What is the Cause of Groin Pain?
The most common cause of groin pain is an injury to the adductor longus tendon, for two reasons. First, the adductor longus has the greater angle of attachment than other hip adductors. So with abduction of the hip, the adductor longus is the first of the hip adductors to feel the strain. Second, the adductor longus has a very narrow attachment to the bone when compared to the other hip adductors.
This injury is most commonly experienced by athletes involved in sports that have rapid changes in direction, such as soccer and hockey. The pain will be high on the inside of the thigh and get worse with adduction of the hip against resistance. Jogging or running in a straight line usually does not cause pain. Often, the pain will get better with rest.
On physical examination, the adductor longus tendon is easily palpable high on the medial aspect of the thigh. Palpation of the enthesis, or origin, will often reproduce the pain. Often a small defect can be identified on the anterior aspect of the tendon. Seldom is the tendon actually torn off the pelvis.
I confirm the diagnosis by injecting the origin of the adductor longus injection with a local anesthetic such as Marcaine. If after the injection the patient has immediate relief, then that confirms the diagnosis. Patients are often anxious to get an imaging test. A MRI or Ultrasound can be used to image the injury but are not usually required. I use imaging tests as needed to confirm a diagnosis.
Non-Surgical Treatment: A steroid injection will often provide significant long term and sometime permanent pain relief. Occasionally, a second or third injection is required. There is no loss of tensile strength of the tendon after the injections. Review the article from Dr. Schilders. He reports a series of excellent results, especially with injures that appear minor on the MRI.
Surgical Treatment: An adductor longus tenotomy is effective treatment. The distal end of the adductor longus tendon should be sown to the fascia or the adductor brevis to prevent the tendon from retracting too far down the leg. It is also important to check the origin of the gracilis tendon as this occasionally requires treatment and can be a cause of continued pain if overlooked. Be sure to completely release the adductor longus. A incomplete release can cause persistent pain and require a second operation. Review the article (pdf) by Christian Akermark.
Please contact me if you have any questions. Comments are always appreciated.