A novel methodology utilizing microchip implants to monitor individual activity and body temperature for assessing knee pain in group-housed rats.

The pain assessment in animals is challenging as they cannot verbally express the site and severity of pain. In this study, we tried a small implantable actimeter, "Nanotag", to monitor spontaneous locomotor activity and body temperature in animals suffering from a chemical-induced rat knee arthritis as compared to naïve and steroid-treated rats. Nanotag could detect the decrease in locomotor activity quickly after the arthritis induction and anti-inflammation analgesic treatment by intra-articular injection of steroid significantly improved locomotor activity.

Presoaking Grafts in Vancomycin Does Not Impair Graft-Bone Healing in a Rat Anterior Cruciate Ligament Reconstruction Model.

Background: The vancomycin presoaking technique (wherein grafts are treated with a vancomycin solution [VS] for anterior cruciate ligament reconstruction [ACLR]) reduces the infection rate after ACLR. However, the effects of this technique on graft-bone healing have not been fully elucidated.

Purpose: To investigate the effects of vancomycin presoaking on graft-bone healing in a rat ACLR model.

Characteristics of the synovial microenvironment and synovial mesenchymal stem cells with hip osteoarthritis of different bone morphologies.

Background: Variations in bone morphology in patients with hip osteoarthritis (HOA) can be broadly categorized into three types: atrophic, normotrophic, and hypertrophic. Despite the investigations examining clinical elements, such as bone morphology, pain, and range of motion, our understanding of the pathogenesis of HOA remains limited. Previous studies have suggested that osteophytes typically originate at the interface of the joint cartilage, periosteum, and synovium, potentially implicating synovial mesenchymal stem cells (SMSCs) in the process.

Association of osteoporosis and high serum homocysteine levels with intraoperative periprosthetic fracture during total hip arthroplasty: a propensity-score matching analysis.

Introduction: Intraoperative periprosthetic fracture, one of the most frequent complications of total hip arthroplasty, is a very important factor that affects rehabilitation, hospitalization time, and cost of treatment. Osteoporosis is common in total hip arthroplasty patients and likely contributes to the increasing incidence of periprosthetic fracture. Despite this awareness, preoperative and postoperative osteoporosis evaluations remain insufficient.

Therapeutic effect of C-type natriuretic peptide on persistent pain in a rat knee arthritis model.

Background: Intra-articular injection of C-type natriuretic peptide (CNP) at the acute inflammatory stage suppressed fibrotic changes in the infrapatellar fat pad (IFP), articular cartilage degeneration, and persistent pain in a monoiodoacetic acid (MIA)-induced rat knee arthritis model. In this study, we administered CNP during the inflammation subsiding period to evaluate CNP effectiveness in knees with osteoarthritis (OA) pathology.

Methods: 20 male Wistar rats were randomly divided into two groups.

Hyaluronic acid sheet transplantation attenuates infrapatellar fat pad fibrosis and pain in a rat arthritis model.

Fibrosis of the infrapatellar fat pad (IFP) occurs after knee joint surgery or during knee osteoarthritis (KOA) and causes persistent pain and limited mobility. Previous studies demonstrated that treating IFP fibrosis alleviated pain in animal models. In this study, we examined the effects of hyaluronic acid (HA) sheet transplantation on IFP fibrosis and articular cartilage degeneration in a monoiodoacetic acid (MIA) rat arthritis model (95 male rats).

Effect of CD44 signal axis in the gain of mesenchymal stem cell surface antigens from synovial fibroblasts .

Tissue-residing mesenchymal stromal/stem cells (MSCs) have multipotent characteristics that are important for adult tissue homeostasis and tissue regeneration after injury. We previously reported that fibroblastic cells isolated from the synovial membrane in the knee joint give rise to cells with MSC characteristics in a two-dimensional culture. To explore the molecular mechanisms underlying these hyperplastic properties, we performed time-course surface antigen expression analyses during culture.

