Chronic hamstring tendon pain can be a very serious problem for athletes and other active adults. The hamstring muscles are the muscles in the back of the thigh that allow the knee to bend (knee flexion). The hamstring muscles turn into tendons at both attachments behind back of the knee and up higher in the pelvis behind the gluteus muscles. They can get tight and inflamed, resulting in a hamstring muscle strain (pain at the back of the thigh) or tendonitis (pain behind the knee). This can result from excessive recent activity or it may occur without predisposing trauma. Some people have tight hamstrings for a long time without knowing it. When hamstring tendon injuries fester and persist, changes can occur in the tendon itself resulting in a kind of degeneration called tendinosis or tendinopathy.
Functionally, the hamstring complex is responsible for propelling your body forward with every step. The hamstring complex is actually composed of three separate muscles that share the same origin at the bottom of the pelvis but all attach to different areas after crossing behind the knee joint. If you were a car, your quads would be the springs and your hamstrings would be the engine. Needless to say, like the engine of a car, more miles frequently means greater chance of the engine breaking down.
Most people with hamstring injuries improve with rehabilitation. This often includes rest, bracing, physical therapy, nonsteroidal anti-inflammatory medications, and a trial of a corticosteroid injection. A specific kind of exercise program called eccentric hamstring strengthening has been shown to be beneficial in preventing new and recurrent hamstring injuries in male soccer players and has been recommended to be part of any physical therapy program. In some very severe cases, surgery can be performed to repair tears and re-attach the tendons, but this should be an option of last resort.
A published double-blind, randomized control trial compared two forms of regenerative therapies–platelet rich plasma injections and whole blood injections–for the treatment of chronic hamstring tendon pain and tears. The results are surprising: Both groups showed improvement, the whole blood group showed earlier improvement, but the PRP group showed more sustained improvement. Although we do not know why the PRP group showed a delayed yet more sustained benefit, it is consistent with what regenerative medicine specialists see clinically. That is, PRP causes a local inflammatory reaction that may transiently WORSEN symptoms, before they improve. This finding may also be related to the platelet concentration. One intent of establishing a higher platelet concentration is to cause an increased inflammatory reaction, which will then result in a long-term healing response in the tendon.
What does this mean for patients? If you’re “stuck,” or not healing after a hamstring injury despite good physical therapy, rehabilitation, and proper instruction in an exercise program, then a PRP injection might be the right choice. The specialists at Columbia Pain Management can help you confirm the right diagnosis, evaluate your options, and plan treatment. Hamstring tendon pain is no joke. Luckily, new regenerative treatment options are showing real effects and real benefits for patients.