Spontaneous Hemarthrosis of the Knee - Late Complication of Flexible Femur Nailing: A Case Report.

We present a case report of acute spontaneous knee hemarthosis due to erosion of the nail through the knee joint capsule in a boy, seven months following retrograde flexible nailing for fractured femur. Careful positioning of the location of the insertion site of flexible nails and proper nail tip management are important to avoid this rare late complication.