Synovial Structure Research Articles

Multicenter study investigating long-term survival after synovial lavage of contaminated and septic synovial structures in horses presented to 10 UK referral hospitals.

To report the long-term survival of adult horses that were subjected to synovial lavage for treatment of contaminated and septic synovial structures. Multicenter, prospective observational trial. Horses (n = 240) presented for synovial sepsis at 10 UK referral centers. Data for horses presented for treatment of synovial sepsis were collected over a 15 month recruitment period. Owners were contacted a minimum of 365 days after surgery using a structured client interview to assess long term survival. Descriptive statistics, and univariable and Cox proportional hazards models for postoperative survival time were developed. Survival to discharge was 228/240 (95%) and overall long-term survival was 89.4% (185/207). Unknown cause of injury (p = .017), increasing duration of surgery (p = .003), increasing weight (p = .008), forelimb injuries (p = .027), and type of synovial structure (p = .008) were found to be associated with death using Cox proportional hazards models. This study provides information on risk factors associated with survival and death after treatment for synovial sepsis at referral hospitals in the UK. Survival to discharge and long-term survival was excellent. Heavier horses, injuries affecting the forelimbs, tendon sheaths and bursae were associated with poorer long term outcomes. Longer duration of surgery was also found to be associated with a worse prognosis. These findings help to provide prognostic information for owners and veterinarians treating horses with synovial sepsis.

Longitudinal evaluation of fentanyl concentrations in equine plasma and synovial fluid following application of transdermal fentanyl patches over one carpal joint.

To determine if transdermally delivered fentanyl can achieve greater concentrations of fentanyl in synovial fluid when applied over a synovial structure. Randomized, experimental study. Six healthy adult horses. Each horse had two 100 μg/h fentanyl matrix patches applied on the dorsal aspect of one, randomly assigned, carpometacarpal joint (CMCJ) for 48 h. Whole blood and bilateral synovial samples from the intercarpal joint were obtained at 0, 2, 6, 12, 24, 36 and 48 h. Fentanyl concentrations were measured with liquid chromatography-mass spectrometry. All subjects achieved detectable concentrations of fentanyl in both plasma and synovial fluid. Time to peak synovial and plasma concentration was 12 h. At 6 h, the synovial concentration in the untreated carpus (0.104 ng/mL ± 0.106) was lower than plasma fentanyl concentrations 0.31 ± 0.27 (p = .036). At 12 h, both treated (0.55 ng/mL ± 0.3) and untreated (0.53 ng/mL ± 0.28) synovial fluid fentanyl concentrations were lower than plasma (0.87 ng/mL ± 0.48) concentrations (p < .001 and p = .001, respectively). Synovial concentrations of fentanyl did not differbetween treated and untreated joints (p > 0.608 for all time points). Application of fentanyl matrix patches directly over the CMCJ did not result in increased fentanyl concentrations in the synovial fluid of the treated intercarpal joint in normal horses. There is likely no analgesic advantage to placing fentanyl patches directly over the affected joint, as it did not result in increased synovial concentrations at the tested site.

Micro-Thrust, Low-Fuel Consumption, and High-Precision East/West Station Keeping Control for GEO Satellites Based on Synovial Variable Structure Control

Aiming at the shortcomings of non-optimal fuel consumption and low accuracy of Geosynchronous orbit (GEO) satellites in the east/west station keeping (EWSK) at the current stage, a micro-thrust EWSK algorithm for GEO satellites based on a single-synovial surface is proposed. This algorithm has the characteristics of low fuel consumption and high control precision. However, when this algorithm performs GEO station switching under the condition of limited velocity increment, the mean longitude capture path may not be optimal, the capture time of the mean longitude is too long, and the engineering applicability is not good. In view of the above problems, a micro-thrust EWSK for GEO satellites based on dual synovial surfaces is proposed. Through the advance planning of the mean longitude, the control lag caused by the limited velocity increment is eliminated, the optimal path-planning problem of the mean longitude is solved, and the capture time of the mean longitude is greatly shortened. The two EWSK algorithms proposed in this paper have the advantages of small calculation amount, optimal fuel consumption, high precision and strong stability, which have good engineering application value.

