Although the word "arthritis" is overused, referring to pain in a joint, the word "osteoarthritis" is referring to the kind from wear and tear, as opposed to trauma, or infection, or inflammatory cause.
Arthritis of the hip area can cause pain with rotating the leg, like moving the knees together and apart. The issue is that these motions move the ball in the socket, and the pain from this motion is typically in the groin.
In the picture above, the absence of the smooth cartilage which is usually on the end of a bone (think about a chicken bone...as they usually don't develop arthritis before we're looking at their joints!!) leads to the xray appearance of the joint space as being more narrow. Other findings include bone spurs, cysts, and more calcium deposits (looks more white) seen on xray, in the R hip in the picture above.
Sometimes patients will point to the painful part of their hip as the back part of their buttock, but often those pains are due to low back issues.
For hip osteoarthritis, the treatment options are generally:
--medications
--activity modification
--injections (sometimes)
--hip replacement
For those patients considering evaluation for hip pain, especially when in the groin, they can be seen at Orthopaedic Associates, and the best person to see would be Dr. Darden. We can discuss the details of your specific case, as each patient's situation is different.