Specialties

Muscle injuries

Muscle Injuries

Background hamstring injury

The acute hamstring injury is the most common sports injury. The injury occurs in high hamstring loading activities such as sprinting, shooting, or excessive stretching. This causes damage to the muscle tendon tissue, which can vary from a minor strain to a major rupture. In addition to the fact that an athlete is not able to exercise for a period ranging from a few days to months, 12-25% of the athletes sustain a hamstring injury again within 2 months after return to sport. A rare, but serious injury that should not be missed is a hamstring avulsion in which the hamstring tendons are completely ruptured from the bone. Most hamstring avulsions involve the proximal hamstring tendons at the ischial tuberosity. In the case of skeletal immature (adolescents), an avulsion fracture of ischial tuberosity apophysis may occur.

Diagnostic work-up

The diagnosis of acute hamstring injury is rather straightforward: acute occurrence of posterior thigh pain and on the physical examination the triad of localized hamstring pain on palpation, stretching and resistance testing. Imaging has very limited additional value for diagnostics, except for a suspected hamstring avulsion injury. The duration of the injury cannot be accurately determined immediately after the injury has occurred: a more accurate estimate can be given with repeated clinical examination in the first week after the injury.

Hamstring avulsion injury

During the anamnesis, the injury mechanism provides important information: typically, there is a traumatic moment with a combination of forced hip flexion and knee extension, such as slipping with a straight leg. A substantial hematoma may be visible on physical examination, there is often (severe) pain at the tuberic isciadium and an inability to contract the hamstrings. The absence of tension on the tendons on palpation during contraction strongly suggests an avulsion. An avulsion lesion is confirmed by MRI or ultrasound. In less experienced hands, avulsion injuries are still regularly missed with ultrasound. An avulsion fracture in adolescents is diagnosed with an X-ray (pelvic AP image).

Treatment

Exercise therapy

A progressive exercise therapy program, ideally supervised by a (sports) physiotherapist, is the basis of hamstring injury treatment. The exercises are aimed at restoring strength, mobility, coordination and stability in the kinetic chain and functioning in sport-specific situations to gradually prepare the damaged muscle tissue for the high loads during sports activity. You can find a good example of an exercise therapy program with the following link.

Additional treatment modalities

High-quality research currently provides insufficient evidence for the use of additional treatment methods, such as anti-inflammatory medications (e.g. NSAIDs and corticosteroids) and injection therapies (e.g. platelet rich plasma). In fact, negative effects of NSAIDs, corticosteroids and platelet-rich plasma on muscle tissue repair have been reported in animal studies.

Surgery

Indication for surgical treatment is limited to hamstring avulsions. The choice of surgery depends mainly on the number of tendons involved, the amount of retraction (> 2 cm is though to give less chance of natural healing), the desired type and level of sport to return to and the failure of conservative treatment. During surgery, the tendons or the bone fragment are fixed at their original insertion. Post-operatively, there is an immobilization period of several weeks, followed by a long-term exercise therapy program. Returning to sports activities can take up to one year and returning to pre-injury levels may not always be possible.

Return to sport

The “timing” of returning to sport remains a challenging decision as there are currently no validated return to sport criteria. The main risk of resuming the sport too early is a recurrent hamstring injury. Mainly based on expert opinion it is suggested that the athlete must have sufficient confidence to be able to fully load the hamstrings and at least the following activities should be pain-free:

  • Maximum hamstring stretch and strength test
  • Maximum sprint work
  • Sport-specific exercises (e.g. being able to shoot a ball for football players)
  • A gradual progression of (team)training before resuming matches