Intra-articular celecoxib improves knee extension regardless of surgical release in a rabbit model of arthrofibrosis.

Aims: Outcomes of current operative treatments for arthrofibrosis after total knee arthroplasty (TKA) are not consistently positive or predictable. Pharmacological in vivo studies have focused mostly on prevention of arthrofibrosis. This study used a rabbit model to evaluate intra-articular (IA) effects of celecoxib in treating contracted knees alone, or in combination with capsular release.

Surface Roughness of Titanium Orthopedic Implants Alters the Biological Phenotype of Human Mesenchymal Stromal Cells.

Metal orthopedic implants are largely biocompatible and generally achieve long-term structural fixation. However, some orthopedic implants may loosen over time even in the absence of infection. fixation failure is multifactorial, but the fundamental biological defect is cellular dysfunction at the host-implant interface.

Molecular pathology of human knee arthrofibrosis defined by RNA sequencing.

Arthrofibrosis is an abnormal histopathologic response, is debilitating for patients, and poses a substantial unsolved clinical challenge. This study characterizes molecular biomarkers and regulatory pathways associated with arthrofibrosis by comparing fibrotic and non-fibrotic human knee tissue. The fibrotic group encompasses 4 patients undergoing a revision total knee arthroplasty (TKA) for arthrofibrosis (RTKA-A) while the non-fibrotic group includes 4 patients undergoing primary TKA for osteoarthritis (PTKA) and 4 patients undergoing revision TKA for non-arthrofibrotic and non-infectious etiologies (RTKA-NA).

Inhibition of COX-2 Pathway as a Potential Prophylaxis Against Arthrofibrogenesis in a Rabbit Model of Joint Contracture.

Arthrofibrosis is a common complication following total knee arthroplasty caused by pathologic fibroblast activation and excessive collagen deposition around a synovial joint leading to debilitating loss of motion. Treatment options are limited because the pathologic mechanisms remain to be characterized. Dysregulation of the inflammatory cascade may lead to communication between myofibroblasts and immune cells triggering tissue metaplasia, and excessive collagen deposition described clinically as arthrofibrosis.

Molecular pathology of adverse local tissue reaction caused by metal-on-metal implants defined by RNA-seq.

Total hip arthroplasty (THA) alleviates hip pain and improves joint function. Current implant design permits long-term survivorship of THAs, but certain metal-on-metal (MoM) articulations can portend catastrophic failure due to adverse local tissue reactions (ALTR). Here, we identified biological and molecular differences between periacetabular synovial tissues of patients with MoM THA failure undergoing revision THA compared to patients undergoing primary THA for routine osteoarthritis (OA).

A Drug Eluting Scaffold for the Treatment of Arthrofibrosis.

Introduction: The inflammatory cascade and production of prostaglandins may play a role in the pathogenesis of arthrofibrosis, a debilitating condition after joint replacement and other orthopedic procedures. Cyclooxygenase 2 (COX-2) inhibitors may mitigate the inflammatory response and formation of arthrofibrosis, but oral delivery is associated with risk of systemic side effects in many patients. The nonsteroidal anti-inflammatory drug, celecoxib, may have therapeutic benefits for arthrofibrosis, but current methods for its local delivery (e.

Joint contracture is reduced by intra-articular implantation of rosiglitazone-loaded hydrogels in a rabbit model of arthrofibrosis.

Trauma, surgery, and other inflammatory conditions can lead to debilitating joint contractures. Adjunct pharmacologic modalities may permit clinical prevention and treatment of recalcitrant joint contractures. We investigated the therapeutic potential of rosiglitazone by intra-articular delivery via oligo[poly(ethylene glycol)fumarate] (OPF) hydrogels in an established rabbit model of arthrofibrosis.

Indirect management of full-thickness tracheal erosion in a complex pediatric patient.

Prolonged tracheostomy dependence in pediatric patients can be associated with significant complications, including damage to the tracheal wall requiring reconstruction. We present a case of an 8 year-old female with full-thickness tracheal erosion secondary to the presence of a tracheostomy tube combined with a narrow thoracic inlet. A direct tracheal reconstruction was considered but eliminated due to the poor tissue quality of the trachea.

Validation of a dynamic joint contracture measuring device in a live rabbit model of arthrofibrosis.

The current method of measuring arthrofibrosis in live rabbits is critically limited. Specifically, this method involves radioactive fluoroscopy, error-prone goniometric measurements, and static joint angle outcomes that fail to approximate the compliance of tissues surrounding the joint. This study aims to validate a novel method of capturing the compliance of contracted tissues surrounding the joint without the use of fluoroscopy or animal sacrifice.

