Academic and Demographic Profile of Orthopaedic Vice Chairs of Research: Implications for Leadership.

BACKGROUND: Vice chairs (VCs) of research play an integral role in orthopaedic departments at academic medical centers; they strategically lead research efforts and support the research careers of faculty and trainees. To our knowledge, no analysis of orthopaedic VCs of research exists in the literature, and no similar analyses have been completed in other medical specialties. We aimed to investigate the academic and demographic characteristics of orthopaedic VCs of research. METHODS: Doximity was used to identify orthopaedic residencies in the U.S. Personal and program websites were queried to identify VCs of research and collect academic and demographic characteristics. The Scopus database, the National Institutes of Health (NIH) RePORTER, and Google Scholar were used to obtain each investigator's Hirsch index (h-index) and the number and type of NIH grants awarded, respectively. RESULTS: Of the 207 orthopaedic residency programs identified, 71 (34%) had a named VC of research in the orthopaedic department. Of the top 50 medical schools, 42 were affiliated with such programs. Most VCs were men (89%). The racial and/or ethnic background of the majority of VCs was White (85%), followed by Asian (14%), and Black (1%). Most held the rank of professor (78%), followed by associate professor (18%), and assistant professor (4%). Over half were PhDs (55%), followed by MDs (37%) and MD/PhDs (8%). On average, the VCs had an h-index of 40.5. Furthermore, 65% had been awarded at least 1 NIH grant for their research, with 43% awarded at least 1 R01 grant. CONCLUSIONS: VCs of research develop research opportunities and shape the brand recognition of academic orthopaedic programs. Most orthopaedic VCs of research are men (89%); 85% each are White and have a rank of professor. Nearly half have been awarded at least 1 R01 grant from the NIH. CLINICAL RELEVANCE: This study outlines important academic and demographic characteristics among orthopaedic surgery VCs of research. Considering the mentorship aspect of their role, VCs of research have an opportunity to influence the diversity of incoming trainees in the field of academic orthopaedics.

Single Position Prone Lateral Lumbar Interbody Fusion: A Review of the Current Literature.

PURPOSE OF REVIEW: Spinal fusion, vital for treating various spinal disorders, has evolved since the introduction of the minimally invasive Lateral Lumbar Interbody Fusion (LLIF) by Pimenta in 2001. Traditionally performed in the lateral decubitus position, LLIF faces challenges such as intraoperative repositioning, neurological complications, and lack of access to lower lumbar levels. These challenges lead to long surgery times, increased rates of perioperative complications, and increased costs. The more recently popularized prone lateral approach mitigates these issues primarily by eliminating patient repositioning, thereby enhancing surgical efficiency, and reducing operative times. This review examines the progression of spinal fusion techniques, focusing on the advantages and recent findings of the prone lateral approach compared to the traditional LLIF. RECENT FINDINGS: The prone lateral approach has shown improved patient outcomes, including lower blood loss and shorter hospital stays, and has been validated by multiple studies for its safety and efficacy compared to the LLIF approach. Significant enhancements in postoperative metrics, such as the Oswestry Disability Index, Visual Analog Scale, and radiological improvements have been noted. Comparatively, the prone lateral approach offers superior segmental lordosis correction and potentially better subjective outcomes than the lateral decubitus position. Despite these advances, both techniques present similar risks of neurological complications. Overall, the prone lateral approach has emerged as a promising alternative in lumbar interbody fusion, combining efficiency, safety, and improved clinical outcomes.

Relative Value Unit (RVU) and Medicare Severity Diagnosis-related Group (MS-DRG) Reimbursement in Cervical Spinal Fusion: A 2011-2023 Trends Report.

