Quantification of Pelvic Tilt in Total Hip Arthroplasty
- 622 Downloads
In THA, anterior or posterior tilt of the pelvis changes the position of the acetabular component on the coronal plane of the body as compared with its anatomic position in the pelvic bone. To understand the occurrence and clinical importance for patients with pelvic tilt on an operating room table in the lateral decubitus position, we studied 436 patients (477 hips) undergoing primary THA using an imageless computer navigation system that measured tilt. We determined the distribution and magnitude of pelvic tilt, especially tilt of 10° or greater. The distribution of tilt had a range of 25° posterior to 20° anterior. Twenty-nine of 477 (6.1%) hips had zero tilt; 251 (52.6%) had tilt of 1° to 5°; 120 (25.2%) had tilt of 6° to 9°; and 77 (16.1%) had tilt of 10° or greater. The conversion factor for acetabular anteversion has been determined by a mathematical formula by Lembeck et al. and was confirmed by us in practice. Measurement of pelvic tilt during the performance of THA will improve the accuracy of cup position, especially allowing anteversion to be measured on the coronal plane.
Level of Evidence: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
KeywordsCoronal Plane Pelvic Tilt Lateral Decubitus Position Computer Navigation Pubic Tubercle
We thank Patricia Paul for assistance in preparing this manuscript.
- 1.American Standards for Testing and Materials. Annual Book of American Society for Testing and Materials Standards. Volume E177–E190a. West Conshohocken, PA: ASTM International; 2002.Google Scholar
- 6.DiGioia AM, Jaramaz B, Blackwell M, Simon DA, Morgan F, Moody JE, Nikou C, Colgan BD, Aston CA, Labarca RS, Kischell E, Kanade T. The Otto Aufranc Award. Image guided navigation system to measure intraoperatively acetabular implant alignment. Clin Orthop Relat Res. 1998;355:8–22.CrossRefPubMedGoogle Scholar
- 7.Dorr LD. Hip Arthroplasty: Minimally Invasive Techniques and Computer Navigation. Philadelphia, PA: Saunders Elsevier; 2006.Google Scholar
- 15.Malik A, Wan Z, Jaramaz B, Bowman G, Dorr LD. A validation model for measurement of acetabular component position. J Arthroplasty. 2009 June 22 [Epub ahead of print].Google Scholar