PT - JOURNAL ARTICLE AU - BRANCHE, KATHERINE AU - NETSANET, RAHWA AU - NOSHCHENKO, ANDRIY AU - BURGER, EVALINA AU - PATEL, VIKAS AU - OU-YANG, DAVID AU - KLECK, CHRISTOPHER J. TI - Radius of Curvature in Patient-Specific Short Rod Constructs Versus Standard Pre-Bent Rods AID - 10.14444/7143 DP - 2020 Dec 01 TA - International Journal of Spine Surgery PG - 944--948 VI - 14 IP - 6 4099 - https://www.ijssurgery.com/content/14/6/944.short 4100 - https://www.ijssurgery.com/content/14/6/944.full SO - Int J Spine Surg2020 Dec 01; 14 AB - Background: Recent studies support the need for sagittal alignment restoration when performing lumbar degenerative spinal fusions. The development of patient-specific spine rods (PSSRs) may help maintain or improve sagittal alignment in these surgeries.Methods: A retrospective review was conducted for patients who underwent posterior spinal surgeries involving 4 or less levels. The preplanned PSSR radii of curvature (ROC) was compared with standard prebent rods with a ROC of 125 mm. All surgeries were performed at a single institution by 3 surgeons from September 2016 through October 2018. Data were then compared using a 2-tailed paired t test. PSSR had either 1 or 2 definitive ROCs.Results: For rods with 2 ROCs, the “cranial” curve was measured between the upper instrumented level and L4 or L5. The “caudal” curve was measured between L4 or L5 and the lower instrumented level. The PSSR with 1 ROC and the caudal portion of the rods with 2 ROCs were significantly smaller than the industry standard ROC.Conclusions: PSSR demonstrate more acute ROC than industry standard rods. In PSRs, the most lordosis occurs between L4-S1 and flattens out at the thoracolumbar junction, mimicking the normal distribution of lumbar lordosis. PSSRs could help achieve or maintain sagittal alignment and prevent the sequela of flat back syndrome.