Journal of Orthopaedic Research : Official Publication of the Orthopaedic Research Society

PURPOSE: The pathogenesis of osteoarthritis (OA) is still unclear, leading to the lack of targeted treatment. We aimed to probe into the effect of Apolipoprotein D (APOD), the key gene from our previous study through bioinformatics analysis, on fibroblast-like synoviocyte (FLS) and chondrocytes in vitro, to confirm its potiential roles on the delay of OA progression. METHODS: Primary FLS and chondrocytes were extracted from synovium and cartilage of OA patients and stimulated with interleukin 1β (IL-1β) in vitro...

A carbon fiber-reinforced polyetheretherketone (CFR/PEEK) hip stem with a special antibiotic elution mechanism is under development to treat periprosthetic joint infection (PJI). The antibiotic elution characteristics of intramedullary implants were experimentally investigated, and the efficacy of revision surgery using a therapeutic stem in treating ovine PJI was examined. To evaluate elution characteristics, the intramedullary vancomycin-loaded CFR/PEEK cylindrical implants were inserted in the distal femur of nine sheep, and the vancomycin elution rate was measured at 2, 7, and 21 days...

Bacteriophage therapy is a promising adjuvant therapy for the treatment of periprosthetic joint infections. However, there is a paucity of knowledge about the activity of bacteriophages in synovial fluid. Therefore, this study evaluated the activity of a clinically used bacteriophage in synovial fluid as well as the ability of that bacteriophage to prevent the formation of and eradicate bacteria in synovial fluid induced aggregates. The results of this study reinforce that synovial fluid induced aggregates form rapidly in numerous synovial fluid concentrations...

The purpose of this retrospective study was to assess whether mortality following a hip fracture can be predicted by a machine learning model trained on basic blood and lab test data as well as basic demographic data. Additionally, the purpose was to identify the key variables most associated with 1-, 5-, and 10-year mortality and investigate their clinical significance. Input data included 3751 hip fracture patient records sourced from the Medical Information Mart for Intensive Care IV database, which provided records from in-hospital database systems at the Beth Israel Deaconess Medical Center...

To investigate the intervention effect of extracorporeal shock wave combined with manual traction on fixation-induced knee contracture and its influence on PTEN-PI3K/AKT signaling pathway. 36 SD male rats were randomly divided into 6 groups. The left knee joints were not fixed in the control group (C group). Rats in other groups underwent brace fixation in the extended position of the left knee. After 4 weeks bracing, it is randomly divided into five groups: Model group (M group), natural recovery group (NR group), extracorporeal shock wave treatment group (ET group), manual traction group (MT group), and extracorporeal shock wave combined with manual traction group (CT group)...

Psychomotor skill and decision-making efficiency in surgical wire navigation can be objectively evaluated by analysis of intraoperative fluoroscopic image sequences. Prior work suggests that such image-based behavior analysis of operating room (OR) performance can predict performer experience level (R2 = 0.62) and agree with expert opinion (the current standard) on the quality of a final implant construct (R2 = 0.59). However, it is unclear how objective image-based evaluation compares with expert assessments for entire technical OR performances...

Eccentric contractions of the wrist extensors worsen lateral epicondylitis (LE), whose pathophysiology may involve sex differences in wrist torque. This study aimed to investigate sex differences in wrist torque in patients with LE. The wrist extension and flexion torques of 22 patients with LE (11 males and 11 females) were measured. Maximum muscle output over time was measured for 20 s, initial torque was defined as muscle strength, and the degree of eccentric contraction was quantified and defined as the eccentric contraction index (ECI)...

Gait modification is a common nonsurgical approach to alter the mediolateral distribution of knee contact forces, intending to decelerate or postpone the progression of mechanically-induced knee osteoarthritis (KOA). Nevertheless, the success rate of these approaches is controversial, with no studies conducted to assess alterations in tissue-level knee mechanics governing cartilage degradation response in KOA patients undertaking gait modifications. Thus, here we investigated the effect of different conventional gait conditions and modifications on tissue-level knee mechanics previously suggested as indicators of collagen network damage, cell death, and loss of proteoglycans in knee cartilage...

Periprosthetic joint infections occur in about 2% of patients who undergo primary total joint arthroplasty, a procedure performed over 1 million times in the U.S. The gold standard of treatment is a two-stage revision. This study aimed to establish a two-stage procedure in a preclinical small animal model (rat) to test and compare the efficacy of an antibiotic-eluting material in managing infection. Joint replacement was simulated by transchondylarly implanting a polyethylene (PE) plug into the distal femur and a titanium screw in the proximal tibia...

The aim of the current study is to compare the clinical outcomes of cast immobilization (CI) versus surgical treatment after 1 year for distal radius fractures (DRFs) in the elderly population. The cohort included patients aged 70-89 who suffered an acute, closed, and displaced DRF and who were treated conservatively or surgically at our clinic between August 2018 and January 2022. Those who had pathological fractures, open fractures, concomitant ulna fractures (except ulna styloid fractures), were not between the ages of 70 and 89, or refused to participate were excluded from the study...

