The mechanical properties of the distal humerus are based on a triangle of stability, comprising the medial and lateral columns, and the articular surface.
In complete articular fractures, all 3 columns have to be restored.
This procedure may be performed with the patient in either a prone position or lateral decubitus position.
For this procedure a posterior approach is normally used:
Clean out the fracture by removing blood clots, loose pieces of bone, and any interposed tissue.
Reduce the articular fragments. In good quality bone, use pointed reduction forceps.
In poor quality bone, use temporary fixation with a K-wire.
Use a lag screw (a partially threaded screw, or a fully threaded screw with overdrilling the near fragment) to obtain interfragmentary compression.
In osteoporotic bone, use a position screw.
Try to use two screws to avoid rotational instability.
In very distal fractures, generally only one screw can be inserted.
An additional K-wire can be used to obtain rotational stability.
Reduce the reconstituted articular (condylar) block to the metaphysis and use K-wires for preliminary fixation.
The plates must be carefully contoured using an appropriate malleable template.
Place the lateral column plate dorsally and the medial column plate medially. In this position they form an angle of approximately 90 degrees to each other.
First place a 3.5 mm reconstruction plate posterolaterally. It may curve around the capitellum which is non-articular posteriorly.
In distal fractures, the reconstruction plate can be bent all the way to the edge of the articular surface. It will not interfere with the radial head during extension of the joint. The more bone is covered by the plate, the more the stability that can be achieved.
Placement of the lateral plate
Place a K-wire through the distal hole. Now insert the proximal screw as a load screw. As the plate is pulled proximally, stable contact with the bone is obtained.
Fix the plate to the bone by inserting the remaining screws.
Place another plate medially on the crest of the medial supracondylar ridge, at a right angle to the plane of the lateral plate to increase stability.
It is recommended to insert the distal screw into the trochlea below the medial epicondyle.
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.