Hip pain is not always just felt directly over the hip. Instead, you may feel it in the middle of your thigh or in your groin. Similarly, pain you feel in the hip may actually reflect a problem in your back, rather than your hip itself. It is extremely important for a professional to make an accurate diagnosis of the cause of your symptoms so that appropriate treatment can be directed at the underlying problem.
Anatomy of the Hip
The hip joint is a ball and socket joint. The femoral head (ball) sits in the acetabulum (socket). Underneath the femoral head lies the femoral neck. Two prominences in the upper part of the femur, the greater trochanter and the lesser trochanter, allow the attachment of muscles onto the bone. The joint surfaces are covered by several millimetres of articular cartilage, which can be seen as a gap between the bones on a hip x-ray.
The hip joint is enveloped by thick ligaments binding the femur and acetabulum together. At the front the ligaments extend down on the line between the greater and lesser trochanter (intertrochanteric line) and at the back of the hip the ligaments insert much higher up on to the femoral neck.
The hip socket is deepened by a thick rim of fibrocartilage that runs around the lip of the acetabulum. This lip is called the acetabular labrum (shown in blue on the image below) and can be a source of pain in patients with a labral tear. The head of the femur is connected to the acetabulum by an internal ligament (ligamentum teres) which is probably more important as a blood supply to the femoral head during growth.
Causes of Hip Pain
The hip joint is designed to withstand repeated motion and a fair amount of wear and tear. Whenever you use the hip (for example, by going for a run), a cushion of cartilage helps prevent friction as the hip bone moves in its socket. Despite its durability the hip joint can be injured directly or by a disease process. With age and use, the cartilage can wear down or become damaged. Muscles and tendons in the hip can get overused. The hip bone itself can be fractured during a fall or other injury. Any of these conditions can lead to hip pain. Here is a general list of causes of hip pain:
- Juvenile rheumatoid arthritis
- Psoriatic arthritis
- Rheumatoid arthritis
- Septic arthritis
- Hip fracture
- Hip labral tear
- Inguinal hernia
- Sprains and strains
- Pelvis fracture
- Herniated disc
- Meralgia paresthetica
- Spinal stenosis
- Advanced (metastatic) cancer that has spread to the bones
- Bone cancer
- Avascular necrosis
- Legg-Calve-Perthes disease
- Paget’s disease of bone
Symptoms of Hip Injury
Depending on the condition that’s causing your hip pain, you might feel the discomfort in your:
- inside of the hip joint
- outside of the hip joint
Sometimes pain from other areas of the body, such as the back or groin (from a hernia), can radiate to the hip.
You might notice that your pain gets worse with activity, especially if it’s caused by arthritis. Along with the pain, you might have reduced range of motion. Some people develop a limp from persistent hip pain.
Tests for Hip Pain
X-rays are often the best way of finding out what’s wrong with the hip as they clearly show the condition of the bones. They’re very good at looking for arthritis in the hip, but they may also show problems in your pelvis which could explain your pain. They’re not as useful for looking at the soft tissues around the joint.
A CT scan can often be very helpful to work out if the hip joint has an unusual shape. There are conditions where the socket of the hip can be very shallow, and a CT scan often helps to show this up.
MRI scans are useful for looking at the muscles and tendons around the hip. They’re particularly helpful for diagnosing avascular necrosis. If your chiropractor suspects you have a torn acetabular labrum, they may suggest you have an MR arthrogram. A small quantity of a compound called gadolinium contrast is injected into the hip joint before an MRI or CT scan is performed. This allows the capsule, the articular surface of the bones and the surface of the cartilage to be examined.
If your chiropractor thinks your pain is caused by an infection or rheumatoid arthritis, blood tests can often help.
Serious Symptoms of Hip Pain
Some hip pain symptoms are considered to be more serious and may point to serious medical conditions. If any of the following symptoms associated with hip pain is felt, consult a professional immediately:
- Weight Loss
- Night Pain
- Feeling unwell
- Fever and night sweats
- Inability to weight bear