Correlated Study: The Disk Height Loss And The Disk Degeneration Of The Lumbar Spine

objective: Applying Frobin's method of measuring the intervertebral disk height, distortion-compensated roentgen analysis(DCRA), and magnetic resonance imaging to discuss the relationship between degeneration of disk tissue and the height loss of disks, and their occurring sequence of the human lumber spine. Methods:1. Apply the method of DCRA to measure the height of 187 intervertebral disks(level:L3 ~ S1), from 63 normal cases, in which, 32men(mean age 35 years), 31women(mean age 33 years). Categories are selected according to the same sex, and same level of disks, and their mean height and mean angle of lordosis of each category are calculated. These values serves as of control group. 2. Applying the method of DCRA to measure the height and the angle of lordosis of the 111 intervertebral disks(level:L3 - S1)from 38 subjects suffering with lower back pain in which 20 men, 18 women, age 19- 78 yeas, and then to correct the each value measured by the mean height and mean angle of lordosis of the control group according to the same sex, same level of disks. 3. Classifying these 111 intervertebral disks of 38 subjects suffering with lower back pain, according to the situation of degenerative changes of these disks on magnetic resonance imaging(T2-weighted, sagittal). Group A~ F are categorized according to the signal change of the nucleus pulposus with or without prolapse. 4.To contrast the mean height(after correction)of each group(A - F)with that of the normal population by the t-test. The level of significance was set to 0.05. Results: 1. The mean disks height in Group A (no signal change, no prolapse, total 32 disks) and group C(moderate signal loss, prolapse, total 23 disks) dose not significantly differ from that of normal(P>0.05). 2.The mean disk height in group D(moderate signal loss, prolapse, total 35 disks)and group F(total signal loss, prolapse, total 15 disks)deviate significantly from that of normal(p<0.01). 3.In each group (A - F)disk height exhibits considerable variation.Conclusion: 1.Lumbar disk degeneration and disk height loss correlate considerably. 2.Lumbar disk degeneration precedes the disk height loss. 3. Lumbar disk height loss occurs in the late stage of disk degeneration, in early stage , no disk height loss. 4. Considering the disk height variation in each group , we should pay more attention to individual variation clinically.