Diagnosis of Soft Tissue Injury in the Sport Horse.

For successful diagnosis of soft tissue injuries in the sport horse, localizing the area of injury during clinical and lameness evaluation will be followed in most cases by an ultrasonographic examination. With MRI more available in equine veterinary clinics, this modality can allow for a complete evaluation of soft tissue and osseous structures and is especially useful for evaluation of structures within the hoof capsule. This article discusses special ultrasonographic techniques, an overview of MRI image generation, and the use of contrast computed tomography for diagnosis of soft tissue injuries.

Comparison of an alcohol-based hand rub and water-based chlorhexidine gluconate scrub technique for hand antisepsis prior to elective surgery in horses.

This prospective clinical study evaluates the effectiveness of an alcohol-based hand rub (Avagard™) for pre-surgical hand antisepsis in an equine hospital and compares it with traditional scrubbing technique using 4% chlorhexidine gluconate sponges and water. Prior to elective surgery, 3 board-certified surgeons were randomly assigned to hand antisepsis with either technique. Culture samples of each hand were taken at 4 times: before and after neutral soap hand wash, after scrub or rubbing technique, and after surgery. There was no significant difference in mean bacterial colony forming units between scrub and rub techniques over the 3 time periods (P = 0.6), controlling for initial counts. One horse from the scrub group had a skin incision infection following stifle arthroscopy; this was resolved with medical treatment. The alcohol-based hand rub is equivalent in efficacy for pre-surgical hand antisepsis to traditional water-based scrubs in an equine hospital setting.

Comparaison de l'alcool à friction et d'une technique de brossage au gluconate de chlorhexidine à base d'eau pour l'antisepsie des mains avant les chirurgies non urgentes chez les chevaux. Cette étude clinique prospective évalue l'efficacité d'un alcool à friction (AvagardMD) pour l'antisepsie des mains préalable à une chirurgie dans un hôpital équin et elle la compare à la technique de brossage traditionnelle au moyen d'éponges de gluconate de chlorhexidine 4 % et d'eau. Avant une chirurgie non urgente, trois chirurgiens agréés ont été assignés au hasard à l'antisepsie des mains avec l'une ou l'autre technique. Des échantillons de chaque main ont été prélevés quatre fois pour culture : avant et après le lavage des mains avec un savon neutre, après la technique de brossage et de friction et après la chirurgie. Il n'y avait aucune différence significative dans les moyennes des dénombrements bactériens d'unités formatrices de colonies entre les techniques de brossage et de friction pendant les trois périodes de temps (P = 0,6), en tenant compte des témoins pour les dénombrements initiaux. Un cheval du groupe de brossage a développé une infection au site de l'incision après une arthroscopie du grasset qui a été résolue par traitement médical. La friction des mains à l'alcool est équivalente, en matière d'efficacité pour l'antisepsie des mains avant la chirurgie, au brossage traditionnel à l'eau dans un milieu hospitalier équin.(Traduit par Isabelle Vallières).

Comparison between palpation and ultrasonography for evaluation of experimentally induced effusion in the distal interphalangeal joint of horses.

OBJECTIVE: To ultrasonographically quantify experimentally induced effusion of the distal interphalangeal (DIP) joint of horses and compare results with those obtained with palpation. SAMPLE: 8 forelimbs from equine cadavers and forelimbs of 5 mares. PROCEDURES: Preliminary ex vivo experiments were performed to validate the methods. Then, the DIP joints of the forelimbs of standing horses were serially distended with saline (0.9% NaCl) solution (1, 4, and 10 mL) by injection through an intra-articular catheter. Two ultrasonographers measured distension of the dorsal recess of the DIP joint, and 2 surgeons, who were not aware of the volume injected, graded joint effusion by palpation. RESULTS: Intraobserver and interobserver repeatability was excellent for ultrasonographic measurements. Interobserver agreement for use of palpation to detect joint distension was moderate (κ = 0.45). There was an overall increase in the palpation distension grade with an increase in injected volume. Sensitivity for detection with palpation of larger volumes (4 and 10 mL) was high (92% and 100%, respectively). However, sensitivity was lower (57%) for detection with palpation of minimal distension (1 mL). CONCLUSIONS AND CLINICAL RELEVANCE: Although palpation provided a reliable clinical assessment of DIP joint effusion for volumes of 4 to 10 mL, ultrasonographic measurements were easy to obtain, more accurate, and able to detect smaller amounts of distension. This may be clinically relevant for the assessment of effusion of the DIP joint that can arise in horses with early osteoarthritis or infectious arthritis with concomitant soft tissue swelling that precludes accurate assessment with palpation.

Diagnosis and management of cranial and caudal nuchal bursitis in four horses.

CASE DESCRIPTION: 4 horses with a history of neck pain, abnormal head carriage, and related inability to perform were examined. Cranial nuchal bursitis was diagnosed in 2 horses, and caudal nuchal bursitis was diagnosed in the other 2. CLINICAL FINDINGS: All 4 horses had prominent swelling in the region between the frontal bone and temporal fossa (ie, the poll) and abnormal head carriage. Ultrasonographic examination revealed fluid distention and synovial thickening of the cranial or caudal nuchal bursa in all 4 horses. Ultrasonography-guided aspiration of the affected region was performed successfully in 3 horses. Radiography revealed bony remodeling and mineralization over the dorsal aspect of the atlas in 1 horse and a radiolucency at the axis in another. Nuclear scintigraphy revealed an increase in radioisotope uptake at the level of C2 in 1 horse. Although a septic process was considered among the differential diagnoses in all horses, a septic process could only be confirmed in 1 horse. TREATMENT AND OUTCOME: All horses were refractory to conservative management consisting of intrabursal injection of anti-inflammatory medications. Bursoscopic debridement and lavage of the affected bursae resulted in resolution of the clinical signs in all horses, and they all returned to their intended use. CLINICAL RELEVANCE: Cranial and caudal nuchal bursitis, of nonseptic or septic origin, should be considered as a differential diagnosis in horses with head and neck pain. Horses undergoing surgical intervention consisting of nuchal bursoscopy have the opportunity to return to their original degree of exercise.

In vitro comparison of two centrally threaded, positive-profile transfixation pin designs for use in third metacarpal bones in horses.

OBJECTIVE: To compare heat generation during insertion, pullout strength, and associated microdamage between a self-tapping positive profile transfixation pin (STTP) and nontapping positive profile transfixation pin (NTTP). SAMPLE POPULATION: 30 pairs of third metacarpal bones (MC3s) from adult equine cadavers. PROCEDURES: One MC3 of each pair was assigned to the STTP group; the other was assigned to the NTTP group. The assigned pin was inserted into the diaphysis in a lateral to medial direction. Bone temperature increase during pilot-hole drilling and pin insertion was recorded at 1 mm from the final thread position with wire thermocouples at cis and trans cortices. Resistance to axial extraction before and after cyclic loading was measured in a material testing device, and microstructural damage caused by transfixation pin insertion was assessed with scanning electron microscopy. RESULTS: The STTP group developed a significant increase in bone temperature, compared with the NTTP group. No significant difference was found between the mean maximal pullout strength of the STTP and the NTTP in both non-cyclic-loaded and cyclic-loaded groups. Microdamage to the bone-pin interface was lower when the STTP versus the NTTP was used, but more bone debris was apparent after inserting the STTP. CONCLUSION AND CLINICAL RELEVANCE: Because of the significant increase in temperature generation and debris accumulation despite similar pullout strengths and lesser microfracture formation, the STTP likely poses a higher risk of bone necrosis and potential loosening than the NTTP. This might be corrected by redesign of the tapping aspect of the STTP.