Skeletal Stem Cells: A Basis for Orthopaedic Pathology and Tissue Repair.

➢ Skeletal stem cells (SSCs) continually replenish mature cell populations to support skeletal homeostasis.➢ SSCs repopulate by self-renewal, have multilineage potential, and are long-lived in vivo.➢ SSCs express specific combinations of cell surface markers that reflect their lineage identity.

Capacity for large language model chatbots to aid in orthopedic management, research, and patient queries.

Large language model (LLM) chatbots possess a remarkable capacity to synthesize complex information into concise, digestible summaries across a wide range of orthopedic subject matter. As LLM chatbots become widely available they will serve as a powerful, accessible resource that patients, clinicians, and researchers may reference to obtain information about orthopedic science and clinical management. Here, we examined the performance of three well-known and easily accessible chatbots-ChatGPT, Bard, and Bing AI-in responding to inquiries relating to clinical management and orthopedic concepts.

A multi-stem cell basis for craniosynostosis and calvarial mineralization.

Craniosynostosis is a group of disorders of premature calvarial suture fusion. The identity of the calvarial stem cells (CSCs) that produce fusion-driving osteoblasts in craniosynostosis remains poorly understood. Here we show that both physiologic calvarial mineralization and pathologic calvarial fusion in craniosynostosis reflect the interaction of two separate stem cell lineages; a previously identified cathepsin K (CTSK) lineage CSC (CTSK CSC) and a separate discoidin domain-containing receptor 2 (DDR2) lineage stem cell (DDR2 CSC) that we identified in this study.

Intermittent parathyroid hormone increases stability and improves osseointegration of initially unstable implants.

Aims: To develop an early implant instability murine model and explore the use of intermittent parathyroid hormone (iPTH) treatment for initially unstable implants.

Methods: 3D-printed titanium implants were inserted into an oversized drill-hole in the tibiae of C57Bl/6 mice (n = 54). After implantation, the mice were randomly divided into three treatment groups (phosphate buffered saline (PBS)-control, iPTH, and delayed iPTH).

A Subset of Osteosarcoma Bears Markers of CXCL12-Abundant Reticular Cells.

Currently, the cell of origin for osteosarcoma or other primary skeletal tumors is largely unknown. Recent reports identifying specific cell types comprising bone now newly enable investigation of this topic. Specifically, CXC motif chemokine 12 (CXCL12)-abundant reticular (CAR) cells are a specific skeletal stromal cell type that orchestrate the bone marrow microenvironment through cross-talk with hematopoietic and endothelial cells and a likely candidate cell of origin for at least a subset of primary skeletal tumors.

Inhibition of PAD4 mediated neutrophil extracellular traps prevents fibrotic osseointegration failure in a tibial implant murine model : an animal study.

Aims: Aseptic loosening is a leading cause of uncemented arthroplasty failure, often accompanied by fibrotic tissue at the bone-implant interface. A biological target, neutrophil extracellular traps (NETs), was investigated as a crucial connection between the innate immune system's response to injury, fibrotic tissue development, and proper bone healing. Prevalence of NETs in peri-implant fibrotic tissue from aseptic loosening patients was assessed.

Alendronate enhances osseointegration in a murine implant model.

Administration of bisphosphonates following total joint arthroplasty might be beneficial to reduce aseptic loosening. However, their effects on peri-implant bone formation and bone-implant interface strength have not been investigated yet. We used a physiologically loaded mouse implant model to investigate the short-term effects of postoperative systemic alendronate on osseointegration.

2020 John Charnley Award: The antimicrobial potential of bacteriophage-derived lysin in a murine debridement, antibiotics, and implant retention model of prosthetic joint infection.

Aims: Current treatments of prosthetic joint infection (PJI) are minimally effective against biofilm. A murine PJI model of debridement, antibiotics, and implant retention (DAIR) was used to test the hypothesis that PlySs2, a bacteriophage-derived lysin, can target biofilm and address the unique challenges presented in this periprosthetic environment.

Methods: The ability of PlySs2 and vancomycin to kill biofilm and colony-forming units (CFUs) on orthopaedic implants were compared using in vitro models.

Femoral Derotation Osteotomy in Adults for Version Abnormalities.

Background: Version abnormalities of the femur can cause pain and hip joint damage due to impingement or instability. A retrospective clinical review was conducted on patients undergoing a subtrochanteric derotation osteotomy for either excessive anteversion or retroversion of the femur.

Methods: A total of 55 derotation osteotomies were performed in 43 patients: 36 females and 7 males.