Fasting horses perioperatively decreases manure production and increases time to manure output postoperatively: a controlled randomized trial.

Objective: To compare 3 perioperative feeding regimens and their effect on anesthetic complications, manure output, and colic proportion in healthy horses.

Methods: 45 horses presenting for elective orthopedic procedures were randomly assigned to 1 of 3 groups: not fasted (NF; continuous access to hay perioperatively), fasted muzzled (FM; 10-hour preoperative fast with slow refeeding postoperatively and muzzle placement), or fasted not muzzled (FNM; same as FM without muzzle placement). Anesthetic protocol was standardized.

A polymer network architecture provides superior cushioning and lubrication of soft tissue compared to a linear architecture.

We report the relationships between linear network polymer architecture and biomechanical outcomes including lubrication and cushioning when the polymers are applied to the surface of articulating knee cartilage. Aqueous formulations of the bioinspired polymer poly(2-methacryloyloxylethyl phosphorylcholine) (pMPC) exhibit tuneable rheological properties, with network pMPC exhibiting increased elasticity and viscosity compared to linear pMPC. Application of a polymer network, compared to a linear one, to articulating tissue surfaces reduces friction, lessens tissue strain, minimizes wear, and protects tissue - thereby improving overall tissue performance.

Quantitative Evaluation of Equine Articular Cartilage Using Cationic Contrast-Enhanced Computed Tomography.

Objective: To investigate the diffusion trajectory of a cationic contrast medium (CA4+) into equine articular cartilage, and to assess normal and degenerative equine articular cartilage using cationic contrast-enhanced computed tomography (CECT).

Design: In the first experiment (Exp1), equine osteochondral specimens were serially imaged with cationic CECT to establish the diffusion time constant and time to reach equilibrium in healthy articular cartilage. In a separate experiment (Exp2), articular cartilage defects were created on the femoral trochlea (defect joint) in a juvenile horse, while the opposite joint was a sham-operated control.

Cationic contrast-enhanced computed tomography distinguishes between reparative, degenerative, and healthy equine articular cartilage.

Cationic contrast-enhanced computed tomography (CECT) is a quantitative imaging technique that characterizes articular cartilage, though its efficacy in differentiating repair tissue from other disease states is undetermined. We hypothesized that cationic CECT attenuation will distinguish between reparative, degenerative, and healthy equine articular cartilage and will reflect biochemical, mechanical, and histologic properties. Chondral defects were created in vivo on equine femoropatellar joint surfaces.

Contrast-Enhanced Computed Tomography Scoring System for Distinguishing Early Osteoarthritis Disease States: A Feasibility Study.

Early detection of osteoarthritis (OA) remains a diagnostic challenge owing to insensitive diagnostic techniques currently available. Herein a new semiquantitative scoring system, based upon contrast-enhanced computed tomographic (CECT) imaging, is described for further refinement of early OA disease staging. Trochlear ridge cartilage defects were surgically created in the femoropatellar joint of an adult horse (ACUC approved protocols).

Biomechanical and histologic evaluation of the effects of underwater treadmill exercise on horses with experimentally induced osteoarthritis of the middle carpal joint.

OBJECTIVE To evaluate the effects of exercise in an underwater treadmill (UWT) on forelimb biomechanics and articular histologic outcomes in horses with experimentally induced osteoarthritis of the middle carpal joint. ANIMALS 16 horses. PROCEDURES An osteochondral fragment was induced arthroscopically (day 0) in 1 middle carpal joint of each horse.

COMPARISON BETWEEN COMPUTED TOMOGRAPHIC ARTHROGRAPHY, RADIOGRAPHY, ULTRASONOGRAPHY, AND ARTHROSCOPY FOR THE DIAGNOSIS OF FEMOROTIBIAL JOINT DISEASE IN WESTERN PERFORMANCE HORSES.

The femorotibial joints are a common source of lameness in Western performance horses. The objective of this prospective study was to compare the radiography, ultrasonography, computed tomographic arthrography (CTA), and arthroscopy findings in horses with lameness localized to the femorotibial joints. Twenty-five stifles in 24 horses were included and were evaluated with all four of these diagnostic methods.

Radiofrequency Probe and Sharp Transection for Tenoscopic-Guided Desmotomy of the Accessory Ligament of the Superficial Digital Flexor Tendon.

