TY - JOUR
T1 - Geographic and ethnic variations in radiographic disability thresholds
T2 - Analysis of North American and Japanese operative adult spinal deformity populations
AU - Ames, Christopher
AU - Gammal, Isaac
AU - Matsumoto, Morio
AU - Hosogane, Naobumi
AU - Smith, Justin S.
AU - Protopsaltis, Themistocles
AU - Yamato, Yu
AU - Matsuyama, Yukihiro
AU - Taneichi, Hiroshi
AU - Lafage, Renaud
AU - Ferrero, Emmanuelle
AU - Schwab, Frank J.
AU - Lafage, Virginie
N1 - Funding Information:
Dr Ames reports receiving funding from Depuy, Medtronic, Stryker, Aesculap, Biomet, Baxano Surgical, and Doctors Research Group. Dr V. Lafage reports receiving grants from SRS and the National Institutes of Health; serving as a board member for Nemaris Inc; and having speaking arrangements with Medicrea, Depuy, Nemaris Inc, and MSD. Dr Matsumoto reports receiving honorarium from Daiichi, Sankyo, and Jansen and grants from Ono, Teiijin, Hisamitsu, Zimmer, Kyocera, Biomet, Chugai, Eizai, and Kaken. Dr Smith reports receiving funding from Biomet, Nuvasive, Cerapedics, Medtronic, and Depuy. Dr Protopsaltis reports receiving funding from Medicrea, Biomet, and Alphaspine and grants from Zimmer. Dr Schwab reports receiving funding from MSD, K2M, and Medicrea; serving as a board member for Nemaris Inc; receiving grants from MSD and AO; and having speaking arrangements with Nuvasive and Biomet. The International Spine Study Group has received a grant from Depuy Synthes Spine. The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.
Publisher Copyright:
© 2015 by the Congress of Neurological Surgeons.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/6/1
Y1 - 2016/6/1
N2 - BACKGROUND: Thresholds for spinal pelvic parameters in adult spinal deformity (ASD) were previously defined in North American patients and are commonly used to guide surgical planning. However, it is unclear whether these same threshold parameters can be more widely applied in other geographic regions and in other ethnicities. OBJECTIVE: To evaluate the variation in the radiographic disability thresholds between North American and Japanese ASD populations and to adjust sagittal modifier thresholds accordingly. METHODS: Retrospective case series of 717 patients with ASD who had baseline radiographs and Oswestry Disability Index (ODI) from North America (n 518) and Japan (n 199) were studied. Patients were compared at baseline for ODI, ODI offset from age- and ethnic-specific values (ODIni), and radiographic parameters. RESULTS: Significant differences in classification were observed: A greater proportion of Japanese patients had marked pelvic tilt deformity, whereas a greater proportion of US patients had marked SVA deformity; no difference in the pelvic incidence-lumbar lordosis mismatch sagittal modifier was observed. Health-related quality-of-life scores also differed, with a greater ODI raw value observed in the US patients but similar ODIni scores between cohorts. Stratifying ODIni scores by sagittal modifier grades revealed similar disability scores corresponding to the 0 to + thresholds for pelvic tilt, pelvic incidence-lumbar lordosis mismatch, and sagittal vertical axis across ethnicities. Finally, linear regression analysis demonstrated that compared with US patients, Japanese patients had a lower estimated ODI corresponding to established thresholds of radiographic deformity. CONCLUSION: Our findings demonstrate significant variability in health-related quality-of-life measures and radiographic parameters between North American and Japanese patients, supporting the need for population-adjusted sagittal modifiers to more accurately classify deformity.
AB - BACKGROUND: Thresholds for spinal pelvic parameters in adult spinal deformity (ASD) were previously defined in North American patients and are commonly used to guide surgical planning. However, it is unclear whether these same threshold parameters can be more widely applied in other geographic regions and in other ethnicities. OBJECTIVE: To evaluate the variation in the radiographic disability thresholds between North American and Japanese ASD populations and to adjust sagittal modifier thresholds accordingly. METHODS: Retrospective case series of 717 patients with ASD who had baseline radiographs and Oswestry Disability Index (ODI) from North America (n 518) and Japan (n 199) were studied. Patients were compared at baseline for ODI, ODI offset from age- and ethnic-specific values (ODIni), and radiographic parameters. RESULTS: Significant differences in classification were observed: A greater proportion of Japanese patients had marked pelvic tilt deformity, whereas a greater proportion of US patients had marked SVA deformity; no difference in the pelvic incidence-lumbar lordosis mismatch sagittal modifier was observed. Health-related quality-of-life scores also differed, with a greater ODI raw value observed in the US patients but similar ODIni scores between cohorts. Stratifying ODIni scores by sagittal modifier grades revealed similar disability scores corresponding to the 0 to + thresholds for pelvic tilt, pelvic incidence-lumbar lordosis mismatch, and sagittal vertical axis across ethnicities. Finally, linear regression analysis demonstrated that compared with US patients, Japanese patients had a lower estimated ODI corresponding to established thresholds of radiographic deformity. CONCLUSION: Our findings demonstrate significant variability in health-related quality-of-life measures and radiographic parameters between North American and Japanese patients, supporting the need for population-adjusted sagittal modifiers to more accurately classify deformity.
KW - Adult spinal deformity
KW - Ethnicity
KW - HRQOL
KW - Radiographic parameters
KW - Sagittal alignment
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U2 - 10.1227/NEU.0000000000001184
DO - 10.1227/NEU.0000000000001184
M3 - Article
C2 - 26692107
AN - SCOPUS:84951299485
VL - 78
SP - 793
EP - 800
JO - Neurosurgery
JF - Neurosurgery
SN - 0148-396X
IS - 6
ER -