STUDY DESIGN: Level 3 retrospective database study. OBJECTIVE: This study aims to compare work RVU (wRVU), practice expense RVU (peRVU), malpractice RVU (mpRVU), and inflation-adjusted facility price alongside MS-DRG relative weight length of stay (LOS) for cervical spine fusions between 2011 and 2023. SUMMARY OF BACKGROUND DATA: Both RVU and MS-DRG reimbursement have been studied in various surgical subspecialties; however, little investigation has centered on cervical spine fusions. To the best of our knowledge, this is the first study to investigate trends in RVU and MS-DRG reimbursement in cervical spine fusion throughout the COVID-19 pandemic. METHODS: Center for Medicaid and Medicare Services (CMS) physician fee schedule was queried between 2011 and 2023 for RVU and facility reimbursement using common single and multilevel anterior and posterior cervical fusion codes. RVU facility prices were inflation adjusted to 2023. MS-DRG reimbursement data from 2011 to 2022 were compiled for cervical spinal fusion procedures with major complication or comorbidity (MCC) 471, complication or comorbidity (CC) 472, and without CC/MCC 473. Compound annual growth rates (CAGRs), Mean Annual Change, and yearly percent changes were calculated. RESULTS: No changes in wRVU were seen for all cervical CPT codes; however, the CAGR of peRVU (-0.51%±0.60%) and mpRVU (0.69%±0.41%) demonstrated marginal fluctuations. Every CPT code displayed an inflation-adjusted facility price decrease (-2.18%±0.24%). When assessing MS-DRG, there were marginal changes in geometric mean LOS (0.17%±0.45%), arithmetic mean LOS (-0.15%±0.84%), and relative weight (1.09%±0.68%). Unlike RVU reimbursement, the yearly percent change differs between each MS-DRG code. CONCLUSIONS: Inflation-adjusted RVU reimbursement facility prices demonstrated a consistent decrease, while DRG code reimbursement stayed relatively consistent over the study period. This data may help surgeons and hospitals become cognizant of temporal variations in reimbursement patterns as it may affect their personal practice. LEVEL OF EVIDENCE: Level III retrospective study.

Evolution of Titanium Interbody Cages and Current Uses of 3D Printed Titanium in Spine Fusion Surgery.

PURPOSE OF REVIEW: To summarize the history of titanium implants in spine fusion surgery and its evolution over time. RECENT FINDINGS: Titanium interbody cages used in spine fusion surgery have evolved from solid metal blocks to porous structures with varying shapes and sizes in order to provide stability while minimizing adverse side effects. Advancements in technology, especially 3D printing, have allowed for the creation of highly customizable spinal implants to fit patient specific needs. Recent evidence suggests that customizing shape and density of the implants may improve patient outcomes compared to current industry standards. Future work is warranted to determine the practical feasibility and long-term clinical outcomes of patients using 3D printed spine fusion implants. Outcomes in spine fusion surgery have improved greatly due to technological advancements. 3D printed spinal implants, in particular, may improve outcomes in patients undergoing spine fusion surgery when compared to current industry standards. Long term follow up and direct comparison between implant characteristics is required for the adoption of 3D printed implants as the standard of care.

A Mechanistic and Preclinical Assessment of BioRestore Bioactive Glass as a Synthetic Bone Graft Extender and Substitute for Osteoinduction and Spine Fusion.