Objective: To compare intra and postoperative clinical features of desmotomy of the accessory ligament of the superficial digital flexor tendon (ALSDFT) using the Saber radiofrequency (SaberRF) electrosurgical probe versus sharp transection with a tenotomy knife.

Study Design: Randomized, controlled, blocked (horse) design.

Animals: Adult horses (n = 6).

Evaluation of a subject-specific finite-element model of the equine metacarpophalangeal joint under physiological load.

The equine metacarpophalangeal (MCP) joint is frequently injured, especially by racehorses in training. Most injuries result from repetitive loading of the subchondral bone and articular cartilage rather than from acute events. The likelihood of injury is multi-factorial but the magnitude of mechanical loading and the number of loading cycles are believed to play an important role.

Effect of forelimb lameness on hoof kinematics of horses at a walk.

Objective: To determine kinematic changes to the hoof of horses at a walk after induction of unilateral, weight-bearing forelimb lameness and to determine whether hoof kinematics return to prelameness (baseline) values after perineural anesthesia.

Animals: 6 clinically normal Quarter Horses.

Procedures: For each horse, a sole-pressure model was used to induce 3 grades of lameness in the right forelimb, after which perineural anesthesia was administered to eliminate lameness.

Effect of forelimb lameness on hoof kinematics of horses at a trot.

Objective: To determine kinematic changes to the hoof of horses at a trot after induction of unilateral, weight-bearing forelimb lameness and to determine whether hoof kinematics return to prelameness values after perineural anesthesia.

Animals: 6 clinically normal Quarter Horses.

Procedures: For each horse, a sole-pressure model was used to induce 3 grades (grades 1, 2, and 3) of lameness in the right forelimb, after which perineural anesthesia was administered to alleviate lameness.

Histomorphometric evaluation of the effect of early exercise on subchondral vascularity in the third carpal bone of horses.

Objective: To investigate histomorphometric changes in the cartilage and subchondral bone of the third carpal bone associated with conditioning exercise in young Thoroughbreds.

Animals: Nine 18-month-old Thoroughbreds. Procedures-Both third carpal bones of 9 horses (4 exercised spontaneously at pasture only and 5 given additional conditioning exercise beginning at a mean age of 3 weeks) were evaluated.

Forelimb muscle activity during equine locomotion.

Few quantitative data exist to describe the activity of the distal muscles of the equine forelimb during locomotion, and there is an incomplete understanding of the functional roles of the majority of the forelimb muscles. Based on morphology alone it would appear that the larger proximal muscles perform the majority of work in the forelimb, whereas the smaller distal muscles fulfil supplementary roles such as stabilizing the joints and positioning the limb for impact with the ground. We measured the timing and amplitude of the electromyographic activity of the intrinsic muscles of the forelimb in relation to the phase of gait (stance versus swing) and the torque demand placed on each joint during walking, trotting and cantering.

Validation of an equine inertial measurement unit system in clinically normal horses during walking and trotting.

Objective: To validate an equine inertial measurement unit (IMU) system rigidly attached to a hoof against a 3-D optical kinematics system in horses during walking and trotting.

Animals: 5 clinically normal horses.

Procedures: 5 swing phases of the hooves of the right forelimb and hind limb were collected via both 3-D optical and IMU systems from 5 horses during walking and trotting.

Histologic and histomorphometric evaluation of midcarpal joint defects in Thoroughbreds raised with and without early conditioning exercise.

Objective: To describe and measure histologic features of midcarpal joint cartilage defects in Thoroughbreds and evaluate the influence of early conditioning exercise on defect development.

Sample: 24 midcarpal joints from twelve 18-month-old Thoroughbreds.

Procedures: Midcarpal joints from 12 horses (6 exercised spontaneously at pasture only and 6 given additional conditioning exercise beginning at a mean age of 3 weeks were evaluated.

Effects of extracorporeal shock wave therapy and polysulfated glycosaminoglycan treatment on subchondral bone, serum biomarkers, and synovial fluid biomarkers in horses with induced osteoarthritis.

Objective: To evaluate effects of extracorporeal shock wave therapy (ESWT) and polysulfated glycosaminoglycan treatment (PSGAGT) on subchondral bone (SCB), serum biomarkers, and synovial fluid biomarkers in horses with induced osteoarthritis.

Animals: 24 healthy 2- to 3-year-old horses.

Procedures: An osteochondral fragment was created on the distal aspect of the radial carpal bone in 1 middle carpal joint of each horse.

