The stenosis of the lateral saphenous fossa can be treated conservatively by applying dexamethasone and mannitol intravenously to reduce the local inflammatory edema of the nerve root and alleviate the symptoms. During the treatment period, bed rest should be strictly enforced and no bed activity should be allowed, because the activity will lead to the bony narrowing of the lateral saphenous fossa, which will produce more stimulation to the nerve roots and is not conducive to recovery. Non-steroidal anti-inflammatory and analgesic drugs should be applied to relieve local inflammation and reduce pain, and methylcobalamin tablets should be applied to nourish the peripheral nerves and nerve roots to promote the recovery of nerve root function. After the above treatment, the symptoms can be relieved significantly in 5-7 days. If the relief is not obvious or the symptoms are aggravated, surgical treatment should be taken. After successful anesthesia, the skin is cut and the paravertebral muscles are peeled away, then the spinal canal is located, opened, and the narrowed bone in the lateral saphenous fossa is partially removed, so that the nerve roots are no longer under pressure and the symptoms will be significantly improved.