title: Application of Navigated Ultrasound for Assessment of the Anterior Pelvic Plane in Patients With Degenerative Hip Diseases.
abstract: OBJECTIVE
  Correct positioning of the acetabular cup is the key for successful total-hip replacement. In common clinical practice, the target alignment of the cup is defined with respect to the anterior pelvic plane. In patients with substantial anterior pelvic plane inclination, this condition may lead to inappropriate distribution of the load on the cup, as most of the forces exerted within the hip joint act along the vertical axis. With the known pelvic inclination, it is possible to readjust the position of the cup with respect to the individual posture of the patient. In this work, we present the first clinical evaluation of a new approach to measurement of the pelvic tilt angle using navigated ultrasound.
  
  
  METHODS
  In our method, the ultrasound probe is tracked with an optical localizer implemented on a handheld mobile device. The method was tested by taking preoperative measurements from 20 patients with osteoarthritis in standing, sitting, and supine positions.
  
  
  RESULTS
  The mean values of the measured angles were consistent with the corresponding results reported by other authors.
  
  
  CONCLUSIONS
  Considering the noninvasiveness of the method and affordability of the hardware used in our system, it can be used in preoperative and postoperative measurements of pelvic orientation for supporting surgery planning and evaluation of treatment outcomes.
authors.affiliation: Trauma and Orthopedic Department, Hospital of the Ministry of Internal Affairs, Wroclaw, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kochman
authors.affiliation: Department of Measurements and Electronics, AGH University of Science and Technology, Krakow, Poland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Goral
authors.affiliation: Aesculap AG, Tuttlingen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Martin
authors.affiliation: Trauma and Orthopedic Department, Hospital of the Ministry of Internal Affairs, Wroclaw, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Marek
authors.affiliation: Aesculap AG, Tuttlingen, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Kozak
authors.affiliation: Department of Otolaryngology and Head and Neck Surgery, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Morawska-Kochman
authors.affiliation: Clinic of Orthopedics and Pediatric Orthopedics, Medical University of Lodz, Lodz, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Synder
mesh_terms: D000465:Algorithms; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D008297:Male; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging* / Q000601:surgery; D056888:Patient Positioning / Q000295:instrumentation* / Q000379:methods; D010384:Pelvic Bones / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods
keywords: computer-assisted surgery; hip osteoarthritis; musculoskeletal ultrasound; total-hip replacement; ultrasound imaging