Subchondral insufficiency fractures and spontaneous osteonecrosis of the knee may not be related to osteoporosis.

Unlabelled: The term insufficiency fracture implies inadequate bone and is applied to some subchondral knee magnetic resonance images. We reviewed bone mineral density, body mass index, meniscal extrusion, comorbidities, and demographics in 32 knee insufficiency fracture patients. Only five were osteoporotic.