Early changes in the hip joint following epiphysiolysis of the femoral head. Results of an MRT study

: With the aim of detecting patients at risk of developing coxarthritis, 34 patients were investigated prospectively by MRI 6-14 years after epiphysiolysis for slipped capital femoral head. In particular, cartilage changes were analysed by gradient-echo sequences. In 40% of the hip joints investigated cartilaginous lesions were present, detectable as irregularity and flattening of contour and more rarely as changes in signal intensity. In contrast, only 18% of the radiographs available revealed any pathology. When pelvic X-rays are normal or reveal slight sclerosis, cartilaginous lesions on MRI are considered early signs of coxarthrosis. This combination was seen especially often in patients with a primarily high angle of dislocation and in those who needed treatment by reposition or osteotomy. Only in 8 of the 17 hip joints showing sclerosis on conventional radiograms, sclerosis was also diagnosed by MRI, possibly because of partial volume and susceptibility effects at high field strength. Even with limited spatial resolution, cartilage examination is warranted in young patients in whom early osteoarthritis can be expected.