One of the most common ways to injure a knee is by receiving a blow from the lateral aspect of the knee, thus causing valgus stress to the knee. Often when such an injury occurs a sprain of the medial collateral ligament ( MCL) also occurs. However, in young children and adolescents a fracture to the distal femoral physis is also a possibility. These fractures can cause fracture displacement, joint motion loss, and growth-plate arrest, with subsequent angular deformity and limb-length discrepancy.
Traditionally, treatment for MCL sprains have included functional rehabilitation, strength maintenance, and a strong emphasis on moving the joint after injury has occured. These activities could impair healing of a femoral physeal fracture if one has occured. So, obviously it is important to exclude this fracture before beginning treatment.
In adolescent athletes who are not yet physically mature, and have what may be perceived as a MCL sprain, a femoral physeal fracture should always be recognized as a possible injury. The possibility of a femoral physeal fracture should always be ruled out before treatment for an MCL sprain starts. This can be accomplished with an MRI.