Lumbar degenerative scoliosis (LDS) has been increased with increased aging population. The conventional surgical treatment method of LDS was posterior decompression followed by lumbar fusion. However, these surgeries usually require long-level fusion with increased risk of much bleeding and perioperative morbidity especially in old patients. The correction of sagittal or coronal imbalance is also important in the surgical treatment of LDS, thus osteotomy may be sometimes required. Direct lateral interbody fusion (DLIF) has been introduced as a part of minimally invasive surgery. With DLIF technique, the stenotic canal or foramen can be decompressed indirectly without laminectomy and the lumbar lordosis can be restored through the disc height distraction. Recently, DLIF has been also used for the surgical treatment of LDS. With use of DLIF for LDS, it has been reported that the lumbar lordosis and coronal curve angle were restored and the clinical outcome was also favorable without significant surgical morbidities. The lateral approach sometimes carries the risk of the lumbar plexus palsy or vessel injuries. DLIF can be a good alternative to the posterior fusion technique for the treatment of LDS in that it can minimize the perioperative morbidity and it can also restore the sagittal or coronal radiographic profiles effectively.

Introduction
Recently, minimally invasive lateral approach for the lumbar spine is revived and getting popularity under the name of XLIF or DLIF by modification of mini-open method using sequential tubular dilator and special expandable retractor system. Purposes: The purposes of this study were to introduce the mini-open lateral approach for the anterior lumbar interbody fusion (ALIF), and to investigate the advantages, technical pitfalls and complications & to provide basic knowledge on XLIF or DLIF
Materials and Methods
Seventy-four patients who underwent surgery by the mini-open lateral approach from September 2000 to April 2008 with various disease entities were included. Blood loss, operation time, incision size, postoperative time to mobilization, length of hospital stay, technical problems and complications were analyzed.
Results
With this approach, we can reach form T12 to L5 subdiaphragmatically. The blood loss and operation time of patients who underwent simple ALIF were 61.2 ml and 86 minutes for one level, 107 ml and 106 minutes for two levels, 250 ml and 142.8 minutes for three levels, and 400 ml and 190 minutes for four levels of fusion, respectively. The incision sizes were on average 4.5cm for one level, 6.3 cm for two levels, 8.5 cm for three levels and 10.0 cm for four levels of fusion. The complications were retroperitoneal hematoma in two cases, pneumonia in one case and transient lumbosacral plexus palsy in three cases.
Conclusion
The mini-open lateral approach is simpler & safer than XLIF or DLIF with very short learning curve. Trial of mini-open lateral approach would be helpful before trial of XLIF or DLIF. However, special attention is required to complications such as transient lumbosacral plexus palsy.