3D CT Analysis of Combined Cup and Stem Anteversion in Cases of Cup Navigation in Hip Arthroplasty

• Published in: Orthopedics (Thorofare, N.J.) Vol. 33; no. 10; pp. 48 - 51
• Main Authors: WASSILEW, Georgi I, PERKA, Carsten, KOENIG, Christian, JANZ, Viktor, ASBACH, Patrick, HASART, Olaf
• Format: Journal Article
• Language: English
• Published: Thorofare, NJ Slack 01.10.2010; SLACK INCORPORATED
• Subjects: Acetabulum - diagnostic imaging; Aged; Aged, 80 and over; Arthroplasty, Replacement, Hip - methods; Biological and medical sciences; Diseases of the osteoarticular system; Female; Hip Joint - diagnostic imaging; Hip Joint - physiopathology; Humans; Imaging, Three-Dimensional - methods; Joint surgery; Male; Medical sciences; Middle Aged; Monitoring, Intraoperative - methods; Navigation systems; Orthopedic surgery; Patients; Posture; Prostheses; Prosthesis Fitting - methods; Range of Motion, Articular; Retrospective Studies; Software; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery, Computer-Assisted - methods; Tomography; Tomography, X-Ray Computed - methods; Transplants & implants; Treatment Outcome; Germany; Hip prosthesis; Orthopedic surgery; Treatment; Radiodiagnosis; Anteversion; Orthopedics; Medical imagery; Computerized axial tomography; Stem; Cup
• ISSN: 0147-7447; 1938-2367
• DOI: 10.3928/01477447-20100510-53

Navigation of the cup in total hip arthroplasty is well analyzed and shows accurate results, reducing cup outliers of Lewinnek’s “safe zone.” With regard to the combined anteversion of cup and stem, however, a “new” safe zone with a range of 25° to 50° has been published. The aim of this study was to analyze total anteversion (cup and stem) by postoperative 3D computed tomography in isolated cup navigation cases. In 46 patients, the mean combined anteversion was 34.4° (range, 16.3°–57.3°, SD±9.3°) with 10 outliers. The mean cup anteversion was 19.5° (range, 11°–27°, SD±3.7°). Regarding Lewinnek’s “safe zone” (cup only), we observed 5 outliers. An improvement of technique of stem implantation or navigation may reduce outliers of combined anteversion.