Presentation
Slipped
Patient Data
Fracture of the distal left femoral diaphysis through a multiloculated expansile radiolucent bony lesion. There is endosteal scalloping of the distal femur at the lesion with cortical thinning. No periosteal reaction or associated soft tissue mass.
The rest of the visualised bones and joint show normal alignment, morphology and density.
Case Discussion
The underlying lesion is multilocular and extends through the medullary cavity, features which favour aneurysmal bone cyst over unicameral bone cyst or non-ossifying fibroma. MRI can help narrow the differential diagnosis by demonstrating fluid-fluid levels but in this case sampling at the time of fixation may be more appropriate.
In children, pathological fractures are often secondary to benign disease. Nevertheless, a malignant condition must always be formally ruled out.
Long above knee back slab cast applied prior to orthopaedic review.