Fig. 3

Illustration scheme of spinal canal decompression. a The dilator and guide rod were properly positioned. b The secondary guide rod and special eccentric guide rod were inserted through the guide wire step by step, and the half-serrated working cannula was inserted into the superior articular process along the eccentric guide rod. c The specially designed reamer was applied for the resection of osteophytes under the endoscopic system. d Dorsal decompression of the nerve roots; e ventral decompression of the nerve roots; f spinal canal decompression