Standardization of hemipelvis alignment for in vitro biomechanical testing. Issue 6 (19th December 2017)

• Record Type: Journal Article
• Authors: Morosato, Federico; Traina, Francesco; Cristofolini, Luca
• Is Part Of: Journal of orthopaedic research. Volume 36:Issue 6(2018)
• Page Start: 1645
• Page End: 1652
• Publication Date: 2017-12-19
• Subjects: anatomical reference frame -- in vitro alignment -- biomechanical testing -- hemipelvis -- acetabular plane; Orthopedics -- Periodicals; Musculoskeletal system -- Periodicals; 616.7
• DOI: 10.1002/jor.23825
• Languages: English
• ISSNs: 0736-0266

Abstract

ABSTRACT: Although in vitro biomechanical tests are regularly performed, the definition of a suitable reference frame for hemipelvic specimens is still a challenge. The aims of the present study were to: (i) define a reference frame for the human hemipelvis suitable for in vitro applications, based on robust anatomical landmarks; (ii) identify the alignment of a hemipelvis based on the alignment of a whole pelvis (including right/left and male/female differences); (iii) identify the relative alignment of the proposed in vitro reference frame with respect to a reference frame commonly used in gait analysis; (iv) create an in vitro alignment procedure easy, robust and inexpensive; (v) quantify the intra‐operator repeatability and inter‐operator reproducibility of the procedure. A procedure to univocally identify the anatomical landmarks was created, exploiting the in vitro accessibility of the specimen's surface. Through the analysis on 53 CT scans (106 hemipelvises), the alignment of the hemipelvis based on the alignment of a whole pelvis was analyzed: differences between male/female and right/left hemipelvises were not statistically significant To overcome the uncertainty in the identification of the acetabular rim, a standard acetabular plane was defined. An alignment procedure was developed to implement such anatomical reference frame. The intra‐operator repeatability and the inter‐operator reproducibility were quantified with four operators, on male and female hemipelvises. The intra‐operator repeatability was better than 1.5°. The inter‐operator reproducibility was better than 2.0°. Alignment in the transverse plane was the most repeatable. The presented procedure to align hemipelvic specimens is sufficiently robust, standardized, and accessible. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1645–1652, 2018. Abstract : In order to identify the alignment of the human hemipelvis based on the anatomical alignment of a whole pelvis, 53 CT scans (106 hemipelvises) were analyzed: differences among males and females were not statistically significant. Results were combined with the alignment of a standard acetabular plane to implement an alignment procedure for in vitro applications. The intra‐operator repeatability was better than 1.5°; the inter‐operator reproducibility better than 2.0°. The proposed alignment will help performing reproducible biomechanical tests involving the hemipelvis.