Glenohumeral Joint Injection

Acute or chronic capsulitis - 'frozen shoulder'

Causes and findings:
• Trauma, osteoarthritis or rheumatoid arthritis
• Idiopathic or secondary to neurological disease, diabetes, stroke, etc
• Pain in deltoid area, possibly radiating down to hand in severe cases, aggravated by arm movements and lying on shoulder
• Painful limitation in the capsular pattern - most: loss of lateral rotation; less: loss of abduction; least: loss of medial rotation, with a hard end-feel

Equipment:
Syringe - 5ml
Needle - 21G 1.5-2 inches (40-50mm) Green
Kenalog 40 - 40 mg
Lidocaine - 4 ml 1%
Total volume - 5ml

Anatomy:
The shoulder joint is surrounded by a large capsule and the easiest and least painful approach is posteriorly, where there are no major blood vessels or
nerves. An imaginary oblique line running anteriorly from the posterior angle of the acromion to the coracoid process passes through the shoulder joint.
The needle follows this line, passing through deltoid, infraspinatus and posterior capsule. The end point should be the sticky feel of cartilage on the head of the humerus or the glenoid.

Technique:
• Patient sits with arms folded across waist, thus opening up the posterior joint space
• Identify posterior angle of acromion with thumb, and coracoid process with index finger
• Insert needle directly below angle and push obliquely anterior towards coracoid process until needle gently touches intra-articular cartilage
• Inject solution as a bolus

Aftercare:
Patient maintains mobility with pendular and stretching exercises within the pain-free range, progressing to stronger stretching when pain is reduced. Strong passive stretching of the capsule can be given when the pain has abated. A strengthening and stabilizing programme is often required, together with postural correction.

Comments:
The less the radiation of pain and the earlier the joint is treated, the more dramatic is the relief of symptoms. If there is resistance to the injection, the needle
has probably been inserted too laterally and must be repositioned more medially. Occasionally there is slight resistance when the needle passes through the capsule. Usually one injection suffices in the early stages of the condition, but if necessary more can safely be given at increasing intervals of 1 week, 10 days, 2 weeks, etc.; it is sometimes necessary in advanced capsulitis to give four to six injections over about 2 months. Advise the patient that a repeat dose might be needed if the symptoms are severe and gradually return as the effect of the drug wears off.

Glenohumeral Joint

Alternative approaches:
Rarely the posterior approach is not effective, so an anterior approach is used. In this case, the arm is held in slight lateral rotation and the needle inserted on the anterior surface between the coracoid process and the lesser tuberosity of the humerus, and aimed postero-medially towards the spine of the scapula. The same dose and volume is used. The disadvantages to this approach are that the patient can see the needle advancing, the flexor skin surfaces are more sensitive and there are more neuro-vascular structures lying on the anterior aspect of the shoulder. Adcortyl (10mg per ml) can be used for this injection, especially in large shoulders where more volume is required; the dose would then be 4 ml of Adcortyl with 4 ml of 1% local anaesthetic. Smaller patients may require only
30 mg of corticosteroid.