Subscapularis Tendon and Bursa Injection

Acute or chronic tendinopathy or bursitis

Causes and findings:
• Overuse or trauma: haemorrhagic bursitis can follow a direct blow to the shoulder
• Pain in deltoid area or anterior to shoulder
• Painful: resisted medial rotation arc on active abduction passive lateral rotation and full passive horizontal adduction (scarf test)

Equipment:
Syringe - Tendon 1ml Bursa 2ml
Needle - 23G 1.25 inches (30mm) blue
Kenalog 40 - tendon 10 mg bursa 20mg
Lidocaine - tendon 0.75ml 2% Bursa 1.5ml 2%
Total volume - Tendon 1ml Bursa 2ml

Anatomy:
The subscapularis tendon inserts into the medial edge of the lesser tuberosity
of the humerus. It is approximately two fingers wide at its teno-osseous insertion
and is a thin, fibrous structure feeling bony to palpation.
The subscapularis bursa lies deep to the tendon in front of the neck of the
scapula and usually communicates with the joint capsule of the shoulder. It
is invariably extremely tender to palpation even when not inflamed.

Technique:
• Patient sits supported with arm by side and held in 45 ° lateral rotation
• Identify the coracoid process. Move laterally to feel small protuberance of lesser tuberosity by passively rotating arm. Mark medial aspect of tuberosity
• Insert needle at this point, angling slightly laterally and touching bone at insertion for tendon, or in sagittal plane through tendon to enter the bursa
• Pepper solution into tendon insertion, or as a bolus deep to tendon into bursa

Aftercare:
Relative rest for 1 week is advised, then progressive stretching and strengthening programme when pain-free. In sporting overuse injuries the cause should also be addressed.

Comments:
Subscapularis bursitis and tendinitis are often difficult to differentiate. The bursa is implicated if there is more pain on the scarf test than on resisted medial rotation, and if there is even more than usual tenderness to palpation.

Alternative approaches:
If the bursa and tendon are inflamed together they can both be infiltrated at the same time by peppering the tendon first and then going through it to infiltrate
the bursa. The total dose is increased to 30 mg in total volume of 3 ml.