The anatomic study and surgical technique for lumbar spinal canal decompression with “pedicle-plasty” strategy

Abstract Background Disc and facet joint are essential for motion between vertebrae.In the treatment of lumbar burst fractures,intervertebral fusion or posterolateral fusion is often required after spinal decompression to rebuild spinal stability, but it may lead to the loss of motor units and the occurrence of adjacent segment diseases. In order to avoid the above situation, we propose lumbar spinal canal decompression with “pedicle-plasty” strategy (DPP).The important adjacent structures of DPP in the lumbar segments on CT and by using anatomical methods were measured and observed in this study. Then, we demonstrated the surgical procedure on cadaveric specimens. The range of the approach, operation space, and precautions were clarified through the above research, and this study can provide the anatomical basis for DPP in clinical practice. Methods First,image measurement analysis,the images of patients with lumbar spine CT examinations in our hospital without lumbar spine disease were selected to measure the osteotomy angle (OA), the distance from the intersection of the osteotomy surface and the skin to the posterior midline (DM), the transverse length of the osteotomy surface (TLOS), and the sagittal diameter of the outer edge of the superior articular process (SD). Secondary, cadaver study, the distance between the muscle space and midline(DMSM), the anterior and posterior diameters of the decompression(APDD), and the lateral traction distance of the lumbosacral plexus(TDLP) were measured on the cadaveric specimens. Finally, the surgical procedure was demonstrated. Results The OA ranged from 27.68°±4.59° to 38.34°±5.97°, the DM ranged from 43.44 ± 6.29 mm to 68.33 ± 12.06 mm, the TLOS ranged from 16.84 ± 2.19 mm to 19.64 ± 2.36 mm, and the SD ranged from 22.49 ± 1.74 mm to 25.53 ± 2.21 mm. DMM ranged from (45.53 ± 5.73) mm to (65.46 ± 6.43) mm. APDD were between 10.51 ± 3.59 and 12.12 ± 4.54 mm, and TDLP was between 3.28 ± 0.81 mm and 6.27 ± 0.62 mm. DPP was successfully performed on cadaveric specimens. Conclusions The approach reaches the outer edge of the articular process through the space between the longissimus and lumbar iliocostalis, and this approach allows for less stripping of both the origin and insertion point of the muscle. An accurate measurement of OA by CT before an oblique osteotomy can reduce pedicle splitting. A spinal canal decompression can be completed through a flat oval lateral window, and then the pedicle is reduced to preserve the integrity of the bone tissue. DPP, as a novel surgical technique for the treatment of lumbar burst fractures with occupation of bone fragments, can preserve the spinal motor unit to decrease the adjacent segment diseases because of no resection of intervertebral discs and no destruction of facet joints,and has certain developmental significance.