Observing The Relationship Between Degeneration And Movement Variation Of Adjacent Segments Disc After Lumbar Fusion By The Dual-source CT

Objectives: Currently, The literature on lumbar spine at different positions(forward bends, after stretching, lateral flexion and rotation)have influence on intervertebral disc is more, which mainly focus on the biomechanical testing.however,the related research in area of subtle change of lumbar intervertebral disc in one direction is less.which have some main reasons, on the one hand,it is restricted by the measuring instruments,on the other hand, the influencing factors of adjacent segment disc degeneration is multifaceted. It provides the convenience on the study of correlation and movement of lumbar spinal structures.In this paper,52 patients who accepted lumbar fusion surgery for lumbar disc disease from June 2009 to May 2012 in our hospital were followed up, lumbar spine were retrospectively analyzed the change of adjacent segment disc height in the process of movement, which can guide postoperative patients to protect the spine.To follow-up and observe the movement of the adjacent segment disc(L3/4, L5 / S1) after L4/5 intervertebral fusion, and analysis the correlation of the movement and degeneration of intervertebral disc.Design of experiment, experiment time and place, selection of subjects investigated and cases:May 2012 to June 2014 in Hebei Medical University Affiliated clinical college of petroleum.Methods: Sujects:select 52 patients with lumbar fusion and internal fixation caused by lumbar intervertebral disc protrusion,which was failed to conservative treatment in 3 years,who accept treatment in clinical petroleum college of Heibei Medical University from June 2009 to May 2012 as operation group(male 16, female 36 cases, age: 39-60 years, mean age: 49.5 years.).According to the sample size calculation choose 50(male13, female 37, age: 35-62, mean age: 48.5 years)outpatients with lumbar disc protrusion as control group, who accept repeated conservative treatment and MRI examination in 3 years.Through operation group compared to non-operation group, observing the movement of postoperative adjacent segment disc in the process of forward bends by dual-source CT. and through the MRI imaging findings,to explore the relationship between the movement and the degeneration of adjacent segment intervertebral disc.Observation indexes: according to VAS score,evaluate the situation before and in the examination with dual-source CT in surgery group and the non- surgery group, and observe the change of adjacent segment disc height in the process of bending forward movement, according to the Pfirrmann grading standard,evaluating the situation of intervertebral disc degeneration.Results :1. The height variation of L3/4 intervertebral disc: when lumbar lordosis Cobb Angle move in 45 °- 50 °, the height loss of L3/4 disc is the most obvious, the surgery group2.205±0.053 mm, the non-surgery group0.875±0.036 mm, both in surgery group and non-surgery group the height variation of L3/4 intervertebral disc is not obvious in other angles. The height variation of L5/S1 intervertebral disc: when lumbar lordosis Cobb Angle move in 30 °- 60 °, both in surgery group and non-surgery group there was no difference in the height reduction of intervertebral disc.2. Both Surgry group and non- Surgry appear degeneration of adjacent segment disc, but the number of degeneration above II leve at L3/4 intervertebral disc is 33 cases in surgery group, however,the non-surgry group is 16 cases.3.There is palpable relationgship between disc height change and the extend of the degeneration,the change of L3/4 disc height is more obvious in the degeneration bove the II level,but in the degeneration of I and II level, the change of L3/4 intervertebral disc height is not obvious.4. The VAS scores variation of the surgery group and non-surgery group before and in the dual-source CT examination were 0.35±0.05 and 0.66 ± 0.06, the symptom of the two groups is not increased,there were no correlation between VAS score and movement of L3/4 intervertebral disc in 45 °- 50 °.Conclusion : After L4/5 lumbar intervertebral fusion surgery, when lumbar lordosis Cobb angle move in the process of 45 °- 50 °, the change of L3/4 intervertebral disc height is more obvious,existing abnormal activities,which be related with degeneration,however,it has nothing to do with VAS score.