Age-related degeneration of each lumbar intervertebral disc in symptomatic patients：MRI analysis

English Keywords:Degenerative intervertebral disc  Low back pain  MRI  Grading

English Abstract:

  【Abstract】 Objective：To determine the most common patterns in symptomatic lumbar intervertibral disc degeneration at various age period.Method：The lumbar MRI imaging data of 529 patients treated for low back pain with or without skelagia in Santa Monica hospital in USA from 2004 to 2006 were reviewed retrospectively in this study.There were 191 females，338 males.Degenerative grading was made for all disc levels in the lumbar spine for each patient. The patients were also classified into five age different groups starting from below age 30，with the intervals of a single decade，until over age 60（≤29 years，30-39 years，40-49 years，50-59 years and ≥60 years）.The degenerative grade of all disc levels（L1/2 to L5/S1） in each patient was classified based on Pfirrmann′s gading system，and locations and the progressive manner of the degeneration were determined for age groups.SPSS software version 13.0（SPSS Inc.，Chicago，IL） on a personal computer was used for statistical analyses.Result：The most common pattern in all ages is normal in all the discs and it is described as 1-1-1-1-1 and this normal pattern was found in 71 patients（13.4%）.There was rare change to develop severe degeneration（grade 4） for low age groups.The upper levels of the lumbar spine had more commonly lower degenerative grades，and the lower levels had relatively higher grades of advanced disc degeneration.In the age groups of below 29 years and 30-39 years，the most common pattern was normal in all the discs of 5 levels as 1-1-1-1-1.And this pattern was more prominent in the age group below 29 years.In the age group of 40-49 years，it was changed to single level L5-S1 degeneration with 1-1-1-1-3（7.6%） but the normal discs in all levels had also a similar portion（6.8%）.In the age groups of 50-59 years and over 60 years，it was changed to the pattern with all discs abnormal as 3-3-3-3-3.Single level involvement was negatively correlated with age（Ｐ<0.01）.On the contrary，whole symmetrical degenerative involvement of all levels was positively correlated with age（Ｐ<0.01）.Single L5/S1 involvement was most common in the age group of below 29 years，but in the age group of 30-39 years，the most common pattern was changed to L4/5 and L5/S1 double involvement（Ｐ< 0.05）.A relative small portion appeared as the most common pattern with less than two-level involvement in the age groups over 50 years.Conclusion：The rate of unilevel degenerative pattern of lumbar spine in overall population decreases with the progression of age, while that of all-level degenerative pattern increases with the progression of age.