The hip joint is made up of a ball (the head of the femur) that fits into a socket in the pelvis (acetabulum). A healthy hip joint is lined by a specialised, smooth, low-friction (articular) cartilage which allows the joint to move smoothly and freely. Hip arthritis occurs when this specialised cartilage degenerates or wears out, and the underlying bone becomes exposed.
There are two main causes for the specialised cartilage in the hip joint to degenerate:
- Osteoarthritis is the most common cause of hip arthritis. Osteoarthritis may run in families, determined by genetics, however it may also occur as a result of injury, trauma or previous surgery. An impaired blood supply to the hip joint may cause collapse of the head of the femur. More rarely, a childhood disorder of the hip may lead to early-onset osteoarthritis.
- Inflammatory arthritis is an immune disorder that leads to inflammation in the (synovial) lining of the hip joint. Common causes are auto-immune disorders such as rheumatoid arthritis. The synovial lining becomes inflamed and thickened with the production of various damaging molecules in the joint. This in turn leads to damage of the specialised articular cartilage. Rheumatologists treat inflammatory arthritis with medications that target the damaging molecules.
- Pain. The most common locations for pain from hip arthritis is in the groin, in the thigh and even down to the knee. Pain on the outside of the hip or in the buttock is less characteristic of hip arthritis and may be due to another condition, such as trochanteric bursitis or lumbar spine arthritis. Pain that shoots down the leg is rarely caused by hip arthritis.
- Stiffness. Hip arthritis can cause a reduced range of motion in the hip joint. This is usually something that develops slowly over time and may be worse in the morning or with inactivity.
- Limp. Hip arthritis may lead to a limp and the need to use a walking stick or walking frame for balance.
- Functional limitations. Pain, stiffness and a limp may lead to every day functional limitations. This may be a reduction in exercise or walking distance over time. More specifically, it may be uncomfortable to sit on low chairs or toilets, or to sit in a car for prolonged periods. It may be difficult to stand after being seated. Putting on or taking off shoes and socks, and cutting toenails, may be a problem.
Hip arthritis is best diagnosed by your treating doctor. A combination of your history, physical examination and an x-ray is usually enough to determine whether the hip joint is arthritic. The hip joint will usually have a painful limitation in range of motion and may impinge in certain positions. An x-ray may show the space in the hip joint to be narrowed with bony deformity. Rarely, an MRI may be needed to determine if the articular cartilage in the hip joint is damaged. Blood tests are used to diagnose the different inflammatory causes of hip arthritis.
There are a multitude of suggested treatments for osteoarthritis, but be careful, not all treatments are supported by the best medical evidence.
The treatments for osteoarthritis with strong supporting evidence in the medical literature include:
- Exercise – referral to a physiotherapist or exercise physiologist may be beneficial.
- Weight loss – for those patients with a body mass index (BMI) greater than 25, a weight loss target of 5-10% of body weight is recommended. Referral to a dietician or upper gastrointestinal surgeon may be beneficial.
Other treatments, that may help, where the medical evidence is less clear, include:
- Cognitive behavioural therapy
- Stationary cycling
- Aquatic exercises (hydrotherapy)
- Massage therapy
- Manual therapy such as stretching
- Heat therapy
- Aids such as walking sticks and frames
- Transcutanous electrical nerve stimulation (TENS)
- Oral anti-inflammatory medications (NSAIDs)
- Corticosteroid injections
Interventions with evidence against use for hip or knee arthritis treatment include opioid medications, viscosupplementation injections, stem cell therapy, glucosamine, chondroitin and omega-3 fatty acid supplements.
The best surgical option for treating hip arthritis is usually a total hip replacement. Total hip replacement involves completely replacing the arthritic ball and socket joint with an artificial joint (prosthesis). Rarely, a joint preservation procedure may be possible. This surgery is performed only in specialised centres and involves realigning the hip joint with an osteotomy (cutting the bone) of the pelvis or femur, to offload the arthritic area.
Pain and discomfort caused by orthopaedic conditions affect our patients negatively every day.
Which is why we work so hard to provide relief for every one of our patients. Our team is highly
trained in the diagnosis, treatment and management of all musculoskeletal conditions and injuries.