Postoperative Clinical Outcome and Risk Factors for Poor Outcome of Foraminal and Extraforaminal Lumbar Disc Herniation

OBJECTIVE: We evaluated postoperative outcomes in patients who have lumbar foraminal or extraforaminal disc herniation (FELDH) and suggested the risk factors for poor outcomes. METHODS: A total of 234 patients were selected for this study. Pre- and post-operative Visual Analogue Scale (VAS) and Korean version Oswestry Disability Index (KODI) were evaluated and the changes of both score were calculated. Outcome was defined as excellent, good, fair, and poor based on Mcnab classification. The percentage of superior facetectomy was calculated by using the Maro-view 5.4 Picture Archiving Communication System (PACS). RESULTS: Paramedian lumbar discectomy was performed in 180 patients and combined lumbar discectomy was performed in 54 patients. Paramedian lumbar discectomy group showed better outcome compared with combined discectomy group. p value of VAS change was 0.009 and KODI was 0.013. The average percentage of superior facetectomy was 33% (range, 0-79%) and it showed negative correlation with VAS and KODI changes (Pearson coefficient : -0.446 and -0.498, respectively). Excellent or good outcome cases (Group I) were 136 (58.1%) and fair or poor outcome cases (Group II) were 98 (41.9%). The percentage of superior facetectomy was 26.5% at Group I and 42.5% at Group II. There was significant difference in superior facetectomy percentage between Group I and II (p=0.000). CONCLUSION: This study demonstrated that paramedian lumbar discectomy with preservation of facet joints is an effective and good procedure for FELDH. At least 60% of facet should be preserved for excellent or good outcomes.

Clinical Experiences in the Treatment of Far Lateral Lumbar Disc Herni

The authors present 12 cases of far lateral disc herniation(FLDH) diagnosed and treated in our institution from march, 1992 to February, 1994. In the author's series the incidence of far lateral disc herniation was 5% of all lumbar disc herniations. The average age of the patients was 4 years and there were 7 men and 5 women. The L4-5 intervertebral disc level was the most commonly involved level. All patients initially presented with symptoms of radiculopathy. Cases with double herniations at the same level and on the same side seemed to have the most potential source of misdiagnosis and mismanagement, and a careful surgical consideration was needed for such cases. In 4 cases, a combined intraspinal and extraforaminal approach was performed with preservation of facet joints and in 2 cases, paramedian muscle splitting approach was performed. Chemonucleolysis and the usual partial hemilaminectomy were undertaken in 5 cases and in 1 case, respectively. The combined approaches proved to be an effective means of treatment for cases with double herniations, but misdiagnosis of such lesion can lead to an inappropriate and an ineffective treatment and poor surgical results. Furthermore, in the diagnosis of far lateral disc herniation, differentiation must be made from symptoms of conjoined nerve root and congested epidural vein.