To obtain diagnostic radiographs, it is important that the patient and the surrounding musculature be completely relaxed. For the comfort and safety of the animal, this requires sedation and/or general anesthesia.
Typically, three separate radiographs are made during an evaluation. The first is the compression view where the femurs are positioned in a neutral, stance-phase orientation and the femoral heads are pushed fully into the sockets. This helps show the true depth of the hip socket and gives an indication of the "fit" of the ball in the socket. The second radiograph is the distraction view. Again, the hips are positioned in a neutral orientation and a special positioning device is used to apply a harmless force to cause the hips to displace laterally.
This position is the most accurate and sensitive for showing the degree of passive hip laxity. Passive hip laxity has been shown to be the primary risk factor associated with the development of DJD. A hip-extended view is also included for the sole purpose of examining for existing joint disease such as osteoarthritis. The PennHIP procedure has been safely performed on thousands of patients.