. Mean age at the time of evaluation was 15.2 ± 2.8 years; 122 patients (83.0%) were female. Mean total arc of motion was 91.5° ± 16.5°. Prone IR and prone ER moderately correlated with FV as measured on both CT (IR r = 0.63; P < 0.001; ER r = −0.63; P < 0.001) and MRI (IR r = 0.60; P < 0.001; ER r = −0.62; P < 0.001). Measurements of FV on CT strongly correlated with those on MRI (r = 0.95; P < 0.001). Discussion: We demonstrate a moderate correlation between prone motion and advanced imaging measurements of FV in the largest adolescent cohort to date. Future studies should seek to limit variability in physical examination and advanced imaging measurements with more standardized techniques for both. Level of Evidence: III (Retrospective cohort study)

ABSTRACT:Cell-free RNA (cf-RNA) has emerged as a critical mediator of intercellular communication and a potential regulator of hemostasis. In this study, plasminogen (Plg), the zymogen precursor of plasmin, was demonstrated to function as a secreted ribonucleoprotein that carries regulatory, extracellular small noncoding RNAs (sRNAs). Purified human and bovine Plg, isolated via lysine-affinity chromatography, were found to transport 25- to 60-nucleotide-long sRNAs derived from both host and microbial sources. In vitro studies revealed that Plg accepted sRNA cargo from primary macrophages and bound candidate sRNAs with moderate (micromolar) affinity. Notably, Plg-sRNA complexes exhibited a distinct RNA profile compared to high-density lipoproteins, and their compositions were sensitive to hypercholesterolemic conditions. Functionally, removal of sRNA cargo from Plg via ribonuclease digestion significantly increased plasmin enzymatic activity and accelerated clot lysis, while also attenuating Plg-induced proinflammatory cytokine expression in both mouse and human macrophages. These findings reveal a dual regulatory role for sRNAs in modulating both the fibrinolytic and immunogenic properties of Plg, offering novel insights into the cross talk between cf-RNA biology and coagulation pathways. This work positions Plg-sRNA interactions as promising targets for therapeutic intervention in thrombotic and inflammatory diseases.

Plasminogen (Plg), the pro-enzyme of the serine-protease plasmin, is known for its role in cleaving blood clots within the fibrinolytic pathway. More recently, Plg has been reported to associate with oxidized phospholipids and accept cholesterol from macrophages, two processes normally observed with lipoproteins. Other non-enzymatic functions of Plg include aiding monocyte migration, activation of immune cells, and angiogenesis. We have previously reported the biological functions of cell-free RNA circulating on lipoproteins. Based on these newly described functions of Plg as a lipoprotein-like particle, we hypothesized that Plg transports functional cell-free RNA. Moreover, we predicted that small RNA (sRNA) cargo regulates Plg’s classic enzymatic and alternative inflammatory capacities. Plg were isolated from plasma by lysine-slurry chromatography and checked for purity and quality by electrophoresis and endotoxin tests, respectively. Highly-pure human and bovine Plg samples were observed to dose-dependently transport RNAs in plasma, namely sRNAs (25-60nt in length). High-throughput small RNA sequencing analyses found that Plg carries both host and non-host (microbial) sRNA. Plg samples were observed to accept sRNAs from donor macrophages in efflux studies, and Plg were observed to have moderate affinity (Kd=nM-µM range) towards candidate host and microbial sRNAs, as quantified by microscale thermophoresis. We also observed that Plg samples were markedly pro-inflammatory towards primary macrophages; however, we demonstrated through PCR and bulk sequencing that sRNA cargo on Plg confers, in large part, Plg’s pro-inflammatory functions towards macrophages, as RNase treated Plg failed to activate cytokine expression in treated human and mouse primary macrophages. Most importantly, RNase treatments of both human and bovine PLG were found to significantly increase Plg’s enzymatic activity, as observed through activity assay and clot lysis assays. Overall, these results support a negative regulatory role for sRNA cargo on Plg’s enzymatic function and a positive role for sRNA cargo driving Plg’s inflammatory properties. Collectively, results from this study suggest that Plg is a novel circulating ribonucleoprotein and that sRNA cargo likely governs the enzymatic capacity and inflammation within the clot or wound microenvironment. Therefore, Plg-sRNA cargo and its receptors provide new therapeutic targets to control fibrinolysis and systemic inflammation.

