Surgery for Lumbar Radiculopathy due to Intervertebral Extraforaminal Lesions

Introduction : Symptoms, diagnosis, and treatments for lumbar radiculopathy due to lumbar intervertebral extraforaminal lesions has often been discussed in recent years. This pathology is by no means a rare condition. We report the treatment of this condition at our institute. Materials and Methods : At our institution, lumbar radiculopathy due to extraforaminal lesions is diagnosed on the basis of neurological findings and confirmed by neuroradiological imagings methods such as magnetic resonance imaging (MRI) and computed tomography (CT). Recently, radiculography and nerve root blocks are not necessarily performed for the management of lumbar radiculopathy. From 2005 to 2010, 21 patients underwent surgery. These patients included 10 patients with far-out syndrome (FOS), 8 with extraforaminal disc herniation, and 3 with extraforaminal tumors. Results : Revision surgery was performed in 6 cases : 4 cases of extraforaminal disc herniation and 2 cases of FOS. Identification of FOS tended to be delayed. In cases of extraforaminal lesions in which insufficient nerve-root decompression was achieved by the first operation, reoperation was performed for appropriate and adequate nerve-root decompression. Transforaminal lumbar interbody fusion (TLIF) methods were performed in a case of FOS, 2 cases of extraforaminal disc herniation, and 1 case of extraforaminal ganglion cyst ; however, in the other cases, only nerve-root decompression was performed by surgery through the Wiltse paraspinal approach. Discussion and Conclusion : In recent times, diagnosis of extraforaminal lesions has become easier because of advancements in MRI. Magnetic resonance neurography enables direct visualization of nerve root edema and root compression itself. Extraforaminal disc herniation can be managed by surgically removing the herniated disc via the Wiltse paraspinal approach. Since aggressive nerve-root decompression is required in cases of lumbar canal stenosis complicated by intra-and extra-foraminal lesions, we consider TLIF as the primary procedure in cases with advanced deformities.