Is gender a factor affecting long-term heterotopic ossification incidence after single-level cervical disc arthroplasty?

Prevalence of Degenerative Spinal Hot Spots on Bone Scintigraphy Among Orthopedic Patients

PURPOSE

Emerging nuclear imaging technologies are advancing the field of spinal diagnostics for degenerative changes. This study aimed to describe the prevalence of spinal hot spots in an orthopedic population undergoing bone scintigraphy (BS) for reasons unrelated to the spine and to assess the correlation of these hot spots with the presence of corresponding spinal complaints.

METHODS

A retrospective analysis of patients from the Department of Orthopedic Surgery and Traumatology who provided general consent for the use of their medical data. Adult patients who underwent single photon emission computed tomography (SPECT) over a two-year period for non-spinal complaints, along with a corresponding whole-body BS, were included. The primary endpoint was the prevalence of degenerative spinal hot spots detectable on BS. The secondary endpoint evaluated clinical complaints recorded in medical records for each spinal region.

RESULTS

Among 30 patients (mean age: 66.1 years; 30% male, 70% female), the prevalence of spinal hot spots on BS was 23.3% (n=7) in the cervical spine, 10% (n=3) in the thoracic spine, 33.3% (n=10) in the lumbar spine, and 6.7% (n=2) in the sacroiliac joint (SIJ). Most patients with cervical and lumbar hot spots had corresponding spinal symptoms, such as pain, tenderness, or stiffness, documented in their medical records, whereas thoracic complaints were less commonly noted.

CONCLUSION

The study outlines the prevalence of spinal hot spots in various spinal regions among a general orthopedic population undergoing bone scans for non-spinal complaints. A strong correlation was found between spinal complaints and high uptake in the cervical spine and lower back. These findings highlight the added value of comprehensive bone scan evaluations in clinical practice.

Artificial intelligence in predicting postoperative heterotopic ossification following anterior cervical disc replacement

OBJECTIVE

This study aimed to develop and validate a machine learning (ML) model to predict high-grade heterotopic ossification (HO) following Anterior cervical disc replacement (ACDR).

METHODS

Retrospective review of prospectively collected data of patients undergoing ACDR or hybrid surgery (HS) at a quaternary referral medical center was performed. Patients diagnosed as C3-7 single- or multi-level cervical disc degeneration disease with > 2 years of follow-up and complete pre- and postoperative radiological imaging were included. An ML-based algorithm was developed to predict high grade HO based on perioperative demographic, clinical, and radiographic parameters. Furthermore, model performance was evaluated according to discrimination and overall performance.

RESULTS

In total, 339 ACDR segments were included (61.65% female, mean age 45.65 ± 8.03 years). Over 45.65 ± 8.03 months of follow-up, 48 (14.16%) segments developed high grade HO. The model demonstrated good discrimination and overall performance according to precision (High grade HO: 0.71 ± 0.01, none-low grade HO: 0.85 ± 0.02), recall (High grade HO: 0.68 ± 0.03, none-low grade HO: 0.87 ± 0.01), F1-score (High grade HO: 0.69 ± 0.02, none-low grade HO: 0.86 ± 0.01), and AUC (0.78 ± 0.08), with lower prosthesis‑endplate depth ratio, higher height change, male, and lower postoperative-shell ROM identified as the most important predictive features.

CONCLUSION

Through an ML approach, the model identified risk factors and predicted development of high grade HO following ACDR with good discrimination and overall performance. By addressing the shortcomings of traditional statistics and adopting a new logical approach, ML techniques can support discovery, clinical decision-making, and intraoperative techniques better.

Visualizing the bibliometrics of the inflammatory mechanisms in intervertebral disc degeneration

OBJECTIVE

Intervertebral disc degeneration (IVDD) constitutes a crucial pathological foundation for spinal degenerative diseases (SDD) and stands as a primary contributor to both low back pain (LBP) and disability. The progression of IVDD is linked to structural and functional alterations in tissues, where an imbalance in the inflammatory microenvironment can induce extracellular matrix (ECM) degradation, senescence, and apoptosis. This imbalance is a key pathomechanism in the disease's development, gaining considerable attention in recent years. This study aims to conduct a bibliometric analysis of publications pertaining to the inflammatory mechanisms of IVDD to quantitatively assess current research hotspots and directions.

METHODS

In this study, we queried the Web of Science Core Collection (WOSCC) database covering the period from January 1, 2001, to November 7, 2023. Content in this area was analyzed and visualized using software such as Citespace, Vosviewer, and the bibliometrix package.