Synovial Extracellular Vesicles: Structure and Role in Synovial Fluid Tribological Performances.

The quality of the lubricant between cartilaginous joint surfaces impacts the joint’s mechanistic properties. In this study, we define the biochemical, ultrastructural, and tribological signatures of synovial fluids (SF) from patients with degenerative (osteoarthritis-OA) or inflammatory (rheumatoid arthritis-RA) joint pathologies in comparison with SF from healthy subjects. Phospholipid (PL) concentration in SF increased in pathological contexts, but the proportion PL relative to the overall lipids decreased. Subtle changes in PL chain composition were attributed to the inflammatory state. Transmission electron microscopy showed the occurrence of large multilamellar synovial extracellular vesicles (EV) filled with glycoprotein gel in healthy subjects. Synovial extracellular vesicle structure was altered in SF from OA and RA patients. RA samples systematically showed lower viscosity than healthy samples under a hydrodynamic lubricating regimen whereas OA samples showed higher viscosity. In turn, under a boundary regimen, cartilage surfaces in both pathological situations showed high wear and friction coefficients. Thus, we found a difference in the biochemical, tribological, and ultrastructural properties of synovial fluid in healthy people and patients with osteoarthritis and arthritis of the joints, and that large, multilamellar vesicles are essential for good boundary lubrication by ensuring a ball-bearing effect and limiting the destruction of lipid layers at the cartilage surface.

Equine heel bulb lacerations: 62 cases (2004-2018).

To characterize clinical findings and outcomes for horses with heel bulb lacerations. Medical records of a teaching hospital were reviewed to identify horses treated for heel bulb lacerations between February 2004 and October 2018. Long-term outcome was assessed by telephone communication with owners. Results were analyzed to determine association with clinical outcome. 31 mares and 31 geldings of various ages, breeds, and uses were evaluated. Thirty-six horses had a wound of 0 to 2 days' duration, and 17 horses had a wound of > 2 days' duration. Horses with a wound duration of < 2 days had a significantly greater likelihood of a higher outcome score (P = .025; OR = 7.08; 95% CI = 1.28% to 39.08%). Synovial communication with the wound was confirmed in 21 of 62 (33.9%) horses. One synovial structure was involved in 17 horses, and > 1 synovial structure was involved in 4 horses. Fifty-nine horses survived to discharge, and follow-up information was available for 18 (30.5%) horses. Of the horses available for follow-up, 78% returned to the previous level of work (14/18). Degree of lameness at presentation, degree of wound contamination, treatment prior to presentation, treatment with foot casting, and involvement of synovial structures were not found to be significantly associated with clinical outcome. Results suggest that horses with heel bulb lacerations have a good prognosis for survival and a favorable prognosis for return to work. Clinical application of additional findings needs further investigation before clinical relevance can be ascertained.

Using systemic serum amyloid A as a biomarker for synovial structure infections in horses with acute limb wounds.

In postoperative monitoring of synovial structure infection due to limb wounds, early recognition of a recurrence of synovial infection is indispensable to prevent further damage to the affected synovial structure. This study evaluated the role of serum amyloid A (SAA) as a systemic biomarker in disease monitoring and correlated this tool with clinical variables. In this prospective cohort study, 55 horses with acute limb wounds were divided into two groups: those with (group 1, n=26) or without (group 2, n=29) a diagnosis of synovial structure penetration. SAA, lameness and body temperature were evaluated repeatedly and compared between groups. Correlations were explored between SAA and body temperature as well as lameness. The long-term outcome was also analysed. In both groups, SAA levels followed the characteristic rise-and-fall pattern observed in previous studies, with a significant increase up to a peak concentration within 48hours, followed by a constant decline. Lameness and body temperature did not change significantly. SAA was not found to correlate with clinical variables at all time points. Three horses in group 1 had a recurrence of synovial sepsis with an associated increase in SAA. The long-term outcome was good. A total of 71% of the study population returned to pre-injury performance levels. Repeated measurements of SAA accurately reflected the course of synovial inflammation and thus provided a reliable and rapidly available tool to monitor the disease course and to adapt the treatment regimen. SAA should be routinely added to the postoperative management of such cases.