STUDY DESIGN: Preclinical animal study. OBJECTIVE: Evaluate the osteoinductivity and bone regenerative capacity of BioRestore bioactive glass. SUMMARY OF BACKGROUND DATA: BioRestore is a Food and Drug Administration (FDA)-approved bone void filler that has not yet been evaluated as a bone graft extender or substitute for spine fusion. METHODS: In vitro and in vivo methods were used to compare BioRestore with other biomaterials for the capacity to promote osteodifferentiation and spinal fusion. The materials evaluated (1) absorbable collagen sponge (ACS), (2) allograft, (3) BioRestore, (4) Human Demineralized Bone Matrix (DBM), and (5) MasterGraft. For in vitro studies, rat bone marrow-derived stem cells (BMSC) were cultured on the materials in either standard or osteogenic media (SM, OM), followed by quantification of osteogenic marker genes ( Runx2, Osx, Alpl, Bglap, Spp1 ) and alkaline phosphatase (ALP) activity. Sixty female Fischer rats underwent L4-5 posterolateral fusion (PLF) with placement of 1 of 5 implants: (1) ICBG from syngeneic rats; (2) ICBG+BioRestore; (3) BioRestore alone; (4) ICBG+Allograft; or (5) ICBG+MasterGraft. Spines were harvested 8 weeks postoperatively and evaluated for bone formation and fusion via radiography, blinded manual palpation, microCT, and histology. RESULTS: After culture for 1 week, BioRestore promoted similar expression levels of Runx2 and Osx to cells grown on DBM. At the 2-week timepoint, the relative ALP activity for BioRestore-OM was significantly higher ( P <0.001) than that of ACS-OM and DBM-OM ( P <0.01) and statistically equivalent to cells grown on allograft-OM. In vivo, radiographic and microCT evaluation showed some degree of bridging bone formation in all groups tested, with the exception of BioRestore alone, which did not produce successful fusions. CONCLUSIONS: This study demonstrates the capacity of BioRestore to promote osteoinductivity in vitro. In vivo, BioRestore performed similarly to commercially available bone graft extender materials but was incapable of producing fusion as a bone graft substitute. LEVEL OF EVIDENCE: Level V.

Preference Sensitive Care and Shared Decision-Making in Lumbar Spinal Stenosis: A Scoping Review.

STUDY DESIGN: Scoping review. OBJECTIVE: The objective of this study was to conduct a scoping review exploring the extent to which preference sensitivity has been studied in treatment decisions for lumbar spinal stenosis (LSS), utilizing shared decision-making (SDM) as a proxy. BACKGROUND: Preference-sensitive care involves situations where multiple treatment options exist with significant tradeoffs in cost, outcome, recovery time, and quality of life. LSS has gained research focus as a preference-sensitive care scenario. MATERIALS AND METHODS: A scoping review protocol in accordance with "Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews" regulations was registered with the Open Science Framework (ID: 9ewup) and conducted across multiple databases from January 2000 to October 2022. Study selection and characterization were performed by 3 independent reviewers and an unbiased moderator. RESULTS: The search resulted in the inclusion of 16 studies varying in design and sample size, with most published between 2016 and 2021. The studies examined variables related to SDM, patient preferences, surgeon preferences, and decision aids (DAs). The outcomes assessed included treatment choice, patient satisfaction, and patient understanding. Several studies reported that SDM influenced treatment choice and patient satisfaction, while the impact on patient understanding was less clear. DAs were used in some studies to facilitate SDM. CONCLUSION: The scoping review identified a gap in comprehensive studies analyzing the preference sensitivity of treatment for LSS and the role of DAs. Further research is needed to better understand the impact of patient preferences on treatment decisions and the effectiveness of DAs in LSS care. This review provides a foundation for future research in preference-sensitive care and SDM in the context of lumbar stenosis treatment.

Safety outcomes and improvement in pain scores after radiologist-performed fluoroscopy-guided interlaminar cervical epidural steroid injection.

INTRODUCTION: Image-guided spine injections are an important tool in the management of patients with a variety of spinal pathologies. Our practice offers radiologist-performed fluoroscopy-guided interlaminar cervical epidural steroid injection (ESI) routinely performed in the outpatient setting. The purpose of this study was to evaluate clinical outcomes and improvement in pain scores after radiologist-performed cervical ESI. METHODS: An institutional database was used to retrospectively identify cervical injections performed between October 2016 and October 2022. All injections were performed at the C7-T1 level utilizing 1.0 mL of 10 mg/mL dexamethasone without epidural anesthetic. The Numerical Rating Scale (NRS) was used to assess pain improvement. Cervical MRI was reviewed to assess pre-injection cervical disease severity. Patient charts were reviewed for any post-injection complications. RESULTS: A total of 251 cervical injections in 186 patients met our inclusion criteria with mean clinical follow up of 28.5 months (range 0.2 - 73.0 months). No patients experienced any major complications after injection. Post-injection pain scores were available for 218 of 251 injections (86.9%) with mean follow-up of 11.8 days (range 6 - 57 days). There was a significant improvement in pain scores from a mean pre-injection NRS score of 5.2/10 to 3.0/10 (p < .0001). 117 patients (53.7%) reported ≥ 50% improvement after injection. Patients who had prior injection were more likely to report ≥ 50% pain improvement after subsequent injection (p = .012). CONCLUSION: Radiologist-performed fluoroscopy-guided interlaminar cervical ESI at the C7-T1 level is a safe and effective tool in the management of patients with cervical pathology.

