The Comparisons of Surgical Outcomes and Clinical Characteristics between the Far Lateral Lumbar Disc Herniations and the Paramedian Lumbar Disc Herniations

Abstract

Objective: The purpose of this study is to analyze clinical characteristics and surgical outcomes of the far lateral and the paramedian disc herniations.

Methods: The 88 patients who underwent an operation for lumbar disc herniations were reviewed. Visual analogue scale of leg and back pain, occurrence of sensory dysesthesia and motor deficit before and after operations were used to compare the far lateral with the paramedian disc herniations.

Results: Statistically, the far lateral herniations had more severe radicular leg pain and showed more frequent occurrence of sensory dysesthesia than paramedian herniations before operation (p<0.05). In the far lateral herniation group, preoperatively, 15 patients (75%) had sensory dysesthesia and among them, 4 patients (27%) showed improvement. In the paramedian herniation group, preoperatively, 25 patients (37%) had sensory dysesthesia and among them, 21 patients (84%) showed improvement. The degree of improvement in sensory dysesthesia was statistically higher in paramedian herniation group (p<0.05). In the far lateral herniation group, preoperatively, 11 patients (55%) had motor deficit and among them, 10 patients (91%) showed improvement. In the paramedian herniations, preoperatively, 29 patients (43%) had motor deficit and among them, 25 patients (86%) showed improvement. The degree of improvement in motor deficit was not statistically significant between groups (p>0.05).

Conclusion: Preoperatively, the far lateral herniations had more severe radicular leg pain and frequent occurrence of sensory dysesthesia. Postoperatively, the sensory dysesthesia was less improved and back pain was more severe in the far lateral herniations.

Keywords: Clinical characteristics; Far lateral disc herniation; Paramedian disc herniation; Surgical outcomes.

Fig. 1

(A) Sagittal T2-weighted MRI shows the superolateral migrated herniated disc and the compression of superior exiting nerve root at L2-3 level. (B) Transaxial T2-weighted MRI shows the far lateral herniated disc and direct compression of the dorsal root ganglion (white arrowhead: superolateral migrated herniated disc, black arrowhead: dorsal root ganglion).

Fig. 2

Far lateral disc herniation associated with additional spinal stenosis (so-called "Double herniations"). (A) T2-weighted MRI shows the superolateral migrated herniated disc at L4-5 level (white arrowhead: superolateral migrated herniated disc). (B) A severe spinal stenosis at the same level (white arrowhead: vertebral canal stenosis).

Fig. 3

(A) T2-weighted MRI shows the far lateral disc herniation at L4-L5 level. (B) CT shows the far lateral disc herniation at L4-L5 level (white arrowhead: herniated disc).