Chondroid Tenosynovial Giant Cell Tumor of the Temporomandibular Joint Presenting as a Deep-Lobe Parotid Tumor

Tenosynovial giant cell tumor (TGCT) is a rare benign craniofacial soft-tissue tumor characterized by overgrowth of the synovial tissue, tendon sheath, bursa, and joint structure. It is classified into two types, diffuse and localized TGCT, and has rarely been reported in the temporomandibular joint. The etiology of TGCT is unknown, and the management of TGCT varies depending on the tumor location and treatment-related morbidity. Here, we describe the case of a 47-year-old man who presented with a complaint of a right parotid mass that had slowly increased over 2 months and was associated with ear fullness. Initially, the lesion was painless, but pain during chewing without any limitation of the jaw movement developed subsequently. The patient was diagnosed with diffuse TGCT with chondroid metaplasia.

Assessment of the efficiency of arthroscopic laser dual-mode synovectomy in patients with chronic synovitis of the knee joint

BACKGROUND: Osteoarthritis (OA) of the knee joint is a common disease and a significant medical, social, and economic problem. Synovitis can be revealed at all stages of ОА, contributing to the progression of cartilage damage, increased pain, and impaired joint function. In patients with OA, the morphological pattern of the synovial membrane structure has characteristic features, such as hyperplasia, sublimating fibrosis, and stromal vascularization. Laser radiation is widely used in medicine. Exposure of two working wavelengths (0.97 m and 1.56 m) to the synovial membrane may lead to good results in the treatment of synovitis. AIM: This study aimed to improve treatment outcomes in patients with chronic synovitis of the knee joint by applying radiation of two different wavelengths. MATERIALS AND METHODS: Treatment outcomes of 50 patients with chronic synovitis of the knee joint, aged 23 to 67 years, with stages IIIV gonarthrosis according to the KellgrenLawrence classification, were prospectively analyzed. All patients underwent arthroscopic sanation and laser partial synovectomy using LSP-IRE-Polus apparatus (OOO NTO IRE-Polus, Russia), with a wavelength of 0.97 m (pulse 100 ms, pause 50 ms) in a pulsed-periodic mode and 1.56 m with a power of 5 W in a continuous mode. Surveys were conducted preoperatively and at 3, 6, and 12 months postoperatively using the following scales and questionnaires: Visual Analog Pain Scale (VAS), Lequesne index, Western Ontario and McMaster Universities Arthritis Index (WOMAC), and Knee Injury and Osteoarthritis Outcome Score (KOOS). RESULTS: The mean age (Ms) of the study subjects, body mass index, and the duration of synovitis were 45.3213.1, 28.634.72 kg/m2, and 2.261.91 years, respectively. Statistically significant improvements in the VAS, WOMAC, Lequesne, and KOOS scales were observed three months after surgery, whereas much more better results were obtained at six months and remained the same within 12 months after surgery (p 0.05). CONCLUSIONS: The results suggest that the proposed technique could be introduced into clinical practice.

Baastrup’s disease (kissing spines syndrome) old but often missed etiology for back pain

Background: Baastrup's disease or "kissing spines syndrome" was first described in 1933 as a cause of postural back pain, which was thought to be related to the adjacent 'kissing' of the spinous processes. The diagnosis was based on 'symptoms' of positional back pain with extension, and plain radiographs showing close approximation of the spinous processes. The aim: Baastrup’s disease is overwhelmingly underdiagnosed and often missed due to a lack of knowledge and/or improper diagnostic techniques, leading to frequent mistreatment. A case of Baastrup’s disease is reported. Case report: 70-year-old patient, with a 4 years history of back pain presented a severe neurogenic claudication for a year. Neurological evaluation was normal. Extension of the lumbar spine exaggerates the pain. Locally the pressure of the spinous processes shows a painful point located next to L4-L5. Lumbar CT scan showed a typic “kissing posterior spinous processes” associated with disc space narrowing at multiple levels especially L4-5 and L5-S1. The patient underwent a decompressive laminectomy. A neoarticulation with synovial structure was noted, between L4 and L5 spinous process. Postoperative was unremarkable with good results after two months physiotherapy program. Conclusion: Baastrup´s syndrome is more common in the lumbar spine with L4-L5 being the most affected region. Baastrup's disease is a part of dynamic degenerative process. Management must be adapted to clinical and radiological findings. Medical treatment can be conservative or surgical and an accurate diagnosis of the disease is necessary for determining appropriate treatment. If the predominant symptoms are related to neurogenic claudication or radiculopathy, surgical decompression or stabilization may be necessary.

