The Trampoline

A 9 year-old boy was jumping on his trampoline when he fell backward onto a fully extended right upper extremity. He presents complaining of right elbow pain, swelling and an "S" shaped deformity. His skin is not broken, radial pulses are normal and the forearm compartment is soft with no pain on passive extension of the fingers. Thumb extension, flexion of the interphalangeal joints and thumb are normal, as are finger abduction, grasp and all sensations. Lateral and AP radiographs show a supracondylar fracture of the humerus.

1. Describe the supracondylar area of the humerus.

2. Discuss the mechanism of injury.

3. Why is this fracture common in individuals of the patient's age?

4. Discuss the described normal movement and sensory findings. What muscles and nerves were being assessed?

5. Based on the anatomy of the area, discuss some possible complications of this injury.