Rationale, secondary outcome scores and 1-year follow-up of a randomised trial of platelet-rich plasma injections in acute hamstring muscle injury: the Dutch Hamstring Injection Therapy study.
BACKGROUND
Platelet-rich plasma (PRP) injections are an experimental treatment for acute muscle injuries. We examined whether PRP injections would accelerate return to play after hamstring injury. The methods and the primary outcome measure were published in the New England Journal of Medicine (NEJM) as 'Platelet-rich plasma injections in acute muscle injury' (2014). This article shares information not available in the NEJM letter or online supplement, especially the rationale behind the study and the secondary outcome measures including 1 year re-injury data.


METHODS
We performed a multicentre, randomised, double-blind, placebo-controlled trial in 80 competitive and recreational athletes with acute hamstring muscle injuries. Details can be found in the NEJM (http://www.nejm.org/doi/full/10.1056/NEJMc1402340). The primary outcome measure was the time needed to return to play during 6 months of follow-up. Not previously reported secondary outcome scores included re-injury at 1 year, alteration in clinical and MRI parameters, subjective patient satisfaction and the hamstring outcome score.


RESULTS
In the earlier NEJM publication, we reported that PRP did not accelerate return to play; nor did we find a difference in the 2-month re-injury rate. We report no significant between-group difference in the 1-year re-injury rate (HR=0.89; 95% CI, 0.38 to 2.13; p=0.80) or any other secondary outcome measure.


CONCLUSIONS
At 1-year postinjection, we found no benefit of intramuscular PRP compared with placebo injections in patients with acute hamstring injuries in the time to return to play, re-injury rate and alterations of subjective, clinical or MRI measures.
Department of Orthopaedics, Erasmus Medical Centre, Rotterdam, The Netherlands Department of Sports Medicine, The Sports Physician Group, St Lucas Andreas Hospital, Amsterdam, The Netherlands.
Gustaaf
G
Reurink
Sports Medical Centre of the Royal Netherlands Soccer Association, Zeist, The Netherlands Department of Sports Medicine, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
Gert Jan
GJ
Goudswaard
Department of Sports Medicine, The Sports Physician Group, St Lucas Andreas Hospital, Amsterdam, The Netherlands Department of Rehabilitation, Nursing Science and Sports, University Medical Centre Utrecht, Utrecht, The Netherlands.
Maarten H
MH
Moen
Department of Sports Medicine, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar Department of Sports Medicine, Medical Centre the Hague, Leidschendam, The Netherlands.
Adam
A
Weir
Department of Orthopaedics, Erasmus Medical Centre, Rotterdam, The Netherlands.
Jan A N
JA
Verhaar
Department of General Practice, Erasmus Medical Centre, Rotterdam, The Netherlands.
Sita M A
SM
Bierma-Zeinstra
Department of Radiology, Academic Medical Centre, Amsterdam, The Netherlands.
Mario
M
Maas
Department of Sports Medicine, The Sports Physician Group, St Lucas Andreas Hospital, Amsterdam, The Netherlands Department of Sports Medicine, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar Amsterdam Centre of Evidence Based Sports Medicine (ACES), Academic Medical Centre, Amsterdam, The Netherlands.
Johannes L
JL
Tol
D000293:Adolescent; D000328:Adult; D001265:Athletic Injuries / Q000534:rehabilitation*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007273:Injections, Intramuscular; D007958:Leukocyte Count; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000293:injuries*; D010808:Physical Examination / Q000379:methods; D053657:Platelet-Rich Plasma; D012008:Recurrence; D000068958:Return to Sport; D016896:Treatment Outcome; D055815:Young Adult
Hamstring; Muscle damage/injuries