Fractures of the humerus (upper arm bone) just above the elbow are difficult to treat. Surgery is the standard way to treat these fractures. But the optimal approach isn’t always clear at the out set. The surgeon must take into consideration many factors. How did it happen? What kind of break is involved? Are the soft tissues around the bone damaged in any way? Did the elbow joint surface crack in the process? How strong is the bone (i.e., does the patient have osteoporosis or brittle bones)?
The orthopedic surgeons who wrote this article are from the University of Maryland in Baltimore. They offer a review of the latest research in the area of distal humeral fractures. Distal is just another way of saying the break occurred at the bottom end of the bone.
Surgeons are seeing more of these injuries with the aging adult population in America. Most of these fractures occur in older adults with poor bone quality. That’s one of the things that really makes surgery so difficult. Conservative (nonoperative) care is possible but only when the fracture is stable and can be immobilized in a cast or splint. That type of fracture isn’t as common as the displaced (bones separate), comminuted (many tiny bone fragments) fractures that require surgery.
The surgical choices are usually: 1) internal fixation, 2) external fixation, and 3) total elbow replacement. Each of these choices has its own indications (when to use them), advantages, and disadvantages.
One of the ways surgeons have of evaluating which approach to use is to examine the results from other patients who were treated with one approach versus another. Outcome measures include elbow range-of-motion, return of normal muscle strength, function, bone healing, and quality of life. The joint should be stable yet move freely. Length of time in the hospital and in rehab along with the associated costs might also be factored in. Complications such as infection, poor wound healing, and nonunion (failure of the bone to heal) are recorded. Implant failure (usually from loosening) and revision surgery are two other possible problems that researchers keep track of as a way to evaluate the final results.
By reviewing all of the available research data, the authors were able to summarize what is known about each of these three surgical treatment approaches. Let’s take a look at each one separately.
Internal Fixation. Internal fixation refers to an open procedure where the surgeon puts the bones back together and holds them in place with wires, metal plates, and/or screws. This is the most commonly used operation. Many decisions come into play with this approach. The surgeon sizes up the injury and decides how best to get into the joint: from the back of the elbow (posterior or from the sides? If it seems best to make the incision from the side, then which side: medial (side closest to the body) or lateral (side away from the body)?
Studies show that the posterior approach gives the surgeon a full view of both sides of the elbow but in order to get to the joint, it’s necessary to cut through the triceps muscle and take a chunk of bone out. Removing a wedge-shaped piece of bone for this approach is called an osteotomy. Anytime an osteotomy is done, there is an increased risk that the bone won’t knit back together nicely. The result would be a nonunion of the bone where the osteotomy was done.
As technology and surgical technique improve, new contoured plating with different shapes to choose from and locking screw techniques have become available. Researchers are just beginning to study and report on the results using these various options. Measurements of the healing site strength and stiffness as well as bending forces are under investigation when the various plating systems are placed in different locations and angles (called the configuration). For example, the surgeon may use a Y-shaped plate or the orthogonal plate and place them perpendicular (at a right angle to each other) or in parallel (one on each side of the joint).
Most of these studies are being done on cadavers. The bone strength can be tested until it breaks to determine the upper limit of force each configuration can withstand. Using cadavers with osteoporosis makes it possible to also study the results of fixation on patients with poor bone quality. Results using different length of screws and strength of the bone-to-screw interface are also being compared.
What they’ve found so far is that locking plates may work better than standard plates. And failure is more likely as a result of the bone-implant interface, not because the hardware itself breaks. There isn’t enough data yet to say at what bone mineral density results will be successful. More study is needed before this information will be available.
External Fixation. Like internal fixation, some type of rigid support is needed to hold the bones together during the healing. But instead of being inside the body and unseen, external fixation consists of pins placed through the skin and soft tissues into the bones with metal rods between them. The rods remain outside of the arm. External fixation is used when the fracture is displaced (separated) and poking out through the skin. The surgeon must get the bones lined back up and keep them there until healing takes place but is unable to do so from the inside. That’s where the external support can be helpful.
Only one small study (eight patients) treated for open fractures with open incision and external fixation was reviewed. The patients were seen at a large trauma center right after the injury. Different surgical approaches were used. Of the three who had a posterior approach with an osteotomy, all ended up with a second surgery to wire the bone together to foster healing. Eventually everyone had healing of the fracture but two of the eight people ended up with poor results as measured by overall elbow range-of-motion and function.
Elbow Replacement. If the patient doesn’t have strong enough bones to hold the hardware needed for fixation, then a joint replacement may be needed. The same is true if the joint surface has been too damaged to fix or repair. Older adults and/or patients who have had a failed internal fixation procedure may also qualify for a total elbow replacement.
Results from studies of elbow replacement for distal humeral fractures that were reviewed showed good-to-excellent results for the majority of patients (85 per cent). Outcomes were better when the surgery was done right away as opposed to being delayed for a time. Complications such as nerve injuries, infection, implant loosening, and chronic pain were reported in 22 per cent. The use of elbow replacements may expand as surgeons are able to reduce the complication rates. Improved surgical techniques, better implant designs, and improved ways of cementing the implant in place may help move this along.
Finding the optimal way to treat distal humeral fractures will take some time. There are just too many things that can go wrong and factors to consider when choosing the right procedure, the best approach, and the necessary fixation or implant for the patient’s injury. The authors conclude that this orthopedic injury is complex, multifactorial, and definitely challenging.