Effects of regional limb perfusion technique on concentrations of antibiotic achieved at the target site: A meta-analysis.

Intravenous regional limb perfusions (RLP) are widely used in equine medicine to treat distal limb infections, including synovial sepsis. RLPs are generally deemed successful if the peak antibiotic concentration (Cmax) in the sampled synovial structure is at least 8-10 times the minimum inhibitory concentration (MIC) for the bacteria of interest. Despite extensive experimentation and widespread clinical use, the optimal technique for performing a successful perfusion remains unclear. The objective of this meta-analysis was to examine the effect of technique on synovial concentrations of antibiotic and to assess under which conditions Cmax:MIC ≥ 10. A literature search including the terms "horse", "equine", and "regional limb perfusion" between 1990 and 2021 was performed. Cmax (μg/ml) and measures of dispersion were extracted from studies and Cmax:MIC was calculated for sensitive and resistant bacteria. Variables included in the analysis included synovial structure sampled, antibiotic dose, tourniquet location, tourniquet duration, general anesthesia versus standing sedation, perfusate volume, tourniquet type, and the concurrent use of local analgesia. Mixed effects meta-regression was performed, and variables significantly associated with the outcome on univariable analysis were added to a multivariable meta-regression model in a step-wise manner. Sensitivity analyses were performed to assess the robustness of our findings. Thirty-six studies with 123 arms (permutations of dose, route, location and timing) were included. Cmax:MIC ranged from 1 to 348 for sensitive bacteria and 0.25 to 87 for resistant bacteria, with mean (SD) time to peak concentration (Tmax) of 29.0 (8.8) minutes. Meta-analyses generated summary values (θ) of 42.8 x MIC and 10.7 x MIC for susceptible and resistant bacteria, respectively, though because of high heterogeneity among studies (I2 = 98.8), these summary variables were not considered reliable. Meta-regression showed that the only variables for which there were statistically significant differences in outcome were the type of tourniquet and the concurrent use of local analgesia: perfusions performed with a wide rubber tourniquet and perfusions performed with the addition of local analgesia achieved significantly greater concentrations of antibiotic. The majority of arms achieved Cmax:MIC ≥ 10 for sensitive bacteria but not resistant bacteria. Our results suggest that wide rubber tourniquets and concurrent local analgesia should be strongly considered for use in RLP and that adequate therapeutic concentrations (Cmax:MIC ≥ 10) are often achieved across a variety of techniques for susceptible but not resistant pathogens.

Functional Outcome of Anterior Cruciate Ligament Reconstruction by Tibial Attachment Preserving versus Sacrificing Hamstring Graft Technique- A Prospective Interventional Study

