Diebo, Bassel GBalmaceno-Criss, MariahLafage, RenaudDaher, MohammadSingh, ManjotHamilton, D KojoSmith, Justin SEastlack, Robert KFessler, RichardGum, Jeffrey LGupta, Munish CHostin, RichardKebaish, Khaled MLewis, StephenLine, Breton GNunley, Pierce DMundis, Gregory MPassias, Peter GProtopsaltis, Themistocles STurner, JayBuell, ThomasScheer, Justin KMullin, JefferySoroceanu, AlexAmes, Christopher PBess, ShayShaffrey, Christopher ILenke, Lawrence GSchwab, Frank JLafage, VirginieBurton, Douglas CDaniels, Alan HInternational Spine Study Group (ISSG)2024-01-312024-01-312024-010362-24361528-1159https://hdl.handle.net/10161/29919<h4>Study design</h4>Retrospective analysis of prospectively collected data.<h4>Objective</h4>Evaluate the impact of correcting to normative segmental lordosis values on post-operative outcomes.<h4>Background</h4>Restoring lumbar lordosis magnitude is crucial in adult spinal deformity surgery, but the optimal location and segmental distribution remains unclear.<h4>Methods</h4>Patients were grouped based on offset to normative segmental lordosis values, extracted from recent publications. Matched patients were within 10% of the cohort's mean offset, less than or over 10% were under- and over-corrected. Surgical technique, PROMs, and surgical complications were compared across groups at baseline and 2-year.<h4>Results</h4>510 patients with an average age of 64.6, mean CCI 2.08, and average follow-up of 25 months. L4-5 was least likely to be matched (19.1%), while L4-S1 was the most likely (24.3%). More patients were overcorrected at proximal levels (T10-L2; Undercorrected, U: 32.2% vs. Matched, M: 21.7% vs. Overcorrected, O: 46.1%) and undercorrected at distal levels (L4-S1: U: 39.0% vs. M: 24.3% vs. O: 36.8%). Postoperative ODI was comparable across correction groups at all spinal levels except at L4-S1 and T10-L2/L4-S1, where overcorrected patients and matched were better than undercorrected (U: 32.1 vs. M: 25.4 vs. O: 26.5, P=0.005; U: 36.2 vs. M: 24.2 vs. O: 26.8, P=0.001; respectively). Patients overcorrected at T10-L2 experienced higher rates of proximal junctional failure (PJF) (U: 16.0% vs. M: 15.6% vs. O: 32.8%, P<0.001) and had greater posterior inclination of the upper instrumented vertebra (UIV) (U: -9.2±9.4° vs. M: -9.6±9.1° vs. O: -12.2±10.0°, P<0.001), whereas undercorrection at these levels led to higher rates of revision for implant failure (U: 14.2% vs. M: 7.3% vs. O: 6.4%, P=0.025).<h4>Conclusions</h4>Patients undergoing fusion for adult spinal deformity suffer higher rates of PJF with overcorrection and increased rates of implant failure with undercorrection based on normative segmental lordosis.<h4>Level of evidence</h4>IV.International Spine Study Group (ISSG)Journal article