What is Hip Impingement Syndrome

Many patients are told that they suffer from hip impingement syndrome when they go to the hospital for examination. But what does hip impingement syndrome mean? It is normal that people do not understand such a profound academic term, but only by understanding this disease can we better prevent it. Here I will give you a detailed introduction to what hip impingement syndrome means.

Hip impingement syndrome is a group of hip joint syndromes caused by developmental dysplasia, femoral head necrosis in children, femoral head slippage, acetabular indentation, trauma, surgical overcorrection and other reasons. It is mainly manifested as intermittent or persistent groin pain in adolescents and middle-aged patients. Pain is induced or aggravated during hip flexion movements such as squatting, bending over, lifting legs, and climbing, accompanied by a certain degree of limited hip joint movement. Some patients present with hip weakness, tenderness, and pseudolocking. Playing sports such as football, walking for a long time, sitting on a low stool for a long time, driving for a long time, etc. may be the triggering factors. The main clinical signs are limited internal rotation of the hip joint, pain induced by hip flexion, adduction and internal rotation (positive anteromedial hip impingement sign), and pain induced by hip extension and external rotation in some patients (positive posterolateral hip impingement test). This disease can lead to labral damage and cartilage damage in the corresponding parts of the hip joint, and develop into osteoarthritis in the late stage.

According to clinical pathology, it is divided into three categories: Pincer type, Cam type, and mixed type.

Hip impingement caused by acetabular overcoverage is called pincer impingement. The main factor is over-coverage, such as acetabular retroversion, acetabular invagination, and acetabular protrusion. Acetabular dysplasia, slipped capital femoral epiphysis, trauma, surgical overcorrection, etc. can lead to acetabular retroversion, which manifests as a "cross sign" of the anterior and posterior lines of the acetabulum on a standard pelvic AP radiograph.

Hip impingement caused by growths on the side of the femoral neck is called cam impingement. The main factor is insufficient eccentricity at the junction of the femoral head and neck, such as an out-of-round femoral head and hyperplasia of the head-neck junction. Hyperplasia of the head-neck junction caused by femoral head necrosis, slipped capital femoral epiphysis, flat hip, etc. in children causes collision between the head-neck junction and the outer upper edge of the acetabulum when the hip is flexed and internally rotated. Routine anteroposterior and lateral hip X-rays show that the bones at the outer edge of the head-neck junction are full, protruding, and cystic. Direct MRI of the hip with contrast media in the oblique view through the femoral neck demonstrates an increase in the Alpha angle.

In fact, in our country, the incidence of hip impingement syndrome is not high. However, even if you have this disease, you don’t have to worry too much. The current medical level is very advanced. As long as you receive correct treatment, you can recover completely. The most important thing is that patients should maintain a good attitude and follow the doctor's instructions. As long as you do this, you will get better soon.