Ultrasound and clinical findings in the metacarpophalangeal joint assessment of show jumping horses in training

Low-Field Magnetic Resonance Imaging Findings of the Fetlock Region of Nonracehorses

Low-field, magnetic resonance imaging (MRI) is an advanced imaging modality widely used to diagnose distal limb pathology in horses, but there are limited data regarding lesion distribution within the metacarpo/metatarsophalangeal joint (MCP/MTPJ) region in lame nonracehorses. The aim of this study was to describe the low-field MRI findings and lesion distribution in nonracehorses with MCP/MTPJ region pain. Clinical records from horses undergoing MRI of the MCP/MTPJ region between July 2016 and March 2023 were reviewed. Horses were included if pain causing lameness was localized to this region and conventional imaging failed to provide a definitive diagnosis. Eighty-four horses met the inclusion criteria. Soft tissues were affected in 76 (90.5%) horses, with suspensory ligament branch injuries being the most frequent (60.7%) soft tissue pathology identified. Osseous pathology was diagnosed in 51 horses. The subchondral bone (SCB) of the distal third metacarpal/metatarsal bone (MC3/MT3) was the osseous structure most frequently affected (40.5%), with 79.4% of these horses having lesions on the dorsal aspect of the bone. Osteoarthritis was present in 48 (57.1%) horses. The main limitations of the study were the lack of a standardized diagnostic analgesia pattern due to varying veterinary surgeon involvement, and the absence of bilateral magnetic resonance (MR) sequences in all limbs. MRI is a useful diagnostic tool to assess soft tissue structures in the MCP/MTP region, especially in horses with thick skin, which may make ultrasonographic imaging unreliable.

Systematic review and meta-analysis of positive long-term effects after intra-articular administration of orthobiologic therapeutics in horses with naturally occurring osteoarthritis

Equine veterinarians face challenges in treating horses with osteoarthritic joint pain in routine veterinary practice. All common treatment options aim to reduce the clinical consequences of osteoarthritis (OA) characterized by persistent synovitis and progressive degradation of articular cartilage. A range of joint-associated cell types and extracellular matrices are involved in the not yet entirely understood chronic inflammatory process. Regeneration of articular tissues to re-establish joint hemostasis is the future perspective when fundamental healing of OA is the long-term goal. The use of intra-articular applied biologic therapeutics derived from blood or mesenchymal stroma cell (MSC) sources is nowadays a well-accepted treatment option. Although this group of therapeutics is not totally consistent due to the lack of clear definitions and compositions, they all share a potential regenerative effect on articular tissues as described in in vivo and in vitro studies. However, the current stage of science in regenerative medicine needs to be supported by clinical reports as in fact, in vitro studies as well as studies using induced OA models still represent a fragment of the complex pathomechanism of naturally occurring OA. This systemic review aims to determine the long-term effect of orthobiologic therapeutics in horses suffering naturally occurring OA. Thereby, a meta-analysis of randomized controlled trials (RCTs) is conducted to describe the efficiency and safety of intra-articular applied orthobiologics in terms of lameness reduction in the long-term. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, thirteen studies met the inclusion criteria for the systemic review. Four of those studies have further been evaluated by the meta-analysis comparing the long-term effect in lameness reduction. Each study was examined for risk of bias. For data evaluation, a random-effects model was used, describing the overall outcome in a forest plot. The I² statistic was used to assess heterogeneity. Results indicate, that orthobiologic therapies represent an effective long-term and safe OA treatment option. Due to the inhomogeneity of included studies, no statements are provided addressing specific orthobiologic therapies, affected joints, OA stage and horse's intended use. Future clinical trials should follow standardized study designs to provide comparable data.

2D-SWE of the Metacarpophalangeal Joint Capsule in Horses

(1) Two-dimensional shear wave elastography (2D-SWE) employs an ultrasound impulse to produce transversely oriented shear waves, which travel through the surrounding tissue according to the stiffness of the tissue itself. The study aimed to assess the reliability of 2D-SWE for evaluating the elastosonographic appearance of the distal attachment of the fetlock joint capsule (DJC) in sound horses and in horses with osteoarthritis (OA) (2). According to a thorough evaluation of metacarpophalangeal joint (MCPJ), adult horses were divided in a sound Group (H) and in OA Group (P). Thereafter, a 2D-SWE of MCPJs was performed. Shear wave velocity (m/sec) and Young’s modulus (kPa) were calculated independently by two operators at each selected ROI. Statistical analysis was performed with R software. (3) Results: 2D-SWE had good–excellent inter-CC and intra-CC in both groups. Differences in m/s and kPa between Groups H and P were found in transverse scans with lower values in Group P. No correlation with age or DJC thickness was found. (4) Conclusions: 2D-SWE was repeatable and reproducible. In Group H, DJC was statistically stiffer than in Group P only in transverse scan. The technique showed poor sensitivity and specificity in differentiating fetlocks affected by OA.

Effects of oral treatment with chondroitin sulfate and glucosamine in an experimental model of metacarpophalangeal osteoarthritis in horses

Background

Combined chondroitin sulfate (CS) and glucosamine (GlcN) has been widely used in oral formulations to prevent and treat osteoarthritis. CS is effective for controlling pain in osteoarthritic patients, whereas GlcN can stimulate glycosaminoglycan synthesis, thus reducing extracellular matrix degradation. Although several studies have been published on this topic, the effectiveness of treatment with oral CS and GlcN remains uncertain. The objective of this study was to analyze the progression of experimentally induced osteoarthritis in horses and verify the effectiveness of an oral compound based on CS and GlcN to treat and/or modulate this disease. The study analyzed the metacarpophalangeal joint of the left thoracic limb of 16 horses divided into two groups, with eight horses treated with CS and GlcN in the treated group (GT) and eight untreated horses in the control group (GC). Chondral lesions were induced through arthroscopy, which was defined as time-point zero (T0). Physical, ultrasonographic, and radiographic examinations and synovial fluid biomarkers measurements were performed on days 0, 30, 60, 90, and 120. At the end of the experiment (T4), arthroscopy was performed again to macroscopically evaluate the joints and collect material for microscopic analysis.

