Hip joint injections for pain relief: when are they a good option?

Chronic pain of any type can be upsetting for any patient. Because walking is such a ubiquitous activity, having a painful hip can be distressing and the limitation of activity that comes with it can be very frustrating.

Mr Constant Busch is a leading orthopaedic surgeon who specialises in primary hip replacement surgery. In this article, he explores how effective hip joint injections are at relieving hip pain and explains exactly how they are administered.

Why can hip pain be so frustrating?

Hip pain can be purely mechanical, meaning the pain only appears when the joint is being used. But sometimes there can be - either solely or in combination with mechanical pain - an inflammatory component that is the most uncomfortable.

Unfortunately, inflammatory pain can become very apparent whilst we are trying to sleep. A disturbed night’s sleep very soon becomes an issue with all the problems that ensue from chronic sleep deprivation.

Most of the time, however, hip pain is a combination of both mechanical and inflammatory induced discomfort and pain, and both causes of pain can be reduced by limiting overall activity. However, not many people do very well with this approach and it’s not an unreasonable ambition to try and conquer the pain and return to normal activity.

Will having joint injections reduce the need for future hip surgery?

Often, mechanical problems within the hip lead to episodes of inflammation in the hip joint. This can lead to an increase in the amount of fluid build up in the joint, and because the joint space is limited, if the fluid amount increases substantially it will increase the pressure within the joint.

The typical symptoms of this appear in the form of pain and reduced movement of the hip joint. A logical step would be to reduce the inflammation, which can be done with anti-inflammatory medications. If these don’t work as well as we would like, we can consider injecting an anti-inflammatory agent directly into the hip joint that will act for a long period to suppress the inflammation in the joint.

The three most common substances used for intra-articular inflammation reduction (injection into the joint) are:

• Steroids
• Hyaluronic acid
• PRP (platelet-rich plasma)

The evidence for each of these types of injections is variable, with steroids probably having the most evidence for helping suppress inflammation.

Ultimately, however, these injections are unlikely to reduce the chances of the patient wishing to go forward for the joint replacement operation in the future. However, because symptoms do tend to oscillate, an injection given at the right time can halt the 'peak' of symptoms and therefore, may allow the patient to endure their more acceptable symptoms for a longer period.

This method can also extend the time until the patient decides that another treatment modality, such as surgery, may need to be considered.

How are the injections administered?

Unlike the knee joint, where the joint space is just under the skin, the hip joint is a structure that is much deeper down in the body and surrounded by soft tissues including ligaments, tendons, muscles and fatty tissue. Consequently, it takes a bit more skill to administer the injection precisely. There are two common ways in which to do this:

• Ultrasound and local anaesthetic: the injection is guided by ultrasound and the use of local anaesthetic numbs the hip area. It can be performed in the outpatient department.
• X-ray and sedation: the other way is to inject under sedation, in a theatre with the guidance of an image intensifier (X-ray machine). This usually requires a few hours in hospital whilst the sedation wears off.

Each patient has their own preference, but in my experience, the vast majority prefer to go under sedation as they have no recollection of the procedure ever happening and there is absolute minimal discomfort.

How often are joint injections required?

If there is a good indication for proceeding with an injection, depending on what materials are used, and also on the result that the injection may have, it can be worthwhile having further injections as part of a long-term pain management plan.

If we take steroid injections as an example, the injection into the joint contains both a short- and long-acting anaesthetic as well as the active ingredient which is a long-acting steroid.

We can typically tell if the injections are a success if the hip pain disappears shortly after the injection. However, this initial pain relief will only last for as long as the long-acting anaesthetic lasts which is usually between six to eight hours. It will then be between 10 days to a couple of weeks for the steroids to start kicking in and the results should improve in six to eight weeks, with hopefully the maximum effect shortly after.

If an injection is considered successful and the pain relief has been long-lasting, then clearly it is worth repeating it on a subsequent occasion. However, if the pain returns promptly within three months, then, unfortunately, the chances are that any further injection is likely to be unsuccessful.

Injections using platelet-rich plasma behave similarly to a steroid injection, but ones with hyaluronic acid may well be needed more frequently to get the desired result.

Are there any other alternative non-surgical therapies for hip pain?

A hip injection aims to level off the 'peak' of symptoms.

Together with optimising other modalities of non-surgical management following injection, it is anticipated that the symptoms can be reduced for a long period to an acceptable level.

Typical non-surgical management will include:

• The before mentioned use of anti-inflammatories and painkillers
• The use of dietary supplements
• Losing weight
• Placing silicone heel cups in shoes
• Low-impact exercise, typically the cross trainer, swimming and, very effectively, cycling on a static bike

Weight loss can be of great benefit to some people, while others try dietary supplements like glucosamine and chondroitin sulphate. These supplements may take between six to eight weeks before it becomes apparent whether they are helpful or not.

Silicon heel cups worn in the shoes allow for a more favourable way of transferring weight to the hip joint and may alleviate symptoms.

Spin classes and medical education programme

I'm involved in a programme that uses a combination of spin classes and medical education to improve the quality of life of people with hip pain and also help them learn to live with a troublesome hip joint.

The system is proving very effective and with appropriate dedication and commitment, patients can delay, or indeed completely postpone the need for operative intervention; in most cases, for an arthritic hip joint, this would be a total hip replacement.

If you are having problems with your either your hip or knee joint, visit Mr Busch’s Top Doctors profile and check his availability to book a consultation with him.