Articular Joint Research Articles

Advances in diagnosis and imaging of cervical dysfunction in the sports horse

Cervical imaging provides an abundance of data. It is important not to lose sight of the horse and to determine what clinical relevance these findings have. Good clinical examination, in combination with knowledge of functional anatomy and biomechanics, are essential in anticipation of more research which will allow veterinarians to work in a more evidence-based manner. The location of cervical pain can be pinpointed to a single or multiple locations with an extensive history, static observation, general palpation, motion evaluation, specific palpation and dynamic evaluation. The whole body should be evaluated. The majority of cervical pathology (80%) is located in the caudal cervical area (C5–T1). Radiography of this region can be improved with good quality equipment, collimation, correct positioning of the horse and a correct distance between generator and plate. Radiography and ultrasonography may underestimate cervical pathology. Computed tomography is the preferred method of imaging but may lead to over interpretation. The most common finding is narrowing of the intervertebral foramen because of enlargement of the articular process joint(s). More than one location with abnormalities is often identified.

KLF2 Inhibits Ferroptosis and Improves Mitochondrial Dysfunction in Chondrocyte Through SIRT1/GPX4 Signaling to Improve Osteoarthritis.

Osteoarthritis (OA), a disease of articular joints, is the leading cause of disability in the elderly. Repressing ferroptosis and improving mitochondrial function can delay the progression of OA. Kruppel-like factor 2 (KLF2) exerts a protective effect on OA. However, whether KLF2 affects ferroptosis and mitochondrial function during OA remains unknown. The OA in vivo and in vitro models were constructed in this work. The structural damage of knee joint in OA mice was evaluated through Micro-CT scanning. H&E, SOFG, TB, and TUNEL staining were applied for pathological examination of cartilage tissues. ELISA was employed to examine the contents of inflammatory factors. Additionally, iron deposition in cartilage tissues was measured by Prussian blue staining, and the levels of proteins related to ferroptosis were assessed by immunoblotting. Besides, mitochondrial morphology and function were estimated using a transmission electron microscope and JC-1 staining. In interleukin (IL)-1β-treated C28/I2 cells, the levels of inflammatory factors, intracellular ROS, mitochondrial ROS, lipid ROS, and Fe2+ were measured. Mitochondrial function was evaluated by detecting the levels of mitochondrial membrane potential (MMP), ATP, mPTP, and OCR. KLF2 overexpression ameliorated the structural damage of knee cartilage in OA mice. KLF2 upregulation inhibited ferroptosis and alleviated mitochondrial damage in knee cartilage of OA mice and IL-1β-treated C28/I2 cells. Moreover, KLF2 overexpression activated SIRT1/GPX4 signaling in vivo and in vitro. EX527 addition blocked the influences of KLF2 upregulation on ferroptosis and mitochondrial dysfunction in IL-1β-treated C28/I2 cells. Altogether KLF2 inhibits ferroptosis and improves mitochondrial dysfunction in chondrocytes through SIRT1/GPX4 signaling to improve OA.

Surgical Strategy and Decision Making in Recurrent Atlanto-Axial Dislocations: The Role of Traction

ObjectiveTo analyse patients with recurrent atlantoaxial dislocation and give a criterion of an ideal patient who can benefit from redo surgery. MethodsThis retrospective study was conducted in a tertiary care centre, which included 20 patients who failed atlantoaxial surgery from January 2013 to June December 2021. They were evaluated using X-ray, CT, and MRI examinations, and their clinical data were accessed from the hospital's medical records department and the picture archiving and communication system. They were given a trial of traction to look for clinical and/or radiological improvement. Those showing clinical and/or radiological improvement underwent redo fixation. The operative steps involved removing joint capsules, denuding articular cartilage and joint preparation followed by reduction of basilar invagination by the combination of spacer and/or bone graft and putting screws in C1/Occiput and C2. A strut graft was placed between Occiput/ C1 and C2. ResultsThe mean change in mJOAS and Nurick grade following the first surgery was statistically significant (1.00 ± 0.73, p-value 0.002 and -0.15 ± 0.27, p-value 0.046, respectively). On similar paths, the mean change in mJOAS and Nurick grade following the second surgery was also statistically significant (4.25 ± 0.32, p-value <0.001 and -1.2 ± 0.11, p-value <0.001, respectively). Improper usage of constructs (31.57%), inadequate/no joint preparation (42.10%/57.90%) and poor choice of graft (100%) were the leading causes of failure of index surgery. ConclusionsThe best candidates who can benefit after re-do surgery are the ones who exhibit either clinical and/or radiological improvement on the trial of traction, as the pathological C1-C2 joints are either not fused or have undergone pseudoarthrosis. Those patients who do not exhibit significant clinical or radiological improvement post-trial of traction should not be offered subsequent surgical intervention.

