Usually degenerative spine showed narrowing of the discs and formation of osteophytes. We studied the clinical significance of the osteophyte compressing the nerve in extra foraminal zone. Forty cases who suffered from lumbago and/or leg symptoms were reviewed in computed tomography. Eight cases had osteophytes which were located in a posterolateral corner of the caudal part of the vertebra. All of them complained of severe pain in the buttock and/or lower extremity which markedly disturbed their walking. They suffered from night pain and rest pain.
These symptom seemed to arise from dorsal root ganglion near the osteophyte. Compression to the dorsal root ganglion, which produces the substance P, may induce severe pain. In some cases with degenerative changes, these conditions may be caused by bony lesion. We must consider these conditions in the treatment of lumbar diseases.
