When evaluating hip pain, I generally think about three broad regions:

• Pain in the groin or front of the hip
• Pain on the side of the hip
• Pain in the buttock or back of the hip

The location of the pain is often the first clue to identifying the cause.

Pain in the groin: often the hip joint itself

When patients have arthritis of the hip, the most common place they feel pain is in the groin.

Many patients think of the hip as the bony area on the side of the pelvis. As a result, they may not realise that groin pain can actually be a sign of a problem inside the hip joint.

Arthritis of the hip usually causes a characteristic set of symptoms. Patients often describe:

• A dull ache rather than a sharp pain
• Stiffness, particularly in the morning
• Difficulty putting on shoes and socks
• Difficulty getting in and out of a car
• Discomfort when walking longer distances
• Gradually worsening symptoms over time

As arthritis progresses, the pain may spread beyond the groin. Patients sometimes describe a “C-shaped” pattern of discomfort that extends around the side of the hip and, in more advanced cases, may even be felt toward the buttock.

Of course, not all groin pain comes from the hip joint.

Other possible causes of groin pain include hernias, muscle or tendon injuries, and, less commonly, problems with the blood vessels supplying the leg.

Pain on the side of the hip: often a tendon problem

Pain on the outer side of the hip is often caused by a condition called greater trochanteric pain syndrome. This is one of the most common causes of lateral hip pain, particularly in middle-aged and older women.

Many cases are related to irritation, degeneration or small tears in the tendons and muscles that attach to the side of the hip.

One of the most characteristic symptoms is difficulty lying on the affected side.
Patients will often tell me that they can no longer sleep comfortably on that hip because it is too painful. There is usually a specific tender spot on the outside of the hip, and pressing on this area often reproduces the pain.

Unlike hip arthritis, these patients frequently have relatively normal movement in the hip joint itself.

The good news is that many people improve with physiotherapy and targeted strengthening exercises.

Pain in the buttock: often the most difficult to diagnose

Buttock pain is often the most challenging type of hip-region pain to diagnose accurately.

Although hip arthritis can sometimes cause pain in this area, it is less common.

More often, buttock pain may be related to:
• Problems in the lower back
• Hamstring tendon problems
• The sacroiliac (SI) joints
• Nerve irritation
• Referred pain from the spine

Because several different structures can cause similar symptoms, a careful assessment is important.

The pain is often activity-related and may develop gradually as a person walks or stands for longer periods.

The challenge of hip pain versus spine pain

One of the most common diagnostic challenges is working out whether symptoms are coming from the hip, the spine, or both.

The spine can mimic many hip conditions, and it is not unusual for patients to have both hip arthritis and spinal problems at the same time.

This is sometimes referred to as hip-spine syndrome.

A patient may have X-rays showing hip arthritis, but some of their symptoms are actually being driven by the spine. Alternatively, a stiff arthritic hip may place extra strain on the lower back and worsen existing spinal symptoms.

One of the key differences I look for is how the symptoms behave.

Patients with hip arthritis often describe stiffness and discomfort that is present from the start of an activity and remains bothersome.

Patients with spinal stenosis or certain nerve-related conditions may describe something different. They often tell me that their legs become heavy, weak or uncomfortable after walking for a period of time. When they sit down and rest, the symptoms improve, only to return again when they start walking.

Many people with spinal stenosis also notice that walking while leaning forward, such as when pushing a shopping trolley, feels easier.

How we diagnose the cause of hip pain

The first step is understanding exactly where the pain is located, what it feels like and how long it has been present.

I will also ask about stiffness, limitations in day-to-day activities, previous injuries and whether the symptoms came on gradually or after a specific event.
The next step is a physical examination. I assess how you walk, whether you are limping, how well the hip moves, and whether certain movements reproduce your symptoms.

Depending on your symptoms, I may also assess the lower back, surrounding muscles and tendons, nerve function, and blood supply to the leg.
If hip arthritis is suspected, an X-ray is usually the first investigation and remains the gold standard for diagnosing osteoarthritis of the hip.

If the diagnosis is not clear, additional investigations such as an MRI may be helpful. MRI scans can provide more detailed information about the tendons, muscles and other soft tissues around the hip and can also help identify possible spinal causes of pain.

Finding the right treatment starts with the right diagnosis

Getting the diagnosis right is important because the treatments for these conditions are very different.

If you are experiencing persistent pain in your groin, the side of your hip or your buttock, an assessment by an orthopaedic surgeon can help identify the source of the problem and determine the most appropriate treatment.

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