Which imaging modality is most sensitive for proximal fifth metatarsal stress fracture (Jones fracture)?

Which imaging modality is most sensitive for proximal fifth metatarsal stress fracture (Jones fracture)?

• A. CT
• B. MRI
• C. X-ray
• D. Ultrasound

Answer: (B)

Bone stress injuries in the proximal fifth metatarsal often start with marrow edema before a visible fracture line appears on X-ray. MRI is the most sensitive way to detect this early marrow signal change, showing edema and any occult fracture, and it can also reveal associated soft-tissue injuries. CT focuses on cortical bone detail and is excellent for outlining a visible fracture, but it misses early stress reactions because it doesn’t capture bone marrow changes as clearly. Ultrasound can assess soft tissues and surface cortex but isn’t reliable for deep, intramedullary injuries like a Jones fracture. Plain radiographs may be normal early and only later show fracture lines or periosteal reaction. Therefore, MRI provides the earliest and most sensitive detection for a proximal fifth metatarsal stress fracture.

Bone stress injuries in the proximal fifth metatarsal often start with marrow edema before a visible fracture line appears on X-ray. MRI is the most sensitive way to detect this early marrow signal change, showing edema and any occult fracture, and it can also reveal associated soft-tissue injuries. CT focuses on cortical bone detail and is excellent for outlining a visible fracture, but it misses early stress reactions because it doesn’t capture bone marrow changes as clearly. Ultrasound can assess soft tissues and surface cortex but isn’t reliable for deep, intramedullary injuries like a Jones fracture. Plain radiographs may be normal early and only later show fracture lines or periosteal reaction. Therefore, MRI provides the earliest and most sensitive detection for a proximal fifth metatarsal stress fracture.