Introduction: Anterior Cruciate Ligament (ACL) is a stout, short intra-articular, extra synovial structure. For a knee with the deficiency of ACL, the ligament reconstruction using an autograft, either a free bone patellar tendon bone graft or a Semi Tendinosus and Gracilis (STG) tendon free hamstring graft, is the most common surgical treatment. Tibial fixation region of the graft is presumed to be a delicate point in arthroscopic ACL reconstruction. There, can be a chance of graft pull out from the tibial tunnel before actual healing of the graft– tunnel can occur. To avoid this problem, the technique of tibial attachment preserved hamstring graft can be used instead of free hamstring graft. Aim: To evaluate and compare the functional outcome of patients who underwent ACL reconstruction with either a free hamstring graft or by tibial attachment preserving hamstring graft. Materials and Methods: A prospective interventional study was conducted in the Department of Orthopaedics, Swami Rama Himalayan University Hospital, Dehradun, Uttarakhand, India, over a period of one year (July 2019-July 2020). A total 52 patients were included and they were divided into two groups. Group A (tibial attachment preserving hamstring graft) and Group B (tibial attachment sacrificing hamstring graft) with each group comprised 26 patients. Patients were assessed with Lysholm score at 6, 12 and 24 weeks of follow-up. For determining the statistical difference between the two groups Independent Student’s t-test was used, whereas for more than two groups Analysis of Variance (ANOVA) test was used and a p-value &lt;0.05 was considered to be significant. Results: The mean age of patients in group A was 30.73±10.02 years whereas in group B it was 29.54±9.84 years. For group A, mean Lysholm score at 6 weeks was 73.23±8.37, at 12 week score was 86.85±5.93 and at 24 week score was 95.58±4.91. For group B, mean Lysholm score at 6 weeks was 74.15±5.82, at 12 weeks score was 87.46±5.95 and at 24 weeks score was 96.92±3.61. Post-hoc analysis showed that there was a significant difference in mean Lysholm score {between preoperative and other time points (p&lt;0.001, respectively)} for both the groups but there was no significant difference in Lysholm score at 6 weeks (p=0.646), 12 weeks (p=0.710) and 24 weeks (p=0.265) when compared between the two groups. Conclusion: ACL reconstruction using hamstring autograft with preserved tibial insertion resulted in no statistically significant difference in functional outcome as compared with free autograft.

Therapeutic Effects of Hypoxic and Pro-Inflammatory Priming of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Inflammatory Arthritis.

Mesenchymal stem cells (MSCs) immunomodulate inflammatory responses through paracrine signalling, including via secretion of extracellular vesicles (EVs) in the cell secretome. We evaluated the therapeutic potential of MSCs-derived small EVs in an antigen-induced model of arthritis (AIA). EVs isolated from MSCs cultured normoxically (21% O2, 5% CO2), hypoxically (2% O2, 5% CO2) or with a pro-inflammatory cytokine cocktail were applied into the AIA model. Disease pathology was assessed post-arthritis induction through swelling and histopathological analysis of synovial joint structure. Activated CD4+ T cells from healthy mice were cultured with EVs or MSCs to assess deactivation capabilities prior to application of standard EVs in vivo to assess T cell polarisation within the immune response to AIA. All EVs treatments reduced knee-joint swelling whilst only normoxic and pro-inflammatory primed EVs improved histopathological outcomes. In vitro culture with EVs did not achieve T cell deactivation. Polarisation towards CD4+ helper cells expressing IL17a (Th17) was reduced when normoxic and hypoxic EV treatments were applied in vitro. Normoxic EVs applied into the AIA model reduced Th17 polarisation and improved Regulatory T cell (Treg):Th17 homeostatic balance. Normoxic EVs present the optimal strategy for broad therapeutic benefit. EVs present an effective novel technology with the potential for cell-free therapeutic translation.

Systemic serum amyloid A in early (

Synovial structure involvement secondary to limb injury is a common emergency in equine practice, requiring an accurate initial diagnosis for immediate treatment. This study aimed to investigate the clinical usefulness of Serum amyloid A (SAA) in the initial diagnosis of synovial structure involvement caused by acute (<24 h) penetrating limb injuries in horses and to correlate SAA with standard diagnostic parameters. Fifty-five horses with acute limb injuries were divided into two groups: Group 1 (G1, n = 26) with a diagnosis of penetrating synovial trauma and Group 2 (G2, n = 29) without synovial structure penetration. Serum SAA, white blood cell (WBC) count and fibrinogen as well as clinical criteria and synovial fluid parameters were assessed on admission. The two groups were compared using a two-sample t-test (metric parameters) or a Wilcoxon-Mann-Whitney test (ordinal parameters). Correlation was determined between serum SAA and the following parameters: WBC count, fibrinogen, synovial total nucleated cell count (TNCC) and percentage of neutrophils (% N), body temperature and the degree of lameness.Serum SAA concentrations were not different between G1 and G2; however, there were statistically significant differences in general health, the degree of lameness, and synovial fluid parameters. In G1, serum SAA concentrations positively correlated with fibrinogen concentrations and synovial fluid % N. Nonetheless, SAA cannot be used as a sole tool to diagnose synovial structure involvement caused by limb injuries. Synovial fluid parameters remain the most important tool in the diagnosis of synovial penetration. In cases where synoviocentesis fails or is not possible, serum SAA might support diagnosis.

