ePoster #740 - ISHA Annual Scientific Meeting 2016

Radial Center-Edge Angle Calculated By Acetabular Coverage Analysis Software “ Acx Dynamics ” In Pincer Type Femoroacetabular Impingement.

Shoichi Nishikino, MD, Hamamatsu, Shizuoka JAPAN
Hironobu Hoshino, MD, PhD, Hamamatsu, Shizuoka JAPAN
Hiroshi Koyama, MD, PhD, Hamamatsu, Shizuoka JAPAN
Yukihiro Matsuyama, Prof., Hamamatsu, Shizuoka JAPAN
Soshi Uchida, MD, PhD, Kitakyushu, Fukuoka JAPAN

Hamamatsu University School of Medicine , Hamamatsu, JAPAN

FDA Status Not Applicable

Summary: RCE calculated by ACX might be a useful tool to evaluate the acetabular morphology followed by pincer resection in hip arthroscopic surgery.

Abstract:
Introduction: ACX dynamics (ACX) software enables evaluation of three dimensional acetabular coverage as radial center-edge angle (RCE) on a plain antero-posterior radiograph of pelvis. RCE is defined by the angle formed by two lines, the line connecting the femoral head center to the acetabular edge and the vertical line through the femoral head, on various radial planes. The purpose of this study was to evaluate the anterosuperior acetabular coverage quantitatively in pincer type FAI using RCE calculated by ACX. Methods: The subjects of the present study were 30 hips (16 males, 14 females, average 37.1 years old) undergoing hip arthroscopic surgery for pincer type FAI (CE angle >=40°, CE angle>=30° and ARO<=0°, or CE angle>=25° and COS positive). We used as a control group 30 hips (15 males, 15 females, average 39.4 years old) who had asymptomatic hip joints with no osteoarthritic change(<=Tönnis grade 1), no pincer type FAI and no dysplasia(CE angle>=25°). RCE was semi-automatically evaluated by ACX and measured on each radial planes (every 15 degrees, from anterior border expressed as 0° to posterior border expressed as 180°). We investigated the difference between pincer type FAI group and control group. Results: There were significant statistical differences between the two groups in 45°-75°RCE (P<0.01). In those regions, RCEs in pincer type FAI group were significantly higher than those in control group. The average differences (absolute value) were 11.9± 4.0° for RCE in 45°, 10.8 ± 3.6° for RCE in 60°, 9.5 ± 3.4° for RCE in 75°, respectively. These regions were clinically important to evaluate acetabular morphology of the patient with pincer type FAI. Conclusions: For the treatment of the patients with pincer type FAI, RCE calculated by ACX might be a useful tool to evaluate the acetabular morphology followed by pincer resection in hip arthroscopic surgery.