In this report, we described an adult case that had a long-term radiculopathy due to an extruded osseous endplate of the lumbar spine at the L5-S1 intervertebral disc level. The osseous material inside the extruded material was not absorbed, and it had continued compressing the nerve root for one year. Endoscopically, the bony fragment was successfully removed. After the surgery, the patient's symptom disappeared, and neurological deficits became normalized. In conclusion, we propose that surgical intervention should be taken into account for the treatment of HNP, when the extruded material contains bony fragment such as osseous endplate.