Fracture nonunion remains an unresolved complication after extremity fracture, with notable costs to patient quality of life and health systems. Nonunion is defined by the inability of fracture ends to unite without evidence of progressive healing over time. Approximately 2 to 10% of all fractures go onto nonunion, with increased rates observed in specific fracture locations and patient populations. Despite advances in fixation techniques and bone grafting, current treatments remain limited and frequently fail to restore durable bone healing. In this review, the current state of emerging biologic and bioengineering therapies for nonunion will be summarized, with a focus on how these advances may shift treatment from palliative reconstruction toward durable healing. Biological therapies such as growth factors, stem cells, and gene-modified constructs show promise but face challenges of short half-life, inconsistent efficacy, and safety concerns. Emerging approaches, including controlled-release scaffolds, immunomodulatory materials, stem cell-derived exosomes, and gene therapy platforms, offer opportunities to more precisely restore the osteogenic, angiogenic, and immunologic environment required for union.

Fracture nonunion or delayed union remains a significant clinical problem that burdens both the patient and the healthcare system. Defined as failure for bone to unite 9 months post injury or 3 months with no progression toward union, the pathology of nonunion may require multiple surgical interventions with associated morbidity. Increasing evidence has highlighted that nonunion is a multifaceted problem, not only a result of mechanical failure, but also a product of persistent dysregulation of the osteoimmune microenvironment manifested as impaired osteogenesis and bone healing. While current approaches focus on enhanced fixation and various bone grafting strategies, these treatments often fail to coordinate healing with osteoimmune regulation. This review summarizes the emerging biologic and bioengineering approaches that target osteoimmunology to enhance fracture repair. Scaffold systems, including metals, bioceramics, hydrogels, and micro/nanoparticle formulations, are being increasingly engineered to provide structural support while directing macrophage polarization and stimulating osteogenic signaling. We also review cell-based therapies and gene-modified constructs that are being developed to introduce osteoimmunology cues that halt chronic inflammation and promote an osteogenic microenvironment.

Purpose: To understand the development and trajectory of endoscopic spine surgery. Methods: The Web of Science Core Collection was searched for full-endoscopic and microendoscopic spine surgery articles published in 19 spine-related journals. Citation analysis identified top authors (first, last, and any position) and top cited articles. Study characteristics were reviewed, examining article type, level of evidence (LoE), topic, and country of origin. Results: 330 articles were identified, all published within the last 35 years. For the most frequently cited authors across all cohorts, a majority were affiliated with institutions in South Korea. Of the top 20 cited articles of all time, 55% were case series/case reports and 25% were randomized controlled trials, with 60% of studies having a LoE of IV. In the last decade (2014–2024), 30% of the top cited studies were case series/case reports, 25% were randomized controlled trials and 20% were systematic reviews/meta-analyses. Among these works, China (40%) and South Korea (25%) contributed the largest share of recent high-impact studies. Similarly, a large portion (35%) of the top articles of all time were associated with South Korean institutions. Conclusion: This bibliometric analysis highlighted the rapid advancement of the field of endoscopic spine surgery and highly cited authors who have been prominent within this field. This work particularly underscores a growing international focus on minimally invasive spinal techniques and the need for continued high-quality comparative studies.

Background and Objective: While other bibliometric analyses have looked at various topics within spine surgery, few have systematically examined highly cited authors and articles within this field as a whole. This study examined the most cited authors and articles within spine surgery research to characterize the intellectual architecture of the field by quantifying publication trends, citation patterns, and authorship networks. Understanding the influence of individual contributors and highly cited publications provides insight into shifts in research priorities and the evolution of evidence within spine surgery. Methods: The Web of Science Core Collection was used to identify reviews and articles in 19 spine surgery-related journals from January 1, 1979, to December 31, 2024, and the 20 most cited authors in first, any, and last author position and the 20 most cited articles from 1979–2024 and 2014–2024 were determined. Key Content and Findings: We found that there were repeat authors in multiple author categories and within the top cited articles, pointing to the presence of a core group of researchers that substantially contributes to research output within this field. Furthermore, comparing the most cited articles of all time to the most cited articles in the last 10 years revealed a shift toward a broader range of topics, higher level of evidence studies and an increase in the number of clinical guidelines. Conclusions: These findings demonstrate the utility of analyzing citation trends and fostering high-quality, up-to-date research that includes a diverse set of perspectives to support the advancement of spine surgery scholarship.