Computed tomography evaluation of frequency of morphological findings of femoroacetabular impingement

The purpose of this study is to determine mean AA and AV angle values; whether the mean AA and AV values differ among sexes; if there is difference in AA values between measurements in different quadrants; the frequency of AA values above 55º, decreased AV angles and CAR and whether there is any difference between males and females. 200 hip joints in 100 patients of ages 20-45 who applied to our Emergency Department between April 2013-August 2013 and had abdominopelvic CT imaging for acute abdomen etiology, who didn't have a history of spine or hip surgery, fractures in vertebrae, pelvic bones or femur, didn't have degenerative or developmental changes involving the hip joint, didn't have chronic renal failure and whose imaging didn't have movement related artifacts, were evaluated. The rotational axis of the neck of femur was determined and 4 radial images were formed with 30 degree intervals passing from anterosuperior quadrant of the femoral neck. CAR was evaluated in transverse images and AV angle was measured in transverse views at the level of fovea capitis. Mean AA values in the radial images varied between 39,0500º±6,32992 in A1 and 44,3200º±8,14366 in A3. When 4 quadrant AA values were compared in pairs, only A2 and A3 quadrants were observed not to be statistically significantly different (p>0.05), AA values in A2 and A3 quadrants were statistically found to be significantly higher compared to other quadrants (p<0.05). Comparing 4 quadrant measurements in men and women, A3 and A4 quadrants were seen to be statistically greater in men (p<0.05) whereas A1 and A2 quadrants were found to lack statistically significant difference (p>0.05). Mean AV angle of 84 hip joints in 42 males was 17,5119º±5,00961 and of 116 hip joints of 58 women was 20,7586º±5.28759, revealing a significantly higher AV angle in women compared to men (p<0.01). In 20% of hip joints, at least one of the measured quadrants had an AA greater than 55º, in 19.5% AV angle was smaller than 15º, and in 21.5% CAR was observed. In 57% of the patients and 44% of the hip joints at least one of the following was found to be present: CAR, AA value greater than 55º in at least one quadrant, AV angle less than 15º. The fact that FAI related morphological findings are observed so frequently suggests that these findings should be evaluated together with symptoms and physical examination findings for proper diagnosis of FAI