Short cytoplasmic isoform of IL1R1/CD121a mediates IL1β induced proliferation of synovium-derived mesenchymal stem/stromal cells through ERK1/2 pathway.

Objectives: IL1β enhances proliferation of synovial mesenchymal stem/stromal cells (synMSCs) although they don't express its receptor, IL1R1/CD121a, on the cell surface. This study was aimed to elucidate the underlying mechanisms of IL1β-mediated growth promotion.

Methods: Human synMSCs were isolated from the suprapatellar synovial membrane.

Comparison of Clinical Outcomes after Revision Anterior Cruciate Ligament Reconstruction using a Bone-patellar Tendon-bone Autograft and that Using a Double-Bundle Hamstring Tendon Autograft.

Purpose:  The purpose of this study was to compare clinical outcomes between revision anterior cruciate ligament reconstruction (ACLR) using a bone-patellar tendon-bone (BPTB) autograft and that using a double-bundle hamstring tendon (HT) autograft.

Methods:  Consecutive cases of revision ACLRs were reviewed. The Lysholm knee scale and Knee Osteoarthritis Outcome Score (KOOS) were recorded at the final follow-up.

Extracellular vesicles derived from mesenchymal stromal cells mediate endogenous cell growth and migration via the CXCL5 and CXCL6/CXCR2 axes and repair menisci.

Background: Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) are promising candidates for tissue regeneration therapy. However, the therapeutic efficacy of MSC-EVs for meniscus regeneration is uncertain, and the mechanisms underlying MSC-EV-mediated tissue regeneration have not been fully elucidated. The aims of this study were to evaluate the therapeutic efficacy of intra-articular MSC-EV injection in a meniscus defect model and elucidate the mechanism underlying MSC-EV-mediated tissue regeneration via combined bioinformatic analyses.

Short-Term Outcomes after High Tibial Osteotomy Aimed at Neutral Alignment Combined with Arthroscopic Centralization of Medial Meniscus in Osteoarthritis Patients.

The study aimed to improve the long-term outcomes of open-wedge high tibial osteotomy (OWHTO); procedures combining OWHTO aimed at neutral alignment and arthroscopic centralization for meniscal extrusion have been introduced. The present study evaluated short-term patient-reported outcome measures; namely, the patient subjective satisfaction scores and Numeric Rating Scale (NRS) for walking pain after OWHTO aimed at neutral alignment with and without arthroscopic centralization for an extruded medial meniscus. A retrospective review of 50 primary OWHTO patients was conducted.

Inflammatory and healing environment in synovial fluid after anterior cruciate ligament reconstruction: Granulocytes and endogenous opioids as new targets of postoperative pain.

Background: Biological processes after anterior cruciate ligament reconstruction (ACLR) is crucial for recovery. However, alterations in the of synovial fluid cell population during the acute phase following ACLR and the relationship between these cells and postoperative pain is unclear. The goal of this study was to reveal alterations in synovial fluid cell population during the acute phase following ACLR and relationship between postoperative pain and proportion of synovial fluid cells.

Comparison of 5-year postoperative results between standard-length stems and short stems in one-stage bilateral total hip arthroplasty: a randomized controlled trial.

Purpose: Short stems have recently become popular in total hip arthroplasty. Previous studies aimed at elucidating the efficacy of short stems did not eliminate the influence of other factors aside from stem length. This study aimed to evaluate the usefulness of short stems compared with that of standard-length stems that have the same proximal morphology, surface coating, and material.

Association between Hemiarthroplasty vs Total Hip Arthroplasty and Major Surgical Complications among Patients with Femoral Neck Fracture.

Previous studies have shown better clinical outcomes after total hip arthroplasty (THA) compared to hemiarthroplasty (HA) for displaced femoral neck fracture. However, few studies have focused on the surgical risks of the two procedures. Therefore, we investigated the perioperative complications of HA and THA in femoral neck fracture, using a large nationwide inpatient database.