The Role of the Gut Microbiome in Orthopedic Surgery-a Narrative Review.

PURPOSE OF REVIEW: The importance of the gut microbiome has received increasing attention in recent years. New literature has revealed significant associations between gut health and various orthopedic disorders, as well as the potential for interventions targeting the gut microbiome to prevent disease and improve musculoskeletal outcomes. We provide a broad overview of available literature discussing the links between the gut microbiome and pathogenesis and management of orthopedic disorders. RECENT FINDINGS: Human and animal models have characterized the associations between gut microbiome dysregulation and diseases of the joints, spine, nerves, and muscle, as well as the physiology of bone formation and fracture healing. Interventions such as probiotic supplementation and fecal transplant have shown some promise in ameliorating the symptoms or slowing the progression of these disorders. We aim to aid discussions regarding optimization of patient outcomes in the field of orthopedic surgery by providing a narrative review of the available evidence-based literature involving gut microbiome dysregulation and its effects on orthopedic disease. In general, we believe that the gut microbiome is a viable target for interventions that can augment current management models and lead to significantly improved outcomes for patients under the care of orthopedic surgeons.

A supramolecular polymer-collagen microparticle slurry for bone regeneration with minimal growth factor.

Recombinant bone morphogenetic protein-2 (BMP-2) is a potent osteoinductive growth factor that can promote bone regeneration for challenging skeletal repair and even for ectopic bone formation in spinal fusion procedures. However, serious clinical side effects related to supraphysiological dosing highlight the need for advances in novel biomaterials that can significantly reduce the amount of this biologic. Novel biomaterials could not only reduce clinical side effects but also expand the indications for use of BMP-2, while at the same time lowering the cost of such procedures. To achieve this objective, we have developed a slurry containing a known supramolecular polymer that potentiates BMP-2 signaling and porous collagen microparticles. This slurry exhibits a paste-like consistency that stiffens into an elastic gel upon implantation making it ideal for minimally invasive procedures. We carried out in vivo evaluation of the novel biomaterial in the rabbit posterolateral spine fusion model, and discovered efficacy at unprecedented ultra-low BMP-2 doses (5 µg/implant). This dose reduces the growth factor requirement by more than 100-fold relative to current clinical products. This observation is significant given that spinal fusion involves ectopic bone formation and the rabbit model is known to be predictive of human efficacy. We expect the novel biomaterial can expand BMP-2 indications for difficult cases requiring large volumes of bone formation or involving patients with underlying conditions that compromise bone regeneration.

Advances in Synthetic Grafts in Spinal Fusion Surgery.

Degenerative spine disease is increasing in prevalence as the global population ages, indicating a need for targeted therapies and continued innovations. While autograft and allograft have historically demonstrated robust results in spine fusion surgery, they have significant limitations and associated complications such as infection, donor site morbidity and pain, and neurovascular injury. Synthetic grafts may provide similar success while mitigating negative outcomes. A narrative literature review was performed to review available synthetic materials that aim to optimize spinal fusion. The authors specifically address the evolution of synthetics and comment on future trends. Novel synthetic materials currently in use include ceramics, synthetic polymers and peptides, bioactive glasses, and peptide amphiphiles, and the authors focus on their success in both human and animal models, physical properties, advantages, and disadvantages. Advantages include properties of osteoinduction, osteoconduction, and osteogenesis, whereas disadvantages encompass a lack of these properties or growth factor-induced complications. Typically, the use of synthetic materials results in fewer complications and lower costs. While the development and tuning of synthetic materials are ongoing, there are many beneficial alternatives to autografts and allografts with promising fusion results.

