MR evaluation of the articular cartilage of the femoral head during traction. Correlation with resected femoral head.

OBJECTIVE

The purpose was to evaluate the articular cartilage of the hip joint with MR during traction and compare the findings with the resected specimen or arthroscopic findings.

MATERIAL AND METHODS

Eight healthy volunteers, 5 patients with osteonecrosis, 5 with acetabular dysplasia, and 5 with advanced osteoarthrosis underwent MR imaging to evaluate the articular cartilage of the hip joint. Coronal fat-suppressed 3D spoiled gradient-echo (SPGR) images were obtained during traction. Identical imaging was performed of all the resected femoral heads of the osteonecrosis and advanced osteoarthrosis patients, and was correlated with the macroscopic pathological findings.

RESULTS

The traction was effective and the femoral articular cartilage was clearly identified in all 8 control subjects, and in all cases of osteonecrosis and acetabular dysplasia. In 4 cases of osteonecrosis, chondral fracture was identified in the boundary between the necrosis and the normal area. In all cases of advanced osteoarthrosis, cartilage was identified only at the medial side. The MR images of osteonecrosis and advanced osteoarthrosis corresponded well with the MR images of the resected femoral heads and the macroscopic findings.

CONCLUSION

Fat suppressed 3D-SPGR during continuous leg traction was useful in detecting cartilage abnormalities.