Lumbar Disc Herniation: Level Increases with Age Ruben Dammers, M.Sc.* and Peter J. Koehler, M.D., Ph.D.,† *Departments of General Surgery, University Hospital Maastricht and †Neurology, Atrium Medical Center Heerlen, CX Heerlen, The Netherlands Dammers R, Koehler PJ. Lumbar disc herniation: level increases with age. Surg Neurol 2002;58:209 –13. BACKGROUND Prompted by the clinical impression that L4 radicular syndrome and disc herniations at L3– 4 occurred at older ages we studied the correlation between age and level of herniated discs. METHODS We retrospectively correlated mean age and level of disc herniation of patients suffering from lumbar disc hernia- tion. Data from 1431 patients were obtained from the neurologic database of the Atrium Medical Center Heer- len from 1995 through 1998. Nonparametric data were analyzed with the Mann-Whitney U test, and correlation was analyzed using linear regression. RESULTS Mean ages of the patients with disc herniation at L5-S1, L4 –5, L3– 4, and L2–3 were 44.1  0.5 years, 49.5  0.6 years, 59.5  0.9 years, and 59.6  2.7 years, respectively. Mean ages were significantly higher with herniation levels at L4 –5, L3– 4, and L2–3 compared to L5-S1 (p  0.0001). Analogously, the mean age of patients with disc hernia- tion at L3– 4 was significantly higher compared to those with herniation at L4 –5 (p  0.0001). No difference in mean age was seen between L3– 4 and L2–3 (p = 0.815). A strong correlation was observed between the level of herniation and increasing age (R = 0.371; p  0.0001). CONCLUSION These results indeed prove that with increasing age, lum- bar disc herniation is more cranially localized. It may help in understanding the patho-anatomic process of disc her- niation, and in recognizing higher level radicular syn- dromes in advanced age. © 2002 by Elsevier Science Inc. KEY WORDS Lumbar disc, herniation, level, age. E ven though we do not know in detail how disc degeneration initiates, it is obviously influ- enced by age [1]. Pathologic processes associated with disc degeneration are 1) the loss of proteogly- cans and water content of the nucleus pulposus, with increasing collagen deposition, 2) subsequent tearing of the annulus fibrosus, and 3) osteophyte formation [1,9]. Several authors have reported intervertebral disc degeneration to proceed cranially from the lumbo- sacral level with increasing age [4,6,10]. On the other hand, some investigations have failed to dem- onstrate any correlation between the level of her- niation and age [12]. Nevertheless, most investiga- tors agree that disc degeneration starts earlier at the lower lumbar level [1], although few recent literature references can be found regarding this subject. Prompted both by the clinical observation that disc herniations at L3– 4 and higher lumbar levels seemed to occur at older age and the fact that a correlation between level and age is not generally known to clinicians, we wished to study the corre- lation between age and level of herniated discs. Patients and Methods Clinical data from 2838 patients suffering from lum- bar back and sciatic pain were obtained from the neurologic database of Atrium Medical Center, Heerlen. Data from a time-span of 4 years (1995– 1998) were collected retrospectively. Lumbar disc herniation was found in 1431 patients (50.4%). Mean age  SEM was calculated. In turn, this was corre- lated to the level at which the disc herniation was localized. Either computed tomography (CT), mag- netic resonance imaging (MRI), or both confirmed localization radiologically. For statistical analysis we used the SPSS 10.0- package (SPSS, Chicago Illinois, USA). Nonparamet- ric data were analyzed with the Mann-Whitney U test and correlation was tested using standard lin- ear regression. Address reprint requests to: Dr Peter J Koehler, Department of Neurol- ogy, Atrium Medical Center Heerlen, H. Dunantstraat 5, PO Box 4446, 6401 CX Heerlen, The Netherlands. Received January 18, 2002; accepted May 24, 2002. © 2002 by Elsevier Science Inc. 0090-3019/02/$–see front matter 360 Park Avenue South, New York, NY 10010 –1710 PII S0090-3019(02)00797-8