Exostosis is a solitary benign bone tumor frequently observed in. children.
It may be totally quiescent or provoke complications. We report a case of
pseudo-aneurysm of the popliteal artery caused by an exostosis on the lower
metaphysis of the femur in a 12-year-old boy. This unusual complication mo
stly reported in young males (mean age 19 years) occurs in the context of a
n initial trauma in half the cases. Surgical treatment is a semi-emergency
requiring both bone and arterial repair. Preventive surgery should be discu
ssed for all cases of exostosis with a risk of arterial damage due to the g
ravity of the potential vascular complications.