It carries your entire body weight with every step you take. It absorbs the impact of running, climbing stairs and getting out of a chair. It allows you to walk, sit, twist, kick and dance. Most of us take it completely for granted – until something goes wrong.
The hip is one of the most remarkable joints in the human body, and it’s one that Mr Nirav Shah has spent his career understanding, treating and restoring. Whether you’re experiencing your first twinge of discomfort or you’ve been managing hip pain for years, understanding how the joint works can help make sense of what’s happening – and what can be done about it.
A joint built for stability and movement
The hip is a ball-and-socket joint, formed where the rounded head of the femur (thigh bone) meets the acetabulum – a cup-shaped socket in the pelvis. It’s a simple design, but an extraordinarily effective one.
Unlike the knee, which moves primarily in one plane, the hip moves in multiple directions simultaneously. Flexion, extension, rotation, abduction – the hip does it all, and often at the same time. Think about the motion involved in stepping over a puddle, climbing into a car or sitting cross-legged on the floor. Each of those movements relies on a finely coordinated interplay between the joint itself, the surrounding muscles and the soft tissues that hold everything together.
What makes the hip particularly impressive is how it balances two competing demands: mobility and stability. A joint that moves freely in all directions could easily become unstable – and instability in a weight-bearing joint is a serious problem. The hip solves this through a combination of its deep socket, a ring of cartilage called the labrum that deepens the cup further, powerful surrounding muscles and a network of strong ligaments. Together, they create a joint that is both highly mobile and exceptionally stable.
The unsung hero of the hip joint
Lining the surfaces of both the ball and the socket is a layer of articular cartilage – a smooth, firm, slightly compressible tissue that is quite unlike anything else in the body. Under normal conditions, it is almost frictionless. The two cartilage surfaces glide across each other with less resistance than ice on ice, cushioned further by synovial fluid – a natural lubricant produced by the joint lining.
This cartilage has no nerve supply and no blood supply of its own. That’s significant for two reasons. First, it means that cartilage damage is often painless in the early stages – by the time symptoms appear, the damage may already be considerable. Second, it means cartilage has very limited capacity to repair itself. Once it’s lost, it doesn’t grow back.
This is why osteoarthritis – the gradual breakdown of articular cartilage – is such a significant problem. The joint has no meaningful way to reverse the process once it begins.
Why the hip is so vulnerable to wear
Given how well-engineered the hip is, it might seem surprising that it wears out at all. But several factors combine to make it susceptible over time.
Load
The forces passing through the hip during everyday activity are considerable. Simply walking generates a load through the joint of roughly three times your body weight. Running can increase that to five or six times. Over a lifetime of movement, the cumulative effect on the joint surfaces is significant.
Alignment
The way the hip is shaped – and how the ball sits within the socket – varies from person to person. Some people are born with subtle abnormalities in the shape of the joint that cause the bones to make contact in ways they shouldn’t. This is known as femoroacetabular impingement, or FAI, and it’s increasingly recognised as a leading cause of early hip arthritis, particularly in younger and more active individuals.
The labrum
The ring of cartilage that deepens the socket plays an important role in distributing load evenly across the joint. When it tears – which can happen through injury, impingement or repetitive stress – that load distribution is disrupted, accelerating wear in certain areas.
Age and biology
As we get older, the cartilage naturally becomes thinner and less resilient. The synovial fluid that lubricates the joint may reduce in quality. Muscles that support the hip can weaken, placing greater demand on the joint itself. None of these changes is inevitable or uniform – genetics, lifestyle and body weight all play a part – but they help explain why hip arthritis becomes more common from middle age onwards.
When the hip starts to feel different
The earliest signs of hip trouble are often easy to dismiss. A stiffness in the groin first thing in the morning. A slight ache after a long walk. A loss of range of motion that only becomes apparent when trying to put on socks or clip toenails.
As the cartilage continues to wear, symptoms typically become more persistent. Pain may begin to occur during activity and then at rest. The joint may start to feel less stable or predictable. Sleep can be disrupted, particularly when lying on the affected side.
What makes hip pain particularly easy to overlook is where it tends to be felt. Many people expect hip pain to occur on the outer side of the hip or the buttock. In reality, the most common location is the groin – which leads many patients to investigate other causes before the hip is identified. Pain can also radiate down the thigh towards the knee, sometimes causing patients to focus on the wrong joint entirely.
What can be done
The reassuring news is that hip conditions are very well understood, and there are effective treatments at every stage.
In the earlier stages, the focus is typically on reducing load, maintaining mobility and managing symptoms. Physiotherapy, targeted exercises, weight management and anti-inflammatory medication can all make a meaningful difference. Cortisone injections can provide effective short-term relief by reducing inflammation within the joint.
For younger patients with impingement or labral tears, hip arthroscopy – keyhole surgery to reshape the bone and repair the labrum – can address the underlying problem and, in some cases, slow the progression towards arthritis.
When arthritis becomes more advanced and conservative measures are no longer providing adequate relief, hip replacement is a highly effective and long-lasting solution. With the right implant and surgical technique, a hip replacement can last a lifetime – allowing patients to return to the activities they love with greater comfort and confidence. Mr Shah’s youngest patient was just 21 years old.
Understanding your hip is the first step
The hip does an extraordinary amount of work, largely without recognition, for most of our lives. When something goes wrong, understanding what’s happening can make the path to treatment feel far less daunting – and the options more hopeful than you might expect.
Mr Nirav Shah is a consultant orthopaedic surgeon based in West Sussex, specialising in hip and knee conditions. With more than 10,000 procedures performed over a 30-year career, he has the experience to assess, diagnose and treat hip problems at every stage – from early impingement to complex revision surgery.
If you’re experiencing hip pain and would like a thorough assessment, get in touch to arrange a consultation.
