Platelet-rich plasma in the treatment of acute hamstring injuries in professional football players

Abstract

Purpose: muscle injuries have a high incidence in professional football and are responsible for the largest number of days lost from competition. Several in vitro studies have confirmed the positive role of platelet-rich plasma (PRP) in accelerating recovery and in promoting muscle regeneration, and not fibrosis, in the healing process. This study examines the results of intralesional administration of PRP in the treatment of primary hamstring injuries sustained by players belonging to a major league football club.

Methods: twenty-five hamstring injuries (grade 2 according to MRI classification) sustained by professional football players during a 31-months observation period were treated with PRP and analyzed. Sport participation absence (SPA), in days, was considered to correspond to the healing time, and we also considered the re-injury rate, and tissue healing on MRI. The mean follow-up was 36.6 months (range 22-42).

Results: there were no adverse events. The mean SPA for the treated muscle injuries was 36.76±19.02 days. The re-injury rate was 12%. Tissue healing, evaluated on MRI, was characterized by the presence of excellent repair tissue and a small scar.

Conclusions: this study confirmed the safety of PRP in treating hamstring lesions in a large series of professional football players. PRP-treated lesions did not heal more quickly than untreated lesions described in the literature, but they showed a smaller scar and excellent repair tissue.

Level of evidence: Level IV, therapeutic case series.

Keywords: football; hamstring healing; injuries; muscle; platelet-rich plasma.

Figures

Fig. 1

The progression of a hamstring injury in a soccer player (a 31-year-old forward). All the images in this series are DPFS-weighted axial views. A: MRI performed 1 day after the injury event. It shows a grade 2b lesion located in the distal part of the long head of the left biceps femoris. There is extensive intramuscular edema and fluid collection between the biceps femoris and the semitendinosus. The lesion was treated with PRP on the day of the MRI. B: Image of the same lesion 14 days after the injury. Examination shows almost complete filling of the defect (except in its deepest part) with granulation tissue. A second PRP injection was performed just after the MRI. C: Image of the lesion 28 days after the injury. The granulation tissue completely fills the lesion, which is smaller, denser and less vascularized, signs of progression of the healing process. D: Image of the lesion 46 days after the injury. The healing process is now complete; the intramuscular septum is uninterrupted and the scar tissue is homogeneous. 10 days later the athlete returned to full sport participation. E: Axial view of an MRI performed 7 months after the injury because of a grade 1 lesion of the proximal part of the contralateral biceps femoris (not showed). The scar of the previous left biceps femoris lesion is hardly visible; the intramuscular septum is thin and homogeneous.