MRI Findings in the Subchondral Bone Marrow: A Discussion of Conditions Including Transient Osteoporosis, Transient Bone Marrow Edema Syndrome, SONK, and Shifting Bone Marrow Edema of the Knee

Abstract

Bone marrow edema signal can be seen in many settings ranging from trauma and arthritis to less common conditions including transient osteoporosis, transient bone marrow edema syndrome, true osteonecrosis, spontaneous osteonecrosis, and shifting bone marrow edema. Terms such as spontaneous osteonecrosis of the knee (SONK) appear frequently in the radiology and orthopedics literature but are rarely described on true, histologic basis. This article reviews the less frequently encountered and less well understood entities and explores their potential pathophysiologies and significance.

Early Stage Spontaneous Osteonecrosis of the Knee: MR Imaging Findings

“…Also in our study subchondral hypointensity was not a bad prognostic factor and the treatment response according to clinical outcomes. In the literature it is reported that wide radial tears are seen more common in the meniscuses of spontaneous osteonecrotic patients (14). In this study, the most common meniscal pathology was found to be grade 2 meniscal degeneration in the medial meniscus posterior horn in 15 cases.…”

“…In the differential diagnosis of spontaneous osteonecrosis, pathologies are defined under the title of oedema in bone marrow (transient osteoporosis, regional migratory osteoporosis, reflex sympathetic dystrophy) and pathologies which cause bone marrow oedema such as osteochondritis dissecans (OCD), trauma and arthritis. In various studies, it is commonly stated that it is difficult to differentiate early spontaneous osteonecrosis and bone marrow oedema syndromes (13,14). Yates et al (13) reported that the most significant difference between early stage spontaneous osteonecrosis and bone marrow oedema syndromes is the presence of focal subchondral lesions on MR images.…”

“…In other 8 cases (5 female, 3 male), medial joint surfaces were affected typicaly. The lateral surface of the femoral condyle is generally involved in osteochondritis dissecans, whereas in spontaneous osteonecrosis the weight bearing medial surface of the femoral condyle and tibial plateau are involved (14). Contour depression was found on medial weight bearing joint surfaces in 2 cases.…”

Dor aguda no joelho do paciente idoso

“…A imagem da RM é totalmente diferente da osteonecrose avascular que ocorre por uso de corticóide, alcoolismo, lúpus, hemoglobinopatias, pacientes portadores de HIV, como descrevem Lecouvet et al (8) . Gil et al consideram que a etiologia é traumática, decorrente de fratura por estresse agravada pela presença de lesão meniscal instável (4) .…”

“…O comprometimento do côndilo femoral medial é muito mais freqüente (4)(5) . O exame radiográfico Figura 1 -RM demonstrando lesão meniscal, com o menisco subluxado e com edema ósseo no côndilo femoral demonstra a presença de lesão, apenas nos casos mais avançados (figura 3).…”