Abstract:[Objective] To investigate the clinical efficacy of debridement and instrumented fusion of affected vertebrae through the pos- terior approach for single- segment brucellar spondylitis. [Methods] A retrospective study was performed on 21 patients who underwent abovementioned surgical treatment for single-segment brucellar spondylitis from November 2016 to December 2019. [Results] All the pa- tients had operation conducted successfully without serious complications. As time went in the follow-up lasted for (18.8±3.4) months, the VAS and ODI scores decreased significantly (P<0.05) , while JOA score increased significantly (P<0.05) . In term of pathological biopsy, a large number of monocytes, lymphocytes and other inflammatory cells were found in the lesion area by HE staining in the 21 patients, which was consistent with brucellosis. In addition, Gimesa staining found brucellosis bacillus. The ESR, CRP and local kyphotic Cobb angle were significantly decreased (P<0.05) , while the intervertebral space height significantly increased postoperatively compared with those preopera- tively (P<0.05) . At the latest follow-up, imaging showed that all patients obtained bone fusion, without implant loosening or fracture. [Conclusion] The debridement and instrumented fusion of affected vertebrae through the posterior approach are safe and effective treatment for single-segment lumbar brucellar spondylitis.