title: Sagittal spinopelvic alignment predicts hip function after total hip arthroplasty.
abstract: The aim of this study was to investigate the association between preoperative sagittal spinopelvic alignment and postoperative clinical outcomes after total hip arthroplasty (THA). This retrospective study included 92 patients with hip osteoarthritis who underwent primary THA between May 2013 and October 2015. Patients' characteristics, radiographic sagittal spinopelvic parameters and modified Harris Hip Scores, including function scores (gait scores and functional activities scores), were investigated. Multivariate linear regression analysis was performed to determine the associations between each preoperative sagittal spinopelvic parameter and postoperative hip function The preoperative sagittal spinopelvic parameters that were associated with postoperative gait scores were sagittal vertical axis (adjusted β-coefficient=-0.28, P=0.02), lumbar lordosis angle (adjusted β-coefficient=0.29, P=0.0089), pelvic tilt (adjusted β-coefficient=-0.25, P=0.045), sacral slope (adjusted β-coefficient=0.27, P=0.017) and pelvic incidence minus lumbar lordosis angle (adjusted β-coefficient=-0.31, P=0.01). The preoperative sagittal spinopelvic parameters that were related to the postoperative functional activities scores were sagittal vertical axis (adjusted β-coefficient=-0.38, P=0.0051) and pelvic incidence minus lumbar lordosis angle (adjusted β-coefficient=-0.39, P=0.0033). Patients with preoperative imbalanced sagittal alignment such as larger sagittal vertical axis, larger pelvic incidence minus lumbar lordosis and retroversion of pelvis had poorer clinical outcomes than others after THA. While, those preoperative imbalanced patients with anteversion of pelvis may have a compensatory ability which could correct the abnormal sagittal alignment after THA. Preoperative sagittal spinopelvic alignment affected postoperative clinical outcomes after THA.
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Ochi
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. Electronic address: yhomma@juntendo.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Homma
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Baba
authors.affiliation: Department of Orthopedic Surgery, Juntendo Tokyo Koto Geriatric Medical Center, 3-3-20 Shinsuna, Koto-ku, Tokyo, 136-3111, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Nojiri
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Matsumoto
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kaneko
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000503:physiopathology / Q000601:surgery*; D010388:Pelvis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011184:Postoperative Period; D011237:Predictive Value of Tests; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013121:Spinal Curvatures / Q000000981:diagnostic imaging / Q000503:physiopathology*
keywords: Hip function; Sagittal alignment; Sagittal vertical axis; Spinopelvic; Total hip arthroplasty