title: Platelet-rich plasma treatment improves outcomes for chronic proximal hamstring injuries in an athletic population.
abstract: BACKGROUND
  chronic proximal hamstring tendinopathies is a disabling activity related condition. Currently, there is no well-accepted or extensively documented non-operative treatment option that provides consistently successful results.
  
  
  OBJECTIVE
  to evaluate the efficacy of ultrasound guided platelet-rich plasma injections in treating chronic proximal hamstring tendinopathies.
  
  
  METHODS
  a total of 18 consecutive patients were retrospectively analyzed. All patients received a single injection of platelet rich plasma via ultra-sound guidance by a single radiologist. Outcome measures included a questionnaire evaluating previous treatments, visual analog scale (VAS) for pain, subjective improvement, history of injury, and return to activity.
  
  
  RESULTS
  the patient population included 12 females and 6 males. The average age at the time of the injection was 42.6 years (19-60). Provocative activities included running, biking, swimming. The average body mass index of patients was 22.9 (17.2-30.2). The average time of chronic pain prior to receiving the first injection was 32.6 months (6-120). All patients had attempted other forms of non-surgical treatment prior to entering the study. The average VAS pre-injection was 4.6 (0-8). Six months after the injection, 10/18 patients had 80% or greater improvement in their VAS. Overall, the average improvement was 63% (5-100). The only documented side effect was post-injection discomfort that resolved within seventy-two hours.
  
  
  CONCLUSIONS
  chronic hamstring tendinopathy is a debilitating condition secondary to the pain, which limits an athlete's ability to perform. For refractory cases of chronic insertional proximal hamstring injuries, platelet-rich plasma injections are safe and show benefit in the majority of patients in our study, allowing return to pre-injury activities.
  
  
  METHODS
  Case series; Level of evidence, 4.
authors.affiliation: University of Colorado Hospital Department of Orthopedic Surgery, Division of Sports Medicine and Shoulder Surgery, Aurora, CO, USA.
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Fader
authors.affiliation: University of Colorado Hospital Department of Orthopedic Surgery, Division of Sports Medicine and Shoulder Surgery, Aurora, CO, USA.
authors.forename: Justin J
authors.initials: JJ
authors.lastname: Mitchell
authors.affiliation: Boulder Community Hospital, Department of Musculoskeletal Radiology, Boulder, CO, USA.
authors.forename: Shaun
authors.initials: S
authors.lastname: Traub
authors.affiliation: Boulder Community Hospital, Department of Musculoskeletal Radiology, Boulder, CO, USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Nichols
authors.affiliation: University of Colorado Hospital Department of Orthopedic Surgery, Division of Sports Medicine and Shoulder Surgery, Aurora, CO, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Roper
authors.affiliation: University of Colorado Hospital Department of Orthopedic Surgery, Division of Sports Medicine and Shoulder Surgery, Aurora, CO, USA.
authors.forename: Omer
authors.initials: O
authors.lastname: Mei Dan
authors.affiliation: University of Colorado Hospital Department of Orthopedic Surgery, Division of Sports Medicine and Shoulder Surgery, Aurora, CO, USA.
authors.forename: Eric C
authors.initials: EC
authors.lastname: McCarty
keywords: outcome; overuse injury; platelet rich plasma; proximal ham-string tendinopathy; proximal hamstring tendinitis