Congenital Cervical Stenosis: a Review of the Current Literature.

PURPOSE OF REVIEW: Congenital cervical stenosis (CCS) is a phenomenon in which an individual has a narrow canal due to abnormal anatomy which can present with earlier degenerative symptoms due to a reduced sagittal diameter. The diagnosis of CCS is important to individual treatment and preventative measures. Often, athletes are warned against sport participation that may cause damage to the cervical spine. There may be a predisposition in certain populations, but lack of data limits conclusions. The current review investigates recent literature on the definition, pathoanatomy, clinical presentation, and management of CCS. It specifically interrogates potential populations predisposed to this condition. RECENT FINDINGS: The current literature reveals a potential predisposition for CCS in the black population when compared to the white population; however, many studies do not report race when discussing CCS patients. The lack of data limits a consensus on specific populations with a congenitally narrow canal. CCS may be more prevalent in specific populations. With knowledge of populations more at risk for this condition, physicians and teams can be alert when evaluating players and young adults. Furthermore, this may provide insight into risk for symptoms with degenerative disease. These findings introduce an avenue for further research into CCS.

The Role of Cervical Disc Arthroplasty in Elite Athletes.

PURPOSE OF REVIEW: Cervical disc arthroplasty (CDA) for the treatment of symptomatic cervical disc herniations (CDH) is a promising treatment for professional athletes. In recent years, a number of high-profile athletes have returned to professional play within three months after CDA, raising important questions about the potential of this procedure within this patient group. We provide the first comprehensive review of available literature for the safety and efficacy of CDA in professional contact sport athletes. RECENT FINDINGS: CDA provides theoretical biomechanical advantages over anterior cervical discectomy and fusion (ACDF) and posterior foraminotomy (PF), as CDA is the only operation for treatment of CDH that provides neural decompression, stability and height restoration, with preserved range of motion. While the comparative long-term results from each procedure are unknown, CDA has provided encouraging promise in its use in professional contact athletes. We aim to aid ongoing discussions regarding the controversies in spine surgery for professional athletes by providing a scientific review of the available evidence-based literature involving cervical disc arthroplasty in this population. In general, we believe that CDA is a viable alternative to ACDF and PF for the contact professional athlete who requires full neck range of motion and desires an expedited return to play. For collision athletes, the short- and long-term safety and efficacy profile of this procedure is promising but still unclear.

Patient and Surgeon Perceptions Regarding Microdiscectomy Surgery: A Cross-Sectional Analysis of Social Media Posts.

BACKGROUND: Social media offers a powerful and expanding platform for sharing the patient experience with a large audience through an unsolicited perspective. The content may influence future perceptions around surgical care. OBJECTIVE: To analyze publicly available content on a major social media outlet related to microdiscectomy surgery based on perspective, location, timing, content, tone, and patient satisfaction. METHODS: A query of content was performed for the study period 1 January 2019 to 1 January 2021. Relevant content was identified by hashtag "#microdiscectomy." The initial query returned 10,050 publicly available posts, and the 1500 most "liked" posts were included for evaluation. Content was subsequently classified, characterized, and analyzed. RESULTS: Patients created 72.9% of microdiscectomy-related content, and spine surgeons created 23.5%. Regarding region, 77.0% of posts originated in the United States. The majority portrayed the patient experience in the postoperative phase of care (86.0%), with the primary reference to activities of daily living (56.9%). Only 1.7% of posts depicted the surgical incision site. The connotation of posts was deemed positive in 78.5% of cases. Of the posts referencing satisfaction, 98.3% depicted patient satisfaction with the surgical outcome. Patient posts in the postoperative phase of care (>1 week after surgery) were more than 2 times as likely to express positive tone (OR = 2.07, P ≤ 0.013) with their clinical course compared with patient posts outside the postoperative period. CONCLUSIONS AND CLINICAL RELEVANCE: Overall, social media posts are written in a positive tone, express satisfaction with surgical outcome, typically occur in the postoperative period of care, and depict activities of daily living. These popular mechanisms of communication, such as Instagram, offer spine surgeons unique insights into the true patient experience and may provide an opportunity for surgeons to assess patient feedback, influence patient perceptions, and enhance delivery of lumbar spine care.