Introduction: Lateral condyle fractures are the second most common pediatric elbow fracture and are at risk for malunion, nonunion or avascular necrosis. The Song or Jakob classification guides management and risk of complications. However, many lateral condyle fractures have accompanying bony or soft tissue injuries, including elbow dislocations, which are not represented in the current Song or Jakob classification systems. Little is known about the incidence and outcomes of these more complex injuries. The purpose of this study was to describe the largest known case series of these injuries and characterize the incidence and outcomes. Methods: Injury, presentation, treatment, and outcome data were retrospectively gathered on pediatric elbow fractures at a single center from November 2007 to October 2017. Results: Of 4607 pediatric elbow fractures, 492 were lateral condyle fractures, with 30 cases (6.1%) presenting with concomitant elbow dislocation. Predominantly affecting males (76.7%) with a median age of 6.9 years, these injuries often resulted from intermediate energy mechanisms. High rates of coincident neurovascular deficits (23%), skin tenting (13.3%), and polytrauma (13.3%) were observed. All cases were treated surgically, primarily within 24 hours, with no instances of AVN, nonunion, or fixation failure reported. Across the cohort, there were 2 (6.7%) pin tract infections, 2 cases required return to the operating room, and 12 (40.0)% patients requiring outpatient physical therapy for elbow stiffness. Conclusions: Lateral condyle fractures with concomitant ulnohumeral dislocation are distinct and unstable injuries requiring prompt inpatient treatment. Current classification systems do not adequately address this fracture-dislocation combination, risking underdiagnosis and potentially delayed reduction of a dislocated elbow. We propose adding a “Song 6” or “Jakob 4” category to existing classifications to ensure these injuries are properly identified and managed. This amendment will improve clinical awareness, facilitate timely intervention, and optimize outcomes for pediatric patients with these complex fractures. Level of Evidence: IV

Background:Severe forms of childhood bone and joint infection (BJI) involve multifocal sepsis, often requiring multiple surgeries and intensive care. Dysregulation of the Acute Phase Response (APR) occurs, as bacterial virulence factors disrupt protective inflammatory and coagulation mechanisms.1,2 Many algorithms attempt to identify severe cases at diagnosis. Factors driving progression to life-threatening disease remain incompletely understood. This review summarizes risk associations for severe BJI in the context of host-pathogen interactions. Methods:A systematic review of the literature was undertaken from 01/01/2000-1/08/2025. Studies reporting host or pathogen factors associated with BJI severity for children </ = 18 years were included. Studies focussed on Kingella kingae or atypical organisms were excluded. C-reactive protein (CRP) trends in the context of severe illness were also examined. ROBINS-E was used to assess risk of bias. As it does not consider specific interventions and exposures, this review was not registered with PROSPERO. Results:Literature search of electronic databases returned 1171 articles, of which 38 met full criteria. These comprised 10,084 patients across multiple continents. Pathogen factors associated with severe illness included Methicillin-resistant Staphylococcus aureus (MRSA), Panton-Valentine Leukocidin (PVL), and individual bacterial virulence factors identified genomically. Notably, these virulence factors may be more important than methicillin resistance, with some MSSA strains causing equally severe disease. Very young children, specific ethnic groups, and those with congenital abnormalities were at higher risk. Early genetic studies propose variability in host inflammatory response genes. Sustained CRP elevation was a feature of worse disease, independent of pathogen subtype. Conclusion:These findings indicate that severe pediatric BJI results from complex interactions between bacterial virulence factors and host response capacity. Awareness of these factors should equip clinicians to recognise potentially high-risk cases early in the course of illness. Future research should ascertain how virulence factors dysregulate the host APR, guiding therapeutic interventions targeting the underlying pathophysiology.

