[Avulsion of the proximal hamstring origin - report of 6 cases]

Proximal hamstring origin avulsions are rare injuries. A common cause for this kind of injury is a trauma with the hamstring in overextension and simultaneously forced hip flexion and knee extension. We report on 6 cases, 5 with an acute rupture of the hamstring origin and one case with a delayed presentation in our emergency room. In 3 cases the injury was related to sport activity, the other 3 are related to accidents during work. None of these patients took part in competitive sports. One case was reported 8 weeks after trauma with an MRI performed one week before. Due to the low functional deficits conservative treatment was preferred. In all of the acute injuries open refixation was done within the first two weeks after trauma using 2-3 suture anchors. Postoperative mobilisation was done with partial weight bearing. Active knee flexion against gravity was not started until six weeks postoperative. All patients who had surgery achieved good results 3-28 months after surgery. They suffered from only little pain (VAS1-2) and had good movement ability. Sport activities were reduced in 3 cases, 2 patients returned to pre-injury sport levels. All patients were able to perform one-legged squats. In the evaluated LEFS (Lower Extremity Functional Scale) 75.6/80 points were achieved (72-79). There were no severe complications within this case study. It is important to distinguish proximal hamstring origin avulsions from the majority of hamstring muscle injuries. If the avulsion is treated with surgery, refixation should be performed within the first weeks to prevent the sciatic nerve from being bound in scar tissue with a consecutive high risk of injury during mobilisation of the tendon.