Abstract:[Objective] To investigate the causes and outcomes of revision surgery within 10 days secondary to primary lumbar instru- mented fusion. [Methods] From January 2015 to August 2020, 1412 patients who underwent lumbar fixation fusion were reviewed. Among them, 26 patients underwent revision surgery in 10 days after the primary operation. The reasons for revision were recorded, and the pa- tients were divided into two groups according to whether nerve symptom deteriorated. The general condition, surgical data, VAS, JOA and ODI scores of the revised patients were compared. [Results] Among 1412 patients who underwent lumbar instrumented fusion, 26 patients (1.84%) received revision surgery within 10 days, including 11 males and 14 females aged ranged from 40 to 80 years, with an average of 58.58±8.33 years. In term of revision reasons, screw misplacement occurred in 11 cases (42.31%) , decompression incomplete in 5 cases (19.23%) , postoperative infection in 4 cases (15.38%), displacement of the fusion cage in 2 cases (7.69%) and poor wound healing in 4 cas- es (15.38%) . Among the 26 patients, 18 cases (69.23%) showed aggravation of nerve damage (the AND group) , mainly due to screw mis- placement and incomplete decompression, while 8 cases (30.77%) had no aggravation of nerve damage (the non-AND group) . The non- AND group proved significantly higher accuracy of screw placement in primary surgery than the AND group (P<0.05) . The VAS, ODI and JOA scores varied in curve manner over time in both groups, which were statistically significant (P<0.05) . At the latest follow-up, the non- AND group proved significantly superior to the AND group in terms of VAS, JOA scores and ODI scores (P<0.05) . With regard to correla- tion analysis, there were no correlations between the time elapsed from primary to revision surgeries and the clinical VAS, ODI and JOA scores at the latest follow-up (P>0.05) . [Conclusion] The screw misplacement and incomplete decompression are the main causes of early revision surgery, while aggravation of nerve damage after lumbar instrumented fusion has worse prognosis than other complications. Accu- rate screw placement and adequate intraoperative decompression are important to reduce the rate of early revision and the incidence of post- operative nerve injury complications.