Background:Consensus regarding which children within orthopedics would benefit from venous thromboembolism (VTE) prophylaxis is lacking. Our objective was to explore the incidence and epidemiology of VTE within pediatric orthopedics through a multicenter review across the United States. Methods:Encompassing 13 pediatric centers nationwide, VTE incidence rates with 95% confidence interval (CIs) were determined for all pediatric nonorthopedic patients (PNOPs) in general (age 0-18 years) and compared with pediatric orthopedic patients (POPs) from both inpatient and outpatient settings between 2014 and 2017. Demographics, risk factors, presence of prophylaxis, treatment, and outcomes for POP VTEs were analyzed using descriptive statistics. Results:Of 10,040,937 total unique patients, the overall 4-year VTE incidence for PNOPs was 2.1 per 10,000 patients (CI 2.01-2.19). Of 141,545 POPs, the VTE incidence was 8.0 per 10,000 patients (CI 6.61-9.63). The weighted median age for POP VTEs was higher than that for PNOP VTEs (11.5 vs. 8.0 years, p = 0.001). Of the 113 POP VTEs, 97 eligible patients (median age 13.3 years, 56% male) with complete data were further analyzed: 85% (82/97) underwent orthopedic surgery for trauma, infection, or an elective procedure. Orthopedic procedures (49%), bacteremia (46%), central venous catheters (38%), and trauma (28%) were the most common risk factors associated with VTE development, mostly occurring during the initial hospitalization (65%). Thirty-four percent (33/97) of VTE cases had received prophylaxis, predominantly pharmacological (26/33, 79%), administered postoperatively. Ninety-seven percent (94/97) of POP VTEs were treated with anticoagulation, most frequently low-molecular-weight heparin (79%). Twenty-two percent of POP VTEs experienced complications, 2 (2%) of which were deaths, with one having received postoperative VTE prophylaxis. Conclusions:Although relatively rare, the true incidence of pediatric orthopedic-related VTE may be greater than that of nonpediatric orthopedic VTE, with child mortality occurring in a small minority of cases. In children diagnosed with VTE, one third had received VTE prophylaxis. Identifying at-risk children undergoing orthopedic surgery and establishing best practice safety protocols for VTE prevention are critical to prevent associated morbidity and mortality.

» NF1 Link and Pathophysiology: Congenital pseudarthrosis of the tibia (CPT) is strongly associated with neurofibromatosis type 1 (NF1), where loss of normal NF1 gene function impairs bone formation and promotes fibrous hamartoma, resulting in recurrent tibial nonunion.» Classifications and Diagnostics: Multiple radiographic classifications (Andersen, Crawford, Boyd, Paley, etc.) guide clinical decision making, while newer imaging (magnetic resonance imaging, quantitative ultrasound) refines diagnosis and helps tailor interventions.» Treatment Modalities: Strategies range from nonoperative bracing (prefracture) to surgical approaches such as intramedullary rods (standard or telescopic), free vascularized fibular grafts, ring fixators (Ilizarov), and "cross-union" procedures-often combined with pharmacologic agents such as bone morphogenetic proteins (BMPs) or bisphosphonates.» Mixed Results With Pharmacologics: While rhBMP and bisphosphonates address bone catabolism and anabolism, neither agent alone has consistently succeeded in NF1-related CPT; combination regimens may offer better outcomes but require more robust research.» Future Directions: Ongoing studies explore early surgery (vs. waiting until age 2-3) and guided growth to address tibial bowing, molecular therapies (e.g., MAPK kinase and Src homology 2 containing protein tyrosine phosphatase 2 inhibitors), and refined fixation techniques. The management of CPT continues to evolve as genetic and cellular mechanisms become clearer.