The Use of Mesenchymal Stem/Stromal Cell-Derived Extracellular Vesicles in the Treatment of Osteoarthritis: Insights from Preclinical Studies.

Osteoarthritis (OA) is a prominent cause of disability, and has severe social and economic ramifications across the globe. The main driver of OA's pervasiveness is the fact that no current medical interventions exist to reverse or even attenuate the degeneration of cartilage within the articular joint. Crucial for cell-to-cell communication, extracellular vesicles (EVs) contribute to OA progression through the delivery of bioactive molecules in the inflammatory microenvironment. By repurposing this acellular means of signal transmission, therapeutic drugs may be administered to degenerated cartilage tissue in the hopes of encouraging regeneration. Positive outcomes are apparent in in vivo studies on this subject; however, for this therapy to prove itself in the clinical world, efforts towards standardizing the characterization, application, biological contents, and dosage are essential.

Modulation of chondroprotective hyaluronic acid and poloxamer gel with Ketoprofen loaded transethosomes: Quality by design-based optimization, characterization, and preclinical investigations in osteoarthritis

Osteoarthritis (OA) is a chronic joint disease that results in biomechanical and morphological changes that contribute to cartilage degradation. Ketoprofen (KP), used in the treatment of OA, is a selective inhibitor of cyclooxygenase-2 (COX-2). Topical administration of KP bypasses gastric irritation as well as first-pass metabolism and increases localized delivery. The research intricates fabrication and optimization of KP-loaded transethosomes (KP-TEs) via Taguchi orthogonal array design and Central composite design (CCD). The optimized KP-TEs depicted an average vesicle size of 110.0 ± 1.70 nm, poly dispersibility index (PDI) of 0.103 ± 0.01, zeta potential −6.08 ± 0.27 mV, and conductivity of 0.049 ± 0.0001 mS/cm. The optimized KP-TEs were loaded in composite hyaluronic acid (HA) and poloxamer 407 (Px407) for an improvement of osteotrophic and chondroprotective transethosomal gel. The drug content of KP-TEs-HA/Px407 gel was found to be 90.08 ± 1.25 %. Preclinical research has been carried out by using the monosodium iodoacetate to develop model for osteoarthritis in male wistar rats. The X-ray imaging of KP-TEs-HA/Px407 gel treated group showed intact meniscus, healthy articular joint, and normal synovial lining same as the healthy control group. The IL − 1β IL-6, IL-22, TNF-α, and IL-10, levels, X-ray imaging, and studies on histopathology demonstrated the effectiveness of transethosomal gel in reducing pain and inflammation.

Brazilian fossils reveal homoplasy in the oldest mammalian jaw joint

The acquisition of the load-bearing dentary–squamosal jaw joint was a key step in mammalian evolution1–5. Although this innovation has received decades of study, questions remain over when and how frequently a mammalian-like skull–jaw contact evolved, hindered by a paucity of three-dimensional data spanning the non-mammaliaform cynodont–mammaliaform transition. New discoveries of derived non-mammaliaform probainognathian cynodonts from South America have much to offer to this discussion. Here, to address this issue, we used micro-computed-tomography scanning to reconstruct the jaw joint anatomy of three key probainognathian cynodonts: Brasilodon quadrangularis, the sister taxon to Mammaliaformes6–8, the tritheledontid-related Riograndia guaibensis9 and the tritylodontid Oligokyphus major. We find homoplastic evolution in the jaw joint in the approach to mammaliaforms, with ictidosaurs (Riograndia plus tritheledontids) independently evolving a dentary–squamosal contact approximately 17 million years before this character first appears in mammaliaforms of the Late Triassic period10–12. Brasilodon, contrary to previous descriptions6–8, lacks an incipient dentary condyle and squamosal glenoid and the jaws articulate solely using a plesiomorphic quadrate–articular joint. We postulate that the jaw joint underwent marked evolutionary changes in probainognathian cynodonts. Some probainognathian clades independently acquired ‘double’ craniomandibular contacts, with mammaliaforms attaining a fully independent dentary–squamosal articulation with a conspicuous dentary condyle and squamosal glenoid in the Late Triassic. The dentary–squamosal contact, which is traditionally considered to be a typical mammalian feature, therefore evolved more than once and is more evolutionary labile than previously considered.

