The Relationship Between Ligamentum Flavum Thickening And Degenerative Intervertebral Discs Of Lumbar Spine

Objective:To study the relationship between the thickness of lumbar ligamentum flavum and age and gender and to research the mechanism of lumbar ligamentum flavum thickening.Methods:The thickness of720LFs at the L2/3, L3/4, L4/5, and L5/S1levels of180(mean age,49.8±8.1yrs) patients who complain low back pain or leg pain was measured prospectively on axialTl-weighed magnetic resonance images, obtained at the facet joint level. Grading all the patients by using improved Pfirrmann classification system. The patients were divided into1of3groups:group A (grade1to5with normal LF thickness),group B(grade1to5with LF thickening), and group C(grade6to8with LF thickening). Analysing the data obtained by using SPSS17.0statistical software, and with P<0.05for the difference has statistical significance. Results: At all of the levels investigated,the thickness of the LF are positively correlated with age (L5/SI:r=0.333, L4/5:r=0.384, L3/4:r=0.358, L2/3:r=0.240, all the levels investigated are P<0.05); At all of the levels investigated, the thickness of the LF have no significant difference between Men and women (P <0.05). The LF thickness of GroupA:L2/3=2.7±0.6,L3/4=2.9±0.7, L4/5=3.4±1.0,L5/S1=3.1±1.0;GroupB:L2/3=4.1±0.7,L3/4=4.1±0.8,L4/5=4.2±0.7,L5/S1=4.2±1.0;GroupC:L2/3=4.5±0.7,L3/4=4.7±0.4,L4/5=5.2±1.0,L5/S1=5.1±1.0(all P<0.05); Conclusion:The thickness of the lumbar LF are positively correlated with age, and are not correlated with the gender; Disk space narrowing secondary to disc degeneration is an important mechanisim of LF thickening.