Achieving appropriate spinopelvic alignment in deformity surgery has been correlated with improvement in pain and disability. Minimally invasive surgery (MIS) techniques have been used to treat adult spinal deformity (ASD); however, there is concern for inadequate sagittal plane correction. Because age can influence the degree of sagittal correction required, the purpose of this study was to analyze whether obtaining optimal spinopelvic alignment is required in the elderly to obtain clinical improvement.
A multicenter database of ASD patients was queried. Inclusion criteria were age ≥ 18 years; an MIS component as part of the index procedure; at least one of the following: pelvic tilt (PT) > 20°, sagittal vertical axis (SVA) > 50 mm, pelvic incidence to lumbar lordosis (PI-LL) mismatch > 10°, or coronal curve > 20°; and minimum follow-up of 2 years. Patients were stratified into younger (< 65 years) and older (≥ 65 years) cohorts. Within each cohort, patients were categorized into aligned (AL) or mal-aligned (MAL) subgroups based on postoperative radiographic measurements. Mal-alignment was defined as a PI-LL > 10° or SVA > 50 mm. Pre- and postoperative radiographic and clinical outcomes were compared.
Of the 185 patients, 107 were in the younger cohort and 78 in the older cohort. Based on postoperative radiographs, 36 (33.6%) of the younger patients were in the AL subgroup and 71 (66.4%) were in the MAL subgroup. The older patients were divided into 2 subgroups based on alignment; there were 26 (33.3%) patients in the AL and 52 (66.7%) in the MAL subgroups. Overall, patients within both younger and older cohorts significantly improved with regard to postoperative visual analog scale (VAS) scores for back and leg pain and Oswestry Disability Index (ODI) scores. In the younger cohort, there were no significant differences in postoperative VAS back and leg pain scores between the AL and MAL subgroups. However, the postoperative ODI score of 37.9 in the MAL subgroup was significantly worse than the ODI score of 28.5 in the AL subgroup (p = 0.019). In the older cohort, there were no significant differences in postoperative VAS back and leg pain score or ODI between the AL and MAL subgroups.
MIS techniques did not achieve optimal spinopelvic alignment in most cases. However, age appears to impact the degree of sagittal correction required. In older patients, optimal spinopelvic alignment thresholds did not need to be achieved to obtain similar symptomatic improvement. Conversely, in younger patients stricter adherence to optimal spinopelvic alignment thresholds may be needed.
Correspondence Paul Park: University of Michigan, Ann Arbor, MI. firstname.lastname@example.org.
INCLUDE WHEN CITING Published online August 10, 2018; DOI: 10.3171/2018.4.SPINE171153.
Disclosures Dr. Park: consultant for Globus, NuVasive, Medtronic, and AlloSource; and royalties from Globus. Dr. Fu: consultant for SI-Bone and 4Web. Dr. Mummaneni: consultant for DePuy Spine, Globus, and Stryker; direct stock ownership in Spinicity/ISD; statistical analysis for study/writing or editorial assistance on manuscript from ISSG; support of non–study-related clinical or research effort from NREF; royalties from DePuy Spine, Springer Publishing, and Thieme Publishing; and honoraria from AOSpine. Dr. Uribe: consultant for NuVasive. Dr. Wang: consultant for DePuy Synthes Spine, K2M, Spineology, Stryker, and Globus; direct stock ownership in ISD; patent holder with DePuy Synthes Spine; and clinical or research support for this study from the Department of Defense. Dr. Nunley: direct stock ownership in Amedica Corp., Paradigm Spine, and Spineology; patent holder with K2M and LDR Spine; consultant for K2M; and speakers’ bureau for K2M and LDR Spine. Dr. Okonkwo: consultant for and royalties from NuVasive and Zimmer Biomet. Dr. Shaffrey: consultant for Medtronic, NuVasive, Zimmer Biomet; direct stock ownership in NuVasive; and patents with and royalties from Medtronic, NuVasive, and Zimmer Biomet. Dr. Mundis: consultant for NuVasive, K2M, and AlloSource; and patent holder with NuVasive and K2M. Dr. Chou: consultant for Medtronic and Globus. Dr. Eastlack: consultant for NuVasive, Aesulap, SeaSpine, K2M, and Titan; and ownership in NuVasive, Alphatec, and SeaSpine. Dr. Anand: consultant for Medtronic; direct stock ownership in Globus Medical and Medtronic; patent holder with Medtronic; and royalties from Medtronic, Globus Medical, and Elsevier. Dr. Than: consultant for Bioventus. Dr. Zavatsky: ownership in Vivex and Innovative Surgical Solutions; consultant for DePuy Synthes Spine, Stryker, Zimmer Biomet, Innovasis, and Integrity; and royalties from Zimmer Biomet.
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