Hip CT measurements 

00:00 - Intro
01:30 - Acetabular Version measurement
04:42 - Femoral Version measurement
08:07 - Alpha Angle measurement
This video shows you how I make the following measurements on a pelvis CT:
Acetabular version or anteversion angle
* triradiate cartilage present (open physis): 14° ± 4°
* triradiate absent (closed physis): 19° ± 4°
* smaller values may indicate acetabular retroversion
Femoral anteversion
* 30-40° at birth, and about 15° by adulthood.
Femoroacetabular alpha angle
* Abnormal if more than 55 - 60 degrees
* Abnormally high values may indicate femeroacetabular impingement (FAI), cam morphology.
3D Anatomy made using Complete Anatomy
#radiology #FAI #CT #pediatricradiology #acetabularversion #femoralversion #alphangle
References:
Hingsammer AM, Bixby S, Zurakowski D, Yen YM, Kim YJ. How do acetabular version and femoral head coverage change with skeletal maturity? Clin Orthop Relat Res. 2015 Apr;473(4):1224-33. doi: 10.1007/s11999-014-4014-y. PMID: 25344405; PMCID: PMC4353546.
pubmed.ncbi.nlm.nih.gov/25344...
Sutter R, Dietrich TJ, Zingg PO, Pfirrmann CW. Femoral antetorsion: comparing asymptomatic volunteers and patients with femoroacetabular impingement. Radiology. 2012 May;263(2):475-83. doi: 10.1148/radiol.12111903. Epub 2012 Mar 8. PMID: 22403167.
pubmed.ncbi.nlm.nih.gov/22403...
Chakraverty JK, Sullivan C, Gan C, Narayanaswamy S, Kamath S. Cam and pincer femoroacetabular impingement: CT findings of features resembling femoroacetabular impingement in a young population without symptoms. AJR Am J Roentgenol. 2013 Feb;200(2):389-95. doi: 10.2214/AJR.12.8546. PMID: 23345362.
pubmed.ncbi.nlm.nih.gov/23345...