Lumbar Sagittal Alignment after Fusion with Stand-alone Rectangular Cages |
Sang-Bok Lee, M.D., Eun-Sang Kim, M.D. and Whan Eoh, M.D. |
Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea |
Lumbar Sagittal Alignment after Fusion with Stand-alone Rectangular Cages |
Sang-Bok Lee, M.D., Eun-Sang Kim, M.D. and Whan Eoh, M.D. |
Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea |
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Abstract |
Objective We investigated whether the lumbar sagittal alignment can be obtained to normal range in patients who have undergone posterior lumbar interbody fusion(PLIF) with stand-alone rectangular cages
Methods Ninty eight patients underwent PLIF with stand-alone rectangular cage in 118 spinal segments. There were hernia- ted lumbar disc in 32 cases, post lamminectomy instability in 31 cases, degenerative disc disease in 21 cases, spondy- lolisthesis in 2 cases. Paired rectangular cages were placed posteriorly at L3-4 in 9 levels, L4-5 in 85 levels and L5-S1 in 24 levels. We measured total lumbar lordosis and segmental lordotic angle of the operative level using plain lateral radiographs preoperatively, 6 month and 12 month postoperatively.
Result: There was a mean increase of 4.6 in total lumbar lordosis, from 30.1 preoperatively to 34.7 12 month after surgery. At the same time point, measurement of segmental lordotic angle demonstrated mean gains of 0.8 at L3-4, 2.3 at L4-5 and 1.7 at L5-S1 segment, respectively. There was average segmental lordotic gain of 2.0 in all of the fused segments during the follow-up periods. Many of these patients showed more subsidence of cages at the posterior part of the body than anterior part.
Conclusion Even though the stand-alone rectangular cage has no intrinsic contour to induce lordosis, the lumbar sagittal alignment improved when PLIF was done at a single level mostly using this type of cage
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Keywords:
Posterior lumbar interbody fusionㆍRectangular cageㆍLordosis |
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