Horse with a pelvic injuryA three year old quarterhorse was found down in the pasture unable to stand and was brought to the clinic for examination - the injury was thought to be in the right pelvic limb and probably involved the hip joint.Radiographs were made of the pelvis and oblique views were made of the hip joints What is your diagnosis? The radiographic diagnosisThe comminuted fractures involve the right acetabulum - the fragments are sharply marginated without any loss of bone density or early callus formation all supporting the clinical diagnosis of an acute injury - the femoral head and neck appear to be unaffected although small fractures from the head would be difficult to identify.Because of the nature of the injury, the horse was euthanized. The radiographs of a second case are presented This patient is younger and the fracture is through the physeal growth plate resulting in separation of the femoral head - this is a Type 1 Salter-Harris fracture, although there is suggestion of a small bone fragment from the acetabular rim (arrows).Note the value in being able to compare the appearance of the two hip joints in making a diagnosis - also note the value of the oblique views in determining the altered width of the physeal plate and the slight displacement of the head indicating that the capital epiphysis has indeed fractured free. Drawing to show patient positioning The drawing illustrates the positioning required to obtain the oblique projection of the hip joint - the drawing also suggests that the tissue in this anatomical area is not particularly thick. The study can be made most easily with a radiographic unit that has a ceiling supported tube - of course, the study is dependent on whether the patient can be anesthetized - a special table used for radiography of large animals has an under-table tray to safely hold the grid and cassette.
