Arm Growth Plate Fractures

Proximal Humerus (Arm Bone):

The term proximal refers to the top. A proximal humerus growth plate fracture means that the fracture occurs through the physis of the humerus (arm) bone near the shoulder joint up at the top of the arm. Luckily, when this growth plate is injured, it very rarely results in permanent damage.

This growth plate accounts for 80% of the growth of the arm. Since so much growth occurs through this area, it is also the reason why fractures at or near the growth area can heal very crooked. As long as your child has at least a few years of growth left remaining, the arm will straighten itself out with time.

Distal Radius (Forearm Bone):

The term distal refers to the bottom end. The distal radius represents the end of the radius (forearm bone) near the wrist. Injury to this growth plate is extremely common. It occurs after someone falls and he puts his hand out to break his fall.

Often, this type of injury separates the epiphysis of the bone far away from the metaphysis. If your child is in the emergency room with this type of injury, it will often be recommended that an orthopaedic physician "set" the bone in a better place to allow the bone to heal without deformity.

However, similar to the proximal humerus, the bone does not have to look perfect on an x-ray to heal perfectly. Again, this is due to the amount of growth potential that the distal radius has compared to its proximal growth area.

Occasionally, injuries to the distal radius, or more commonly, the distal ulna (the other forearm bone) growth plate may lead to a growth arrest. If growth arrest occurs in only one bone but not the other, this may lead to one bone growing longer than the other in the forearm. This may make the wrist appear crooked. Your provider will often ask you and your child to return for an x-ray approximately six months after the fracture to look for this type of growth problem. If it is caught early, there are measures that can be done prior to the wrist growing crooked.