In the condition of femoroacetabular impingement, the abnormal shape of the bone leads to abnormal forces on the labrum and articular cartilage and causes early damage and hip pain.
The x-ray picture below demonstrates the loss of sphericity, or rounded shape, of the femoral head at the junction between the head and neck along the top portion of the femur (the ball portion of the ball and socket joint). This type of impingement on the femoral side is termed CAM impingement.
Along the acetabulum, or the cup side of the joint, impingement may also occur, termed pincer impingement. The overcoverage on the acetabular side also leads to joint damage.
Mixed forms of impingement, in other words, having both CAM and Pincer impingement, also may occur.
In addition to treating the damage in the hip joint, the shape of the femoral head and neck can be reshaped arthroscopically to recreate a normal contour.
Evaluation of femoroacetabular impingement is completed through x-rays, and additional imaging may be helpful including MRI, CT scan, and software programs that interpret these types of images and guide the surgeon to the specific areas around the joint where FAI exists. Dr. Carreira may order additional imaging on a case by case basis, as the additional imaging serves as a detailed “road map” of the alignment of the pelvis. Femoral rotation and its contribution to stability and impingement are additional potential benefits of CT scanning and software processing of the images.
Hip Arthroscopy Rim Trimming
Hip Dynamic Examination
The hip arthroscopy video below demonstrates dynamic examination of the hip following acetabular rim trimming and femoral osteoplasty and labral (labrum) repair. The hip is brought through range of motion under anesthesia to check for adequate treatment of femoroacetabular impingement (FAI). The labral tissue is free of any impingement forces which had contributed to its damage.
Photos of Femoroacetabular Impingement (FAI)
Dr. Carreira presented a summary of FAI at the Georgia Orthopedic Society meeting in September of 2019 as a review for orthopedic surgeons in attendance.