13C3 distal humeral fractures and possible olecranon osteotomy

A challenging injury

Complex distal humeral fractures are particularly challenging to treat. In younger patients, this type of fracture typically results from a high-energy impact, such as a fall from a ladder or a motor-vehicle accident. As a result, the fracture may be open, but extensive soft tissue damage and additional injuries may delay treatment. Among older patients, particularly those with osteoporosis, the impact necessary to cause this grade of fracture can be comparatively light; however, the incidence of comorbidities is high.

Question 1: Which preoperative images are best for the diagnosis of a 13C3 fracture

In all cases where a complex distal humerus fracture is suspected, proper diagnosis and treatment calls for the most informative imaging available. If you have access to 3D computed tomography (CT), this is one place where it will be very useful. Because of the number of bone fragments involved, a 2-dimensional CT scan can actually add to the confusion. In order to plan the operation, a set of 3D CT scans can show the relative sizes, locations and orientations of all fragments. As noted below, if a 3D CT scanner is not available, an arthrogram or arthroscope will also provide high-quality, useful images at the time of surgery.

Question 2: What are the indications and contraindications for an olecranon osteotomy

Other possible approaches for distal humeral fractures include paratricipital (medial or lateral) or transtricipital. If either of these will allow adequate visualization and access (particularly if plating is planned), no olecranon osteotomy will be necessary. And if a distal humeral prosthesis—but not a full elbow arthroplasty—is planned, the olecranon must be kept intact, as it is necessary to stabilize the prosthesis.

If no 3D CT scanner is available, an arthrogram, or, preferably, an arthroscope will provide a full view of the joint at the time of surgery.

If an osteotomy is necessary—as is usually the case for a 13C3 humeral fracture—then it is necessary to choose the optimal points to begin and end the cut or cuts. As indicated below by the black arrow in the photo on the left, and by the WB in the upper right photo, the least harmful position is the transverse trochlear ridge, i.e., the cartilage-free area strip across the proximal ulna. However, to avoid damaging nearby structures, the cut should not go completely through, i.e., the final millimeter should be broken loose.

Chevron cut pattern reduces the risk of non-union

As for the cut recommended for the osteotomy, the chevron pattern is currently preferred. Although this takes longer to perform, a meta-analysis by Feinstein et al. (2023) showed that, compared to a simple transverse cut, it is significantly less likely to result in non-union.

Elevating the triceps protects it while making room for the surgery

To prepare for the osteotomy, it is necessary to detach the triceps tendon from the shaft of the humerus and keep it elevated. For this purpose, a Cobb elevator can be used to open a channel between the triceps and the humerus. A hemostat can then be used to pull one end of a lab sponge back through. The two ends of this sponge can then be used to pull the triceps back from the humerus and expose the joint. This strategy both keeps the joint clear of obstructions and protects the triceps.

Question 3: Orthogonal or lateral plating: Which offers the greatest biomechanical advantage?

For the reduction of the fracture, it will be necessary to choose between orthogonal or lateral plating. In terms of loss of fixation, complications or other clinical results, there are no significant differences between the two. However, for more distal fractures and those with larger fragments, orthogonal plates are preferable. When dealing with highly comminuted or osteoporotic bone, or short medial and lateral fragments, lateral/ parallel plating offers more biomechanical stability, which is essential.

Case studies illustrating indications for orthogonal versus lateral plating

To illustrate indications for orthogonal and lateral plating, Labronici presents two case studies. X-rays and 3D CT images are available for both.

Case study 1 is of an injury sustained by a 30-year-old man in a motor-vehicle accident. Neurovascular status is normal. The diagnostic imaging reveals mainly large fragments, indicating that orthogonal plating will be most useful. As a damage control measure, external fixation is applied to the proximal humerus.

Following an olecranon osteotomy, the fracture is anatomically reduced very accurately using K-wires , after which plating is added.

Two years post-operatively, the subject shows very good extension and flexion.

Case Study 2 shows the result of a ladder fall by a 58-year-old woman with otherwise healthy bone. The degree of comminution is quite severe; therefore, after the olecranon osteotomy, the surgeon opts for parallel plating. To maximize stability, a third plate is added.

Question 4: Understand when a total elbow arthroplasty is indicated.

In some patients, there is no reasonable hope of recovery from an acute distal humeral fracture using reduction. Amjid et al. (2010) specify five groups for whom a total elbow arthroplasty is automatically indicated:

1. Non-rheumatoid patients over the age of 75 years;
2. Patients with rheumatoid elbow disease (any age);
3. Patients with reduced life expectancy (any age);
4. Patients with pathological bone (any age);
5. Patients with degenerative elbow disease over the age of 60 years

As an illustrative case, Labronici has chosen that of a 66-year-old woman with rheumatoid arthritis. She has suffered a fall with a closed fracture. Her neurovascular status is normal.

As the 3D CT image shows, the fractured elbow has no cartilage. Therefore, a total elbow arthroplasty is performed. Eighteen months post-operatively, the patient shows normal flexion and roughly 35 degrees of extension, with normal rotation of the radius and ulna.

According to Evans et al. (2022), there is a strong chance that this prosthesis will still be functional in ten years’ time. In their study of 1238 total elbow replacements, they found an overall 10-year joint survival rate of over 80%.

Question 5: How should the joint be immobilized postoperatively?

Depending on the details of the surgery and the specific patient characteristics, the surgeon may choose partial immobilization in a sling or full immobilization in a cast. In either case, an angle of 30 degrees extension, i.e., 120 degrees relative to the humerus, is preferable to the previously-favored 90 degree bend.

Labronici comments that not only does greater extension ease the return to normal functionality, it also protects the joint from edema, hematoma and other complications.

Wherever possible, though, the sooner a patient can safely begin functional exercises, the better. These can relieve pain and yield better long-term outcomes regarding flexion and extension.

Take-home messages

1. To give your patient the best possible outcome, it is essential to plan the surgery as fully as possible. This will mean
   a. using the most informative images available to you:
   i. preferably 3D CT scans;
   ii. but possibly also an arthrogram or arthroscopy at the time of surgery.
   b. choosing the approach that will allow you the best visualization and access to the joint (an olecranon osteotomy may not be necessary);
2. deciding on whether parallel/transverse or orthogonal plates will offer the necessary containment and stability; and
3. enrolling the patient as soon as possible post-operatively in functional therapy.

Other questions, such as whether or how much the ulnar nerve should be transposed, are dealt with in the questions following the presentation.

Watch a video recording of the original AO webinar: