The shoulder is a complex ball and socket type joint. Its anatomy allows for a wide range of motion, which is of course very useful, but this comes with some disadvantage. Compared to other joints, there is relatively little sturdy ligament support (hence the wide range of motion). The shoulder is secured mostly by a group of muscles and tendons that we call the “rotator cuff”.
By contrast, the knee has many more ligaments that hold the joint securely together and for that reason it can only move in one direction. We trade stability for range of motion.
If should come as no surprise that tearing of the tendons that make up the rotator cuff is the most common cause of chronic disability involving the upper body. This can be due to sport injury (esp. throwing), trauma or repetitive/over use (esp. doing overhead work). Degeneration of tendons is also a natural phenomenon that occurs with age. The weakest point of any connective tissue is the point where it attaches to the bone, in this case, at the head of the humerus.
In this image, the 3 muscles attaching to the top and back part of the humerus are 3 of the 4 muscles that make up the ‘rotator cuff’. The white part of the muscle is the tendon. It is important to notice that there are no major arteries that supply blood this deep into the shoulder and so when these tendons tear, the healing process is slow, arduous and often never complete. Chronic pain and long-term disability are common with moderate and severe rotator cuff tears.
Prolotherapy is an injection therapy that aims to regenerate (or ‘prol’iferate) healthy cells. The medicine that is used encourages the body to accelerate healing, increase local blood flow and stimulate new cell growth. Tendons that are treated with prolotherapy become larger and stronger. The advantage of prolotherapy in a rotator cuff tear is that the treatment can be directed to the exact site of injury – ie. where the tendon attaches to bone.
With a proper assessment and history, it is possible to isolate which tendons are involved. MRIs, CTs or ultrasound images are helpful in confirming the diagnosis and the specific tear location, but are not necessary for effective prolotherapy treatment.
Dr. Meli offers Free 15 min consultations to anyone in pain who is wondering if prolotherapy is right for them.