Influence of muscle activation on articular ankle joint mechanics

Influence of muscle activation on articular ankle joint mechanics

Degradation of lubricating molecules in synovial fluid alters chondrocyte sensitivity to shear strain.

Articular joints facilitate motion and transfer loads to underlying bone through a combination of cartilage tissue and synovial fluid, which together generate a low-friction contact surface. Traumatic injury delivered to cartilage and the surrounding joint capsule causes secretion of proinflammatory cytokines by chondrocytes and the synovium, triggering cartilage matrix breakdown and impairing the ability of synovial fluid to lubricate the joint. Once these inflammatory processes become chronic, posttraumatic osteoarthritis (PTOA) development begins. However, the exact mechanism by which negative alterations to synovial fluid leads to PTOA pathogenesis is not fully understood. We hypothesize that removing the lubricating macromolecules from synovial fluid alters the relationship between mechanical loads and subsequent chondrocyte behavior in injured cartilage. To test this hypothesis, we utilized an ex vivo model of PTOA that involves subjecting cartilage explants to a single rapid impact followed by continuous articulation within a lubricating bath of either healthy synovial fluid, phosphate-buffered saline (PBS), synovial fluid treated with hyaluronidase, or synovial fluid treated with trypsin. These treatments degrade the main macromolecules attributed with providing synovial fluid with its lubricating properties; hyaluronic acid and lubricin. Explants were then bisected and fluorescently stained to assess global and depth-dependent cell death, caspase activity, and mitochondrial depolarization. Explants were tested via confocal elastography to determine the local shear strain profile generated in each lubricant. These results show that degrading hyaluronic acid or lubricin in synovial fluid significantly increases middle zone chondrocyte damage and shear strain loading magnitudes, while also altering chondrocyte sensitivity to loading.

Comparative Evaluation of Temporomandibular Joint Parameters in Unilateral and Bilateral Cleft Lip and Palate Patients Using Cone-Beam CT: Focus on Growing vs. Non-Growing Subjects.

Morphological differences in the temporomandibular joint (TMJ) are crucial for the treatment of patients with cleft lip and palate (CLP). This study aims to evaluate and compare the TMJ parameters in patients with unilateral and bilateral CLP across growing and non-growing age groups using cone-beam computed tomography (CBCT). CBCT records from 57 patients (23 males and 34 females) aged 6-50 years with a diagnosed unilateral or bilateral CLP were analyzed. Patients were categorized into four groups: growing unilateral (UGCLP), growing bilateral (BGCLP), non-growing unilateral (UNGCLP), and non-growing bilateral (BNGCLP). Measurements of TMJ parameters, including the mandibular fossa, articular eminence inclination, joint spaces, and roof thickness of the glenoid fossa, were conducted using CBCT images. Significant differences were observed in the anterior joint space (AJS) and the roof of the glenoid fossa (RGF) between growing and non-growing unilateral cleft patients. Additionally, significant discrepancies were found in the articular eminence angle when comparing the cleft and non-cleft sides within the unilateral growing group. No significant differences were observed in TMJ parameters between the right and left sides among bilateral cleft patients. The study highlights distinct TMJ morphological differences between growing and non-growing patients with CLP, emphasizing the importance of age-specific considerations in the treatment planning and growth monitoring of these patients.

CT Arthrography With Traction in Femoro-Acetabular Impingement: How to Do It?

Computed tomography arthrography (CTA) highly correlates with arthroscopy in detecting labral tears, especially in patients with positive impingement tests. CTA enables the acquisition of isotropic datasets with high spatial resolution within a single acquisition. However, the hip is a close-fitting, congruent, and nearly spherical joint, with relatively thin cartilage. We describe herein a simple and cost-effective method using traction for hip CTA, with axial manual distraction, that helps overcome the usual limitations, by widening the articular joint space and thus better delineating both acetabular and femoral cartilages.