BACKGROUND:Necrotizing soft tissue infections (NSTI) are rare but potentially life-threatening infections that can occur in both pediatric and adult patients. To date, few studies have examined NSTI in pediatric populations. Thus, the majority of guidelines for diagnosis and managing NSTI are based on adult data. The goal of this study was to utilize a large retrospective database to compare and contrast adult and pediatric cases of NSTI from a single center. METHODS:A retrospective review from a single tertiary center identified 446 patients with confirmed NSTI, 27 children (below 18 years of age) and 419 adults. Records were verified for the presence of disease based on retrospective review of a deidentified EMR (notes, reports, etc.). Demographics including age, sex, infection origin, comorbidities, patient presenting symptoms, and mortality rate were compared. RESULTS:Between children and adults with confirmed NF, similar rates of sex and ethnic distribution were observed. Upon admission, pain, erythema, and swelling were present at similar rates between cohorts. The origin and mechanism of infection were markedly different between cohorts with children experiencing extremity infections at double the rate of adults (76.9% vs. 34.1%). In patients with available culture data, tissue culture results were significantly different between cohorts with children developing culture-negative NSTI at more than 5× the rate of adults (20.0% vs. 4.6%). Finally, children had significantly lower mortality rates than adults (3.7% vs. 20.3%). Given this variability, a focused analysis of extremity cases of NSTI was conducted. Similar rates of ICU admission and peak C-reactive protein levels were identified, but adults experienced a significantly greater rate of amputation (5.5% vs. 27.8%) and organ dysfunction (38.9% vs. 76.7%) compared with children. As such, adults still maintained a significantly higher mortality rate compared with children (5.5% vs. 27.8). CONCLUSION:Cases of pediatric NSTI differ from those of adults, including variable patient outcomes. These unique features raise the question of whether equally aggressive operative management of NSTI, traditionally applied in adults, is necessary for pediatric cases. As such, future studies differentiating NSTI from other severe forms of infection, efforts to optimize treatment, and continued education for adult community providers remain warranted to support physicians treating pediatric cases of NSTI. LEVEL OF EVIDENCE:Level III.

Amid the ongoing changes across the healthcare and research environment—marked by funding constraints, shifting institutional priorities, and increasing clinical demands—faculty are facing mounting challenges to sustaining meaningful research mentorship. At the same time, medical student interest in research continues to rise, driven by both personal curiosity and career-oriented goals. This monograph explores how team-based mentorship models can help bridge this growing divide, offering a flexible and collaborative approach that distributes the responsibilities of guiding student research across mentors with complementary expertise. Drawing from the experience of seasoned faculty mentors across diverse settings, this monograph provides practical strategies to maintain high-quality mentorship despite time pressures and competing priorities. Topics include honest time assessment, shared project design, aligning student timelines with research feasibility, peer mentoring structures, and effective navigation of institutional support. Rather than viewing mentorship as an added burden, this model reframes it as a shared, strategic investment in the future of academic medicine. By embracing mentorship as a team sport, faculty can cultivate environments that celebrate curiosity and perseverance, equipping medical students with the skills, confidence, and passion to meaningfully engage in research—and to carry that commitment forward into their careers as future physician-scholars.

Background:Bone graft use for pediatric posterior spinal fusion (PSF) is highly variable and can lead to additional cost and risk. Biological failures of fusion are rare in children, suggesting that higher-risk grafts used for their perceived efficacy in adults may be unnecessary. This study aims to assess current expert perspectives on graft choice for pediatric PSF to provide guidance in this unique population, thus aiding risk and cost minimization. Methods:We conducted an institutional review board-approved Research Electronic Data Capture (REDCap) survey of surgeon members from an international spine deformity study group. Participants were asked about their graft choices for a routine adolescent idiopathic scoliosis case. Results:Of the 49 invited surgeons, 35 (71%) completed the survey. Most respondents (57%) had over 20 years of experience and performed more than 75 pediatric spine deformity surgeries annually (63%). The majority (83%) used local autograft and cancellous allograft, with 51% using this combination without additional graft products. Surgeons cited side-effect profile, clinical evidence, cost, and training as primary factors influencing graft choice. Notably, 42% of participants acknowledged that iliac crest bone graft (ICBG) and bone morphogenic protein (BMP)-2 may promote better bone formation but were not routinely used due to costs and potential side effects. Conclusions:This expert survey suggests that local autograft combined with allograft represents the prevailing graft strategy among experienced surgeons. However, there is considerable variability in the adjunct use of other graft types/additives indicating a need for further research to establish the value of these adjuncts in pediatric PSF relative to risks and costs. Key Concepts:(1)Bone graft choices vary widely among pediatric spine surgeons, with some using higher-risk grafts that lack evidence in children, even though fusion success rates are similar regardless of graft type.(2)An international survey of experienced pediatric spine deformity surgeons identified local autograft combined with cancellous allograft as the prevailing baseline strategy, with most surgeons avoiding additional graft products.(3)This choice is primarily influenced by side-effect profile, available clinical evidence, cost considerations, and training.(4)Among surgeons who do use adjunct grafts, the specific products selected vary considerably, reflecting heterogeneous practice patterns.(5)Given the low rate of biologic fusion failure in children, further research is needed to clarify when additional graft products provide value beyond the baseline strategy. Level of Evidence:V, Expert opinion.

