Abstract: Objective：Ankylosing spondylitis(AS)and diffuse idiopathic skeletal hyperostosis(DISH) are both spinal ankylosing conditions.Simultaneous occurrence of both conditions is rare,and the present of  lumbar spinal stenosis(LSS) had not been reported at the same time.We encountered a patient with this diagnosis whose initial operation had failed through analyzing the characteristics of the this example patient,review of the literature,So as to improve the understanding of clinicians to such rare diseases,improve the level of diagnosis and treatment ，and improve the level of diagnosis and treatment.Methods：The clinical and imaging data of this patient before and after the initial operation and during the followup were collected.Combined with relevant literature,the reasons for the failure of the initial operation were analyzed，to guide reoperation plan；reoperation was completed  according to the preoperative plan,followed up for a short time after surgery to observe the clinical efficacy of the patients and whether there were implantsrelated complications,so as to provide preliminary guidance for the diagnosis and treatment of such diseases.Results：In this case,the diagnosis was wrong during the first operation and the operation plan was not made properly,so the first operation failed and the internal plants loose.the failure of the was internal plants related to the stress concentration in the surgical stage,the short fixation stage,the absence of intervertebral fusion and many other factors.The long stage fixation in revision surgery,after intervertebral fusion,had satisfactory clinical efficacy,and no implantrelated complications in the following up.Conclusion：AS and DISH  should not be seen as mutually exclusive.DISH is associated with lumbar spinal stenosis requiring surgery.Decompression and shortsegment fixation in LSS patients with DISH was characterized by high rate of reoperation，longsegment fixed fusion is recommended.

Key words: ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis, lumbar spinal stenosis, implant, complication