Orthopedic Surgeon. Management will vary depending on the severity of the injury. Your uncle can either begin with his primary care physician or a sports physician, but it may ultimately lead to a consultation with an orthopedic surgeon.
Orthopedist. An orthopedic surgeon would take care of this. If he is in an area with a lot of doctors, then an orthopedist specializing in sports or upper extremity problems might be best. The actual treatment depends on a lot of things, including your uncle's age and which end of the biceps was torn.