The results of 79 high resolution ultrasound examinations of the forefoot that were performed for suspected Morton's metatarsalgia were retrospectively assessed. Scans were only obtained if the pain was poorly localized or if there were atypical features that made the clinical diagnosis uncertain. Ultrasound detected 92 hypoechoic intermetatarsal web space masses in 63 patients. Surgery was performed on 23 web spaces in 22 patients where the response to nonsurgical management had been poor. The surgical specimens were retrieved and reviewed by a pathologist in 21 cases. The histopathology in 20 of 21 operated cases was that of Morton's neuroma; however, prominent mucoid degeneration was also found to involve the adjacent loose fibroadipose tissues in 19 of 20 neuroma specimens. Ultrasound was sensitive in the detection of web space abnormality (sensitivity, 0.95), but could not clearly separate Morton's neuroma from associated mass-like mucoid degeneration in the adjacent loose connective tissues. The implications of these observations for both diagnosis and treatment are discussed.

The intra-articular anatomy of 103 equine tarsi was studied by contrast radiography with image intensification and computerized tomography. There was communication between the tarsometatarsal and distal intertarsal joints in 21 of 55 (38%) interpretable tarsometatarsal arthrograms, and in 11 of 48 (23%) interpretable distal intertarsal arthrograms. The difference was not significant. The volume of contrast agent and the pressure of injection did not correlate with communication. Forced injection caused subcutaneous leakage of contrast medium but not communication. Communication occurred via the tarsal canal and the space between the third and the combined first and second tarsal bones. Injection of the distal intertarsal joint from the dorsomedial aspect of the limb, distal to the palpable distal border of the medial branch of the tendon of the tibialis cranialis muscle and between the central, third, and combined first and second tarsal bones, provided reliable access except in the presence of severe periosteal proliferations.

Real–time ultrasonography was used to confirm diaphragmatic rupture in a horse that developed pleural effusion following a traumatic event. Pleural effusion, a cranially displaced crus, and a cranially positioned sacculated loop of bowel were seen radiographically. The presence of gas–filled intestine cranial and dorsal to the diaphragm was detected by ultrasound imaging. The use of ultrasound and radiography in the diagnosis of diaphragmatic rupture is discussed.