Hip osteoarthritis – what you need to know
Osteoarthritis of the hip may cause pain and stiffness in the affected joint.
Osteoarthritis is the name given to age-related arthritis which causes the affected joint to become painful and stiff. The process of osteoarthritis involves wearing or thinning of the smooth cartilage joint surfaces as well as stiffening to the soft tissue surrounding the joint. These aspects combine to produce swelling, inflammation and pain.
Several factors normally combine to cause symptoms of osteoarthritis:
- Previous joint damage
- Increased bodyweight
- Age (risk increases with age)
- Family history (genetics)
General exercise such as walking, cycling and playing sports does not increase the risk of developing or increase the rate of deterioration of hip osteoarthritis.
Most commonly the pain is felt in the groin region. Sometimes the pain may also be felt in the buttock or outside of the hip. Some individuals may suffer from referred pain radiating into the thigh and knee area. The presence of hip osteoarthritis does not always cause pain so it is quite possible to have reasonably advanced arthritis with mild pain. In addition, the hip undergoes a ‘wear and repair’ cycle so pain can improve.
Pain on walking is often the main aggravating activity. If hip osteoarthritis becomes more severe the movements of the hip may become increasingly stiff which may cause a problem with activities of daily living such as sitting, lying in bed, getting out of a car or putting on shoes.
Hip osteoarthritis can be reliably diagnosed by your doctor or physiotherapist by taking a history of your condition and by conducting a physical examination.
The main feature on examination is often a reduced range of movement.
X-rays are not routinely required, but may be requested if symptoms are severe enough that total hip replacement surgery is being considered.
In the majority of cases, the symptoms of hip osteoarthritis can be managed effectively by non-invasive measures as described below. The most effective are exercises and in those who are overweight, weight loss.
An ideal BMI is less than 25. You can use a BMI calculator to advise if it might be advisable for you to try to lose some weight.Losing weight reduces the load on your joints as you move about. Evidence shows that weight loss can result in improved mobility. There is also evidence to suggest that weight loss alone may actually help to reduce pain. However, in combination with exercise, the results can significant.
For many people, losing weight feels like an uphill struggle. However, there is lots of support and advice available.
You can find some excellent ideas, including recipes and advice on making healthy food choices, on the NHS Change 4 Life website, which also has information about activities local to you.
Regular exercises to maintain flexibility and strength to the affected hip joint:
3×10 repetitions 3-4x per week
3×10 repetitions 3-4x per week
3×10 repetitions 3-4x per week
Using painkillers when needed
Over-the-counter analgesia is available through pharmacies when needed. Paracetamol is most commonly prescribed. Anti-inflammatories, such as Ibuprofen, are also used, but as there is little or no inflammation involved in osteoarthritis these are best avoided without discussing with your GP. Side effects are even more common than with paracetamol so please ensure to take appropriate medical advice. There is a good booklet on the Arthritis Research UK website with information about the various drug options.
Using a walking stick when needed
Apos Therapy trial
For patients with advanced osteoarthritis who satisfy the referral criteria for surgery but wish to avoid it, Apos Therapy provides a treatment option. The concept is based around a shoe-like biomechanical device which can help to distribute the forces more evenly through the joint and aid in strengthening the joint. Your clinician will discuss this with you if this option is suitable.
Total hip replacement (THR) surgery is an effective option for patients with advanced stage hip osteoarthritis who:
- Have trialled a course of non-surgical management without success
- Have consistent, disabling pain significantly limiting mobility and/ or affecting sleep pattern
- Have a Body Mass Index (BMI) within a normal range or have made lifestyle changes to lose excess bodyweight
You may be asked to complete a questionnaire called an Oxford Hip score. This can help the clinician assess the impact of your symptoms which can be useful in assessing suitability for surgery.
Further information about Osteoarthritis – Arthritis Research UK
Hip osteoarthritis: an overview
Hip osteoarthritis is very common in the UK. It’s a condition that develops over time, causing the hip joint to become stiff and painful, a factor leading many people to need a hip replacement in the longer term.
Osteoarthritis is different from Rheumatoid arthritis, however. The latter is caused by an autoimmune disorder in the body, causing inflammation around the joints.
