Hip osteoarthritis (coxarthrosis)

Osteoarthritis of the hip is due to wear and tear on the protective cartilage layer of the bones in the hip joint. This leads to increasing pressure on the bones and gradually reduces the mobility of the joint. Pain in the hip and groin area when moving are often the first signs. Those affected are usually over 45 years of age.

With osteoarthritis of the hip, the pain is initially often only felt when the person exerts themselves or after strenuous activity. It usually begins gradually and can drag on for several years or months. Those affected report pain when climbing the stairs or walking or when moving the (tightened) thigh, for example when crossing their legs. For some people the pain goes to the inside of the thigh, the buttocks or knee.

The hip joint can feel slightly stiff in the morning or generally after prolonged periods of rest for up to 30 minutes. More prolonged morning stiffness is more likely to be a different condition such as rheumatoid arthritis. If the hips are in pain when the person is at rest or during the night, the osteoarthritis has usually already reached an advanced stage.

If the hip joint is healthy, both the head of the femur and the socket of the pelvic bone are surrounded by cartilage. If this cartilage becomes thinner, this can lead to osteoarthritis of the hip. It becomes softer, starts to tear and can eventually lose strength. Osteoarthritis is therefore also called “degenerative joint disease”, or simply “joint degeneration”.

Healthy, resilient joint cartilage provides the bones with smooth sliding surfaces making movements without friction possible. Cartilage cells cannot really "grow back" by themselves and therefore do not so easily renew themselves as other tissues. Once damage has occurred, it therefore usually remains permanent.

In many cases, there are several factors that play a role in the development of osteoarthritis of the hip. Various circumstances make the wear and tear more likely, including the following:

• family history
• congenital anomalies of the hip (hip dysplasia)
• rare congenital hip disorders
• inflammatory joint diseases such as rheumatoid arthritis
• previous hip injuries, e.g. bone fractures in the hip joint or a dislocated hip joint
• hip impingement: bone spurs on the joint are the reason for constrictions between the head of the femur and socket
• obesity
• heavy physical work, for example construction work
• types of sport that put intense pressure on the body such as football and handball

The joints change more and more the older they are. The cartilage wears out and the joint cavity becomes narrower accordingly. This means that the bones are not as well protected against pressure. This results in new bone substance being formed. The new bone formations, known as bone bridges or osteophytes, are visible on the x-ray.

These processes of wear and tear and repair on bones can balance each other out for a long time. Joint changes therefore do not always lead to symptoms. It is estimated that 25 percent of those examined have little or no symptoms, even though the x-ray shows signs of osteoarthritis. In these cases, it is an age-related change and measures to treat it are not required.

How osteoarthritis of the hip develops varies considerably. A large study in the Netherlands observed how the course of the disease by regularly examining those affected for 5 years. This produced the following results:

• 40 percent had mild, relatively constant pain over the entire period.
• 20 percent had moderate, likewise relatively constant pain.
• 25 percent had moderate pain that became more intense over the 5 year period.
• 15 percent suffered from persistent, severe pain.

Usually establishing typical symptoms is enough to make an initial diagnosis. The doctor asks questions about how it is developing and its symptoms – since when has the person been experiencing the pain, when does it occur, how does it feel? Does it for example only happen when moving or also at rest, does the patient suffer from morning stiffness, are there previous injuries? A typical symptom is one known as “start-up pain” that occurs if there are prolonged periods of inactivity and that disappears again quickly as the person moves the joint.

As well as asking questions, the doctor feels the joint and examines how well it can move, looks at the person’s gait and checks whether there is any pelvic obliquity or whether the legs are different lengths.

Typical changes such as for example a narrowed joint space are visible on x-ray images. Additional examinations such as ultrasound scans, computed tomography scans or magnetic resonance imaging scans are very rarely required.

If the symptoms point to another medical condition such as rheumatoid arthritis, other tests such as evaluation of a blood sample may be required.

The treatment will depend on how intense and distressing the pain is. The stage of the condition, the patient’s overall state of health and personal aspects such as their job and their expectations of the treatment are also considered.

The effectiveness of many of the measures used to treat osteoarthritis of the hip has not been sufficiently studied. There is much more extensive knowledge about knee osteoarthritis. The treatment is therefore based on methods that have been proven to be successful with knee osteoarthritis. 

The recommended measures include:

• exercises to strengthen the muscles, improve mobility and balance,
• aqua aerobics,
• use of non-steroidal anti-inflammatory drugs (NSAIDs),
• losing weight if very overweight, and
• wearing flat, well-cushioned and comfortable shoes.

Exercise and regular movement are often difficult to imagine for people with joint pain. Some are afraid that they will damage their joints further. In fact, studies prove otherwise. According to them, strengthening, mobility and endurance training reduce the pain and can improve joint function. It is even possible for hip surgery to be delayed a little as a result.

For more detailed information such as what you can do yourself to strengthen your hip joints visit gesundheitsinformation.de.

If the symptoms make everyday life very difficult and pain medication and movement do not improve them very much, an artificial hip joint may be necessary (also called total hip replacement or total hip arthroplasty, THR or THA for short). An artificial hip joint can significantly alleviate the symptoms in over 90 percent of people.

Advanced osteoarthritis of the hip can make everyday life more difficult on many levels. But over time many people learn to manage their life despite their condition – for example they take more time for different kinds of strenuous activity, such as household work, and adjust what they do accordingly.

Walking aids can make movement easier, both inside and outside the apartment – walking sticks, walkers or wheeled walkers take pressure off the joints. Experts – both physiotherapists or ergotherapists and medical practitioners of different specialties such as orthopedics, rheumatology and geriatrics – will explain how to use and correctly set up the devices.