Functional Insights into the Sphingolipids C1P, S1P, and SPC in Human Fibroblast-like Synoviocytes by Proteomic Analysis.

The (patho)physiological function of the sphingolipids ceramide-1-phosphate (C1P), sphingosine-1-phosphate (S1P), and sphingosylphosphorylcholine (SPC) in articular joints during osteoarthritis (OA) is largely unknown. Therefore, we investigated the influence of these lipids on protein expression by fibroblast-like synoviocytes (FLSs) from OA knees. Cultured human FLSs (n = 7) were treated with 1 of 3 lipid species-C1P, S1P, or SPC-IL-1β, or with vehicle. The expression of individual proteins was determined by tandem mass tag peptide labeling followed by high-resolution electrospray ionization (ESI) mass spectrometry after liquid chromatographic separation (LC-MS/MS/MS). The mRNA levels of selected proteins were analyzed using RT-PCR. The 3sphingolipids were quantified in the SF of 18 OA patients using LC-MS/MS. A total of 4930 proteins were determined using multiplex MS, of which 136, 9, 1, and 0 were regulated both reproducibly and significantly by IL-1β, C1P, S1P, and SPC, respectively. In the presence of IL-1ß, all 3 sphingolipids exerted ancillary effects. Only low SF levels of C1P and SPC were found. In conclusion, the 3 lipid species regulated proteins that have not been described in OA. Our results indicate that charged multivesicular body protein 1b, metal cation symporter ZIP14, glutamine-fructose-6-P transaminase, metallothionein-1F and -2A, ferritin, and prosaposin are particularly interesting proteins due to their potential to affect inflammatory, anabolic, catabolic, and apoptotic mechanisms.

Recent Advances in Hydrogel Technology in Delivering Mesenchymal Stem Cell for Osteoarthritis Therapy.

Osteoarthritis (OA), a chronic joint disease affecting over 500 million individuals globally, is characterized by the destruction of articular cartilage and joint inflammation. Conventional treatments are insufficient for repairing damaged joint tissue, necessitating novel therapeutic approaches. Mesenchymal stem cells (MSCs), with their potential for differentiation and self-renewal, hold great promise as a treatment for OA. However, challenges such as MSC viability and apoptosis in the ischemic joint environment hinder their therapeutic effectiveness. Hydrogels with biocompatibility and degradability offer a three-dimensional scaffold that support cell viability and differentiation, making them ideal for MSC delivery in OA treatment. This review discusses the pathological features of OA, the properties of MSCs, the challenges associated with MSC therapy, and methods for hydrogel preparation and functionalization. Furthermore, it highlights the advantages of hydrogel-based MSC delivery systems while providing insights into future research directions and the clinical potential of this approach.

Short-term effectiveness of unilateral biportal endoscopy technique in treatment of lumbar lateral saphenous fossa combined with intervertebral foramina stenosis via contralateral sublaminar approach

