Friday, June 1, 2012

Adolescent Supracondylar Humerus Fracture – should it be treated as a pediatric or adult injury?

The Case of the Month for June 2012 is of a 12 year old healthy young lady who sustained a displaced supracondylar humerus fracture after a fall from a balance board. She presented with a completely displaced distal humerus fracture, similar in appearance to a pediatric Type III supracondylar humerus injury. She had mild paresthesias in her thumb but otherwise had an unremarkable neurovascular examination. Her injury radiographs are shown below:

Of note, her distal humerus growth plate was closed but she still had a partially open olecranon growth plate and radial head growth plate.

This fracture represents a very unstable pattern. Given the patient’s age and the fact that her growth plates were nearly closed, it was felt that she would be better treated with a plate construct that would allow for early range of motion. Also, at age 12, she does not have much, if any, potential to remodel so an accurate and anatomic reduction is imperative to restore elbow function. Therefore, an adult approach to this fracture was felt to be appropriate.

The patient was taken to the operating room within 24 hours of her injury. She was placed in the lateral position and a paratricipital (triceps-sparing) approach to the distal humerus was performed. The ulnar nerve was identified but not transposed. A significant amount of force was required to reduce the fracture and it was held provisionally with Kirschner wires.

It was clear that the Kirschner wires would not have been adequate fixation (as would be used in a younger child) as the fracture deformed once the clamp was removed. A posterior plate was chosen of sufficient thickness to help reduce the residual extension deformity, to buttress the articular segment and prevent it from going back into the extended position it was in at the time of injury.

A second plate was added medially for extra stability and the construct was stable through a full range of motion.

The arm was placed into a padded splint for 48 hours to allow the incision to seal and then active and active assisted motion was started. The majority of motion was regained by 6 weeks. At three months, the fracture was completely healed and the patient had regained full range of motion. At final follow-up at six months, she had returned to all activities including dance and gymnastics with no pain and no limitations.

This patient had an excellent result with her injury. This fracture pattern in adolescents should not be confused with a pediatric supracondylar fracture that is readily treated with percutaneous pinning and a cast for 3 to 4 weeks. Intraoperatively, it was clear in this case that wire fixation would have been inadequate since multiple wires were not sufficient to maintain the reduction, even provisionally. In adolescents, stiffness and loss of fixation and subsequent malunion may occur with percutaneous fixation and an adult approach is appropriate.

Author by Daphne M. Beingessner, MD

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