Molecular pathology of total knee arthroplasty instability defined by RNA-seq.

Total knee arthroplasty (TKA) is a durable and reliable procedure to alleviate pain and improve joint function. However, failures related to flexion instability sometimes occur. The goal of this study was to define biological differences between tissues from patients with and without flexion instability of the knee after TKA.

Local Cellular Responses to Titanium Dioxide from Orthopedic Implants.

We evaluated recently published articles relevant to the biological effects of titanium dioxide (TiO) particles on local endogenous cells required for normal bone homeostasis, repair, and implant osseointegration. Structural characteristics, size, stability, and agglomeration of TiO particles alter the viability and behavior of multiple bone-related cell types. Resulting shifts in bone homeostasis may increase bone resorption and lead to clinical incidents of osteolysis, implant loosening, and joint pain.

Intra-articular injection of a substance P inhibitor affects gene expression in a joint contracture model.

Substance P (SP), a neurotransmitter released after injury, has been linked to deregulated tissue repair and fibrosis in musculoskeletal tissues and other organs. Although SP inhibition is an effective treatment for nausea, it has not been previously considered as an anti-fibrotic therapy. Although there are extensive medical records of individuals who have used SP antagonists, our analysis of human registry data revealed that patients receiving these antagonists and arthroplasty are exceedingly rare, thus precluding a clinical evaluation of their potential effects in the context of arthrofibrosis.

Laterality and grip strength influence hand bone micro-architecture in modern humans, an HRpQCT study.

It is widely hypothesized that mechanical loading, specifically repetitive low-intensity tasks, influences the inner structure of cancellous bone. As such, there is likely a relationship between handedness and bone morphology. The aim of this study is to determine patterns in trabecular bone between dominant and non-dominant hands in modern humans.

Seasonality of Periprosthetic Femur Fractures in 12,700 Primary and Revision Total Hip Arthroplasties.

Background: Periprosthetic femur fractures after primary and revision total hip arthroplasty (THA) are one of the most common long-term reasons for reoperation after THA. Previous investigations have analyzed the incidence and risk factors of these fractures. No previous study, however, has analyzed a variation in periprosthetic femur fractures between meteorologic seasons.

Patient Perceptions of the Direct Anterior Hip Arthroplasty.

Background: The quest for less invasive surgical approaches for total hip arthroplasty (THA) has garnered much attention recently in the community, as well as media outlets. There are very little data demonstrating the actual differences in these approaches. We are unaware of any information documenting patients' perceptions of the direct anterior approach (DAA) for THA.

Safety of Intra-Articular Implantation of Oligo[Poly(ethylene glycol) Fumarate] Scaffolds into the Rabbit Knee.

Implantable biomaterials supporting extended release of pharmacologic agents may permit localized intra-articular delivery of drugs that modulate the fibrotic response to injuries and surgery. Oligo[poly (ethylene glycol)] fumarate (OPF) is an attractive organic carrier, but its safety profile within synovial joints remains unclear. Here, we assessed the safety of OPF sponges using a validated in vivo model of knee arthrofibrosis.

Values-Based Measures of Impacts to Indigenous Health.

Values-based indicators of risks to Indigenous health have the potential to improve the accuracy and quality of a wide range of decisions affecting Native lands and cultures. Current health impact assessment approaches often omit important health priorities rooted in the history, social structures, and cultural context of Indigenous communities. Insights and methods from the decision sciences can be used to develop more culturally appropriate and context-relevant health indicators that can articulate and track changes to important dimensions of Indigenous health.

Development of a support tool for complex decision-making in the provision of rural maternity care.

Context: Decisions in the organization of safe and effective rural maternity care are complex, difficult, value laden and fraught with uncertainty, and must often be based on imperfect information. Decision analysis offers tools for addressing these complexities in order to help decision-makers determine the best use of resources and to appreciate the downstream effects of their decisions.

Objective: To develop a maternity care decision-making tool for the British Columbia Northern Health Authority (NH) for use in low birth volume settings.

Compensating aboriginal cultural losses: an alternative approach to assessing environmental damages.

We first identify six primary problems with conventional practice: lack of context, inadequate participation from aboriginal communities, exclusion of important losses, reliance on market-based measures, neglect of uncertainty, and inadequate treatment of time. We then propose a different approach to compensation, based on insights from the decision sciences and structured decision making. Using case-study examples, we discuss how the proposed approach might address common sources of cultural loss and, in a concluding section, summarize some of the implications for compensation agreements and for environmental management practices.