Salter-Harris type III fracture of the lateral femoral condyle with a ruptured posterior cruciate ligament: an uncommon injury pattern.

We report a case of an obscure injury to the distal femoral epiphysis with an uncommon pattern in a 12-year-old boy following a road traffic accident. Initial plain radiographs of the knee were inconclusive. Further investigation with magnetic resonance imaging revealed Salter-Harris type III fracture of the lateral femoral condyle with a gap at the fracture site associated with avulsion of the posterior cruciate ligament. This potentially serious injury can be underestimated on plain radiographs and therefore any suspected injury to the distal femoral epiphysis should be thoroughly assessed and investigated to institute appropriate treatment and minimise the risk of long-term complications.