To understand hip osteoarthritis more, we need to take a step back and look at the inner workings of the hip joint…
Hip joint anatomy – how your hip works
When we talk about the hip anatomy, it’s easy to forget about how we’ve evolved to modern day life.
Humans have evolved from being on all fours to walking on two legs. The hip therefore has a crucial, yet difficult, role to play in everyday life.
It holds your bodyweight but also helps you maintain a wide range of movement.
A ball and socket joint
Your hip is essentially a ball and socket joint.
A ball (femoral head) is at the top of the femur (thigh bone). This has cartilage covering the whole surface of the ball, acting much like a shock absorber for the joint.
This sits within the hip socket (acetabulum), within the pelvis, which is also lined with cartilage.
Ligaments are mainly around the whole circumference of the joint, forming part of what we call the ‘joint capsule’. There are also over 20 muscles around the hip joint, which is why targeted exercises are so important during your recovery from surgery.
When you have arthritis in your hip, it essentially means this cartilage has worn away. Eventually you end up with the bones rubbing together on both sides of the joint, which is extremely painful.
The main symptoms of hip osteoarthritis
The three main symptoms of hip osteoarthritis are pain, stiffness and shortening of the leg.
Your hip depends on an effective relationship between the ball and the socket. Any variations in the design of the ball and socket, whether naturally occurring or not, can lead you to develop osteoarthritis.
Part of the arthritic process is when you develop additional spurs of bone forming around the edges of the joint, which are the body’s attempt to repair the cartilage. Spurs are trying to regrow cartilage inside the joint, but the body doesn’t do this process effectively.
Arthritic pain is different for everyone, so it’s not a straight line of deterioration towards agonising, constant pain. You do have periods when it’s ok, and times when it’s much worse.
Another typical symptom is a tightening up of the joint capsule which goes around the hip joint, which causes stiffness in the hip.
You also sometimes get shortening of the leg as well, as the bone inside of the femoral head can collapse because of the arthritic process.
Why it’s not just a factor of age
Quite often it’s actually naturally occurring variations in the shape of the ball and socket that cause hip osteoarthritis. Much like people have different coloured eyes or hair, you can have subtle differences in how your hip joint is designed. In fact, around 90% of the time it’s these small deformities, which ultimately result in the need for a hip replacement. It may not cause a problem until you’re in your 40s or 50s, but over time arthritis can develop.
Osteoarthritis in the hip is not just a factor of age - you could get through to 100 without having it. It’s mostly related to the shape of your hip.
Hip shape matters
If you have a hip socket that is too shallow or too deep, this can lead to arthritis. If the socket is very shallow, it’s like having a saucer rather than a socket. The ball is always trying escape out. Alternatively, if you have a deep socket, it’s like having a lobster claw around the femoral head, which is pinching it, stopping it moving properly.
A lump of bone on the edge of the femoral head makes it rugby ball shaped rather than football shaped. It means smooth rotation doesn’t happen in the socket, as the socket is hemisphere shaped.
Loss of the cartilage is the key feature of arthritis.
This is due to a mechanical process where it is damaged and eventually leaves an exposed bone surface. Cartilage in joints is very poor at healing itself as it doesn’t have a good blood supply.
Such a specialised tissue is very good at what it does, but is poor at healing itself when damaged. When you start to lose the cartilage, you go from having a round ball in a round socket, to have a square peg in a round hole. Cartilage tends to wear away at the front of the hip, which then spreads to the rest of the joint.
Many of these changes probably develop during childhood and adolescence. Some people get hip pain at a relatively young age, from 30 through to 50. They don’t necessarily have advanced arthritis, but may have early damage to their hips.
The degenerative process of arthritis
The degenerative process takes a long time. However the onset and progression of symptoms can sometimes be quite quick. There isn’t a direct one-to-one link between how severe your arthritis is and how much pain you have. Some people can have a bad hip on an X-ray, but have very little pain. Others can have quite a good hip on an X-ray, but lots of pain.
So what does hip arthritis feel like? And where would you feel pain? Find out more in our guide to ‘Do I need a hip replacement?’.Hip replacement surgery overview Do I need a hip replacement?