FATTY MARROW CONVERSION OF THE PROXIMAL FEMORAL METAPHYSIS IN TRANSIENT BONE MARROW EDEMA SYNDROME
Shin-Yoon
Kim*, Kyung-Hoi Koo**, Keun-Taek Seo†, Yong-Sik Kim‡,
Yoon-Je Cho ?, and Byung-Woo Min MD ?
*Department of Orthopaedic Surgery, Kyungpook National University School
of Medicine, Taegu, South Korea;
**Department of Orthopaedic Surgery, Gyeong-Sang National University
School of Medicine, Chinju, South Korea;
†Department of Orthopaedic Surgery, Pusan National University School
of Medicine, Pusan, South Korea;
‡Department of Orthopaedic Surgery, The Catholic University of
Korea College of Medicine, Seoul, South Korea;
?Department of Orthopaedic Surgery, Kyung-Hee University School of Medicine,
Seoul, South Korea;
?Department of Orthopaedic Surgery, Keimyung University School of Medicine,
Taegu, South Korea;
The conversion of hematopoietic to fatty marrow of the proximal femoral metaphysis has been suggested as an etiologic factor of ischemia in the pathogenesis of femoral head osteonecrosis. To evaluate the marrow component of the proximal femoral metaphysis in transient bone marrow edema syndrome of the hip, T1-weighted magnetic resonance images of the hips in seven patients with transient bone marrow edema syndrome were reviewed. There were six men and one woman with a mean age of 36 years (range, 19-45 years). During the presence of marrow edema the marrow component of the proximal metaphysis is hard to determine with magnetic resonance images due to fluid collection in the marrow space. Thus, the marrow component was evaluated in follow-up magnetic resonance images, which showed resolution of the edema. The signal intensity of the proximal femoral metaphysis was compared with that of the greater trochanter. In all patients, the signal intensity of the proximal femoral metaphysis was isointense relative to that of the greater trochanter, which meant the fatty marrow conversion of the proximal femoral metaphysis. The current study suggests that ischemia is an etiologic factor of transient bone marrow edema syndrome.