Correlation between spinopelvic sagittal parameters and adjacent segment disease after lumbar fusion / 第二军医大学学报

ABSTRACT

Objective To analyze the correlation between adjacent segment disease (ASDis) after lumbar fusion and spinopelvic sagittal parameters, and to explore the risk factors. Methods From Jan. 2013 to Oct. 2017, the patients undergoing revision surgery for ASDis after lumbar fusion in Changhai Hospital of Naval Medical University (Second Military Medical University) were enrolled as ASDis group, and the patients who did not have ASDis after lumbar fusion during the same follow-up period were taken as controls. The clinical data of the patients in the two groups were retrospectively analyzed. The differences of the general data (age, gender, body mass index [BMI], follow-up time and the etiology of the first operation) and the spinopelvic sagittal parameters (thoracic kyphosis [TK], sagittal vertical axis [SVA], lumbar lordosis [LL], segmental lumbar lordosis [sLL], pelvic incidence [PI], pelvic tilt [PT] and sacral slope [SS]) were compared between the two groups. Results There were 25 patients in the ASDis group and 50 patients in the control group. There were no significant differences in the age, gender, BMI, follow-up time or the etiology of the first operation between the two groups (all P>0.05). Compared with the control group, the LL, sLL and SS were significantly lower in the ASDis group (36.00°±5.44°vs 43.88°±10.62°, 17.80°±5.79°vs 27.62°±6.74°, 27.50°±5.30°vs 31.06°±7.48° all P0.05). Meantime, the proportion of patients with SVA>50 mm, the difference of PT and LL (PT-LL)=10°, and the ratio of sLL to LL (RL)<60% were significantly higher in the ASDis group than those in the control group (18/25 vs 21/50, 16/25 vs 11/50, 21/25 vs 17/50; all P<0.05). Conclusion The sagittal imbalance after lumbar fusion is closely associated with ASDis, and compensatory kyphosis of adjacent lumbar segments due to surgical segmental lordosis may be one of the causes of ASDis after lumbar fusion.