title: Influence of hip position on knee flexion angle in patients undergoing total knee arthroplasty.
abstract: The influence of hip position on knee flexion angle before total knee arthroplasty (TKA) and that after TKA were investigated and compared. Sixty-six patients (70 knees) with osteoarthritis who were undergoing TKA were examined using lateral radiographs of maximum knee flexion angle with the hip joint at 0 degrees extension and 90 degrees flexion. The postoperative rate of decrease in knee flexion angle caused by hip extension was significantly larger compared with the value before surgery. The preoperative rate of decrease in knee flexion angle caused by hip extension showed strong inverse correlation with the preoperative and postoperative knee flexion angle ratio. In conclusion, tightness of the extensor mechanism is present in all knees undergoing TKA and especially has a strong influence on the postoperative flexion angle of the knee.
authors.affiliation: Department of Orthopedic Surgery, Hyogo Rehabilitation Center Hospital, Kobe, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tsumura
authors.forename: Seiji
authors.initials: S
authors.lastname: Kubo
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Shiba
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yoshiya
mesh_terms: D019645:Arthroplasty, Replacement, Knee; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011187:Posture; D011859:Radiography; D016059:Range of Motion, Articular