How do steroids work and why do we use them so much for musicians?
One of the commonest things that I do for musicians who need more than advice, stretches and physiotherapy, is a steroid injection. Thankfully, more invasive procedures such as surgery are very uncommon and only about one patient in 10 requires an operation. On the other hand, many patients benefit from a steroid injection. Many patients are reluctant to consider steroid injections until they understand how they may be helpful for them. They are also fairly harmless.
There are many conditions for which we consider steroid use in the hand. Simply put, they work by removing the inflammation in the area in which they are injected. We use it to treat inflammation in the lining of a joint, ligament inflammation and tendon inflammation. Essentially, they work by stopping the process of inflammation by blocking the production of prostaglandin, which is a chemical released in response to injury – it then causes a ‘cascade’ of chemical and cellular responses such as the release of growth factors and recruitment of more cells to come and help the healing response. Inflammation of course is an essential part of healing of all tissues. Why would we therefore want to stop that useful process? We only consider using steroids when the healing response seems to be ineffective. This is usually the case in chronic conditions where the body has shown that it is not capable of healing this condition spontaneously or it is taking too long and other deadlines are pressing. Many of the conditions that we use steroids for are indeed self-limiting but can take one or 2 years to settle down. Good examples would be tennis elbow or trigger finger or DeQuervain’s tendonitis. Ligaments should also heal if only a small proportion of the fibres are injured. Sometimes however patients cannot rest sufficiently to allow the ligament to heal spontaneously. This is common both in sport, the work environment and in music.
The steroids that we tend to use most commonly are ‘Depot’ injections. The type that I use is called DepoMedrone. I always inject this with some local anaesthetic. It doesn't seem to help to put the local anaesthetic in first because that hurts just as much. The other common brands are Kenalog, triamcinolone and Cortisone.
Patients need to be aware that all of these can cause a steroid flare (pain for a few days after the injection). I usually advise my patients that about a third of my patients will have quite a serious steroid flare, but the rest have milder symptoms. These are usually controlled by anti-inflammatory medications such as ibuprofen and rest ice compression and support as necessary. Knowing that it will eventually settle is useful. Many patients suspect this may be an infection causing redness swelling and pain. This is extremely rare and probably occurs on less than one in 1000 injections.
Skin thinning and depigmentation is also quite common and usually resolves but can take a year or so to do that.
People are often concerned about weakening tendons and ligaments by stopping the repair process. If a small proportion of the fibres of the structure being injected are damaged, then it is unlikely that any weakness will result. There are some tendons which are more susceptible two tearing after steroid injections for some these are quite well recognised as being the biceps tendon, the Achilles tendon, the long extensor tendon to the thumb at the wrist (EPL) and the flexor carpi radialis (FCR) tendon. Other tendons rupture exceedingly rarely. I have never heard a case of a flexor tendon rupturing after injection for carpal tunnel syndrome or trigger finger. Other tendons around the wrist are also robust. Many of these have been injected many (10 or even more) times without adverse event.
A large dose in the hand would be 40 milligrammes of DepoMedrone. A medium dose would be 20 milligrammes, and a small dose would be 10 milligrammes. A tiny dose would be 5 milligrammes. The larger doses I believe are more effective in the longer term, but would cause more of a steroid flare and more skin thinning. Smaller doses are less effective but cause less discomfort in the days after the injection. Smaller doses are ideal for patients wanting to return to performance level very quickly who have quite mild symptoms. Larger doses may be indicated for somebody who is unable to perform and has been off work for some time.
These Depot injections linger in the local tissue for about 6 to 8 weeks and very little goes into the general circulation. The peak benefit is usually felt at around 5 to 10 days but can take three or four weeks before doing this. When the steroids wear off the symptoms may return. For over half my patients the symptoms do not return. The reason for this is that the damaged fibres within the structure have given up on any attempted repair and the remaining intact fibres are now functioning normally. This usually leads to a thinner structure whether it is a tendon or ligament or some cartilage or joint lining. This often has benefits in itself. Tendons often traumatise themselves by passing through tunnels that are too narrow because the tendon is now swollen. If the tendon becomes less swollen, then it can pass through the tunnels more easily. Tendon inflammation as it passes through a tunnel is often more troublesome than where it doesn't pass through a tunnel. These tunnels are necessary as they keep the tendons close to the bone at as they pass near to joints. Otherwise the tendons would ‘bowstring’ away from the joint. This is where the tendons are particularly prone to inflammation. Information then causes a ‘vicious cycle’ of entrapment of the tendon. This further traumatises the tendon and perpetuates the cycle. A steroid injection will reduce the inflammation by stopping the frustrated healing process. I know that that sounds counter-intuitive but it seems to help the vast majority of patients with little adverse effect.
The worst thing that can happen is that the symptoms are not cured, or they come back after the steroids wear off at around 6 to 8 weeks. I often review my patients at around two months after the injection to see what sort of response they have had. If all is well at two months then it is likely to stay that way. If mild symptoms are returning, then I often advise patients to have a second injection for some if it persists after a second injection then surgery may be required, and surgery is very effective as a last resort for trigger finger, DeQuervain’s tenosynovitis and carpal tunnel syndrome. In fact, steroid injections are very likely to be helpful in the long term for carpal tunnel syndrome and the vast majority of patients who have had a steroid injection for this condition tend to go into surgery at some point in the future.
