corticosteroid injections

Sports physician Chris Bradshaw counts down seven winning ways with a needle.

One of the rules of The House of God, a novel about a young intern and his struggles to get to grips with the demands of life in a large teaching hospital, is: ‘There is no body cavity which cannot be reached with a 14gauge needle and a strong arm’. Certainly this has been the attitude of many medicos as they ply their trade in different medical fields.

In sports medicine, injection therapy has traditionally been accepted by participants and treating practitioners alike, and even encouraged by coaches and managers. In the not-too-distant past, injection therapy has been used in a ‘whatever the cost’ attempt to keep sportsmen and women on the battlefield, often to the long-term detriment of the participant.

These days we like to think that we are a little more scientific and discerning, and that we don’t put our clients at risk so much. Certainly the incidence of administering local anaesthetic injections to enable sportspeople to take part appears to have dropped dramatically in recent years. Players and participants appear much better educated and informed about such practices and make their decisions accordingly.

Corticosteroid injections are still widely used, although the perspective of a sports physician can be very different from that of a rheumatologist or orthopaedic surgeon. While some sportspeople are definitely after a ‘quick fix’, sports physicians and discerning practitioners recognise a very real diagnostic component to these procedures: if a very well placed injection provides temporary relief, that information can often help with an anatomical diagnosis.

More excitingly, a well deployed corticosteroid injection, by taking away the inhibition of some of the controlling musculature, and by relieving, even temporarily, some of the spasm associated with the initial injury, can provide a real window of opportunity in which the treating practitioner can successfully rehabilitate the patient.

Aside from corticosteroid and local anaesthetic injections, there are a variety of other substances that can be injected to provide a therapeutic effect. Beyond the scope of this current article, these include ‘synvisc’ and other synthetic joint fluids, aprotonin, calcium gluconate and the mildly controversial autologous blood injection. The latter has had some media attention lately, particularly in reference to English Premiership soccer players, but it is actually a scientifically proven and very useful method.

I have a few house rules of my own when using the combination therapy of corticosteroid injection and local anaesthesia:

I am very wary of the effects of repeated corticosteroid injections on large, weight- bearing joints;
I am cautious not to inject into major tendons because of the reported association with tendon rupture;
I never inject the same region more than twice in rapid succession;
I am also aware of the fact that if the first injection has no effect, and you are confident of your anatomy, a second injection into the same spot probably won’t work either.

With these points in mind, here, in true High Fidelity tradition, is my list, in reverse order, of my top seven injections to be used in sports and musculoskeletal medicine.

Bradshaw’s seven

No 7: Obturator nerve injection

In cases of undiagnosed groin pain, especially in the sportsperson with exercise- related adductor pain, the diagnosis of obturator nerve irritation should always be considered. Post-exercise examination, looking for weakness of the adductor muscle group and parasthaesia in the cutaneous distribution of the obturator nerve, should be the first diagnostic port of call. EMG studies, looking for chronic denervation of the adductors, is often helpful in making the diagnosis. However, if the clinical picture remains unclear, a diagnostic injection into the obturator nerve, using either local anaesthetic alone or a combination of anaesthetic and corticosteroid, can be very helpful, and in some cases can have good therapeutic effect. Dr David Connell and his colleagues will shortly be publishing an article outlining a posterior approach to the obturator nerve.

No 6: Infra-patellar branch of the saphenous nerve

An often-missed cause of anterior knee pain is an entrapment or irritation of the infra-patellar branch of the saphenous nerve. This occurs most commonly after arthroscopic knee surgery, but can occur as a primary entrapment. As a first port of call, I will always exercise the patient and try and reproduce their pain. If it is possible to demonstrate numbness in the distribution of the infra-patellar branch of the saphenous nerve, and if the nerve itself is tender to palpate, then I would consider a local anaesthetic infiltration of the nerve in the hope of increasing the parasthaesia and relieving the patient of their pain. I would then ask the patient to exercise again, in order to prove that the pain has been relieved by the injection, thus clinching the diagnosis.

Sometimes corticosteroid can help in the mid- to long-term in settling the patient’s symptoms, although this definitely isn’t the norm. More usually the injection helps with the diagnosis, and points the physiotherapist or other treating practitioner in the right direction for conservative management.

No 5: Facet joint injection

In recalcitrant cases of back pain, or in athletes with pain which may be being referred from the lumbar spine, the facet joint injection can be a useful adjunct to conservative management. In the case of a running athlete with chronic hamstring pain, if treatment by a physiotherapist of the lumbar spine and gluteal trigger points provides temporary relief, it is worth considering a facet joint injection as a therapeutic and diagnostic procedure. If the hamstring pain is relieved by the injection, then the diagnosis of pain referred from the facet joint is confirmed. If the injection provides no relief, we know we have to keep hunting for the source of the pain. Again, if good relief is provided by the procedure, a window of opportunity opens up in which the treating practitioner can give effective treatment, including a good core stability programme.

This injection can be given by any good interventional radiologist, usually under fluoroscopic or CT-guided control. It is important, however, for the referring doctor to identify the level or levels at which he or she feels that the facet joint dysfunction exists.

