Arthritis is a condition affecting the joints, causing pain and inflammation. It is relatively common and can affect people of all ages, even children, however, it is most common in people over the age of 60. Arthritis may affect one or several joints and often affects the “weight-bearing” joints, such as the knees and hips. There are over 100 kinds of arthritis and it is a progressive disease, meaning it cannot be cured and may worsen over time. Osteoarthritis is the most common form of arthritis and is caused by stress on the joints.
The hip joint is shaped like a ball and socket. The “ball” is the femoral head (the top of the thigh bone/femur) and the “socket” is the pelvis (or acetabulum), which is shaped like a cup. Like all joints, the hip needs its protective cartilage layer for smooth movement. Hip osteoarthritis occurs when the firm, rubbery tissue that coats the bone joints, called articular cartilage, becomes worn away. Cartilage enables the smooth movement of the joint, as well as providing a protective cushion to prevent the bones from rubbing together. Cartilage can repair itself to some extent, but it does not regenerate once lost. One of the first signs of osteoarthritis is often stiffness or pain in the joint.
Cartilage layers in the hips aid movement and provide shock-absorption. These layers can become damaged from trauma, repeat movement or just everyday “wear and tear”, which is why osteoarthritis is more common in older people. There are several risk factors for hip osteoarthritis including:
- Occupation: work that involves repetitive or strenuous movement or is very physical
- Obesity: increased pressure on the load-bearing joints, particularly hips
- Bone deformation or injury: a hip forming incorrectly, like in hip dysplasia, or one that has been affected by an injury or accident
- Age & gender: people over 60 or women, particularly post-menopausal
- Family history: those with a family history of osteoarthritis
Hip osteoarthritis symptoms tend to happen gradually but can occur suddenly for some. The symptoms can range in severity and may be affected by factors such as the time of day or activity. Often, the early signs will be stiffness and/or pain, particularly after activity, which can affect the range of motion of the joint. Generally, symptoms may include:
- Pain: as well as inside the hip, pain may be felt in the groin, buttocks or thighs. It can occur at rest or even when sleeping, if more advanced. It might feel like a stabbing or sharp pain, or an ache.
- Stiffness: especially after sitting for prolonged periods or getting out of bed.
- Swelling: excess fluid in the hip joint may cause swelling.
- Mobility: simple daily routines, such as putting on socks, getting out of a car or even walking, may be difficult.
- Sensations: the feeling of “grating” or “scraping” on movement.
- Noises: the sound of “crunching” or “bone rubbing on bone”.
Conditions such as “bone spurs” (known as osteophytes) can develop as a result of swelling. Progressive cartilage loss can lead to breakages and, in the most severe cases, the bones rubbing together which can cause distortion. Patients with advanced osteoarthritis can be at a higher risk of falls.
Diagnosis will start with an examination and questions about your medical history and symptoms. It will be important to find out how you move the hip and if any activities or movements cause more pain than others. A physical exam may look for swelling and check your gait (how you stand).
To assess your hip thoroughly, it is often necessary to do other tests alongside the physical exam. An x-ray can help show how advanced the arthritis is by looking at the space between the bones as well as how worn the joint is. Additional tests, such as an MRI scan, may be done to look at the soft tissues and cartilage. Blood tests can look for conditions, such as inflammatory arthritis, and you may need antibiotics if you are found to have bacterial inflammation.
Treatment for hip osteoarthritis focuses on pain relief and optimising mobility.
- Painkillers or anti-inflammatories: these can be bought over the counter but, if needed on a long-term basis, should be discussed with a doctor.
- Corticosteroids: cortisone-like medicines used to provide relief for inflammation.
- Hyaluronic acid (viscosupplements): artificial synovial fluid, which may preserve cartilage.
- Glucosamine or chondroitin sulphate supplements: as natural components of cartilage, these may be suggested to help preserve cartilage. Their effectiveness has not been proven in studies, but some patients find they are helpful.
- Weight loss: to reduce pressure on the hip.
- Walking aids or assistive devices: using a stick or cane on the opposite side of the affected hip may help relieve pressure and encourage safer mobility.
- Physiotherapy: to support life-style modifications and possibly low-impact exercise to improve strength and/or flexibility, such as swimming, cycling and Tai Chi.
- Diet: some foods like those rich in Omega-3, may reduce inflammation or even the signs of arthritis.
- Rest: getting plenty of sleep and rest may help the body recover from stress.
If more advanced, surgery to preserve the function of the hip or replace it may be the only option.
There are several surgical procedures which may help either preserve the function of the hip or, if needed, replace it entirely. They are typically for patients with more advanced symptoms rather than the early stages of osteoarthritis.
- Hip Arthroscopy: Arthroscopy is kind of keyhole surgery where instruments are passed into the joint to both examine and treat it. Hip arthroscopy is more challenging due to the deep joint and need for specialised tools. Early arthritis signs, such as loose cartilage, can be debrided removed this way, which may have a positive effect on symptoms. Learn More
- Hip Resurfacing: Hip resurfacing aims to prevent worsening cartilage loss or joint damage by replacing the surface lining in the hip with a metal covering. While this option removes less bone than other surgeries, it is not being used as much anymore due to the damage the metal can cause to the surrounding soft tissue.
- Hip Osteotomy: An osteotomy is an operation for people with arthritis who need the bones moved to a better position to “unload” the uneven weight. This can relieve pain as well as help to preserve function. Periacetabular osteotomy (“hip osteotomy”) aims to move the socket to better cover the femoral head. Cuts are made in the bones, then they are moved to their new position where they are secured with screws. These kinds of operations tend to have the best results in patients up to 40 years of age and those whose cartilage is still in relatively good condition. Older patients, or those with significant cartilage damage, are likely to be recommended a total hip replacement. Learn More
- Partial Hip Replacement: Partial hip replacements remove part of the joint that is damaged, usually the femoral head only. An artificial joint called a prosthesis is used as a replacement. This kind of joint replacement surgery is not used as commonly with osteoarthritis because usually the acetabulum is too affected and needs replacing. Learn More
- Total Hip Replacement: A total hip replacement is a widely-performed procedure that removes the damaged parts of the hip bone and cartilage entirely and replaces them with artificial joints called “prostheses”. It is typically performed when non-surgical methods can no longer control pain. Both the acetabulum and the femoral head are removed and replaced with a prosthesis, which is usually made of steel and special plastic. It is ideal for patients to be in the best possible health before the operation to help with recovery and achieving the best results. Learn More
- Custom Made Hip Replacement: The difference with a custom made hip replacement and a standard hip replacement is the use of a CT scan to measure the joint being replaced. The position of the joint and surrounding muscles and tissues are also assessed. The produced made-to-measure prosthesis has connecting surfaces made of ceramic rather than metal. This process has implications on cost but many argue that function is enhanced because the custom hip achieves better muscle tension and fits the person exactly. Learn More
- Stem Cell Cartilage Repair: This pain-relieving procedure uses the body’s own regenerative cells by extracting them from fat or bone marrow and reinjecting them to stimulate repair. It serves to delay the possibility of more invasive surgery or a hip replacement. While this therapy may not benefit all patients, new research suggests it can show real improvement in pain and for some even stop arthritic progress.