The patient had a history of intramuscular penicillin injection as a child due to flu and other reasons. As an adult, she found that her lower limbs could not come together when she stood, and when she sat, her knees were separated and could not come together, and she could not cross her legs. When running, the lower extremities are externally rotated and abducted (outwardly eight, forked legs running), and cannot take big steps, so every physical education class lower extremity sports are failing, like running, long jump, high jump. The squat has a special posture, squatting process, but hip flexion 90 °, both knees flashing outward, drawing an arc after the knees can be close together completely squat. Part of the squatting double hip abduction external rotation of the knees apart, showing the frog leg sign, like a frog squatting to stand. This time you flex and extend the hip joint, whether you feel the hip has a popping sound, this popping sound and our finger joint activities appear different popping sound, you can use the palm of one hand to feel the femur big thick rung, flex and extend the hip joint can obviously feel the surface of the rope belt slide through the popping sound, the feeling is like a rope in a raised surface slide through the feeling. At this time, if the hip joint is then internally rotated, a cord-like object can be touched at the hip. The affected side is on top, and the knee joint cannot come close to the knee joint of the healthy side below, so we can only increase the hip flexion angle first and press the affected knee across the front of the healthy knee to the bed surface and come close to the healthy knee. Why does this happen? It turns out that we liked to inject penicillin into the hip in the 1970s and 1980s, and the powder penicillin needs to be dissolved in benzyl alcohol solvent. And benzyl alcohol, the solvent, tends to cause fibrous scarring of the gluteus muscle fibers, and the muscle tissue is replaced by fibrous scarring in the same direction as the gluteus maximus fibers. Some of the gluteus fascia is thickened while the gluteus muscle itself is not severe. At this time, the gluteus maximus fascia and gluteus muscle are significantly atrophied white fibrosis, which also gives a striated appearance. In this case, conservative treatment is ineffective, and surgery is needed to release the contracted fibrotic fascia in a Z-shaped manner. The surgery is simple, so now it is done with arthroscopic minimally invasive, three small incisions, no sutures, short surgery time and fast recovery. During the operation, the limbs were moved passively and the operation was completed only after the hip was flexed freely without popping. After the surgery, the lower limbs were fixed together for 1 week, and the hip and knee were flexed at 90° within 1 week, which was a bit uncomfortable, mainly to prevent re-adhesion of the released fascia.