To investigate the short-term effectiveness of unilateral biportal endoscopy (UBE) in treatment of lumbar lateral saphenous fossa combined with intervertebral foramina stenosis via contralateral sublaminar approach. A clinical data of 15 patients with lumbar lateral saphenous fossa combined with intervertebral foramina stenosis, who were admitted between September 2021 and December 2023 and met selective criteria, was retrospectively analyzed. There were 5 males and 10 females with an average age of 70.3 years (range, 46-83 years). Surgical segment was L 4, 5 in 12 cases and L 5, S 1 in 3 cases. The disease duration was 12-30 months (mean, 18.7 months). All patients were treated by UBE via contralateral sublaminar approach. The operation time, intraoperative blood loss, postoperative hospital stay, and the occurrence of complications were recorded. The visual analogue scale (VAS) score was used to evaluate the degree of lower back and leg pain before and after operation; the Japanese Orthopaedic Association (JOA) score and the Oswestry disability index (ODI) were used to evaluate the lumbar function; and the clinical outcome was evaluated using the MacNab criteria at 6 months after operation. Postoperative MRI and CT were taken to observe whether the lateral saphenous fossa and intervertebral foramen stenosis were removed or not, and the cross-sectional area of the spinal canal (CSA-SC), cross-sectional area of the intervertebral foramen (CSA-IVF), and cross-sectional area of the facet joint (CSA-FJ) were measured. The operation time was 55-200 minutes (mean, 127.5 minutes); the intraoperative blood loss was 10-50 mL (mean, 27.3 mL); the length of postoperative hospital stay was 3-12 days (mean, 6.8 days). All patients were followed up 6-12 months (mean, 8.9 months). At 1 day, 1 month, 3 months, and 6 months after operation, the VAS scores of low back and leg pain and ODI scores after operation were significantly lower than preoperative scores and showed a gradual decrease with time; the JOA scores showed a gradual increase with time; the differences in the above indexes between different time points were significant ( P<0.05). The clinical outcome was rated as excellent in 10 cases, good in 4 cases, and poor in 1 case according to the MacNab criteria at 6 months after operation, with an excellent and good rate of 93.33%. Imaging review showed that the compression on the lateral saphenous fossa and intervertebral foramina had been significantly relieved, and the affected articular process joint was preserved to the maximum extent; the CSA-SC and CSA-IVF at 3 days after operation significantly increased compared to the preoperative values ( P<0.05), and the CSA-FJ significantly reduced ( P<0.05). The UBE via contralateral sublaminar approach can effectively reduce pressure in the lateral saphenous fossa and the intervertebral foramina of the same segment while preserving the bilateral articular process joints. The short-term effectiveness is good and it is expected to avoid fusion surgery caused by iatrogenic instability of the lumbar spine. However, further follow-up is needed to clarify the mid- and long-term effectiveness.

Ultrasound-guided caudal cervical articular process arthrocentesis is accurate in live horses with and without arthropathy.

Cervical articular process joint (CAPJ) therapy is advocated for horses with neck disorders. Several ultrasound-guided CAPJ techniques have been described in cadaver studies with 72%-89% intra-articular injection accuracy; however, the CAPJ injection accuracy in clinical equine practice has not been extensively reported. To describe a modified cranial approach for ultrasound-guided caudal CAPJ injections, to investigate the accuracy of this CAPJ injection technique in live horses, and to assess the effect of CAPJ injection location, laterality, operator, and radiographic CAPJ enlargement on injection accuracy. Retrospective case study. Medical records of adult horses in which ultrasound-guided caudal (C4-T1) CAPJ injections were performed using a modified cranial approach between November 2006 and December 2020 were reviewed. Radiographic images of caudal cervical vertebrae were assessed by a blinded radiologist and the degree of CAPJ enlargement was graded using a previously described grading system (Rgrade 1-5b). Ultrasound-guided caudal CAPJ injection accuracy was determined by synovial fluid retrieval during an individual CAPJ injection. Statistical analysis was performed using mixed-effects multivariable logistic model to evaluate the association of CAPJ injection accuracy and the CAPJ injection location, Rgrade, laterality (right, left), and operator. The study included 149 horses with 177 hospital admissions. Synovial fluid was obtained from 586/658 (89.1%) caudal CAPJs using modified cranial ultrasound-guided approach for CAPJ injections. C6-C7 CAPJ injections had 7-fold higher likelihood (OR = 6.78, 95% CI: 1.67-27.52; p = 0.007) of synovial fluid retrieval compared with C4-C5 CAPJ injections. Operator, CAPJ injection side (left, right), and degree of radiographic CAPJ enlargement did not have significant effects on the success of synovial fluid retrieval from ultrasound-guided caudal CAPJ injections. Retrospective study design. Intra-articular ultrasound-guided caudal CAPJ injections using a modified cranial approach can be performed accurately in live horses with and without CAPJ arthropathy.

Bottlebrush Polymers for Articular Joint Lubrication: Influence of Anchoring Group Chemistry on Lubrication Properties.

The role of carboxylic, aldehyde, or epoxide groups incorporated into bottlebrush macromolecules as anchoring blocks (or cartilage-binding blocks) is investigated by measuring their lubricating properties and cartilage-binding effectiveness. Mica modified with amine groups is used to mimic the cartilage surface, while bottlebrush polymers functionalized with carboxylic, aldehyde, or epoxide groups played the role of the lubricant interacting with the cartilage surface. We demonstrate that bottlebrushes with anchoring blocks effectively reduce the friction coefficient on modified surfaces by 75-95% compared to unmodified mica. The most efficient polymer appears to be the one with epoxide groups, which can react spontaneously with amines at room temperature. In this case, the value of the friction coefficient is the lowest and equals 0.009 ± 0.001, representing a 95% reduction compared to measurements on nonmodified mica. These results show that the presence of the functional groups within the anchoring blocks has a significant influence on interactions between the bottlebrush polymer and cartilage surface. All synthesized bottlebrush polymers are also used in the preliminary lubrication tests carried out on animal cartilage surfaces. The developed materials are very promising for future in vivo studies to be used in osteoarthritis treatment.

