These partial articular multifragmentary fractures are often associated with impaction of the posterior part of the lateral column, and/or the posterior trochlea. Lateral and frontal fracture types will be considered together.
Most apparently isolated capitellar fractures are more complex than they initially appear.
Computed tomography - particularly 3D CT - can help define the fracture anatomy and facilitate planning of the surgery.
Sometimes the appearance is more complex, but it can be difficult to understand the fracture pattern on standard radiographs, particularly if a cast obscures the view.
Computed tomography, with 3-dimensional reconstruction in particular, is very useful for understanding apparently simple capitellar fractures that turn out to be more complex.
Here it is apparent that the lateral epicondyle is fractured.
The posterior aspect of the lateral column is also abnormal.
In this image, it is apparent that the articular fragments may not fit, suggesting impaction of the posterior trochlea and particularly the lateral column.
An end-on view shows the complexity, particularly on the lateral side.
Also, one can see a fracture - albeit very subtle - between the medial epicondyle and the medial trochlea.
Here the medial side fracture can be seen as well as what appears to be impaction (narrowing of the olecranon fossa). These injuries are very subtle, but were confirmed during operative exposure.
Depending on the approach, the patient may be placed in the following positions:
The best approach to the distal humerus depends on the main fracture morphology. In very complex fracture situations the posterior approach, using an osteotomy of the olecranon, provides an excellent access.
For less complex fractures, a lateral or anterior approach can be chosen to access the articular segment of the distal humerus.
For capitellar fractures, either a lateral or an anterior approach should be chosen as it gives direct access to the fracture.
The following describes the use of a lateral approach.
The fracture surfaces are cleared of clot and debris.
The fracture fragments are pieced together like a puzzle.
If the pieces do not fit properly, this is usually a result of impaction of the posterior aspect of the lateral column, and sometimes of the posterior trochlea.
A posterior view of the impaction of the posterior aspect of the lateral column.
If impaction is identified, this should be gently disimpacted with a fine osteotome used as a lever.
The disimpacted fragments can be provisionally stabilized with smooth K-wires.
Entirely articular fragments can be secured with buried headless screws, small threaded K-wires, or absorbable pins.
This illustration shows insertion of a headless double-pitch screw.
The lateral epicondyle can be provisionally fixed with a K-wire. Small epicondylar fractures may benefit from fixation with a tension band wire that incorporates the soft tissue attachments.
Use a large gauge needle to pass the wire through the soft tissues on the lateral epicondyle.
The wire is passed through a drill hole in the lateral column proximally, in a figure-of-8 fashion and tensioned to achieve stable fixation.
Larger partially articular fragments can be fixed with an additional plate and screws.
The final combined fixation.
Fractures that involve the posterior aspect of the trochlea, or of the medial epicondyle, may be best treated via an olecranon osteotomy.
An olecranon osteotomy provides exposure to the entire articular surface.
The posterior trochlea is gently disimpacted using a fine osteotome as a lever. Care is taken to try to preserve some of the inherent stability.
The lateral column must also be disimpacted.
End-on view of the disimpaction.
Headless countersunk screws can be used to secure articular fragments that are large enough and of adequate bone quality.
Dedicated plates with many small distal screws can be used to engage the subchondral bone of the articular fracture fragments. Alternatively, standard reconstruction plates are used, as illustrated.
Medial and lateral plates were used here to stabilize a complex articular comminution.
The arm is immobilized in a splint for comfort with the elbow at 90° of flexion. Active exercises of the elbow should be initiated as soon as possible, as the elbow is prone to stiffness. For this reason, it is important that fixation is adequate to allow functional use of the arm for light tasks.
Avoidance of shoulder abduction will limit varus elbow stress. Shoulder mobility should be maintained by gravity-assisted pendulum exercises in the sling.
Active assisted elbow motion exercises are performed by having the patient bend the elbow as much as possible using his/her muscles, while simultaneously using the opposite arm to push the arm gently into further flexion. This effort should be sustained for several minutes, the longer the better.
Next, a similar exercise is done for extension.
Load bearing
No load-bearing or strengthening exercises are allowed until early fracture healing is established, a minimum of 6-8 weeks after the fracture. Weight bearing on the arm should be avoided until bony union is assured.
Follow up
After suture removal, 2 weeks after surgery, the patient should be seen every 4-6 weeks for follow-up examination and x-rays, until union is secure and full functional range of motion and strength have returned.
Implant removal
Generally, the implants are not removed. If symptomatic, hardware removal may be considered after consolidated bony healing, certainly no less than 6 months for metaphyseal fractures, and 12 months when the diaphysis is involved. The avoidance of the risk of refracture requires activity limitation for some months after implant removal.