Anterior cruciate ligament (ACL) injuries are historically thought to be a result of a single acute overload or traumatic event. However, recent studies suggest that ACL failure may be a consequence of fatigue damage. Additionally, the remodeling response of ACLs to fatigue loading is unknown. Therefore, the objective of this study was to investigate the remodeling response of ACLs to cyclic loading. Furthermore, given that women have an increased rate of ACL rupture, we investigated whether this remodeling response is sex specific...

Bio-integrative, mineral fiber-reinforced bone fixation implants recently introduced in orthopedic surgery have expanded available treatment options for fractures and bone deformities. This new technology aims to address the disadvantages of permanent metallic implants while overcoming inherent concerns of adverse inflammatory reactions when using polymer-based orthopedic implants. The purpose of this double-arm preclinical study was to evaluate the safety, biocompatibility and bio-integration of fiber-reinforced plates, following implantation on the tibias of eight sheep...

Majority of ultra-high molecular weight polyethylene (UHMWPE) medical devices used in total joint arthroplasty are crosslinked using gamma radiation to improve wear resistance. Alternative methods of crosslinking are urgently needed to replace gamma radiation due to rapid decline in its supply. Peroxide crosslinking is a candidate method with widespread industrial applications. Oxidative stability and biocompatibility, which are critical requirements for medical device applications, can be achieved using vitamin-E as an additive and by removing peroxide by-products through high temperature melting, respectively...

Cartilage and synovial fluid are challenging to observe separately in native computed tomography (CT). We report the use of triple contrast agent (bismuth nanoparticles, CA4+, and gadoteridol) to image and segment cartilage in cadaveric knee joints with a clinical CT scanner. We hypothesize that bismuth nanoparticles will remain in synovial fluid while the CA4+ and gadoteridol will diffuse into cartilage, allowing 1) segmentation of cartilage, and 2) evaluation of cartilage biomechanical properties based on contrast agent concentrations...

The aim of this study was to evaluate the muscle activation of the vastus medialis, vastus lateralis, and gluteus medius during different strength and stability exercises with a water tank compared to a sandbag. A cross-sectional study was conducted in the Functional Anatomy Laboratory, and the sample consisted of 28 athletes. The main outcome measures were surface electromyography (dependent variable), water tank and sandbag, and exercise type (independent variables): Isometric Single Leg Stance (ISLS), One Leg Deadlift (OLDL), Front Rack Forward Lunge (FRFL), and Lateral Lunge (LL)...

Several tendon and ligament animal models were presented at the 2022 Orthopaedic Research Society Tendon Section Conference held at the University of Pennsylvania, May 5 to 7, 2022. A key objective of the breakout sessions at this meeting was to develop guidelines for the field, including for preclinical tendon and ligament animal models. This review summarizes the perspectives of experts for eight surgical small and large animal models of rotator cuff tear, flexor tendon transection, anterior cruciate ligament tear, and Achilles tendon injury using the framework: "Why, Who, What, Where, When, and How" (5W1H)...

While finite element (FE) models have been used extensively in orthopaedic studies, validation of their outcome metrics has been limited to comparison against ex vivo testing. The aim of this study was to validate FE model predictions of the initial cup mechanical environment against patient-matched in vivo measurements of acetabular cup migration using radiostereometric analysis (RSA). Tailored musculoskeletal and FE models were developed using a combination of three-dimensional motion capture data and clinical CT scans for a cohort of eight individuals who underwent primary total hip replacement and were prospectively enrolled in an RSA study...

Chronic neck pain is a common reasons for doctor visits in the U.S. This diagnosis can be evaluated through patient history, physical examination and judicious use of radiographs. However, possible inappropriate magnetic resonance imaging ordering persists. We hypothesized that no difference in ordering practices, ordering appropriateness and subsequent intervention would be appreciated regarding physician specialty, location, patient characteristics, and history and physical exam findings. A multisite retrospective review for cervical spine MRIs between 2014 and 2018 was performed...

Cam femoroacetabular impingement (FAI) syndrome is associated with hip osteoarthritis (OA) development. Hip shape features, derived from statistical shape modelling (SSM), are predictive for OA incidence, progression and arthroplasty. Currently, no 3D SSM studies have investigated whether there are cam shape differences between male and female patients which may be of potential clinical relevance for FAI syndrome assessments. This study analysed sex-specific cam location and shape in FAI syndrome patients from clinical magnetic resonance (MR) examinations (M:F 56:41, age: 16-63 years) using three-dimensional focused shape modelling-based segmentation (CamMorph) and partial least squares (PLS) regression to obtain shape features (latent variables (LVs)) of cam morphology...

Dysregulation of Wnt signaling has been strongly associated with development and progression of osteoarthritis (OA). Here, we set out to investigate the independent effects of either mechanical stress or inflammation on Wnt signaling in human neo-cartilage pellets, and to relate this Wnt signaling to OA pathophysiology. OA synovium conditioned media (OAS-CM) was collected after incubating synovium from human end-stage OA joints for 24 hours in medium. Cytokine levels in the OAS-CM were determined with a multiplex immunoassay (Luminex)...