Radiographic evaluation of femoral acetabular impingement
10.3760/cma.j.cn121113-20230808-00081
- VernacularTitle:髋臼股骨撞击症的影像学评估
- Author:
Xin ZHANG
1
;
Gang YANG
;
Yan XU
;
Hongjie HUANG
;
Jiayi SHAO
;
Jianquan WANG
;
Dingge LIU
;
Kaiping LIU
Author Information
1. 北京大学第三医院运动医学科（北京大学运动医学研究所，运动医学关节伤病北京市重点实验室，运动创伤治疗技术与器械教育部工程研究中心），北京 100191
- Keywords:
Hip;
Diagnostic imaging;
Sports medicine;
Femoral acetabular impingement
- From:
Chinese Journal of Orthopaedics
2023;43(23):1621-1630
- CountryChina
- Language:Chinese
-
Abstract:
Femoral acetabular impingement (FAI) is a condition characterized by abnormal anatomical structures of the femoral head and/or acetabulum, leading to impingement between the proximal femur and the rim of the acetabulum during hip movement. This impingement causes damage to the acetabular cartilage, labrum, chronic hip pain, and limited range of motion. The diagnosis of this condition requires evaluation based on symptoms, physical signs, and imaging examinations. Among these, imaging plays a crucial role in assessing the pathology of FAI. In recent years, imaging techniques have contributed to a deeper understanding of the mechanisms underlying FAI and the development of hip-preserving surgeries. The purpose of this paper is to provide a reference for the imaging-related diagnosis and measurement of FAI. X-ray films include pelvic anteroposterior view, false-profile view and 45°Dunn view. Doctors can understand the anatomical morphology of the femur and acetabulum by measuring relevant indicators in the X-ray films. For example, the α Angle of the femur >50°-60 ° in the pelvic anteroposterior view can indicate CAM-type FAI. However, the crisscross sign, posterior wall sign and LCE Angle >40° suggest Pincer type FAI. The ACE Angle, which reflects the anterior coverage of the acetabulum, was mainly measured on the false-profile view. The ACE Angle <20° is considered as insufficient anterior acetabular coverage, and acetabular dysplasia may be present.If it >40° is the anterior acetabular overcoverage, suggesting pincer-type FAI. The 45°Dunn view is mainly used to show the femoral head and neck deformity at 3 o'clock, where the femoroacetabular impingement is obvious. This position has a good indication effect for CAM-type FAI. CT can show the shape of the hip joint more intuitively by three-dimensional reconstruction of the patient's hip joint, which is convenient for surgical planning and postoperative evaluation. In addition, CT can also be used for the differential diagnosis of external hip impingement, such as ischiofemoral impingement, anterior inferior iliac spine impingement and greatertrochanteric impingement. MR Has excellent soft tissue imaging ability and can show other lesions that are difficult to be found by X-ray and CT, such as acetabular labrum and cartilage injury. It is essential for preoperative evaluation. Appropriate imaging examination plays a key role in the diagnosis and treatment of FAI.
