A Randomized Control Trial to Evaluate the Efficacy of Autologous Blood Injection Versus Local Corticosteroid Injection for Treatment of Lateral Epicondylitis

Much controversy has been there over the pathophysiology and there is not enough scientific evidence to favour any particular type of treatment for acute lateral epicondylitis. Currently degeneration of the origin of the extensor carpi radialis brevis (ECRB), repeated micro trauma and incomplete healing response has been accepted as the cause of lateral epicondylitis by most of the researchers.

Histopathological reports have shown that lateral epicondylitis is not an inflammatory process but a degenerative condition termed 'tendinosis'. There are numerous treatment modalities for lateral epicondylitis both conservative and operative. Most conservative modalities such as local corticosteroid injection have focused on suppressing inflammatory process that does not actually exist. A recent review article concluded that for short term outcomes (6 weeks), statistically significant and clinically relevant differences were found on pain and global improvement with corticosteroid injection compared to placebo, local anaesthetic, or other conservative treatments. For intermediate (6 weeks to 6 months) and long term outcomes (more than 6 months), no statistically significant or clinically relevant results in favour of corticosteroid injections were found. So it is not possible to draw a firm conclusion on the effectiveness of corticosteroid injection.

Recently an injection of autologous blood has been reported to be effective for both intermediate and long term outcomes for the treatment of lateral epicondylitis. There was a significant decrease in pain. It is hypothesized that mitogens such as platelet derived growth factor induce fibroblastic mitosis and chemotactic polypeptides such as transforming growth factor cause fibroblasts to migrate and specialize and have been found to cause angiogenesis. A specific humoral mediator may promote the healing cascade in the treatment of tendinosis as well. These growth factors trigger stem cell recruitment, increase local vascularity and directly stimulate the production of collagen by tendon sheath fibroblasts.

Autologous blood was selected as the medium for injection because (1) its application is minimally traumatic, (2) it has a reduced risk for immune-mediated rejection, devoid of potential complications such as hypoglycemia, skin atrophy, tendon tears associated with corticosteroid injection (3) it is simple to acquire and prepare, easy to carry out as outpatient procedure and (4) it is inexpensive.

There are very few studies done to evaluate injection of autologous blood for lateral epicondylitis as treatment modality. Hence it is evaluated by comparing with the corticosteroid injection which is a commonly practiced conservative treatment modality.