Introduction
Etiology and pathophysiology
Cam lesions | Pincer lesions | |
---|---|---|
Primary | Idiopathic | Idiopathic |
Secondary | • Developmental | • Developmental |
• Coxa vara | • Coxa profunda | |
• Perthes disease | • Protrusio acetabuli | |
• SCFE | • Traumatic | |
• Traumatic | • Post-traumatic deformity of acetabulum | |
• Malunited femoral neck fracture | • Iatrogenic | |
• Iatrogenic | • Overcorrection of hip dysplasia | |
• Femoral head osteotomy |
MR imaging technique
3T (1.5T) | Coronal STIR wide FOV | Axial PD wide FOV | Sagittal PD | Axial oblique PD | Coronal PD |
---|---|---|---|---|---|
TR/TE (ms) | 4000/19 (4000/17) | 4800/40 (4000/30) | 4000/30 (3500/26) | 4000/40 (4000/26) | 4000/32 (4000/26) |
Flip angle | 180 (180) | 180 (180) | 180 (180) | 180 (180) | 180 (180) |
ETL | 12 (7) | 12 (7) | 12 (8) | 12 (9) | 12 (7) |
RBW (kHz) | 50 (32) | 50 (32) | 50 (32) | 50 (32) | 50 (32) |
NEX | 2 (2) | 1 (2) | 2 (3) | 2 (3) | 2 (3) |
Matrix | 288 × 288 (256 × 192) | 512 × 256 (512 × 256) | 512 × 384 (512 × 384) | 512 × 320 (512 × 256) | 512 × 384 (512 × 384) |
FOV (cm) | 38 (34) | 36 (36) | 19 (20) | 19 (20) | 19 (20) |
Slice thickness (mm)/gap | 5.5/0 (5.0/0) | 5.0/0 (5.0/0) | 2.5/0 (2.5–2.8/0) | 3.0/0 (3.0/0) | 3.0 (3.0/0) |
Preoperative evaluation
Preoperative FAI reporting checklist | |
---|---|
Osseous morphological abnormalities | Cam lesion Pincer lesion - Superior acetabular retroversion - True acetabular retroversion - Global acetabular overcoverage: coxa profunda or protrusio Mixed cam/pincer deformity |
Labral lesions | Chondrolabral separation Labral tear or degeneration Intralabral ossification |
Cartilage | Chondral delamination Chondral loss Other signs of osteoarthritis: subchondral cysts, sclerosis, osteophytes |
Measurements | Alpha angle Femoral anteversion |
Associated injuries | Pubic symphysis stress reaction Adductor aponeurosis injury Tendinopathy and tendon tears: hip flexors, abductors, and hamstrings. |