General Session: MIS-1
Presented by: J.C. Lee - View Audio/Video Presentation (Members Only)
J.C. Lee(1), H.-D. Jang(1), S.-W. Choi(1), M.-S. Kim(2), B.-J. Shin(1)
(1) Soonchunhyang University Seoul Hospital, Orthopedic Surgery, Seoul, Korea, Republic of
(2) Incheon Medical Center, Orthopedic Surgery, Incheon, Korea, Republic of
Introduction: Traditional anterior approach to the L5-S1 intervertebral disc space is associated with extensive soft tissue dissection and requiring supine position. Minimally Invasive Surgery (MIS) for lateral transpsoas approach to the lumbar spine is an innovative and effective method, however, it cannot reach L5-S1 because of obstruction by iliac crest and laterally located lumbosacral nerve plexus. Recently, MIS oblique lumbar interbody fusion for L5-S1 (OLIF L5-S1) has been introduced. It is a modification of traditional ALIF using specially designed retractors. With this technique, L5-S1 also can be approached in lateral decubitus position when a surgeon performs multi-level lateral lumbar fusion at L2-5. Purpose of this study is to report our early clinical experience of MIS OLIF L5-S1, and to compare its radiographic results with MIS TLIF.
Materials and Methods: From Jul. 2015 to Jan. 2016 OLIF L5-S1 procedure was performed on 16 patients. There were 4 male and 12 female patients and average age at operation was 62 years (range, 52-72). Average follow-up period was 8.3 months (range, 6-12). Diagnosis was spinal stenosis in 9 patients, lumbar degenerative kyphosis in 3, degenerative scoliosis in 2, and spondylolisthesis in 1. Clinical outcome was evaluated by VAS of low back pain (LBP) and leg pain, and ODI score. Radiologic evaluation included intervertebral disc height, segmental lordosis, lumbar lordosis in plain radiograph, and foraminal height on computed tomography and they were compared with those of MIS TLIF.
Results: Total numbers of fused segments were 2 segments in 10 patients, 1 segment in 4, and 3 segments in 2. Single level OLIF L5-S1 was performed in 4 patients, 2 level OLIF (L4-5-S1) in 10, 3 levels in 1, and 4 levels in 1. All cases were supplemented by posterior pedicle screw fixation; open instrumentation in 13 patients and percutaneous instrumentation in 3 patients. Staged operation was performed in 12 patients and single-staged OLIF and simultaneous posterior fixation in 4 patients. Average size of OLIF cage was 11.3 mm (range, 10-14) in height and 28.9mm (range, 26-30) in width. DBM was used for graft materials in all patients. Amount of intraoperative bleeding was average 84.7 ml (range, 50-150) per level and operating time was average 41.2 minutes (range, 36-100) per level. Mean VAS score of LBP was decreased from preoperative 6.5 to 2.2 at final follow-up, leg pain from 4.9 to 2.7, and mean ODI from 24.8 to 17.1. Complication was left common iliac vein injury in 1 patient. Mean intervertebral disc height was increased from preoperative 6.8 mm to 12.6mm at final follow-up, lumbar lordosis was from 24.4 degree to 38.8, segmental lordosis from 19.1 degrees to 27.7. The perioperative increase of disc height (p=0.008), lumbar lordosis (p< 0.001), and left foraminal height (p=0.028) of OLIF was significantly greater than those of TLIF.
Conclusion: Minimally invasive OLIF enables a surgeon to approach both L5-S1 and L2-5 lateral interbody space simultaneously in one lateral position. OLIF L5-S1 is a useful method to achieve restoration of disc height, lumbar lordosis, and foraminal height with small amount of intraoperative bleeding and relatively short operating time.
Keywords: Minimally invasive oblique lumbar interbody fusion, L5-S1, degenerative lumbar disease