HIP DISORDERS IN ADULTS

HIP PAIN

Hip pain can be due to a number of conditions but most commonly arthritis, trauma, soft tissue disorders such as labral tears and tendon inflammation, as well as referred pain.

HISTORY

In the history you should ask about the nature of the pain:

• Determine how severe it is
• What medications are being taken
• What exacerbates the pain
• What treatment has been undertaken.

As well as pain, you should also ask about mechanical symptoms such as clicking, locking or catching in the hip. As a general rule, activity related type pain suggests a mechanical cause such as a labral tear or osteoarthritis, whereas pain at rest suggests a probable inflammatory cause.

Pain from the hip is usually located in the groin or sometimes the ischium and the lateral thigh but can radiate into the knee. This is particularly relevant in children who, not uncommonly, present with knee pain where the pathology is in fact at the hip.

Do not forget referred pain which can occur from the spine. Pain below the knee is rarely from the hip and pain in the groin is rarely from the spine but there are exceptions to these rules.

EXAMINATION

Often you can detect hip pathology by the way the patient walks. If they walk with an antalgic (short stance phase) or a Trendelenburg gait (swaying to one side), then straight away you can assume that there is hip pathology. As far as the examination goes, local tenderness is important to diagnose trochanteric bursitis and other soft tissue disorders but deeper hip pathology such as arthritis will have no local tenderness.

Rolling the hip is the most sensitive test for hip pathology. This basically means having the patient lying on the bed and rotating the hip internally and externally. Pain with the hip flexed to 90 degrees, with internal rotation, is also pathognomonic of hip pathology and in patients with arthritis this movement will be restricted as compared to the other side.

INVESTIGATIONS

The basic investigations include X-ray, CT scan, MRI, ultrasound and bone scan.

X-RAYS

These should be of good quality otherwise they will need to be repeated. These should be an AP of the pelvis centred over the pubis. The reason for centering it over the pubis is to see the hips rather than the lumbar spine. On the same x-ray form you should also request for an AP and a lateral of that particular hip.

CT SCANS

A CT scan is only useful for looking at bony architecture and should not be routinely ordered. They are not very useful for looking at arthritis. It is quite reasonable to order these after trauma or if you are suspicious of a loose body.

BONE SCANS

This is a good screening test to pick up unexpected pathology such as stress fractures, tumours or inflammatory arthritis. They can also pick up pathology elsewhere in the pelvis. Again, they should not be routinely ordered unless the location of the pain is not at all clear. They are useful to pick up fractures not seen on x-ray and early avascular necrosis.

MRI SCANS

This is the best test for identifying soft tissue disorders such as labral tears and tendon disorders. They are not so good for looking at the chondral surface and should not replace x-rays when suspecting arthritis. They are the best investigation looking for the severity of avascular necrosis.

TREATMENT OPTIONS

HIP ARTHROSCOPY

This procedure is becoming more frequently performed. It is a relatively small procedure usually performed as a day surgery. It is very useful for the young patient with mechanical symptoms who has a labral tear. The other benefits are the ability to remove loose bodies, debriding chondral lesions causing mechanical symptoms, biopsies and washing out infections. The results of hip arthroscopy are good in patients with no arthritis and diminish with the degree of arthritis.

OSTEOARTHRITIS

The ultimate treatment for osteoarthritis is a total hip replacement. Prior to this, the various treatment modalities include; modifications of activities, weight loss, simple analgesics, a walking stick and anti-inflammatories. If all else fails, then a hip replacement should be discussed.

When to have a hip replacement is not a simple question and is quite subjective. The basic question to ask your patients is “Does the pain significantly affect their activities of daily living?” Once it prevents patients from doing what they enjoy or stopping them from working, it is quite reasonable to send them for an opinion as to whether they are suitable for a hip replacement.

TROCHANTERIC BURSITIS

This is a soft tissue disorder over the lateral side of the greater trochanter. It is very common and can be resistant to treatment. There is an inflamed bursa and sometimes inflammation of the gluteal tendons. The pain is generally, specifically, localised around the greater trochanteric region. It is usually activity-related and painful to lie on. On examination the patient has local tenderness in this area. The best treatment for this is physiotherapy and injections of local anaesthetic and steroid into the area of tenderness. These injections can be repeated several times per year.

AVASCULAR NECROSIS

This means the death of bone leading to collapse of the articular surface. It is reasonably uncommon but does need to be thought about, especially in a patient who has sudden onset of unexplained pain and a normal x-ray. The x-ray is usually normal for approximately 3 months. There are various predisposing factors including; trauma, alcohol, steroids, blood disorders, and scuba diving which should be kept in mind. The best investigation for this is an MRI scan or a bone scan. Early treatment is optimal before the articular surface collapses.

INFECTION

Infection is also extremely rare. It does however need to be thought about and not missed. An infection presents as sudden onset of groin pain. The patient is usually systemically unwell with a temperature. These patients should be sent to casualty or an urgent appointment made with an orthopaedic surgeon.

This is a brief summary of some common hip conditions which may help you in your general practices. Our website www.drpeterwalker.com.auelaborates on some of these conditions.