Clinical and Radiological Findings of Foraminal Disc Herniation / 대한척추외과학회지

STUDY DESIGN: Retrospective study of clinical experiences. OBJECTIVES: The correct discrimination of a compressed root is very important for proper decompression. With a foraminal disc herniation, the cephalad root is compressed. The diagnostic importance of the clinical and radiological findings was investigated. SUMMARY OF LITERATURE REVIEW: A compressed root, due to a herniated disc, is known as a caudal root (i. e. L5 root compressed by L4-5 disc herniation). In some cases, a prolapsed disc may compress the cephalad root, resulting in a difficult diagnosis. MATERIAL AND METHOD: The medical records, plain X-ray and MRI of 17 patients were reviewed, and the physical examination and MRI findings were carefully evaluated to retrospectively document the efficacy of the diagnoses. Every MRI image of each patient was graded according to the 4 point ranking system of diagnostic efficacy devised by the authors. The clinical outcomes and postoperative complications were also investigated. RESULTS: Ten, 5 and 2 of the 17 patients had L4-5, L5-S1 and L3-4 foraminal disc herniations, respectively. Eight of 10 L4-5 cases showed a positive femoral nerve stretching test. The knee jerk reflex was diminished in 7 patients, with bilateral hyporeflexia in the other 3. The body-cut axial MRI image was the most effective, and the coronal images were also very helpful, whereas the routine axial images were of least value. Most cases achieved a satisfactory clinical result. CONCLUSIONS: Foraminal disc herniations seem to be reasonably common. For the accurate discrimination of a compressed root, a thorough physical examination seems to be very important. When MRI is performed for these cases, in addition to routine studies, the body-cut axial and coronal MRI images are effective and useful, and their use is strongly recommended.

Isthmic Spondylolisthesis Associated with Foraminal Disc Herniation Treated by Anterior Lumbar Interbody Fusion

A 45-year-old man presented with lower back pain and pain in the right leg of 3years duration. A plain radiographic examination revealed grade I isthmic spondylolisthesis, with instability at L4-5. Computed tomography and magnetic resonance imaging demonstrated bilateral foraminal stenosis, with soft foraminal disc herniation on the right side at the L4-5 level. He underwent anterior lumbar interbody fusion(ALIF) with percutaneous posterior fixation(PF) at the L4-5 level. Without removing the posterior bony structures, removal of foraminal disc herniation and reduction of spondylolisthesis were successfully performed using ALIF with percutaneous PF. When there is no hard disc herniation or lateral recess stenosis, ALIF with percutaneous PF can be one of the treatment options for isthmic spondylolisthesis, even in the presence of foraminal disc herniation, as in our case.

Surgical Experience of Lumbar Foraminal Disc Herniation by Resecting the Spinous Process and a Part of Hemilamina

Foraminal disc herniation is considered to be a part of extreme lateral disc herniations which have relatively frequent occurrence of about 10% of all lumbar disc herniations. It presents a different clinical feature from that of usual intraspinal disc herniation, in that the prolapsed foraminal disc material compresses the nerve root at the level of disc herniation. Previously many operative procedures for foraminal disc herniations have been introduced with the aids of various diagnostic methods. Intervertebral foraminotomy and total facetectomy are still the most widely used options in treating extreme lateral lumbar disc herniation. But these techniques could result in an unfortunate structural disruption and frequently cause spinal instability and continued postoperative back pain. Recently unilateral partial hemilaminectomy and resection of spinous process followed by discectomy were performed in our hospital. For this procedure, paraspinal muscles were elevated subperiosteally and retracted bilaterally exposing the spinous process and laminae on both sides. After the unilateral partial hemilaminectomy and resection of spinous process preserving articular facet joint, then obliquely downward looking through intervertebral foramen allowed direct visualization of prolapsed foraminal disc and compressed nerve root. Thereafter prolapsed foraminal disc could be successfully removed under direct vision with the preservation of spinal stability. When extraformainal disc coexisted, intertransverse approach was additionally performed.