When there is a sudden pain in the iliac fossa, the affected hip cannot be straightened and is in an abducted and externally rotated position. It is caused by the narrowing of the sheath through which the femoral nerve travels, resulting in compression of the femoral nerve, which, if left untreated, can cause quadriceps paralysis that is difficult to recover. Clinical manifestations The onset of the disease after trauma is often sudden and gradually aggravated. The course of the disease is related to the degree of urgency of the iliopsoas muscle bleeding. The patient first complains of pain in the iliac fossa on the affected side, and the affected hip cannot be straightened and is in an abducted and externally rotated position. This is often due to the increased tension in the iliopsoas muscle, which causes muscle spasm. At this time, a lump or fullness can be palpated in the affected iliac fossa, and there is significant pressure pain over the inguinal ligament and pressure pain in the lower abdomen. Neurologic symptoms often appear only a few hours after the injury and are related to the degree of increased pressure in the myofascial sheath. There is first numbness of the anteromedial thigh up to the knee and anteromedial calf, followed by complaints of weak knee extension, weak to absent knee tendon reflexes, gradual weakness and paralysis of the quadriceps, and muscle atrophy. The syndrome is often accompanied by lateral femoral cutaneous nerve entrapment and lateral femoral skin sensory dysfunction. Treatment After the diagnosis of this disease is confirmed, surgical treatment should be performed as soon as possible. The recovery of nerve function is closely related to the timing of surgical decompression. If the decompression is not timely and the nerve is compressed for a longer period of time, the recovery of nerve function will be incomplete or not recovered. Timely and complete decompression can lead to complete recovery of nerve function. However, a clear diagnosis must be made before surgery. If the patient is hemophiliac, surgical decompression is not advisable, and active hemostasis, analgesia and functional protection are required according to the principles of hemophilia treatment. Hemostasis is mainly achieved by transfusion of fresh blood or anti-hemophilic globulin. Compression wrapping and cold compresses can also help to stop bleeding, but care should be taken not to wrap too tightly to avoid excessive pressure causing tissue damage. Elevation of the affected limb and braking and traction can not only stop the pain, but also reduce bleeding. For non-hemophiliac patients, nerve decompression surgery is performed under epidural crestal gap block or general anesthesia. The nerve is externally released to remove blood clots, scarring, and other compression-causing materials. If the nerve is deformed by compression or feels hard to the touch, the epineurium should be carefully cut with a sharp knife under the operating microscope. The epineurium is released. There is no need to suture the musculofascial sheath, the inguinal ligament is sutured in situ, negative pressure suction is built into the incision, and the muscle layer and skin are sutured by layer. After surgery, the affected limb is elevated and the negative pressure suction is removed within 48h. After removal of the sutures, physical therapy that facilitates the recovery of the femoral nerve should be performed, and regular follow-up should be performed. Surgery should be performed as soon as possible after the diagnosis of this disease is confirmed. If left untreated, it can cause quadriceps palsy that is difficult to recover from. It will not be good at that time. So when a person is uncomfortable and the symptoms worsen in the short term it is important to go to the hospital for medical attention. To avoid causing unnecessary damage.