The hip joint is a large weight bearing joint that attaches the leg bone (femur) to the pelvis, allowing the body to walk, run, and sit. The hip is a very strong structure, but, like all bones and joints, is not immune to damage. Sports-related injuries, motor vehicle accidents (MVA), and falls in the elderly are cause some of the worst hip injuries. However, arthritis is usually the culprit in severe chronic hip pain.
In 2007 the Centers for Disease Control (CDC) stated, “Arthritis continues to burden the U.S. population as the leading cause of physical disability and affects women disproportionately: women with arthritis report greater prevalence of activity and work limitations, psychological distress, and severe joint pain than their male counterparts” (Theiss 2007).
As stated before, the hip joint is a ball and socket joint, where the femur (large thigh bone) connects to the pelvis. The top of the femur is a round ball, which fits into the socket (acetabulum) formed by the pelvic bone, and the ball is allowed to glide and rotate within the acetabulum because a group of ligaments and muscles support the joint and inhibit over extension. Within the joint is, also, a synovial lining, which provides lubricating fluid to decrease friction.
Hip dislocations and femur fractures are often acute injuries and are treated as such. There are other conditions that can produce chronic progressive hip pain, however, and these are more common.
Diseases, besides trauma, that can cause chronic hip pain:
- Osteoarthritis (OA)- also known as degenerative arthritis or degenerative joint disease. OA is the most common cause of arthritis in the United States. It is most common in women, people over the age of 55, obese people, and those with a history of previous joint trauma or disease. OA results from repetitive wear and tear of the joint. OA can cause a chronic, non-inflammatory arthritis of any moveable joint. The most common joints involved in OA are the DIP joints (small joints closest to your fingernails) of the fingers and the knees. Typically the joint involvement is one-sided and asymmetric. Patients typically experience crepitus, which is a crackling or popping sound and sensation. This is created when the cartilage has broken down and two rough edges are coming into contact with each other. This can also cause a decrease in range of motion, pain that worsens with activity, and improves with rest. There is typically no localized swelling or redness seen with this cause of arthritis.
- Rheumatoid Arthritis (RA)- Unlike OA, RA is a chronic, systemic, destructive, inflammatory arthritis. It is commonly seen in younger aged women 35-50, although can be seen in anyone. Infections by viruses, and bacteria and genetic factors (HLA-DR4) are thought to possibly trigger the destructive inflammation.RA is characterized by symmetric involvement of the large and small joints. The originating cause is by a nonspecific inflammation which then produces T-cell activation (cell of your immune system) and a pannus (flap of tissue) is formed. The pannus erodes into the surrounding cartilage, tendons, and even bones.
- Avascular Femoral Head Necrosis- Results from incomplete blood supply to the bone. The bone then typically develops necrosis or destruction of normal tissue. A fracture of the femoral neck or dislocation of the femoral head may damage the blood vessels that supply the femoral head. Other causes can be from arthritis syndromes, local or systemic steroids, infection, radiation, or unknown causes. When there is necrosis in the femoral head, the bone typically cannot support the body weight and the femoral head can eventually collapse and fracture causing pain and further complications.
- Labral Tears- The hip socket or acetabulum is lined by cartilage. This cartilage is called your labrum and allows for smooth movements of the femur ball in your hip joint. A labral tear can result from injury or wear and tear arthritis. Labral tears can often be painful and those affected often complain of a “catching” or “locking” sensation with certain movements. Treatment often involves medications, injections, physical therapy, and sometimes surgery.
- Lumbar Radiculitis- Spinal nerve in the low back can become irritated and aggravated by various conditions. If a nerve root becomes irritated it can cause painful radiation into the lower extremity. The pain is called referred because it is felt in the hip, but the pathology is in the low back. Typically radiculitis can be diagnosed with a physical exam and relevant spinal imaging.
Diagnosing patients with hip pain can be difficult, as many of the symptoms are similar those of other conditions. The first step in evaluating a patient with hip pain is to get a comprehensive history and physical exam. Some questions that a doctor may ask a patient suffering from hip pain are –
- Where is the pain located?
- How long has the pain been there?
- What were you doing when you first noticed the pain?
- Is there anything you can do that alleviates the pain?
- Are you currently taking any medications for the pain? Do they work?
- Is there any family history of arthritis or other autoimmune disease?
After conducting a full history and physical exam your physician may want additional studies. These might include radiological films and blood work. Imaging techniques, like MRIs, CT scans, or Xrays, are useful because the help your doctor see directly into the effected joint.
Common imaging techniques to evaluate arthritis include:
- X-Ray – a diagnostic test which uses an electromagnetic energy ray to produce images of internal tissues. Bones are well visualized.
- CT Scan – a diagnostic test that combines x-rays with computer technology to produce cross sectional views of the body. This is helpful because it helps to visualize detailed images of the body, including the bones, muscles, and organs.
- MRI Scan – a diagnostic image that uses large magnets and a computer to produce detailed images of the structures within the body. This is even more detailed than the CT Scan and X-Ray.
Common laboratory tests that your physician may want to check are complete blood count (CBC), complement, antinuclear antibody (ANA) for rheumatalogical conditions, creatinine, erythrocyte sedimentation rate, rheumatoid factor, urinalysis, and a white blood cell count (WBC). Additionally, your physician may want to perform an arthrocentesis to look at the fluid in the joint. This is especially crucial when gouty arthritis or a septic arthritis is suspected. Another method in evaluating the joint is called an arthroscope. This procedure involves placing a small, optic tube (arthroscope) into the joint, so that your doctor can get an inside view of your joint.
There are many treatment options for arthritis and joint pain. The most common and recommended methods are conservative. Staying active and engaging in physical therapy, taking NSAIDs and Acetaminophen (Tylenol), have all proven to be quite helpful to most arthritis sufferers. Physical therapy has been noted to significantly improve the postural stability in hip OA patients (Giemza 2007). Also, intra-articular joint injections have gained popularity, because they are successful, minimally invasive, and long-lasting.
A joint injection may be considered for patients who have not found relief with other methods. The injection can help relieve pain by reducing the inflammation and numbing the joint. It can, also, help to diagnose the source of the pain. Joint injections offer rapid relief of symptoms, which allow the patient to quickly resume regular activity. Often times, this method is superior to oral medications for many arthritis sufferers.
There are many treatments available to those suffering from arthritis, and Arkansas Pain Specialists can answer any of your questions.
- Hip Pain– PainDoctor.com
- Arthritis burden and impact are greater among U.S. women than men: intervention opportunities. J Womens Health (Larchmt). 2007 May;16(4):441-53 Theis KA, Helmick CG, Hootman JM.
- The effect of physiotherapy training program on postural stability in men with hip osteoarthritis. Giemza C, Ostrowska B, Matczak-Giemza M. Aging Male. 2007 Jun;10(2):67-70