Accuracy tradeoffs between individual bone and joint-level statistical shape models of knee morphology

Statistical shape models (SSMs) are useful tools in evaluating variation in bony anatomy to assess pathology, plan surgical interventions, and inform the design of orthopaedic implants and instrumentation. Recently, by considering multiple bones spanning a joint or the whole lower extremity, SSMs can support studies investigating articular conformity and joint mechanics. The objective of this study was to assess tradeoffs in accuracy between SSMs of the femur or tibia individually versus a combined joint-level model. Three statistical shape models were developed (femur-only, tibia-only, and joint-level) for a training set of 179 total knee arthroplasty (TKA) patients with osteoarthritis representing both genders and several ethnicities. Bone geometries were segmented from preoperative CT scans, meshed with triangular elements, and registered to a template for each SSM. Principal component analysis was performed to determine modes of variation. The statistical shape models were compared using measures of compactness, accuracy, generalization, and specificity. The generalization evaluation, assessing the ability to describe an unseen instance in a leave-one-out analysis, showed that errors were consistently smaller for the individual femur and tibia SSMs than for the joint-level model. However, when additional modes were included in the joint-level model, the errors were comparable to the individual bone results, with minimal additional computational expense. When developing more complex SSMs at the joint, lower limb, or whole-body level, the use of an error threshold to inform the number of included modes, instead of 95 % of the variation explained, can help to ensure accurate representations of anatomy.

Obesity, Metabolic Syndrome, and Osteoarthritis Require Integrative Understanding and Management.

Osteoarthritis (OA) is a progressive chronic disease affecting the articular joints, leading to pain and disability. Unlike traditional views that primarily link OA to aging, recent understanding portrays it as a multifactorial degenerative disease of the entire joint. Emerging research highlights metabolic and immune dysregulation in OA pathogenesis, emphasizing the roles of obesity, dyslipidemia, and insulin resistance in altering joint homeostasis. Recent studies have increasingly focused on the complex role of white adipose tissue (WAT) in OA. WAT not only serves metabolic functions but also plays a critical role in systemic inflammation through the release of various adipokines. These adipokines, including leptin and adiponectin, have been implicated in exacerbating cartilage erosion and promoting inflammatory pathways within joint tissues. The overlapping global crises of obesity and metabolic syndrome have significantly impacted joint health. Obesity, now understood to contribute to mechanical joint overload and metabolic dysregulation, heightens the risk of developing OA, particularly in the knee. Metabolic syndrome compounds these risks by inducing chronic inflammation and altering macrophage activity within the joints. The multifaceted effects of obesity and metabolic syndrome extend beyond simple joint loading. These conditions disrupt normal joint function by modifying tissue composition, promoting inflammatory macrophage polarization, and impairing chondrocyte metabolism. These changes contribute to OA progression, highlighting the need for targeted therapeutic strategies that address both the mechanical and biochemical aspects of the disease. Recent advances in understanding the molecular pathways involved in OA suggest potential therapeutic targets. Interventions that modulate macrophage polarization, improve chondrocyte function, or normalize adipokine levels could serve as preventative or disease-modifying therapies. Exploring the role of diet, exercise, and pharmacological interventions in modulating these pathways offers promising avenues for reducing the burden of OA. Furthermore, such methods could prove cost-effective, avoiding the increase in access to healthcare.

Primary phenotypic features associated with caudal neck pathology in warmblood horses.

