Neck axis distance
Citation, DOI & article data
The neck axis distance is a measurement of acetabular version, although it has only been described in one study (c.2022) 1.
On an AP pelvic x-ray, a line (N) is drawn along the axis of the femoral neck bisecting a circle of best fit drawn around the femoral head. The neck axis distance is the measurement between the anterior and posterior acetabular walls along line N 1,2.
- ≥14 mm is associated with excessive acetabular anteversion (i.e. >20°) 1,2
- 1. Nitschke A, Petersen B, Lambert J et al. Validation of Neck Axis Distance as a Radiographic Measure for Acetabular Anteversion. J Hip Preserv Surg. 2016;3(1):72-8. doi:10.1093/jhps/hnv082 - Pubmed
- 2. Welton K, Jesse M, Kraeutler M, Garabekyan T, Mei-Dan O. The Anteroposterior Pelvic Radiograph. J Bone Joint Surg. 2018;100(1):76-85. doi:10.2106/jbjs.17.00500 - Pubmed