Using Machine Learning and Deep Learning Algorithms to Predict Postoperative Outcomes Following Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: A retrospective cohort study from a multisite academic medical center. OBJECTIVE: To construct, evaluate, and interpret a series of machine learning models to predict outcomes related to inpatient health care resource utilization for patients undergoing anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: Reducing postoperative health care utilization is an important goal for improving the delivery of surgical care and serves as a metric for quality assessment. Recent data has shown marked hospital resource utilization after ACDF surgery, including readmissions, and ED visits. The burden of postoperative health care use presents a potential application of machine learning techniques, which may be capable of accurately identifying at-risk patients using patient-specific predictors. METHODS: Patients 18-88 years old who underwent ACDF from 2011 to 2021 at a multisite academic center and had preoperative lab values within 3 months of surgery were included. Outcomes analyzed included 90-day readmissions, postoperative length of stay, and nonhome discharge. Four machine learning models-Extreme Gradient Boosted Trees, Balanced Random Forest, Elastic-Net Penalized Logistic Regression, and a Neural Network-were trained and evaluated through the Area Under the Curve estimates. Feature importance scores were computed for the highest-performing model per outcome through model-specific metrics. RESULTS: A total of 1026 cases were included in the analysis cohort. All machine learning models were predictive for outcomes of interest, with the Random Forest algorithm consistently demonstrating the strongest average area under the curve performance, with a peak performance of 0.84 for nonhome discharge. Important features varied per outcome, though age, body mass index, American Society of Anesthesiologists classification >2, and medical comorbidities were highly weighted in the studied outcomes. CONCLUSIONS: Machine learning models were successfully applied and predictive of postoperative health utilization after ACDF. Deployment of these tools can assist clinicians in determining high-risk patients. LEVEL OF EVIDENCE: III.

Social Media Posts Pertaining to Anterior Cervical Discectomy and Fusion (ACDF) Surgery: A Cross-sectional Analysis of Patient and Surgeon Perceptions.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To analyze publicly available content on a major social media outlet related to anterior cervical discectomy and fusion (ACDF) surgery based on perspective, location, timing, content, tone, and patient satisfaction. SUMMARY OF BACKGROUND DATA: Social media offers a powerful platform for sharing the patient experience with the public through an unfiltered perspective. Social media content may influence future perceptions around surgical care and postings around ACDF have not been previously reported. METHODS: A query of content from a major social media outlet was performed for the study period January 1, 2018, to January 1, 2020, and returned 6500 publicly available posts. Content was identified by the hashtags "#acdf" or "#acdfsurgery." Content was ranked by number of "likes." Of the 1500 most popular posts, 1136 related to ACDF surgery and were included. Post content was characterized and classified. RESULTS: Patients created 85% of ACDF-related content and spine surgeons created 11.8%. Most posts portrayed the patient experience in the postoperative period and depicted patients performing activities of daily living, participating in sports, or completing work activities (54.4%). The connotation of posts was deemed to be positive in 79.2% of cases. In regard to their care or state of health as it related to ACDF surgery, 59.8% of patients expressed satisfaction, whereas 14.1% expressed dissatisfaction. Female patients were >4 times as likely to express dissatisfaction (odds ratio=4.16, P =<0.0001), with their clinical course compared with their male counterparts. CONCLUSIONS: Patients were the source of most posts on a major social media outlet that pertained to ACDF surgery with a majority reporting positive tone and satisfaction. These mechanisms of communication offer surgeons unique insights into patient experience and may provide an opportunity for surgeons to assess patient feedback, influence patient perceptions, and enhance delivery of cervical spine care.