Relationship between muscle forces, joint loading and utilization of elastic strain energy in equine locomotion.

Storage and utilization of strain energy in the elastic tissues of the distal forelimb of the horse is thought to contribute to the excellent locomotory efficiency of the animal. However, the structures that facilitate elastic energy storage may also be exposed to dangerously high forces, especially at the fastest galloping speeds. In the present study, experimental gait data were combined with a musculoskeletal model of the distal forelimb of the horse to determine muscle and joint contact loading and muscle-tendon work during the stance phase of walking, trotting and galloping.

Effects of early exercise on metacarpophalangeal joints in horses.

Objective: To determine the effects of exercise at an early age on tissues in the metacarpophalangeal joints of horses.

Animals: Twelve 18-month-old horses.

Procedures: All horses were pasture reared, but 6 horses had additional exercise starting at 3 weeks of age until 18 months of age.

Correlation of mechanical properties within the equine third metacarpal with trabecular bending and multi-density micro-computed tomography data.

Computed tomography (CT) data can be employed with respect to determining mechanical properties and has been used to predict parameters such as elastic modulus, yield strength, and ultimate strength of intact bone. Micro-computed tomography (muCT) possesses the resolution capable of detecting apparent bone density in extremely local regions and can characterize the trabecular structure. It has been asserted that this micro-structure is susceptible to micro-buckling and bending, which has a controversial role in predicting the global mechanical properties of bone.

Evaluation of adipose-derived stromal vascular fraction or bone marrow-derived mesenchymal stem cells for treatment of osteoarthritis.

The purpose of this study was the assessment of clinical, biochemical, and histologic effects of intraarticular administered adipose-derived stromal vascular fraction or bone marrow-derived mesenchymal stem cells for treatment of osteoarthritis. Osteoarthritis was induced arthroscopically in the middle carpal joint of all horses, the contralateral joint being sham-operated. All horses received treatment on Day 14.

Influence of early conditioning exercise on the development of gross cartilage defects and swelling behavior of cartilage extracellular matrix in the equine midcarpal joint.

Objective: To investigate the influence of early conditioning exercise on the development of gross cartilage defects and swelling behavior of cartilage extracellular matrix (ECM) in the midcarpal joint of horses.

Animals: 12 Thoroughbreds.

Procedures: 6 horses underwent early conditioning exercise from birth to 18 months of age (CONDEX group), and 6 horses were used as control animals (PASTEX group).

Evaluation of topically administered diclofenac liposomal cream for treatment of horses with experimentally induced osteoarthritis.

Objective: To assess the clinical, biochemical, and histologic effects of topically administered diclofenac liposomal cream (DLC) in the treatment of horses with experimentally induced osteoarthritis.

Animals: 24 horses.

Procedures: Osteoarthritis was induced arthroscopically in 1 middle carpal joint of all horses.

Evaluation of polysulfated glycosaminoglycan or sodium hyaluronan administered intra-articularly for treatment of horses with experimentally induced osteoarthritis.

Objective: To assess clinical, biochemical, and histologic effects of polysulfated glycosaminoglycan (PSGAG) or sodium hyaluronan administered intra-articularly in treatment of horses with experimentally induced osteoarthritis.

Animals: 24 horses.

Procedures: Osteoarthritis was induced arthroscopically in 1 middle carpal joint of all horses.

Evaluation of increased subchondral bone density in areas of contact in the metacarpophalangeal joint during joint loading in horses.

Objective: To quantitatively evaluate contact area under 2 loads and subjectively compare contact areas with subchondral bone (SCB) density patterns in intact metacarpophalangeal joints of horses.

Sample Population: 6 forelimbs from horses without musculoskeletal disease.

Procedures: Computed tomographic scans of intact metacarpophalangeal joints were analyzed to obtain SCB density measurements.

Evaluation of subchondral bone mineral density associated with articular cartilage structure and integrity in healthy equine joints with different functional demands.

Objective: To determine and correlate subchondral bone mineral density and overlying cartilage structure and tensile integrity in mature healthy equine stifle (low magnitude loading) and metacarpophalangeal (high magnitude loading) joints.

Animals: 8 healthy horses, 2 to 3 years of age.

Procedure: Osteochondral samples were acquired from the medial femoral condyle (FC) and medial trochlear ridge (TR) of the stifle joint and from the dorsal (MC3D) and palmar (MC3P) aspects of the distal medial third metacarpal condyles of the metacarpophalangeal joint.