Platelet rich plasma (PRP) therapy

In platelet rich plasma (PRP) therapy, a sample of blood is extracted from the patient and processed to provide a platelet rich injectable. The draw is that it comes from the patient and is relatively safe representing a reinfusion of the patient's own fluids back into the patient. Over the last few years the technology has been advocated for a wide variety of orthopaedic conditions. It's use in tendinopathies about the shoulder and especially in lateral epicondylitis (tennis elbow) has been impressive if preliminary. The presumed mechanism of action is an accelerated healing or reactivation of healing of tendon tears and generally is plausible in the context of current understanding of the growth factors within the extract. Basic science data has been lacking and it can be difficult to draw any strong conclusions.

In osteoarthritis there have been a number of papers in recent literature. These tend to be cohort based studies prospectively followed. The data is interesting but strong conclusions on advocacy cannot be drawn. Specifically many insurance companies do not support reimbursement for its use.

The conclusions of the better designed studies are that as it does no further harm it's use is justifiable in osteoarthritis. Specifically it has some benefit in reducing pain for patients with early cartilage lesions. In established arthritis, however, it has not been found to be useful. This perhaps makes sense in the context of the growth factor mechanism of action inferred above.

It's place in the management of osteoarthritis should therefore be positioned in the same set of indications as the injectables described elsewhere on this site (ie. a relatively safe procedure which gives symptomatic relief). It cannot based on present knowledge be advocated as a routine therapeutic option in the treatment of osteoarthritis of the knee.

Figure 1. The procedure of PRP injection is fairly straight forward. We house the processing equipment on-site and this minimises any delay in providing for the needs of our patients. An initial period of pain is to be expected and this gradually improves over the ensuing 6 weeks.

Figure 2. The latest version of the system allows a further concentration of the preparation resulting in a smaller volume and less pain of injection from distension of the injection site.

Figure 3. The preparation of PRP results in concentration of platelets. This should not be confused with APS which seems similar but is platelet deficient and anti-inflammatory.

Figure 4. (a)This patient had all the classic signs of right shoulder impingement with limited abduction despite physiotherapy for one year. Three months after PRP injection and physiotherapy he had full abduction. The original MRI showed tendinosis of the supraspinatus tendon (c) regenerated back to normal after the PRP injection 6 months later (d).