Detailed descriptions of clinical signs associated with radiological findings of the caudal cervical vertebral column are not available. Describe the clinical features associated with neck pain or stiffness, neck-related thoracic limb lameness, proprioceptive ataxia consistent with a cervicothoracic spinal cord or nerve lesion, and their frequency of occurrence compared with control horses. A total of 223 Warmblood horses. Case-control study. Controls and cases were recruited prospectively. All horses underwent predetermined lameness and neurologic examinations. The frequency of occurrence of each clinical feature was compared between cases and controls and relative risk (RR) were calculated. Ninety-six cases and 127 controls were included. Forty-seven (49%) of the cases were classified as neurologic, 31 (32.3%) had thoracic limb lameness, and 18 (18.7%) had neck stiffness or pain or both. Focal caudal cervical muscle atrophy (46, 47.9%), hypoesthesia (38, 39.6%), patchy sweating (16, 16.7%), hyperesthesia (11, 11.5%), and pain upon firm pressure applied over the caudal cervical articular process joints and transverse processes (58, 60.4%) were only observed in cases (P < .001). Sideways flexion of the neck was restricted in a higher proportion of cases (47/96, 49%) compared with controls (40/127, 31.8%; P = .009, RR 1.5). Hopping-type thoracic limb lameness was only observed in cases, (30, 31.6%). Deterioration in lameness after diagnostic anesthesia occurred in 13/31 (41.9%) cases. Systematic clinical evaluation using the methods described should enable clinical differentiation between horses with caudal cervical lesions and horses with other causes of gait abnormalities.

Growth hormone-receptor disruption in mice reduces osteoarthritis and chondrocyte hypertrophy

Excessive growth hormone (GH) has been shown to promote joint degeneration in both preclinical and clinical studies. Little is known about the effect of disrupted GH or GH receptor (GHR) on joint health. The goal of this study is to investigate joint pathology in mice with either germline (GHR-/-) or adult inducible (iGHR-/-) GHR deficiency. Knee joints from male and female GHR-/- and WT mice at 24 months of age were processed for histological analysis. Also, knee joints from male and female iGHR-/- and WT mice at 22 months of age were scanned by micro-CT (μCT) for subchondral bone changes and characterized via histology for cartilage degeneration. Joint sections were also stained for the chondrocyte hypertrophy marker, COLX, and the cartilage degeneration marker, ADAMTS-5, using immunohistochemistry. Compared to WT mice, GHR-/- mice had remarkably smooth articular joint surfaces and an even distribution of proteoglycan with no signs of degeneration. Quantitatively, GHR-/- mice had lower OARSI and Mankin scores compared to WT controls. By contrast, iGHR-/- mice were only moderately protected from developing aging-associated OA. iGHR-/- mice had a significantly lower Mankin score compared to WT. However, Mankin scores were not significantly different between iGHR-/- and WT when males and females were analyzed separately. OARSI scores did not differ significantly between WT and iGHR-/- in either individual or combined sex analyses. Both GHR-/- and iGHR-/- mice had fewer COLX+ hypertrophic chondrocytes compared to WT, while no significant difference was observed in ADAMTS-5 staining. Compared to WT, a significantly lower trabecular thickness in the subchondral bone was observed in the iGHR-/- male mice but not in the female mice. However, there were no significant differences between WT and iGHR-/- mice in the bone volume to total tissue volume (BV/TV), bone mineral density (BMD), and trabecular number in either sex. This study identified that both germline and adult-induced GHR deficiency protected mice from developing aging-associated OA with more effective protection in GHR-/- mice.

Potential Roles of Inflammation on Post-Traumatic Osteoarthritis of the Ankle.

Post-traumatic osteoarthritis of the ankle (PTOA) is frequently observed following a debilitating consequence of intra-articular ankle fractures. Numerous risk factors contribute to the pathogenesis of PTOA, including articular incongruity, joint malalignment, and concomitant soft tissue damage. Despite attempts to restore joint anatomy and manage soft tissues to avoid long-term complications after intra-articular ankle fractures, the incidence of PTOA remains markedly elevated. Inflammatory processes triggered by intra-articular ankle fractures have emerged as potential instigators that expedite the progression of PTOA. Injury to the articular cartilage and subchondral bone may lead to the release of inflammatory mediators, which can contribute to cartilage degradation and bone resorption. This study provides a narrative review on the current knowledge concerning the association between inflammation and the development of PTOA following intra-articular ankle fractures. We also discuss novel therapeutic agents that target inflammatory pathways to impede the progression of post-traumatic osteoarthritis after intra-articular ankle fractures. These medication and interventions were summarized within this review article.