Intervertebral foraminoscopic surgery for lumbar spine disorders mainly involves removing the herniated discs and proliferated bone spurs to make the area where the nerves pass spacious and release the compression on the nerves. But isn’t it true that after the compression is removed, the symptoms of back and leg pain, numbness in the lower extremities and difficulty in urination and defecation can be completely relieved? The answer is not necessarily. Whether the symptoms disappear completely depends mainly on the damage to the nerve. After surgery Low back and leg pain can be relieved immediately after surgery. Low back and leg pain caused by lumbar spine disease is often due to the nerve being compressed, so the pain will be relieved at that time after the surgery to remove the compression. The answer can be obtained by comparing the results of straight leg elevation before and after the patient’s surgery. The pain disappeared significantly when the patient did straight leg elevation after surgery.TIPS: Principle of straight leg elevation test: When the lower limb is elevated, the sciatic nerve is stretched, causing the nerve root to move within the spinal canal, which aggravates the irritation of the nerve root by the herniated lumbar disc. Leg elevation test practice: the patient lies supine with legs straight, the examiner holds the patient’s knee with one hand to straighten the knee joint, and holds the ankle with the other hand to slowly elevate the leg until the pain radiates from the lower back to the buttocks and thighs. Record the angle between the leg and the bed at this point, which is the angle of straight leg elevation. Normal people can generally reach about 80 degrees without radiating pain. If the elevation is less than 70 degrees and is accompanied by radiating pain at the back of the thigh, it means that the nerve is compressed. The recovery of leg and foot numbness and bowel problems depends on the nerve damage. Back and leg pain can be relieved immediately, but lower limb numbness and bowel problems require time to recover slowly, usually one to three months, and the degree of recovery is related to the nerve damage. If the patient has symptoms of leg numbness and difficulty in urination and defecation before surgery, it means that the nerve has been compressed for a long time and irreversible damage has occurred. After surgical removal of the compression, if the nerve damage is very mild, the patient’s symptoms can be relieved quickly; if the nerve damage is severe, it will take some time to recover; however, not all patients can be completely relieved because once the nerve is necrotic, it cannot be regenerated, and normal nerves are needed to gradually replace its function, and whether it can be completely replaced varies greatly among individuals. In many patients, due to the severity of the nerve damage before surgery, the remaining normal nerve can no longer completely replace its function, and a part of the numbness or urinary and fecal dysfunction will remain. The surgeon will have a general judgment of the degree of nerve damage before surgery, and the surgery will only give the nerve a chance to recover and compensate for its function. The same goes for urinary and fecal problems, depending on the degree of damage to the cauda equina nerve. Therefore, we remind patients that numbness is more frightening than pain, and the presence of numbness indicates more severe nerve damage. Some patients often feel no pain lately, just numbness, thinking it is getting better, when in reality it is serious.