Objective To analyze the correlation between the poor position of pedicle screw after lumbar internal fixation and the occurrence of postoperative neurological symptoms.Methods The clinical data of patients who underwent lumbar pedicle screw surgery in our hospital from January 2017 to December 2023 were analyzed retrospectively.Record the patient's sex,age,diagnosis,surgical segment,the presence of postoperative neurological complications,the types of neurological complications.According to the postoperative CT,the screw penetration zone and grade were evaluated,and the distribution of different pedicle screw penetration types was recorded.The correlation between different types of pedicle screw penetration and postoperative neurological symptoms was analyzed.Results A total of 184 patients were included,including 80 males and 104 females.Age ranged from 18 to 82 years,with an average of 60.1±14.2 years.35 patients developed new neurological symptoms after operation.The incidence of postoperative neurological symptoms caused by pedicle medial quadrant screw penetration and lower quadrant screw penetration was higher than that of pedicle superior quadrant and lateral quadrant screw penetration.From L1 to L5,the risk of postoperative neurological symptoms caused by screw penetration in the medial quadrant of the pedicle increases gradually.When the penetration distance of pedicle medial quadrant screws in L4 and L5 segments is≥2mm,the risk of postoperative neurological symptoms is high.When the penetration distance of pedicle medial quadrant screws in L1,L2 and L3 segments is greater than 4mm,the risk of postoperative neurological symptoms is high.The distance of pedicle screw penetrating the medial quadrant of pedicle was positively correlated with the incidence of postoperative neurological symptoms(P<0.05).Conclusion The lateral and superior quadrants of the pedicle may be regarded as safety zones for lumbar pedicle screw placement.For the L1～L3 segments,screw penetration depth should not exceed 4 mm;whereas for the L4～L5 segments,the safety threshold must be strictly controlled within 2 mm.

Objective To analyze the correlation between the poor position of pedicle screw after lumbar internal fixation and the occurrence of postoperative neurological symptoms.Methods The clinical data of patients who underwent lumbar pedicle screw surgery in our hospital from January 2017 to December 2023 were analyzed retrospectively.Record the patient's sex,age,diagnosis,surgical segment,the presence of postoperative neurological complications,the types of neurological complications.According to the postoperative CT,the screw penetration zone and grade were evaluated,and the distribution of different pedicle screw penetration types was recorded.The correlation between different types of pedicle screw penetration and postoperative neurological symptoms was analyzed.Results A total of 184 patients were included,including 80 males and 104 females.Age ranged from 18 to 82 years,with an average of 60.1±14.2 years.35 patients developed new neurological symptoms after operation.The incidence of postoperative neurological symptoms caused by pedicle medial quadrant screw penetration and lower quadrant screw penetration was higher than that of pedicle superior quadrant and lateral quadrant screw penetration.From L1 to L5,the risk of postoperative neurological symptoms caused by screw penetration in the medial quadrant of the pedicle increases gradually.When the penetration distance of pedicle medial quadrant screws in L4 and L5 segments is≥2mm,the risk of postoperative neurological symptoms is high.When the penetration distance of pedicle medial quadrant screws in L1,L2 and L3 segments is greater than 4mm,the risk of postoperative neurological symptoms is high.The distance of pedicle screw penetrating the medial quadrant of pedicle was positively correlated with the incidence of postoperative neurological symptoms(P<0.05).Conclusion The lateral and superior quadrants of the pedicle may be regarded as safety zones for lumbar pedicle screw placement.For the L1～L3 segments,screw penetration depth should not exceed 4 mm;whereas for the L4～L5 segments,the safety threshold must be strictly controlled within 2 mm.