title: Reconstructed hip joint position and abductor muscle strength after total hip arthroplasty.
abstract: We evaluated 60 limbs in 30 patients with unilateral primary total hip arthroplasty and nondiseased contralateral hip. The ratio of femoral offset (FO) to the body weight lever arm (FO ratio) and the ratio of the height of hip center (HC) to pelvic height (HC ratio) were calculated on radiographs. Isometric hip abductor strength was measured by dynamometer. The ratio of normalized strength of the reconstructed side to that of the nonoperated side was calculated (strength ratio). The FO ratio correlated positively to the strength ratio (r = 0.491; P = .0059), whereas the HC ratio correlated negatively (r = -0.568; P = .0011). Slight increase of FO ratio along with restoration of normal hip joint center erring on the side of slight inferomedial cup positioning appeared to optimize hip abductor function.
authors.affiliation: Department of Orthopaedic Surgery, Kawasaki Hospital, Yame, Fukuoka, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Asayama
authors.forename: Samatchai
authors.initials: S
authors.lastname: Chamnongkich
authors.forename: Kathy J
authors.initials: KJ
authors.lastname: Simpson
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Kinsey
authors.forename: Ormonde M
authors.initials: OM
authors.lastname: Mahoney
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D011859:Radiography