Surgeons evaluate problems like elbow fractures and classify them in some way to help direct treatment. In the case of humeral lateral condyle fractures, the current classification system isn’t working. It doesn’t predict which fractures should be treated with pins to hold the bones together and which fractures need to be wired back together.
A humeral lateral condyle fracture involves the lower part of the upper arm bone (the humerus). The condyle is the round end of the humerus that slides and glides against the bones of the forearm to form the elbow joint. Lateral fractures refer to the condyle on the outside of the elbow (medial would refer to the side of the elbow closest to the body). Humeral lateral condyle elbow fractures are fairly common in children. For every 100 cases of elbow fracture, 12 of them will be humeral lateral condyle fractures (12 per cent).
The new proposed classification scheme comes from pediatric orthopedic surgeons at the University of Southern California School of Medicine in conjunction with the Children’s Orthopaedic Center at the Children’s Hospital of Los Angeles. The surgeons there suggest using X-rays and arthrograms to place the fractures in one of three categories. Type I is a fracture with less than two millimeters (mm) of displacement (bone separation). The separated ends of the fractured condyle remain in place and have not shifted. These kinds of fractures can be treated with immobilization (casting or splinting).
Type 2 (two or more millimeters of displacement) and Type 3 (two or more millimeters of separation and the two ends of the fractured bone have shifted away from the normal alignment) require surgical treatment. With type 3 humeral lateral condyle fractures, the elbow joint is disrupted. When the joint is no longer lined up and able to move properly, there is no longer articular congruity (a medical term that means the joint surfaces don’t line up).
Most type 2 humeral lateral condyle fractures can be pinned back together. But type 3 fractures must be reduced (ends of the bones fit back together where they belong) and wired together to hold them in place during the healing process. Children with type 2 or 3 elbow fractures of this kind are immobilized after surgery as well.
The question posed in this study was: could this new classification system be used to predict what kind of treatment to use and to look at the number and type of surgical complications for each group? To find out, the authors went back and used this system on all cases of humeral lateral condyle fractures in children treated at their hospital between 1996 and 2003. A total of 158 children had type 2 or 3 fractures requiring surgery. Their medical records were reviewed for type of complications, age, number of days between fracture and surgery, and length of time in a cast.
When the data was analyzed, they found an overall surgical complication rate (major and minor problems) of 25 per cent. Most of those were minor problems that were easily treated like infections (treated with antibiotics). Others didn’t need any further treatment (e.g., bony bump felt on the outside of the elbow or thickened scar). Only six per cent of the patients had a major complication (e.g., malunion or nonunion of the fracture, stiffness, refracture) requiring further surgery. Further analysis showed that there was no link between the age of the patient, number of days between fracture and surgery, or length of time in a cast and the complication rate.
Type 3 humeral lateral condyle fractures had more significantly major and minor complications compared with type 2 fractures. In fact the risk of complications was three times higher for children with type 3 elbow fractures of this kind compared with children who had the type 2 fractures. The exact reason for this is unknown. It could be linked to the amount of energy transferred through the joint at the time of injury. Or it might be related to the fact that type 3 fractures were treated with open surgery. Type 2 fractures could be pinned percutaneously (through the skin without an open incision). More study will be needed to identify cause and effect.
The authors pointed out several other findings from this study. All the children with type 3 fractures had more than four millimeters of separation (not just two millimeters, the cut off point suggested by the authors). There were a fair number of children who had a stiff elbow with loss of motion (17 per cent) after treatment. A closer look showed that loss of motion was not linked with the type of fracture or the length of time in a cast. No one was able to identify risk factors that might account for this complication.
The findings in this study support the use of this new classification system based on degree of fracture displacement and articular congruity both to predict complications and to direct surgical treatment. None of the methods currently used to classify these fractures recommend treatment or predict the results. Other studies are still needed to follow-up children to see what the long-term effects are of this treatment. The authors also suggest another study to see if type 2 fractures with more than four millimeters of separation could be treated with closed (percutaneous) pinning.