With tendinosis, there is an increased amount of blood flow to the area but the tendons aren't inflamed. Instead, the nerve tissue is irritated and inflamed, which may be what's causing the long-term pain and other neurogenic symptoms.

Blood flow can be assessed using a device and testing procedure called real-time color Doppler ultrasonography. Doppler ultrasonography shows blood volume and velocity (speed). In a normal tendon, there is a low-rate of blood flow so it can't be detected. But with a chronic tendinosis, Doppler ultrasonography shows increased blood volume and velocity.

In some patients, the increased blood supply results in intratendinous calcifications. These are tiny streaks of calcified bone material in between the tendon fibers. This finding tells the physician that the condition has been present a long time. Based on the presence of these calcium deposits, the condition is classified as a stage four epicondylitis.

Treatment decisions are more easily made when the physician has a better idea what's going on inside the elbow. Stage four may not respond to conservative care, requiring surgery to address the soft tissue abnormalities. The results of Doppler ultrasonography are usually combined with MRI findings to guide treatment decisions.