No 4. Sinus tarsi injection

Ankle pain, both as an overuse condition and as a post-traumatic entity, is very common among sportspeople. When we classify the causes of ‘the difficult ankle’, in other words the ankle sprain that doesn’t settle as quickly as it should, there are many causes to consider. These include talar dome injuries, avulsion fractures, posttraumatic synovitis, syndesmosis sprains and impingement syndromes. Most of these conditions may require a scan to confirm or exclude the diagnosis, and if clinical suspicion exists it is important to do this. After this, if the patient is still struggling, a sinus tarsi syndrome should be considered.

The patient should be examined for subtalar joint stiffness, tenderness on the subtalar joint margins and, more importantly, point tenderness in the sinus tarsi. This is an opening in the subtalar joint, located just in front of and below the lateral malleolus.

Likewise, if an athlete presents with an insidious onset of lateral ankle pain, the diagnosis of sinus tarsi syndrome should be considered. This condition is often related to poor biomechanics, being more prevalent in athletes who over-pronate. Every high jumper worth his or her salt has experienced this condition at some stage in their career, because of the position of the foot on take-off. In these cases conditions such as stress fracture of the postero-lateral body of the talus should be excluded, either clinically or radiologically, before proceeding to definitive treatment.

Both of the above conditions can be treated effectively by a sinus tarsi injection. The treating practitioner infiltrates the sinus tarsi with local anaesthetic and corticosteroid. Once again there may be a diagnostic component to the injection. It is very important to address the biomechanical issues before performing the injection. In the case of the high jumper this may involve addressing technical issues.

No 3: Shoulder hydrodilatation

As a clinical entity, frozen shoulder (adhesive capsulitis) is relatively easy to diagnose, although treatment of this condition can be frustrating. But subtle forms of capsular restriction can either mimic or enhance other causes of shoulder pain, such as a subacromial impingement. If a patient with shoulder pain presents with nocturnal pain (in the absence of a rotator cuff tear), and their range of motion is subtly restricted in end abduction, internal rotation and horizontal flexion, and their anterior-posterior glide is diminished, then a component of capsular restriction should be considered. In cases of subacromial impingement in which this capsular restriction is present, it is very difficult to treat the impingement successfully without dealing with the capsular restriction.

Capsular restriction does not usually respond favourably to manual therapy. Often attempts to mobilise the shoulder result in a flare-up of the patient’s pain. One efficient way to treat these patients is with a hydrodilatation procedure. This is performed by a radiologist under X-ray control. A needle is inserted into the offending glenohumeral joint, and a mixture of corticosteroid, local anaesthetic and saline is injected. A large volume is required, and in ideal circumstances capsular rupture is achieved. When this happens, the communication between the shoulder joint and the subscapularis bursa is seen to open up. If this treatment is successful, it is very rewarding and satisfying for practitioner and patient alike. It also allows for expedient rehabilitation of the coexisting condition.

No 2: Hip joint injection

Among the many causes of groin pain is the hip joint and all of the conditions that can affect it. Often the clinical presentation in patients with groin pain is mixed, and often the diagnosis of a certain condition with ‘a hip joint component’ is made. In such cases, a diagnostic hip joint injection can help to make sense of the clinical picture. If a patient’s groin pain is entirely relieved by a hip joint injection, even temporarily, then an anatomical diagnosis is made. The patient will then need further investigation to make an accurate assessment of the hip joint pathology. In some patients, particularly younger ones with ‘the irritable hip of adolescence’, this procedure can be pleasingly therapeutic. I find the hip joint injection a very valuable weapon in my clinical practice.

No 1: Psoas sheath injection

I find the psoas sheath injection one of the most useful adjuncts to physical treatment that there is. Once again performed under imaging control, in this case using ultrasound, the psoas sheath is injected anteriorly and posteriorly using corticosteroid and/or local anaesthetic. This injection is useful in cases of groin pain in which there is a large and difficult-to-treat psoas component, but can also be used to treat back pain, lower abdominal pain, period pain and even shoulder pain.

Here, too, it is important to utilise the effects of the injection to ‘ramp up’ the rehabilitation, but used in conjunction with physical treatment it can be very rewarding. It is not obvious why it can be so effective, but it is almost certainly because of the extensive and far-reaching fascial connections of the psoas muscle, which connect to the pubis, the fascia lata, the adductors and even the diaphragm. The psoas also has intimate relationships with the lumbar spine, the sacroiliac joints and a wealth of neural tissue. Definitely an injection worth considering in patients with a ‘psoas component’!

Summary

There are many other therapeutic and diagnostic injections that are regularly used in sports medicine. The above list represents my personal favourites, the ones I find clinically rewarding. Remember, though, injection therapy should never be seen as the be-all and end-all to treatment of any patient, nor as a substitute for good clinical practice.

This article is based on a lecture to the MA Healthcare conference on Orthopaedics, Sports Injuries and Trauma, held in November 2004.

Dr Chris Bradshaw is a sports physician at Pure Sports Medicine