Clinicians should be cautious when considering platelet rich plasma (PRP) as a treatment for hip and knee osteoarthritis, according to a review of the evidence.

The review identified 18 randomised controlled trials of intra-articular injections of PRP, mostly against hyaluronic acid, and found most studies were of low to moderate quality.

However there was some evidence in small, low-powered studies that PRP could reduce pain and improved physical functioning for up to 12 months.

Co-author Professor David Hunter, from the University of Sydney, said it was difficult to know how widely PRP was used in Australia but it was typically administered in radiology practices and some sports medicine facilities.

“The treatment looks like it may have promise but the quality of the trials is not sufficient to strongly recommend it at this point,” he said.

“Ultimately clinicians will choose to use it or not. Based on existing evidence we cannot make a strong recommendation but rather recommend further research is needed in order to provide that clarity.”

The review found a wide variation in protocols for preparing and administering PRP, which further clouded the findings.

However there was some evidence that the best protocol might include fresh, leukocyte poor PRP, administered weekly for three weeks.

Patients who were younger and with less severe disease were more likely to respond to PRP treatment although any benefit was usually short term.

“There is a lot of pressure and a strong desire on the part of many patients to find less invasive alternatives to surgery,” Professor Hunter said.

Alternative treatment options including weight loss, exercise and the use of biomechanical aids should also be considered, he said.

While PRP appeared to be safe, it was unproven in terms of driving structural change in the joint, and costly due to the significant preparation time and resources required to prepare the injections.