The iliopsoas muscle is a complex structure. The muscular part arises from the so-called transverse processes up in the lumbar spine and they converge downwards and into the pelvis and ultimately form a tendon as the structure passes over the front of the pelvic rim. That tendon then courses down and medially in the thigh and inserts onto a small bump on the upper end of the medial side of the thigh bone called the lesser trochanter.
Many maladies can befall the iliopsoas construct. Sometimes the muscle can be torn away from its origins up in the lumbar spine.
Hip pain from the iliopsoas is typically associated with abnormalities of the tendon between the pelvic rim and the lesser trochanter. The tendon itself can become inflamed. This is the so-called tendonitis where “itis” is the Latin word for inflammation. In addition, the tendon rubs over the front of the hip joint halfway between the pelvis and the lesser trochanter. Whenever we have two tissues rubbing against each other in the body, we form a small fluid-filled sac called a bursa. An analogy would be to fill a balloon with tap water and tie off the top. As you hold the balloon between your two outstretched hands and rub backwards and forwards, the movement is almost frictionless. That is how a bursa works. We have eight or nine of these bursae around the hip and about sixteen around the knee. The bursa between the iliopsoas tendon and the front of the hip capsule is just one of those bursae. It can also become inflamed.
Patients with iliopsoas tendonitis or iliopsoas bursopathy usually complain of groin pain. It is made worse by flexing the hip, especially against resistance. Attempting to get into or out of a car is often painful. Other activities which may provoke pain with hip arthritis are usually not so uncomfortable with iliopsoas tendinopathy.
The diagnosis requires the taking of a careful history, the performance of a thorough physical examination, and sometimes ancillary investigation with an ultrasound scan or an MRI scan.
Treatment options can be of a non-operative or operative nature. Those of a non-operative nature usually include rest, the avoidance of provocative activities and sometimes the ultrasound-guided administration of hydrocortisone preparations.
From an operative perspective, a release of the tendon can often be very successful. This is not infrequently performed during the course of a hip replacement and sometimes it is also required following hip replacement surgery.