CT more accurately detects foreign bodies within the equine foot than MRI or digital radiography.

Identification and characterization of foreign bodies in the distal limb of horses poses a diagnostic challenge. The aims of this prospective experimental cadaver study were to describe the appearance of five foreign body materials within the equine hoof using CT, MRI, and digital radiography (DR) and to compare interrater agreement among three reviewers. Fifty foreign bodies consisting of five materials were implanted at a solar location or a coronary location in 25 equine cadaver feet. The images were reviewed by three equine veterinarians experienced in advanced imaging interpretation, who were blinded to the material of the foreign body. Foreign bodies were graded on visibility and appearance. Sensitivity and specificity were calculated for accurate identification of the different materials. Interrater agreement was assessed using Fleiss' kappa. Computed tomography had higher visibility score, sensitivity/specificity, and interrater agreement for detection of all materials; particularly slate, glass, and dry wood, compared to the other imaging modalities. Soaked wood and plastic had lower sensitivity (31-33%) on CT with a similar attenuation of the two materials. Foreign bodies were often visible on MRI, although with similar appearance and unclear details. On DR, only slate and glass were visible. The interrater agreement for identifying the correct material was almost perfect for slate, glass, and dry wood (κ = 0.92-1.00) and poor for plastic and soaked wood (κ < 0.20) on CT. Interrater agreement was poor for all materials on MRI and DR (κ < 0.20), with the except for fair (κ = 0.28) for slate on DR and moderate (κ = 0.28) for soaked wood on MRI.

Assessment of intrasynovial injection in horses by contrast-enhanced ultrasonography using air bubbles created by agitation of solution.

BACKGROUND: Accuracy of intrasynovial injections can be challenging to assess in a clinical setting in horses. Contrast-enhanced ultrasonography (CEUS) using injectate agitated with air has been used to determine the success rates of synovial injections in human rheumatology. OBJECTIVES: To assess the diagnostic sensitivity and specificity of CEUS and to describe its clinical use. STUDY DESIGNS: Cadaveric study followed by a prospective descriptive observational study. METHODS: Part 1: CEUS was performed following injection of agitated methylene-blue solution targeting 13 different anatomical synovial structures from three equine cadavers. Contrast was seen as hyperechoic dots, patches or lines on ultrasonography. CEUS was classified as positive if contrast was considered to be intrasynovial and negative if contrast was considered to be extrasynovial. A second synoviocentesis was performed to determine if the injection was intrasynovial based on the presence or absence of methylene-blue. Estimates of sensitivity and specificity were calculated. Part 2: CEUS was performed following injection of agitated solutions targeting synovial structures as part of routine investigation and treatment of clinical cases. RESULTS: Part 1: CEUS was correctly classified as positive or negative in all intrasynovial and extrasynovial injections respectively. The sensitivity estimate was 100% (CI 93%-100%) and the specificity estimates was 100% (CI 16%-100%). Part 2: The technique was used safely for 26 injections (14 horses; 19 different synovial structures) administered to localise or treat lameness. Traumatic intersynovial communications or synovial membrane defects were identified using CEUS in 3 horses. MAIN LIMITATIONS: The low number of extrasynovial injections in Part 1 resulted in an imprecise specificity estimate. CONCLUSIONS: In horses, CEUS performed following intended intrasynovial injection can be useful for identifying unsuccessful injections.

Management of an extensive equine juvenile ossifying fibroma by rostral mandibulectomy and reconstruction of the mandibular symphysis using String of Pearls plates with cortical and cancellous bone autografts.

OBJECTIVE: To describe a surgical technique for rostral mandibulectomy and reconstruction of the mandibular symphysis. STUDY DESIGN: Case report. ANIMAL: One 5-month-old warmblood cross filly. METHODS: A preoperative diagnosis of a juvenile ossifying fibroma was made on the basis of clinical appearance and was later confirmed via histology. The tumor was large, rapidly growing and extending to the caudal aspect of the mandibular symphysis. Computed tomography was performed for surgical planning. The tumor was excised by performing a mandibulectomy caudal to the symphysis. The mandibular symphysis was reconstructed with String of Pearls (SOP) plates. Cortex screws placed in lag fashion, a cortical bone graft from one of the mandibles and a cancellous graft harvested from the tuber coxae. RESULTS: At 9 months of age there was no sign of tumor reoccurrence, the implants were removed because of infection and the mandible had formed a new stable symphysis. The horse was able to prehend food and masticate normally. The owner was pleased with the cosmetic and functional outcome. CONCLUSION: The described surgical technique is a viable option for mandibulectomy and reconstruction of the mandibular symphysis. The technique provided adequate stability for healing to occur in the face of infection. CLINICAL SIGNIFICANCE: Neoplasia and other conditions affecting the entire mandibular symphysis can be treated by complete surgical excision and reconstruction.