Fetal cervical zygapophysial joint with special reference to the associated synovial tissue: a histological study using near-term human fetuses

Human fetal cervical vertebrae are characterized by the large zygapophysial joint (ZJ) extending posteriorly. During our recent studies on regional differences in the shape, extent, and surrounding tissue of the fetal ZJ, we incidentally found a cervical-specific structure of synovial tissues. This study aimed to provide a detailed evaluation of the synovial structure using sagittal and horizontal sections of 20 near-term fetuses. The cervical ZJ consistently had a large cavity with multiple recesses at the margins and, especially at the anterior end, the recess interdigitated with or were located close to tree-like tributaries of the veins of the external vertebral plexus. In contrast to the flat and thin synovial cell lining of the recess, the venous tributary had cuboidal endothelial cells. No or few elastic fibers were identified around the ZJ. The venous-synovial complex seems to be a transient morphology at and around birth, and it may play a role in the stabilization of the growing cervical ZJ against frequent spontaneous dislocation reported radiologically in infants. The venous-synovial complex in the cervical region should be lost and replaced by elastic fibers in childhood or adolescence. However, the delayed development of the ligament flavum is also likely to occur in the lumbar ZJ in spite of no evidence of a transient venous-synovial structure. The cuboidal venous endothelium may simply represent the high proliferation rate for the growing complex.

Evaluation of the Olecranon Bursa: An Anatomical Structure in the Normal Horse

This study aimed to determine whether a true synovial structure exists over the olecranon tuberosity, which could be attributed to a noninflamed olecranon bursa. Contrast radiography, gross anatomical dissection, and histopathology were used to evaluate the olecranon bursa in horses with no previous elbow pathology. The radiographic study revealed that the contrast was positioned subcutaneously, superficial to the long head of the triceps and its insertion on the olecranon tuberosity and did not extend cranial to the triceps tendon. The contrast region was consistent in shape, size, and location. Gross anatomical dissection of the area revealed a potential bursal space overlying the tendons of the lateral and medial heads of the triceps brachii and the tensor fascia antebrachii in the normal horse. Histopathology confirmed a bursal lining, which was of mesenchymal origin and suggestive of a single-cell membrane, lined by fibroblast-like synoviocytes.

The inhibition by human MSCs-derived miRNA-124a overexpression exosomes in the proliferation and migration of rheumatoid arthritis-related fibroblast-like synoviocyte cell

BackgroundRheumatoid arthritis is a long-term, progressive autoimmune disease. It is characterized by synovial hyperplasia leading to swelling, stiffness, and joint deformity in more than one joint. Fibroblast-like synoviocytes are the major cell types that make up the synovial intima structure, which is one of the decisive factors in the development and course of rheumatoid arthritis.MethodsThe potential therapeutic effects of MSCs-derived miRNA-124a overexpression exosomes were evaluated in vitro by the method including MTT assay and cell cycle test for cell proliferation, scratch wound closure and transwell for cell migration, flow cytometry and western for the apoptosis detection.ResultsExosomes derived from human MSCs that overexpression miRNA-124a were prepared and characterized. We found that the pretreatment of this exosome was able to inhibit the proliferation and migration of fibroblast-like synoviocyte cell line and promote the apoptosis of this cell during the co-incubation.ConclusionsExosomes derived from MSCs were proved to be a suitable vector for the delivery of therapeutic miRNA-124a, and such miRNA-124a overexpression exosomes were expected to provide a new medicine and strategy for the treatment of rheumatoid arthritis.

Synovial sarcoma of the neck

Synovial sarcomas are rare malignant neoplasms commonly arising from articular tendons and joint capsules. Despite being termed synovial sarcomas due to their histologic similarity to the synovium, they rarely involve a synovial structure. Although they mostly occur in lower extremities, rare cases originating from the thorax, abdomen, head, and neck have also been reported. A 60-year-old male patient was admitted to the hospital with a complaint of swelling in left side of the neck. CT revealed a mass of approximately 6.5x5 cm, occupying the left parapharyngeal space and left submandibular fossa and protruding into the pharynx lumen. The lesion was non-infiltrative, well circumscribed, and uniformly ovoid. The patient underwent surgery, and subsequent pathological examination confirmed the diagnosis of synovial sarcoma. Despite their rarity, synovial sarcomas should be considered, along with Ewing’s sarcoma, rhabdomyosarcoma, and other sarcomas, in the differential diagnosis of a large juxtaarticular mass containing calcifications.