BACKGROUND:There are few publications on the presentation and management of septic arthritis of the foot and/or ankle (SAFA) in children. The purpose of this study was to describe the presenting characteristics, microbiologic profile, and treatment outcomes of SAFA in a pediatric population from a multicenter database. METHODS:Patients aged 18 years or younger with SAFA were identified from a multicenter retrospective musculoskeletal infection database. Demographics, laboratory tests, culture results, surgical data, and complications were collected. RESULTS:A total of 684 patients were identified to have SA. Patients who had SA of the ankle and/or foot with or without concomitant lower leg musculoskeletal infection were included, yielding 82 patients (12%). The median age of the cohort was 7.0 years (range, 0.5 to 15.8 years), and 56% were male (46/82). Fifty-nine percent of the cohort had ankle-only involvement (48/82), 15% had foot only (12/82), 2% had ankle and foot (2/82), and 24% had ankle and leg (20/82). Fifty-two percent of patients had an additional diagnosis to SA, the most frequent being osteomyelitis (39/82; 48%). Ninety-four percent of patients underwent surgical irrigation and debridement, with 12 patients (16%) receiving more than one surgical intervention. Positive tissue cultures were obtained in 77% (59/79), with methicillin-sensitive Staphylococcus aureus being the most commonly identified organism. Three patients (4%) had recurrence of SAFA, and two of those patients underwent additional surgery. Musculoskeletal complications were rare, with osteonecrosis and pathologic fracture being the most common (4%). CONCLUSION:In children with SA, 12% of cases occur within the foot and/or ankle, with ankle-only involvement being the most common presentation. Methicillin-sensitive Staphylococcus aureus is the most common causative organism. In patients with SAFA, multifocal infection occurs relatively frequently, but antibiotic treatment combined with irrigation and débridement results in excellent short-term outcomes with low rates of recurrence and complications. LEVEL OF EVIDENCE:Level IV, prognostic.

BACKGROUND:Accurately determining the presence and severity of pediatric musculoskeletal infection (MSKI) is crucial for effective triage and treatment. Although the white blood-cell (WBC) count is often used as a marker for MSKI, we hypothesized that the use of the WBC count is limited by age-related variability in children. We proposed that the absolute neutrophil-to-lymphocyte ratio (NLR), which has less age-related variability, is a more reliable indicator for both diagnosing and assessing the severity of MSKI. The present study aims to compare the utility of WBC against that of the NLR, as well as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), for predicting MSKI presence and severity in children. METHODS:A retrospective cohort study was conducted with use of a database of pediatric orthopaedic consultations for suspected MSKI between January 2013 and July 2022. Diagnoses were categorized as MSKI or no infection, and the severity of any present infection was stratified as local or disseminated. Admission laboratory values were collected. Statistical modeling was performed to assess the capabilities of the WBC, NLR, CRP, and ESR to diagnose MSKI and to assess infection severity, with cutoff thresholds established for clinical use. RESULTS:This study included 650 patients (median age, 5.2 years; 63% male; 75% White). Of these, 247 patients had no infection, while 403 were diagnosed with an MSKI. Median WBC count, NLR, CRP, and ESR were all significantly higher in pediatric cases of confirmed MSKI. WBC was a poor predictor of infection severity, whereas NLR, CRP, and ESR each positively correlated with infection severity. At the time of admission, an NLR of 4 was highly specific for detecting the presence of infection, and an NLR of 5.8 was highly specific for predicting infection dissemination. CRP was the best predictor of both infection presence and severity, demonstrating the highest specificity and sensitivity, followed by NLR, which outperformed ESR and WBC. CONCLUSIONS:Because of considerable age-related variability, the predictive value of the WBC count for pediatric MSKI presence and severity is limited. NLR, which is less affected by age-related variability, is superior at predicting MSKI severity. Although CRP remains the benchmark, the NLR offers a valuable alternative to the WBC. Our study provides a comparative framework for these biomarkers, enhancing MSKI assessment across various clinical settings. LEVEL OF EVIDENCE:Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.