RESULTS

Findings indicate a consistent annual increase in the number of publications, highlighting the widespread attention garnered by research on the inflammatory mechanisms of IVDD. In terms of journal research, Spine emerged with the highest number of publications, along with significantly elevated total citations and average citations compared to other journals. Regarding country analysis, China led in the number of publications, while the USA claimed the highest number of citations and total link strength. Institutional analysis revealed Sun Yat-sen University as having the highest number of publications and total link strength, with Thomas Jefferson University securing the highest total citations. Author analysis identified Ohtori, S. with the highest number of publications, Risbud, M.V. with the highest number of citations, and Inoue, G. with the highest total link strength, all of whom have made significant contributions to the field's development. Citation and co-citation analyses indicated that highly cited documents primarily focused on classical studies exploring inflammatory mechanisms in IVDD pathogenesis. Keyword analysis showcased the ongoing research hotspot as the further investigation of mechanisms and treatment studies. Recent years have seen a shift towards exploring pyroptosis, necrotic apoptosis, autophagy, ferroptosis, oxidative stress, and bacterial infection, among other mechanisms. In terms of treatment, alongside traditional monomer, drug, and compound therapies for IVDD, research is increasingly concentrating on stem cell therapy, exosomes, hydrogels, and scaffolds.

CONCLUSION

This bibliometric analysis of research on inflammatory mechanisms in IVDD provides insights into the current status, hotspots, and potential future trends. These findings can serve as a valuable reference and guide for researchers in the field.

Sex as a Critical Variable in Basic and Pre-Clinical Studies of Fibrodysplasia Ossificans Progressiva

Heterotopic ossification (HO) is most dramatically manifested in the rare and severely debilitating disease, fibrodysplasia ossificans progressiva (FOP), in which heterotopic bone progressively accumulates in skeletal muscles and associated soft tissues. The great majority of FOP cases are caused by a single amino acid substitution in the type 1 bone morphogenetic protein (BMP) receptor ACVR1, a mutation that imparts responsiveness to activin A. Although it is well-established that biological sex is a critical variable in a range of physiological and disease processes, the impact of sex on HO in animal models of FOP has not been explored. We show that female FOP mice exhibit both significantly greater and more variable HO responses after muscle injury. Additionally, the incidence of spontaneous HO was significantly greater in female mice. This sex dimorphism is not dependent on gonadally derived sex hormones, and reciprocal cell transplantations indicate that apparent differences in osteogenic activity are intrinsic to the sex of the transplanted cells. By circumventing the absolute requirement for activin A using an agonist of mutant ACVR1, we show that the female-specific response to muscle injury or BMP2 implantation is dependent on activin A. These data identify sex as a critical variable in basic and pre-clinical studies of FOP.

Diversity in Orthopaedic Surgery Medical Device Clinical Trials: An Analysis of the Food and Drug Administration Safety and Innovation Act

INTRODUCTION

Demographic factors contribute markedly to orthopaedic surgery outcomes. However, women and minorities have been historically excluded from clinical trials. The United States passed the Safety and Innovation Act (Food and Drug Administration Safety and Innovation Act [FDA-SIA]) in 2012 to increase study diversity and mandate reporting of certain demographics. The purpose of this study was to investigate demographic reporting and analysis among high-risk orthopaedic medical device trials and evaluate the effectiveness of the FDA-SIA in increasing diversity of study enrollment.

METHODS

The premarket approval database was queried for all original submissions approved by the Orthopedic Advisory Committee from January 1, 2003, to July 1, 2022. Study demographics were recorded. Weighted means of race, ethnicity, and sex were compared before and after FDA-SIA implementation with the US population.

RESULTS

We identified 51 orthopaedic trials with unique study data. Most Food and Drug Administration device trials reported age (98.0%) and sex (96.1%), but only 49.0% and 37.3% reported race and ethnicity, respectively. Only 23 studies analyzed sex, six analyzed race, and two analyzed ethnicity. Compared with the US population, participants were overwhelmingly White (91.36% vs. 61.63%, P < 0.001) with a significant underrepresentation of Black (3.65% vs. 12.41%, P = 0.008), Asian (0.86% vs. 4.8%, P = 0.030), and Hispanic participants (3.02% vs. 18.73%, P < 0.001) before 2013. The FDA-SIA increased female patient enrollment (58.99% vs. 47.96%, P = 0.021) but did not increase the enrollment of racial or ethnic minorities.

CONCLUSION

Despite efforts to increase the generalizability of studies within the FDA-SIA, orthopaedic medical devices still fail to enroll diverse populations and provide demographic subgroup analysis. The study populations within these trials do not represent the populations for whom these devices will be indicated in the community. The federal government must play a stronger role in mandating study diversity, enforcing appropriate statistical analysis of the demographic subgroups, and executing measures to ensure compliance.

LEVEL OF EVIDENCE

I.