Surgeons from the Mayo Clinic recently reported on the results of surgical treatment for patients who had a bone fracture around the ulnar side of an elbow joint replacement. The ulna is the larger of two bones in the forearm.
The elbow implant inserts up into the humerus (upper arm) and down into the ulna. It’s not exactly that the bone has come loose around the implant. But there may be some bone thinning or bone loss around the implant. Without a firm circle of bone around the implant, it will loosen. Movement of the implant combined with the bone loss can result in bone fractures around the implant called periprosthetic fractures.
The fractures occur in one of three places: at the olecranon, around the stem, and below the stem. The olecranon is a large, thick, curved part of the ulnar bone that forms what you feel as the back of the elbow.
This type of periprosthetic fracture is fairly uncommon and studies are few and far between. So this study was important in giving surgeons (and patients) an idea of what to expect in terms of managing the problem and results of surgery to correct the problem.
There are several surgical options to choose from including strut allografts, allograft-prosthetic composites, and impaction grafting. These are all ways to augment (build up) the areas of weak, thin, or absent bone.
The specific method of surgical reconstruction used is based on the severity of bone loss. The surgeon will likely remove the loose component, found the fracture site, and cleaned out any debris or loose fragments in the area.
Then bone graft material (struts or impaction grafting) are used to support the fracture until it can heal. Metal plates or wires may be used to hold the graft in place. In the case of a prosthetic composite, a replacement implant is partially cemented into a bone graft. This unit is then placed inside the patient’s remaining ulna.
These are just examples of the types of surgery available for this type of problem. Your surgeon may have a different idea in mind for you. Your age, bone density, and activity level will all be taken into consideration when planning treatment. The location, type, and severity of fracture will be factored in as well.