Predictive Analysis of Healthcare Resource Utilization after Elective Spine Surgery.

Introduction: The management of degenerative spine pathology continues to be a significant source of costs to the US healthcare system. Besides surgery, utilization of healthcare resources after spine surgery drives costs. The responsibility of managing costs is gradually shifting to patients and providers. Patient-centered predictors of healthcare utilization after elective spine surgery may identify targets for cost reduction and value creation. Therefore, our study aims to quantify patterns of healthcare utilization and identify risk factors that predict high healthcare utilization after elective spine surgery. Methods: A total of 623 patients who underwent elective spine surgery at a tertiary academic medical center by one of three fellowship-trained orthopedic spine surgeons between 2013 and 2018 were identified in this retrospective cohort study. Healthcare utilization was quantified including advanced spine imaging, emergency and urgent care visits, hospital readmission, reoperation, PT/OT referrals, opioid prescriptions, epidural steroid injections, and pain management referrals. Patient variables, namely, the Charlson comorbidity index (CCI) and the American Society of Anesthesiologists (ASA) classification system, were assessed as potential predictors for healthcare utilization. Results: Among all patients, a wide range of health utilization was identified. Age, body mass index, Charlson Comorbidity Index, and American Society of Anesthesiology class were identified as positive predictors of postoperative healthcare utilization including emergency department visits, spine imaging studies, opioid and nerve blocker prescriptions, inpatient rehabilitation, any referrals, and pain management referrals. Conclusions: Markers of patient health-such as CCI and ASA class-may be used to predict healthcare utilization following elective spine surgery. Identifying at-risk patients and addressing these challenges prior to surgery is an important step to deliver efficient postoperative care. Level of Evidence: 3.

Measuring Value in Elective Spine Surgery.

Objective: To summarize the main findings from research on measuring the value in spine surgery. Summary of Background Data: Determining the value of surgical interventions, which is defined by the quality and efficacy of care received divided by the cost to deliver healthcare, is inherently complex. The two most fundamental components of value-quality and total cost-are multifactorial and difficult to quantify. Methods: A narrative review of all the relevant papers known to the author was conducted. Results: It is straightforward to calculate the aggregate hospital cost following a surgical procedure, but it is not simple to estimate the total cost of a procedure-including the direct and indirect costs. These individual metrics can help providers make more educated decisions with regards to improving patient quality of life and minimizing unnecessary costs. A consensus of the appropriate cost-per-quality-adjusted life-year threshold of different spine surgeries needs to be established. As these metrics become more commonplace in spine surgery, the potential for personalized health care will continue to be developed. Conclusions: As the healthcare system shifts toward value-based care, there is a substantial need for research assessing the value as defined by the quality and efficacy of care received divided by the cost to deliver healthcare of specific spine surgery procedures. Studies on different predictors-both patient-specific and surgical-that may influence outcomes, cost, and value are required.

Sex-Based Difference in Bone Healing: A Review of Recent Pre-clinical Literature.

PURPOSE OF REVIEW: Recent literature has sought to understand differences in fusion failure, specifically considering how patient sex may play a role. Overall, there exists inconclusive data regarding any sex-based differences in bone healing. RECENT FINDINGS: In vitro studies examining the roles of sex hormones, 5-LO, IGF-1, VEGF, osteoclasts, and OPCs seem to show sexually dimorphic actions. Additionally, donor characteristics and stem cell environment seem to also determine osteogenic potential. Building on this biomolecular basis, in vivo work investigates the aforementioned elements. Broadly, males tend to have a more robust healing compared to females. Taking these findings together, differences in sex hormones levels, their timing and action, and composition of the inflammatory milieu underlie variations in bone healing by sex. Clinically, a robust understanding of bone healing mechanics can inform care of the transgender patient. Transgender patients undergoing hormone therapy present a clinically nuanced scenario for which limited long-term data exist. Such advances would help inform treatment for sports-related injury due to hormonal changes in biomechanics and treatment of transgender youth. While recent advances provide more clarity, conclusive answers remain elusive.

