Dutch Hamstring Injection Therapy study.

Muscle injuries account for up to 30% of injuries sustained in a sports event. In soccer, muscle injuries mostly occur in the calf and thigh. When injured, usually the RICE principle (rest, ice, compression, elevation) is practised, NSAID's are supplied and exercise therapy is given. However, there is little scientific evidence for the effectiveness of therapeutic interventions in muscle injuries.

In the last decade research has focussed on developing new treatment options for muscle injuries, including the use of growth factors. Research has shown that myoblasts can be proliferated by growth factors. Growth factors are present in autologous conditioned plasma (ACP). Injection of ACP has shown to increase regeneration in deliberately injured muscle in animals.

Only two studies examined the effect of ACP in human muscle injuries in relatively small heterogenous group of patients. Both studies showed that patients treated with ACP injections recovered faster from injury than patients in a non-randomized control group.



Objective:

In this study two treatment groups will be compared: ACP injection in combination with exercise therapy and placebo injection in combination with exercise therapy.



Study design:

Multi centre, double blind, randomized controlled trial comparing two treatment groups.



Study population:

80 patients with an acute hamstring lesion with MRI abnormalities.



Intervention:

Both the intervention group as the control group will perform exercise therapy. The intervention group is treated with ACP injection at maximal 5 days after the injury and the control group will receive placebo injection at the same time interval. A second injection is provided 5-7 days after the first injection. Injections are performed ultrasound guided in the lesion of the hamstring muscle.



Outcome measurements:

Primary: Time to return to full sports activity; either training or match play.

Secondary: Rate of recovery, hamstring force, recurrent hamstring lesions, pain score in rest, during sprinting and during isometric contraction assessed with the visual analogue scale (VAS), length of pain area during palpation, clinical hamstring- and sacroiliacal tests, hip- and knee range of motion, functional outcome, subjective patient satisfaction, prediction of patient and sports physician for time to return to sports, rediction of the patient of the used intervention (ACP or placebo),platelet count in whole blood and ACP, recovery hamstring lesion on MRI.



Follow-up will be performed after 1, 3, 4, 8, 10, 16, 26, 52 weeks and at return to sports.

The time to return to sport is shorter in the patient group treated with Autologous Conditioned Plasma (ACP) injections in combination with exercise therapy in comparison with the patient group treated with saline injections in combination with exercise therapy.

Follow-up will be performed after 1, 3, 4, 8, 10, 16, 26, 52 weeks and at return to sports.

Follow-up after 3, 4, 8, 10, 16 and 52 weeks will be performed by phone and will not consist a physical examination.

In this double-blind randomised controlled trial two patient groups are compared:

1. Intervention group: ACP injections (3 ml in depots of 1 ml) in combination with exercise therapy;

2. Control group: Saline injections in combination with exercise therapy.

Two injections will be given with 5-7 days in between.