title: Dynamic Hip Kinematics During the Golf Swing After Total Hip Arthroplasty.
abstract: Although most surgeons allow their patients to play golf after total hip arthroplasty (THA), the effect on the implant during the golf swing is still unclear.
  
  
  
  To evaluate hip kinematics during the golf swing after THA.
  
  
  
  Descriptive laboratory study.
  
  
  
  Eleven hips in 9 patients who underwent primary THA were analyzed. All patients were right-handed recreational golfers, and these 11 hips included 6 right hips and 5 left hips. Periodic radiographic images of the golf swing were taken using a flat-panel x-ray detector. Movements of the hip joint and components were assessed using 3-dimensional-to-2-dimensional model-to-image registration techniques. Liner-to-neck contact and translation of the femoral head with respect to the acetabular cup (cup-head translation) were examined. Hip kinematics, orientation of components, and maximum cup-head translation were compared between patients with and without liner-to-neck contact.
  
  
  
  On average, the golf swing produced approximately 50° of axial rotation in both lead and trail hips. Liner-to-neck contact was observed in 4 hips with elevated rim liners (2 lead hips and 2 trail hips) at maximum external rotation. Neither bone-to-bone nor bone-to-implant contact was observed at any phases of the golf swing in any of the hips. Four hips with liner-to-neck contact had significantly larger maximum external rotation (37.9° ± 7.0° vs 20.6° ± 9.9°, respectively; P = .01) and more cup anteversion (26.5° ± 6.1° vs 10.8° ± 8.9°, respectively; P = .01) than hips without liner-to-neck contact. No significant differences between hips with and without contact were found for cup inclination (42.0° ± 2.5° vs 38.1° ± 5.5°, respectively; P = .22), combined anteversion (45.3° ± 8.9° vs 51.4° ± 7.9°, respectively; P = .26), or maximum cup-head translation (1.3 ± 0.3 mm vs 1.5 ± 0.4 mm, respectively; P = .61).
  
  
  
  In this analysis, the golf swing did not produce excessive hip rotation or cup-head translation in any hips. However, liner-to-neck contact during the golf swing was observed in 36% of the hips, with unknown effects on the long-term results.
  
  
  
  Golf is an admissible sport after THA because dynamic hip stability was observed. However, the implant position, especially cup anteversion and the use of elevated rim liners, promoted liner-to-neck contact.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hara
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan yasunaka@ortho.med.kyushu-u.ac.jp.
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Nakashima
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hamai
authors.affiliation: Department of Biorobotics, Faculty of Engineering, Kyushu Sangyo University, Fukuoka, Japan.
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Higaki
authors.affiliation: Department of Biorobotics, Faculty of Engineering, Kyushu Sangyo University, Fukuoka, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Ikebe
authors.affiliation: Department of Information and Systems Engineering, Faculty of Information Engineering, Fukuoka Institute of Technology, Fukuoka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimoto
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Kensei
authors.initials: K
authors.lastname: Yoshimoto
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
mesh_terms: D000077:Acetabulum / Q000502:physiology; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D001696:Biomechanical Phenomena; D005260:Female; D005270:Femur Head / Q000502:physiology; D006055:Golf / Q000502:physiology*; D006621:Hip Joint / Q000502:physiology* / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009068:Movement; D012189:Retrospective Studies; D012399:Rotation
keywords: 3D-to-2D model-to-image registration techniques; cup-head translation; golf swing; kinematics; liner-to-neck contact; total hip arthroplasty