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Three-dimensional assessment of cam engagement in femoroacetabular impingement
Emmanuel A Audenaert1, Peter Mahieu, Christophe Pattyn
1Department of Orthopaedic Surgery and Traumatology, Ghent University Hospital, Ghent, Belgium. emmanuel.audenaert@ugent.be
Insights
This study reveals how cam engagement occurs in femoroacetabular impingement. Cam lesions frequently abut acetabular cartilage during hip flexion, abduction, and internal rotation, particularly in the anterosuperior quadrant.
Area of Science:
- Orthopedic surgery
- Biomechanical analysis
- Hip joint imaging
Background:
- Symptomatic femoroacetabular impingement (FAI) involves abnormal hip joint contact.
- Cam-type FAI is characterized by an abnormal femoral head-neck junction.
- Understanding cam engagement during motion is crucial for FAI management.
Purpose of the Study:
- To 3-dimensionally assess cam engagement in male patients with symptomatic femoroacetabular impingement during motion.
- To analyze the dynamic interaction between the cam lesion and acetabular cartilage.
Main Methods:
- Investigated 13 hips with cam-type impingement.
- Determined patient anatomy and clinical range of motion.
- Utilized 3-dimensional segmentation and reconstruction for dynamic analysis of cam lesions.
Main Results:
- Cam engagement with acetabular cartilage occurred in flexion (54%) and abduction (84%).
- Internal rotation at 90° flexion caused cam intrusion in 77% of cases.
- Neutral rotation showed no conflict; anterosuperior acetabular quadrant was consistently involved.
Conclusions:
- Cam lesions typically abut the anterosuperior acetabular cartilage during internal rotation in 90° flexion.
- Abduction and flexion involve different cam lesion portions (lateral and medial, respectively).
- Cam intrusion consistently affects the anterosuperior acetabular cartilage area across various motions.
Purpose:
The purpose of our study was to 3-dimensionally assess cam engagement in male patients with symptomatic femoroacetabular impingement during motion.
Methods:
A total of 13 hips with cam-type impingement were investigated. Patient anatomy and clinical range of motion were determined. After 3-dimensional segmentation and reconstruction, the dynamic behavior of the cam lesion was investigated for the previously analyzed motions.
Results:
Important differences in the pattern of cam engagement were noticed. Abutment of the cam lesion and the acetabular cartilage was observed in flexion in 7 hips (54%) and in abduction in 11 hips (84%). Internal rotation with the hip in 90° of flexion caused intrusion of the cam lesion into the joint in 10 of the investigated cases (77%). Neutral rotation did not cause any conflict between the cam lesion and acetabulum for the measured range of motion. A similar area in the anterosuperior quadrant of the acetabulum appeared to be involved in the different motions that were analyzed.
Conclusions:
Typically, during internal rotation in 90° of flexion, the centromedial portion of the cam lesion was found to abut against the anterosuperior quadrant of the acetabular cartilage. During abduction and flexion, this appeared to be the lateral and medial portions of the cam lesion, respectively. All motions causing cam intrusion appeared to focus on the same cartilage area of the acetabulum in its anterosuperior quadrant.
