Renaud Lafage1, Frank Schwab1, Steve Glassman2, Shay Bess3, Bradley Harris3, Justin Sheer4, Robert Hart5, Breton Line6, Jensen Henry3, Doug Burton7, HanJo Kim1, Eric Klineberg8, Christopher Ames9, Virginie Lafage1. 1. Spine Service, Hospital for Special Surgery, New York, NY. 2. Department of Orthopedic Surgery, University of Louisville Medical Center, Louisville, KY. 3. Spine Division, Department of Orthopaedics, NYU Langone Medical Center, New York, NY. 4. Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL. 5. Department of Orthopaedic Surgery, Oregon Health Sciences University, Portland, OR. 6. Rocky Mountain Hospital for Children Denver, Denver, CO. 7. Department of Orthopaedic Surgery, University of Kansas Medical Center, Kansas City, KS. 8. Department of Orthopedic Surgery, University of California, Davis, Sacramento, CA. 9. Department of Neurosurgery, San Francisco Medical Center, University of California, CA.
Abstract
STUDY DESIGN: Retrospective cohort. OBJECTIVE: To explore proximal junctional kyphosis (PJK) as a function of age-adjusted surgical correction goals. SUMMARY OF BACKGROUND DATA: Recent adult spinal deformity (ASD) studies show that alignment targets are age-specific. Despite recognizing age and malalignment as PJK risk factors, no study has assessed the age-specific effects of alignment on PJK. METHODS: ASD patients with fusions to the pelvis were included and stratified into three groups: young adults (YA <40 years old), middle aged (MA: 40-65 years old), and the elderly (ED >65 years old). Analysis of variance compared the groups with respect to 1-year postoperative alignments and 1-year offsets from age-specific alignment targets. RESULTS: A total of 679 patients were enrolled (mean age = 61 years old, 77% female, body mass index = 28.1). At 1 year postoperatively, there was a significant decrease in pelvic tilt (PT; 29-23°), spinopelvic mismatch (pelvic incidence [PI]-lumbar lordosis [LL]) (28-5°), and sagittal vertical axis (SVA; 110-37 mm); overall incidence of PJK was 45.1%. Stratification by age (YA, n = 28; MA, n = 389; ED, n = 262) revealed an increase in PJK incidence with age: YA = 17.9%, MA = 43.8%, and ED = 50.2% (P < 0.001). PJK patients had smaller postoperative PI-LL mismatches (ED 0.8° vs. 9.8°, MA 3.1° vs. 7.3°) than non-PJK patients, without any significant differences in PT or SVA. Analysis of the postoperative offsets from age-specific norms revealed that PJK patients in the two older subgroups and in the study cohort as a whole were overcorrected as compared to non-PJK patients (PI-LL offset-all: -5.2° vs. 2.8°, MA: -1° vs. +4°, ED: -11° vs. -2°; SVA offset-all: -10 mm vs. 7 mm, MA: -3 mm vs. 10 mm, ED: -18 mm vs. -6 mm). The correlation coefficients between PJK angles and the offsets from age-adjusted objective were small (0.320 for PI-LL, 0.114 for PT, and 0.136 for SVA). CONCLUSION: Overall, this study suggests that PJK patients were overcorrected when compared to age-adjusted alignment goals. Certainly, elderly patients are subject to independent risk factors for PJK, making the prevention of PJK complex. However, individualized optimization of surgical alignment can improve outcomes. This emphasizes the need for surgeons to incorporate age-specific alignment targets into the standard preoperative planning process. LEVEL OF EVIDENCE: 3.
STUDY DESIGN: Retrospective cohort. OBJECTIVE: To explore proximal junctional kyphosis (PJK) as a function of age-adjusted surgical correction goals. SUMMARY OF BACKGROUND DATA: Recent adult spinal deformity (ASD) studies show that alignment targets are age-specific. Despite recognizing age and malalignment as PJK risk factors, no study has assessed the age-specific effects of alignment on PJK. METHODS:ASDpatients with fusions to the pelvis were included and stratified into three groups: young adults (YA <40 years old), middle aged (MA: 40-65 years old), and the elderly (ED >65 years old). Analysis of variance compared the groups with respect to 1-year postoperative alignments and 1-year offsets from age-specific alignment targets. RESULTS: A total of 679 patients were enrolled (mean age = 61 years old, 77% female, body mass index = 28.1). At 1 year postoperatively, there was a significant decrease in pelvic tilt (PT; 29-23°), spinopelvic mismatch (pelvic incidence [PI]-lumbar lordosis [LL]) (28-5°), and sagittal vertical axis (SVA; 110-37 mm); overall incidence of PJK was 45.1%. Stratification by age (YA, n = 28; MA, n = 389; ED, n = 262) revealed an increase in PJK incidence with age: YA = 17.9%, MA = 43.8%, and ED = 50.2% (P < 0.001). PJK patients had smaller postoperative PI-LL mismatches (ED 0.8° vs. 9.8°, MA 3.1° vs. 7.3°) than non-PJK patients, without any significant differences in PT or SVA. Analysis of the postoperative offsets from age-specific norms revealed that PJK patients in the two older subgroups and in the study cohort as a whole were overcorrected as compared to non-PJK patients (PI-LL offset-all: -5.2° vs. 2.8°, MA: -1° vs. +4°, ED: -11° vs. -2°; SVA offset-all: -10 mm vs. 7 mm, MA: -3 mm vs. 10 mm, ED: -18 mm vs. -6 mm). The correlation coefficients between PJK angles and the offsets from age-adjusted objective were small (0.320 for PI-LL, 0.114 for PT, and 0.136 for SVA). CONCLUSION: Overall, this study suggests that PJK patients were overcorrected when compared to age-adjusted alignment goals. Certainly, elderly patients are subject to independent risk factors for PJK, making the prevention of PJK complex. However, individualized optimization of surgical alignment can improve outcomes. This emphasizes the need for surgeons to incorporate age-specific alignment targets into the standard preoperative planning process. LEVEL OF EVIDENCE: 3.
Authors: Javier Pizones; Francisco Javier Sánchez Perez-Grueso; Lucía Moreno-Manzanaro; Fernando Escámez; Caglar Yilgor; Alba Vila-Casademunt; Nicomedes Fernández-Baíllo; José Miguel Sánchez-Márquez; Ibrahim Obeid; Frank Kleinstück; Ahmet Alanay; Ferran Pellisé Journal: Eur Spine J Date: 2021-11-08 Impact factor: 3.134
Authors: Jeffrey M Hills; S Tim Yoon; John M Rhee; Dheera Ananthakrishnan; Elliot Kim; Keith W Michael; Byron Stephens Journal: Int J Spine Surg Date: 2019-04-30