Modified Pfirrmann Classification Of Lumbar Disc Degeneration Degree And Measurement Study Of Anantomic Parameters

Objective: The impact of lumbar disc degeneration degree on measured anatomic parameters still remains unknown. The current study was aimed to measure the anatomic parameters by X-ray film in 100 patients at L1/2 level, L2/3 level, L3/4level, L4/5 level and L5/S1 level, correlated with the modified Pfirrmann classification of disc degeneration assessed by magnetic resonance imaging(MRI).Methods: We retrospectively collected the radiographic data of 100 patients admitted from 2010 January to 2015 December in Orthopedic Department of our hospital. We used X-ray film to measure foramen area, longitude distance of foramen,latitude distance of foramen, superior articular process distance, and vertebral arch height at different levels. Meanwhile, we equally divided the vertebrae into four parts by three points on the inferior edge and superior edge of the vertebrae. As a result,when we connected the three points on the inferior edge and superior edge of the vertebrae, the were three connecting lines(A, B, C) for vertebrae and another three connecting lines(D, E, F) for intervertebral space. We used ANOVA test to demonstrate the measured parameters in different groups based on the modified Pfirrmann classification of disc degeneration. Spearman correlation test was used to investigate the potential relationship between lumbar disc degeneration and measured anatomic parameters, year, height, as well as weight, respectively. Multiple variable linear return analysis was used to investigate the correlated factors on foreman area.Result: A total of 500 levels were measured by X-ray film and assessed by MRI.At L1/2 level, there were significant differences in latitude distance of foramen,superior articular process distance, connecting line A, and connecting line B between different degrees of L1/2 disc degeneration(p< 0.05). At L2/3 level, there were significant differences in latitude distance of foramen, longitude distance of foramen,superior articular process distance, connecting line A, connecting line B and connecting line E between different degrees of L2/3 disc degeneration(p< 0.05). At L3/4 level, there were significant differences in latitude distance of foramen,longitude distance of foramen, superior articular process distance, connecting line D,connecting line E and connecting line F between different degrees of L3/4 disc degeneration(p< 0.05). At L4/5 level, there were significant differences in foramen area, longitude distance of foramen, vertebral arch height, connecting line D,connecting line E and connecting line F between different degrees of L4/5 disc degeneration(p< 0.05). At L5/S1 level, there were significant differences in latitude distance of foramen, connecting line D, connecting line E and connecting line F between different degrees of L5/S1 disc degeneration(p< 0.05).At L1/2 level, foramen area= 0.345* longitude distance of foramen+0.977*latitude distance of foramen+0.434* superior articular process distance-0.257*vertebral arch height+0.501; At L2/3 level, foramen area=0.619* longitude distance of foramen-0.882* superior articular process distance +1.253*connecting line A+0.592* connecting line B+0.462;At L3/4 level, foramen area=-0.497*connecting line D+1.259*connecting line A+0.663*connecting line B-0.343*vertebral arch height+0.016*height-2.265;At L4/5 level, foramen area=-0.132*modified Pfirrmann classification-1.207*connecting line D+0.728* connecting line E+1.610* connecting line A+0.053; At L5/S1 level, foramen area=-0.157* latitude distance of foramen+0.888*connecting line A+0.537*connecting line C+0.387. There were moderate correlations between lumbar disc degeneration and age at all levels except L5/s1.Conclusions: Different impact of lumbar disc degeneration degree on measured anatomic parameters at different levels.