Tips for giving Shoulder Injections
My name is Gavin Jennings, a shoulder surgeon in Bath, UK
This short presentation will discuss the technique of shoulder injections,
particularly in the General and Physiotherapy Practice settings.
Firstly a few principles. Shoulder injections are intended to not only be therapeutic but also are very useful in diagnostic terms. Having assessed a patient we may have concluded that the issue is either in the subacromial space, glenohumeral joint or AC joint. We will then want to inject the appropriate site and the response to the injection will hopefully help prove the hypothesis. The type of steroid used is not important and studies have failed to show a significant difference between for example Triamcinolone and the more expensive Depomedrone. As a local, I use 2% Lidocaine because of its speed of onset and any response to the injection can thus been seen rapidly. It is important to record the immediate response (after about five minutes) and the percentage improvement and for how long thereafter. Patients will often say “it hasn’t worked” on subsequent review, but this can mean anything from it didn’t help even for ten minutes to it was great for two weeks but then the pain recurred and is now no better. A negative response to an injection may infer an incorrect diagnosis, or a correct diagnosis but incorrect placement or a correct diagnosis and correct placement but the injection has just failed to help. Thus in order to prevent unnecessary repetition of injections it is very useful to put the above information in any subsequent referral to tertiary care as well as including the intended site of the injection. It is also important not to keep repeating injections to often as to do so can lead to tissue damage, particularly in the case of subacromial injections. If the problem hasn’t resolved after a maximum of two injections in one site, consideration should be given to other forms of treatment.
The most common and fortunately easiest injection is given into the subacromial space and is given for rotator cuff problems. I prefer to use a posterior approach, but will occasionally go laterally if the patient is large and very muscular. Firstly palpate the posterolateral corner of the acromion. The entry point is about one cm inferior and medial to this point. Aim upwards towards the undersurface of the front half of the acromion, keeping parallel to the lateral border of the acromion as shown next.
Glenohumeral injections are usually performed for arthritis or frozen shoulder. The same needle, syringe and mixture is used for both subacromial and glenohumeral injections. The entry site for glenohumeral injection, however, is a little lower, and the direction different. The patient’s arm should be placed across the lap. Place your thumb on the posterolateral corner of the acromion, and place your finger on the patient’s coracoid. Enter the skin about 1cm lower than for the subacromial injection and aim for your finger on the coracoid. The needle should enter the joint without significant resistance. Sometimes however, the bone of either the humeral head or glenoid can be encountered. If this happens very gently internally and externally rotate the patients’ arm. If the needle moves, it is in contact with the humeral head, if not, it is on the glenoid. Thus you will know in which direction to adjust the needle to enter the joint correctly.
The ACJ has a small volume and I thus perform ACJ injections using an orange needle with a smaller volume of local. I enter the front of the joint where it is most capacious and angle down 45 degrees as shown next. It can be difficult to locate the joint …
and if you cannot initially feel it you can first palpate the soft spot as shown here which will mark the back of the joint.
Finally, I would advise against injecting the sheath of the long head of biceps blind in the clinic environment. Firstly, isolated biceps pathology is relatively uncommon and if the biceps is indeed the cause of pain, it might be at risk of rupture. It could present an awkward situation if a rupture occurred shortly after administering a blind injection!
Many thanks for listening.