Factors Associated With Survival and Return to Function Following Synovial Infections in Horses.

Synovial infections (SI) are common in horses of all ages and can be associated with high rates of morbidity and mortality. Identifying factors influencing survival and return to function may be useful for management of affected individuals and determination of prognosis. The objectives of this study were to identify factors associated with survival and return to function of horses and foals with SI presented to an equine hospital. This study is a retrospective case series. Data were collected from medical records of all horses with SI that were presented to a single equine hospital between April 1st, 2008 and May 1st, 2017. Long–term follow up was obtained by a semi-structured telephone questionnaire of clinical outcomes and analysis of online race records. Univariate models were created using generalized linear and linear mixed models to assess factors associated with outcomes. Multivariable models were created using generalized linear and linear mixed models to determine factors significantly associated with outcomes. Of 186 horses presented with SI, 161/186 (86.6%) were treated and 145/161 (90.1%) survived to discharge. The majority of joints were treated with synovial lavage (93.8%). One hundred and twenty horses were included in the return to function analysis and 79 (65%) returned to function. Increasing number of days of treatment with systemic antimicrobials was associated with increased likelihood of survival for each horse (OR 1.15, 95% CI 1.04−1.27, P = 0.025) and when considering each individual synovial structure (OR 1.11, 95% CI 1.04−1.17, P = 0.004). Horses treated with doxycycline were less likely to return to function (OR 0.39, 95% CI 0.19−0.8, P = 0.031). The overall rate of survival of horses treated with SI is good. The likelihood of return to function is lower than for survival. The findings of this study, combined with relevant antimicrobial stewardship practices, can be used as a part of evidence-based decision-making when veterinarians are treating horses with SI.

Long bone failure after intraosseous regional perfusion

SummaryA 5‐year‐old Australian Stock Horse gelding was initially referred to the Charles Sturt University Veterinary Clinical Centre (CSUVCC) for assessment of a penetrating laceration over the medial splint bone (second metacarpal bone) of the left foreleg. Clinical examination failed to reveal a communication with a synovial structure, but radiographs showed a palisading bone reaction on the proximal aspect of the medial splint bone which was thought to be a characteristic of infection. Soft tissue swelling precluded access to a peripheral vein, so a decision was made to use intraosseous regional limb perfusion. This was achieved through an access portal in the lateral diaphysis of the third metacarpal bone (McIII). Subsequently, the horse developed lameness and further investigation revealed a nondisplaced longitudinal fracture of McIII propagating from the intraosseous regional perfusion access portal.

Synergy between Zwitterionic Polymers and Hyaluronic Acid Enhances Antifouling Performance

Challenges associated with nonspecific adsorption of proteins on sensor surfaces have steered the development of novel antifouling materials and strategies. Inspired by human synovial fluid composition and structure, we designed synergistic antifouling coatings with mixtures of hyaluronic acid (HA) and a zwitterionic bottlebrush polymer (BB). Using a fast and convenient online surface modification method, the polymers were immobilized on the Au surface, significantly increasing its hydrophilicity. Using surface plasmon resonance (SPR), a 10:1 ratio of HA to BB was found optimal to provide the best antifouling performance. Bovine serum albumin (BSA) adsorption on HA-BB coated surfaces was 0.2 ng/cm2, which was 60 times lower than BB or HA alone and 25 times lower than the commonly accepted ultralow adsorption limit (<5 ng/cm2), demonstrating the synergistic effect of HA and BB against nonspecific protein adsorption. This was found to be independent of BSA concentration up to physiological concentrations. Furthermore, the antifouling performance of HA-BB coated surfaces was tested against milk and serum, showing almost 92% lower protein adsorption than that on bare surfaces, suggesting the potential efficacy of this antifouling coating in real life settings.