statistical difference in obturator height in mm (AP 16.0 + 0.3 and FL 17.8 + 0.2; P = 7.2E-10). The mean intraobserver variability for the acetabular index was 1.8 + 0.2 and 1.7 + 0.2 degrees for AP and FL alignments, respectively (P = 0.58), and the mean interobserver variability was 1.7 + 0.1 and 1.7 + 0.1 degrees, respectively (P = 0.75). The measurements of linear variability between the AP and FL showed no statistical significant difference with the exception of the left Hilgenreiner distance in mm (AP 1.00 + 0.08 and FL 0.81 + 0.08; P = 0.02).
DISCUSSION: These results demonstrate that there is little clinical difference in variability of positioning and rotational variables between AP and FL radiographs for hip dysplasia. These results indicate that either image could be used assess to acetabular dysplasia thus decreasing risks of ionizing radiation.
LEVEL OF EVIDENCE: Level III.

PMID: 23389578 [PubMed - indexed for MEDLINE]

Read more... http://www.ncbi.nlm.nih.gov/pubmed/23389578?dopt=Abstract