Sex-based Difference in Response to Recombinant Human Bone Morphogenetic Protein-2 in a Rat Posterolateral Fusion Model.

STUDY DESIGN: This was a preclinical study. OBJECTIVE: Evaluate sex-dependent differences in the bone healing response to recombinant human bone morphogenetic protein-2 (rhBMP-2) in a rat posterolateral spinal fusion model. SUMMARY OF BACKGROUND DATA: Minimal and conflicting data exist concerning potential sex-dependent differences in rhBMP-2-mediated bone regeneration in the context of spinal fusion. MATERIALS AND METHODS: Forty-eight female and male Sprague-Dawley rats (N=24/group), underwent L4-L5 posterolateral fusion with bilateral placement of an absorbable collagen sponge, each loaded with 5 µg of bone morphogenetic protein-2 (10 µg/animal). At eight weeks postoperative, 10 specimens of each sex were tested in flexion-extension with quantification of range of motion and stiffness. The remaining specimens were evaluated for new bone growth and successful fusion via radiography, blinded manual palpation and microcomputed tomography (microCT). Laboratory microCT quantified bone microarchitecture, and synchrotron microCT examined bone microstructure at the 1 µm level. RESULTS: Manual palpation scores differed significantly between sexes, with mean fusion scores of 2.4±0.4 in females versus 3.1±0.6 in males ( P <0.001). Biomechanical stiffness did not differ between sexes, but range of motion was significantly greater and more variable for females versus males (3.7±5.6° vs. 0.27±0.15°, P <0.005, respectively). Laboratory microCT showed significantly smaller volumes of fusion masses in females versus males (262±87 vs. 732±238 mm 3 , respectively, P <0.001) but significantly higher bone volume fraction (0.27±0.08 vs. 0.12±0.05, respectively, P <0.001). Mean trabecular thickness was not different, but trabecular number was significantly greater in females (3.1±0.5 vs. 1.5±0.4 mm -1 , respectively, P <0.001). Synchrotron microCT showed fine bone structures developing in both sexes at the eight-week time point. CONCLUSIONS: This study demonstrates sex-dependent differences in bone regeneration induced by rhBMP-2. Further investigation is needed to uncover the extent of and mechanisms underlying these sex differences, particularly at different doses of rhBMP-2.

The Drivers of Persistent Opioid Use and Its Impact on Healthcare Utilization After Elective Spine Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study was to determine the incidence of and risk factors for persistent opioid use after elective cervical and lumbar spine procedures and to quantify postoperative healthcare utilization in this patient population. METHODS: Patients were retrospectively identified who underwent elective spine surgery for either cervical or lumbar degenerative pathology between November 1, 2013, and September 30, 2018, at a single academic center. Patients were split into 2 cohorts, including patients with and without opioid use at 180-days postoperatively. Baseline patient demographics, underlying comorbidities, surgical variables, and preoperative/postoperative opioid use were assessed. Health resource utilization metrics within 1 year postoperatively (ie, imaging studies, emergency and urgent care visits, hospital readmissions, opioid prescriptions, etc.) were compared between these 2 groups. RESULTS: 583 patients met inclusion criteria, of which 16.6% had opioid persistence after surgery. Opioid persistence was associated with ASA score ≥3 (P = .004), diabetes (P = .019), class I obesity (P = .012), and an opioid prescription in the 60 days prior to surgery (P = .006). Independent risk factors for opioid persistence assessed via multivariate regression included multi-level lumbar fusion (RR = 2.957), cervical central stenosis (RR = 2.761), and pre-operative opioid use (RR = 2.668). Opioid persistence was associated with higher rates of health care utilization, including more radiographs (P < .001), computed tomography (CT) scans (.007), magnetic resonance imaging (MRI) studies (P = .014), emergency department (ED) visits (.009), pain medicine referrals (P < .001), and spinal injections (P = .003). CONCLUSIONS: Opioid persistence is associated with higher rates of health care utilization within 1 year after elective spine surgery.