Platelet-rich plasma for sports injuries - Benefits insufficiently proven: Acute muscle injuries such as contusions, strains and muscle fibre tears often cause athletes unwanted breaks in training. The treatment options range from conservative procedures (e.g. icing, elevation, physiotherapy) to surgery (1). Muscle lesions and other musculoskeletal system injuries (e.g. to tendons, ligaments and cartilage) are now also increasingly being treated with a product called platelet-rich plasma, which is obtained by centrifugation of autologous blood and is injected into the damaged tissue (2-4). In the belief that the platelets present in the plasma produce a large number of growth factors once activated, injection of the autologous blood product is said to stimulate regenerative processes and angiogenesis in the damaged tissue and to accelerate healing (2,3). To the best of our knowledge, only one small randomised clinical trial involving 30 professional athletes has been published on its use in acute muscle injuries (5). Although it reported a benefit, its assertions are not, however, viable because of considerable methodological shortcomings - an open-label design, the lack of blinded documentation of subjective endpoints, and the lack of a definition of the primary endpoint. Now, a randomised, double-blind, placebo-controlled trial (4) has examined the autologous blood product in 80 mainly male (95%) recreational and competitive athletes with grade I and grade II* acute injuries of the posterior thigh muscles. Traumas due to external causes were excluded from the study (4). The study subjects were given an injection of platelet-rich plasma or saline solution in the affected muscle within five days after the injury and five to seven days later. At the same time, they performed a rehabilitation programme. Measured by the time to training resumption (primary endpoint), the use of platelet-rich plasma delivered no benefits over placebo: The median time to resumption of training for all patients was 42 days (hazard ratio [HR] 0.96; 95% confidence interval [CI] 0.61-1.51). The rate of new injuries within two months after the resumption of sports activities (secondary endpoint) was also almost identical, at 16% on plasma versus 14% on placebo (odds ratio [OR] 1.17; 95% CI 0.33-4.18). No severe adverse reactions were reported on the autologous blood product (4). The authors of a Cochrane Review also found no satisfactory evidence of a benefit from the use of platelet-rich plasma in acute and chronic injuries of the tendon and ligament systems (e.g. tennis elbow) (2). According to the present knowledge, we advise against the treatment of sports injuries with platelet-rich plasma, -Ed.

(R = randomised trial, M = meta-analysis)

1

GILLE, J. et al.: Dtsch. Z. Sportmed. 2013; 64: 98-102

2

MORAES, V.Y. et al.: Platelet-rich therapies for musculoskeletal soft tissue injuries. Cochrane Database of Systematic Reviews, as at June 2013, accessed July 2014

3

DHILLON, M.S. et al.: Indian J. Orthop. 2014; 48: 1-9

4

REURINK, G. et al.: N. Engl. J. Med. 2014; 370: 2546-7

5

BUBNOV, R. et al.: Med. Ultrason. Funkt. 2013; 15: 101-5

6

ROPIAK, R. et al.: Bull. NYU Hosp. Jt. Dis. 2012; 70: 41-8

*

Grade I: Tear of few muscle fibres, minor loss of function (1,6).
Grade II: Greater ruptures of several muscle fibres with markedly impaired function (1,6).
Grade III: Rupture of the whole muscle or complete tendon rupture (4,6).