Results

Significant differences were observed between groups in some evaluated parameters, such as visual lameness assessment, synovial concentrations of prostaglandin E2, and ultrasound examination. However, the GT still presented slightly improved results for joint flexion angle, analysis of lameness using sensors, and histopathological analysis of chondral repair tissue, however, without the statistical significance (p>0.05).

Conclusions

The treatment was considered effective in the clinical modulation of experimental osteoarthritis, with improvement of some parameters in the GT. However, this type of treatment may not be entirely effective to change the catabolic process in articular cartilage and the progressive induced chondral damage.

Who Is Healthy? A Review of How Equine Control Groups Are Defined in Clinical Orthopaedic Research 1999-2021

INTRODUCTION

 Proper identification of healthy subjects is essential in case-control studies. However, standardized definitions of healthy controls are lacking in equine orthopaedic research.

OBJECTIVES

 The aim of this study was to define the non-invasive methods used for selecting healthy control horses in osteoarthritis (OA), desmitis and tendinitis research.

METHODS

 Systematic review. Case-control studies with a healthy control group and longitudinal studies where horses had to be healthy at the start were included. Studies where joints were visualized by arthroscopy or post-mortem examination were excluded.

RESULTS

From 2,472 OA papers and 2,746 desmitis/tendinitis papers, 127 and 84 papers met the inclusion criteria respectively. For OA, 11 methods were identified for defining healthy subjects with a median of three methods used per paper. Dynamic examination, radiographic evaluation and clinical examination were the most frequent. Eight different methods were identified in the desmitis/tendinitis papers with a median of three methods per paper; ultrasonography, clinical- and dynamic examination were the most frequent.

CONCLUSIONS

 Overall, the OA and desmitis/tendinitis studies used similar methods for defining subjects as healthy, but the way the examinations were performed and interpreted was inconsistent. In several studies, healthy controls were not examined for lameness. The most common methods have limitations for detecting horses with early OA, which may have implications for interpretation of results. Standardized use of more sensitive and objective methods could be beneficial.

HOSPITALISATION AND DISEASE SEVERITY ALTER THE RESTING PATTERN OF HORSES

In humans, hospitalisation, disease type, and environmental factors evidently affect the quality of sleep, further influencing patient recovery. The objective of the present study was to report the resting and lying behaviour of hospitalised horses, and whether lying behaviours differ depending on the physiological severity of joint damage. We hypothesised that the resting and lying behaviour can change during the hospitalisation and physiological severity of joint damage affect the time of rest in horses. A descriptive observational study was performed to evaluate the effect of hospitalisation on the recumbency time of eight adult horses with different degrees of osteoarthritis of the metacarpophalangeal joint. The horses' rest time was monitored using cameras during the first 5 days of hospitalisation. The total time of lateral recumbency and frequency of recumbency were greater after the 4th day of hospitalisation (p<0,05), while the total time of sternal recumbency was greater after the 3rd day (p<0,05). Furthermore, we compared the recumbency time among animals with different degrees of osteoarthritis on the 5th day of hospitalisation. Increased recumbency time in mild osteoarthritis spared the animal's limb and reduced the overload on the affected limb; however, severe osteoarthritis decreased the frequency and time of recumbency probably due to greater difficulty during joint flexion in the transition from standing to recumbency. The severity of disease appeared to affect recumbency time, as horses with mild osteoarthritis spent more time in recumbency whilst those with severe osteoarthritis may have been partially sleep-deprived because they lay down less.

Elastosonographic features of the metacarpophalangeal joint capsule in horses

Background

Capsulitis leads to the release of inflammatory mediators in the joint, causing capsular fibrosis and osteoarthritis (OA). Strain elastosonography (SE) measures the elasticity of tissue by evaluating its strain in operator-dependent deformation. The aims of the study were to assess the feasibility, repeatability, and reproducibility of SE for imaging the distal attachment of the joint capsule (DJC) of metacarpophalangeal joints in sound horses (Group S) and in horses with metacarpophalangeal OA (Group P) and to evaluate differences in the elastosonographic patterns of these horses. After a whole lameness examination, fore fetlock DJCs were assigned to Group S and Group P and were thereafter examined by two operators using SE. Qualitative (i.e., colour grading score) and semi-quantitative (i.e., elasticity index (EI) and strain ratio (SR)) methods were used to evaluate the elastograms. The inter-rater reliability (IRR), intraclass correlation coefficient (intra-CC) and interclass correlation coefficient (inter-CC) were used to compare colour grading scores and the repeatability and reproducibility of EI and SR outcomes. The same parameters were compared between groups. P < 0.05 indicated a significant finding.

Results

Forty-one horses were included: 11 were in Group S and 30 were in Group P (16 with bilateral OA, 8 with left OA and 6 with right OA). IRR outcomes ranged from good to excellent. For transverse and longitudinal ultrasound scans, the colour grading score of Group S was significantly higher than the metacarpophalangeal DJCs of Group P. Both Inter-CC and intra-CC were higher in Group S than in Group P, with values always > 0.8. Significative differences in EI and SR were detected between groups and between Group S and the affected limb of Group P; values were lower in Group S than in Group P.

Conclusions

SE can be a useful technique for evaluating DJCs, with good repeatability and reproducibility. DJCs appear softer in sound horses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02897-8.