Arthritis of the hip is one of the leading causes of hip pain. Arthritis is an umbrella term for a group of over 100 conditions affecting joints within the body. These conditions cause damage to the cartilage surfaces lining the joints, usually resulting in pain and stiffness. Typically, arthritis is a progressive disease, meaning that it starts gradually and continues to deteriorate with time.
Osteoarthritis is the most common form of arthritis affecting the hip, and it involves breakdown of the smooth cartilage surfaces lining the bone ends within the joint. The normal function of healthy cartilage is to act as a ‘cushion’ between the bones and to ease the friction within the joint. As the disease progresses and the cartilage is worn away, changes can affect the underlying bone and surrounding soft-tissues. It can be catagorised into primary and secondary osteoarthritis:
- Primary osteoarthritis – as a result of advancing age and typically affects older patients. The cause is a complex interplay of aging, joint degeneration, repetitive use, inflammation, and in some patients, a genetic pre-disposition, causing cartilage loss in an otherwise normal joint.
- Secondary osteoarthritis – osteoarthritis that is caused as a result of a number of other conditions affecting the hip. Conditions that can predispose to secondary osteoarthritis include trauma to the hip, inflammatory conditions such as rheumatoid arthritis and ankylosing spondylitis, gout, avascular necrosis and infection.
Osteoarthritis of the hip affect each person differently but the typical symptoms include pain (hip, groin, buttock and thigh pain that can radiate to the knee), and stiffness of the joint along with impaired mobility. The pain may be felt as felt as sharp, stabbing pain or a dull, burning ache. It is most often worse with activity or after long periods of inactivity. The pain and stiffness may interfere with everyday activities including walking, putting on shoes and socks, going up and down stairs, getting into and out of low chairs, getting into and out of a car or using public transport. As symptoms progress, a limp may become noticeable or the symptoms may occur at rest or at night.
The diagnosis of arthritis of the hip is usually made after a thorough history, clinical examination of the hip and x-rays of the pelvis and affected hip. Typical x-ray findings include joint space narrowing and osteophyte or ‘spur’ formation.
Occasionally an MRI is required for the younger patient with early arthritis who does not have advanced changes visible on x-ray.
- Activity modification – minimising activities that exacerbate the symptoms, such as climbing stairs or high-impact exercise (e.g. running), may ease the pain and slow the worsening of symptoms.
- Weight loss – losing weight has a significant role in reducing the symptoms of osteoarthritis and delaying the progression of the disease. Weight loss does reduce the amount of stress going through the damaged hip joint. This could lead to less pain and improved mobility. A study looking into the effect of exercise and weight loss in people who have hip osteoarthritis demonstrated an improvement in self-reported physical function, a decrease in pain, and an improvement in walking tests.
- Exercise – Regular, low-impact exercise is one of the most important ongoing treatment options for arthritis of the hip. It helps to reduce pain and maintain your general fitness, strength and muscle tone. Ideal low-impact activities include walking, cycling and water exercise/hydrotherapy. There is high-level evidence that land-based exercise will reduce hip pain, and improve physical function among people with symptomatic hip osteoarthritis.
- Medication – simple pain medication (such as paracetamol/Panadol) or Non-Steroidal Anti-Inflammatory Drugs (such as ibuprofen/Nurofen, meloxicam/Mobic, celecoxib/Celebrex) are often the first line used when the pain and discomfort worsens, interferes with activities of daily living, or prevents a good night’s sleep. There are many other treatments for hip arthritis that are either untested or have been shown to provide little benefit including glucosamine, chondroitin and herbal therapies.
- Platelet-Rich Plasma (PRP) and stem cells – At this time, there is not enough high-quality evidence to recommend their use. Ongoing scientific trials are underway to assess whether these have any role in hip osteoarthritis.