The far lateral approach to lumbar disc herniations.

Abstract

The diagnosis of extreme lateral lumbar disc herniation (ELLDH) as a cause of lumbar radiculopathy was first described by Abdullah in 1974 [1]. This discal pathology has been recognized for many years as an occasional cause of negative disc exploration and immediate failure of classical disc surgery in sciatica [1,18, 24, 25, 29, 31, 30, 31, 33, 35, 41]. Only since the introduction of computed tomography (CT) for the diagnosis of lumbar disc disease have the characteristics of ELLDH become fully appreciated [3, 6,13,17,23, 30,32,47]. Myelography alone was an insufficient diagnos- tic tool to detect this specific pathology. With the rapid development of neuroradiologic diagnostic imaging, including magnetic resonance imaging (MRI) [13, 32], recognition of this particular type of lumbar disc disease has increased its incidence, ranging from 0.7% to 11.7% of the total operated herniated discs [1, 22, 24, 45]. In a recent review of our series of patients with lumbar disc disease we found an overall incidence of ELLDH of 5.8% over a period of 8 years [38]. 78% of all ELLDH occured at the L4-L5 and L5-S1 levels, with an almost equal frequency, but the overall incidence of ELLDH per level varied relative to the level of the pathological disc.