The Pattern of Lumbosacral List Curve in Patients with Lumbar Disc Herniation

There are many unanswered questions about the characteristics and mechanism of the lumbosacral scoliotic list (LSL). In the current study, the pattern of LSL, the level of maximal opened disc space (take-off) in addition to the relationship between the location of disc herniation (DH) on magnetic resonance imaging (MRI) and LSL direction on radiographs, were investigated. A total of 37 patients, with extruded lumbar DH and LSL, were included in the current study. The following variables were measured on standing anteroposterior and lateral lumbar x-rays: LSL (from L1 to L5), the take-off level, and the coronal shift (the distance between the plumb line from T12 spinous process to the central sacral vertical line). The direction of LSL was recorded as the bending side of the patient opposite to the convexity of the curve. The location of DH was determined as right, left, or central on an MRI. The magnitude of the LSL curve averaged 9.9° ± 6.9°. Regarding the right or left herniation, the list occurred mostly toward the opposite side of the herniation direction (P = 0.04). There was no significant matching between the location of herniation and the take-off segment (P = 0.391); however, in 67.6% of patients with L4 - L5 or L5 - S1 herniation, the take-off point occurred one segment above the involved levels. The take-off was found only at L3 - L4 or L4 - L5 levels in all the patients. LSL usually occurs on the opposite side of the herniation location. Furthermore, take-off is found in L3 - L4 or L4 - L5 segments in most of the patients with LSL. It seems that LSL curve characters are not affected by the level of herniation.