A common and potentially serious fracture in children is a supracondylar fracture of the humerus (upper arm bone). Humeral fractures are named for the location of the break. A supracondylar fracture tells us the bone is broken at the lower end of the humerus above the elbow. In children, this fracture occurs most often around ages six to seven.
Surgery is needed to reduce and fix the fracture. Reduction refers to the process of putting the two displaced ends of the bone back together. A pin or a special wire called Kirschner (K-wire) is used to hold it in place until healing occurs. The surgeon uses a special X-ray imaging technique called fluoroscopy to see the bone. This can be done without making an incision and opening up the arm.
The surgery is usually done with the child in the supine position (on his or her back). But there are problems using this position. It’s difficult to hold the bone in place while inserting the wire.
The elbow must be fully flexed making it difficult to get the fluoroscope arm around it. The arm must be rotated externally (outward) to get the proper view. Even with two people working together, it’s difficult to keep the fracture reduced. When there’s swelling it’s difficult to see or feel the nerve. It’s very easy to poke the ulnar nerve with the wire and cause nerve damage.
In this study, surgeons from Europe show how using the prone (face down) position can be done easily and safely without complications. The child is placed at the edge of the table with the arm hanging down freely over the edge. Gravity helps pull the bone down and aids in the reduction process.
The elbow position in less than 90-degrees of flexion is an added benefit of this position. Blood supply to the arm is better. And there’s less chance that the ulnar nerve will get pinched or compressed in this position. One surgeon can manipulate, distract, reduce, and fix the arm without an assistant. The wire can be inserted from both sides of the elbow.
The authors showed excellent results with 455 patients treated this way over a period of 17 years. An equal number of right and left arms were reduced using the prone method. Children ranged in age from three to 14 years old.
Everyone was rechecked after 14 days to make sure the arm position was maintained. A second X-ray was taken when the K-wire was removed at the end of six weeks. A recheck was done at three months and again after six months. Only 3.5 per cent of the fractures had moved. The cause of this problem was incorrect wire placement.
Other complications were minimal. One per cent of the group had infection at the pin (wire) site. No one had loosening of the pin. Everyone was wearing a full arm cast, which helped support the arm and the pin.
The authors conclude that treatment for supracondylar fractures can be technically difficult. There can be lots of problems. One way to get around this is with the method described here. There is less risk of blood vessel and/or nerve damage.
Once the arm has been reduced, the arm doesn’t have to be moved again. This makes passing the wires through the arm easier and more accurate. There’s less risk of damage to the surrounding soft tissues. Being able to pass the wires through the arm without flexing the elbow so far reduces the risk of injury to the ulnar nerve.
There are a few problems to consider when using the prone position to reduce a supracondylar fracture. Sometimes getting the patient into a face-down position is difficult. It takes longer, which means the patient is exposed to the anesthesia for a longer period of time.
They may be other injuries to consider. Some injuries could make it difficult or impossible to use the prone position. And if surgery is needed to open the elbow, the patient must be repositioned to expose the area. For patients with a simple supracondylar fracture, the prone position simplifes the reduction process.