The Changes of Adjacent Segments after Spinal Fusion: Follow-up more than Three Years after Spinal Fusion / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: A retrospective analysis of 166 patients was undertaken to observe radiologically the changes of adjacent segments at follow-up more than three years after lumbar fusion. OBJECTIVES: The purpose of this study is to analyse the changes of adjacent segments and to correlate these changes to the length of using level and to the degree of deviation from physiologic lumbar lordosis. The authors also correlate these radiologic changes to the clinical symptoms. MATERIALS AND METHODS: In simple x-ray, authors observed traction spur, disc space narrowing, endplate sclerosis and vacuum phenomenon of adjacent segments. Authors used Gelb's criteria in segmental lordosis angle(SLA) and Katz's classification in clinical results. RESULTS: The average age was 49.6 years old and the average follow-up period was 57.2 months(4 years and 9.2 months). We observed radiologically the traction spurs in 35 cases(21.1%), end-plate sclerosis in 32 cases(19.3%), disc space narrowing in 33 cases(19.9%) and the vacuum phenomenon in 10 cases(6.0%). The numbers of fusion segments and the degree of unphysiologic segmental lordosis angle in fusion segments were related with the frequency and degree of changes of adjacent segments(P<0.05). The clinical results showed satisfaction in 142 cases(85.5%), unsatisfaction in 24 cases(14.5%) and low back pain in 24 cases(14.5%), leg pain in 11 cases(6.6%) and extension of fusion level in 4 cases(2.4%). In low back pain patients more than two kinds of radiological changes were frequently observed than the patients without low back pain(P<0.05). CONCLUSIONS: The radiological changes of adjacent segments were more frequently observed in long fusion and in fusion with unphysiologic lumbar lordosis angle. And these changes are frequently associated with low back pain. Thus long fusion and fusion with unphysiologic lumbar lordosis angle should be avoided if possible.