Tender et al. Journal of Medical Case Reports 2011, 5:454 http://www.jmedicalcasereports.com/content/5/1/454 Page 4 of 6 Figure 4 Intraoperative lateral fluoroscopic images of grade 2 L5-S1 anterolisthesis and grade 1 L4-5 retrolisthesis reduction and distraction (case 3). The spondylolisthesis (left) is reduced by using the percutaneous pedicle screws (middle), and the L5-S1 interspace is further distracted by using the two-level anterior axial rod. improvements in back function (65% to 10%), and no complications. Our patient was discharged from the hospital two days after the procedure. Wide indirect neuroforaminal decompression and solid fixation con- structs were achieved with successful fusion at one-year follow-up. In the third case, a 50-year-old Caucasian man pre- sented with an 18-year history of axial low back pain and a one-year history of radiculopathy. The pain was described as 8 out of 10 on average and 10 out of 10 at its worst, of mechanical type, and refractory to conser- vative treatment. During a physical examination, our patient showed no sensory-motor deficits. Lumbar MRI showed a grade 2 spondylolisthesis at L5-S1 with severe bilateral foraminal stenosis and a grade 1 spondylolisth- esis at L4-5. The operative time was 323 minutes, and blood loss was minimal (50 mL). Treatment with the AxiaLIF System reduced the spondylolisthesis to grade 0 at L5-S1 and at L4-5. Our patient was ambulatory fol- lowing surgery and reported relief from back pain (10 to 3), resolution of radicular symptoms (10 to 2), improve- ments in back function (69% to 14%), and no complica- tions. Our patient was discharged from the hospital three days after the procedure. Wide indirect neurofor- aminal decompression and solid fixation constructs were achieved with successful fusion at one-year follow-up. Discussion Lumbosacral spondylolisthesis presents a challenge for the spine surgeon and is traditionally treated by either open anterior or posterior approaches. The surgical goals are to decompress the neural structures and to provide the appropriate environment for a solid fusion. The decompression, which is important for sagittal bal- ance preservation [8], can be performed directly by removal of the lamina and pars interarticularis or indir- ectly by distraction of the spinal interspace or reduction of spondylolisthesis or both [9-11]. The advent of minimally invasive access techniques has revolutionized the field of spine surgery. The Figure 5 Computed tomographic midline sagittal images of the lumbosacral spine demonstrate postoperative spinal alignment for L5-S1 (case 1, left) and L4-5, L5-S1 (case 3, right) constructs.