The back bone is connected with the hip bone. The hip bone is connected with the leg bone. Sounds simple enough; however, when someone complains of hip pain, the "hip" in question is usually not the actual hip joint. When someone says that his/her "hip" hurts, she/he is actually pointing to the Greater Trochanter, which is on the side of the pelvis. The actual hip joint is in the groin area. But, before we get ahead of ourselves, let's talk about what the hip joint is made of.
Like all joints, two bones are joined together by ligaments and a joint capsule. In the case of the hip, the femur (leg bone) is connected to the pelvis (the hip bone). This connection occurs deep in the groin. Thus, hip joint pain and inflammation is felt in front, near the pubic bone. Other areas, like the buttock and low back, can also be painful with hip arthritis. Getting back to this business about the Greater Trochanter, this boney prominence serves as the attachment point of some major muscles groups that move the hip. This area will get painful with conditions like tendonitis (inflammation of the tendon attaching the muscle) and bursitis (inflammation of the sack-like cushioning for the tendon). This soft tissue pain around the Greater Trochanter is treated very differently than the boney pain of hip arthritis; thus, an accurate diagnosis is critical.
Differentiating between the different causes of "hip" pain is usually quite simple with a physical exam by a doctor. First, a doctor will evaluate the range of motion of the hip. How does the hip move? Flexion, extension, rotation, and side to side; the hip usually has a very wide range of motion as a ball-and-socket joint. The first sign of hip arthritis is limitation and pain with internal rotation and flexion. Comparing the left and right hip helps to determine what is normal for an individual and what is not. (I always like to say that God gave us two sides for comparison.) Next, a doctor will evaluate strength in the hip. Any pain with resisted hip motion may be an indication of tendonitis or muscle strain. Palpation along the Greater Trochanter can also assist in making the diagnosis of tendonitis or bursitis.
A thorough evaluation should also evaluate the areas above and below the area of pain. In the case of hip pain, a low back examination and leg examination should be included as well. Finally, a doctor may order an X-ray of the hip to evaluate this boney connection if a bone problem is strongly suspected. An X-ray gives a doctor a good picture of the joint in order to assess things like joint space and inflammatory changes in the bone. If the joint space is completely obliterated, a patient will be told that the arthritic condition is severe and "bone-on-bone." All of the physical signs from examination and X-rays help to determine the cause of "hip" pain.
Once the pain location is clarified, and once the physical exam renders further clues, then and only then can the diagnosis of hip arthritis be made. As already stated, the importance of differentiating the source of the pain is critical to arriving at the right treatment plan. The diagnosis of hip arthritis means that the actual hip joint is inflammed and painful. However, other areas can be mistakenly referred to as "hip" pain including the Greater Trochanter, the buttocks and the low back. Unfortunately, some low backs get mistakenly operated on when the pain source is actually coming from the hip joint. And sometimes, a hip joint is mistakenly replaced when the low back is the actual source of pain. These mistakes can be avoided with an accurate diagnosis by a thorough doctor. Such thoroughness is critical to save someone from a potentially unnecessary, unhelpful surgery. So, just because someone says he/she has "hip arthritis" does not necessarily mean that it is true. A "hip" is not a hip joint until further questions are thoroughly answered by a doctor, or two.