ORIF - Headless screw fixation

Take care when approaching an apparently simple capitellar fracture. These are often complex.

The majority extend into the lateral trochlea and should not be considered for nonoperative treatment.

Many fractures also involve a fracture of the lateral epicondyle and impaction of posterior aspect of the lateral column, or the posterior trochlea.

Computed tomography with 3D reconstructions helps to identify these fracture characteristics, and facilitates planning.

This module addresses coronal plane fractures of the capitellum and part of the trochlea, without fracture of the lateral epicondyle, or of the posterior aspect of the distal humerus.

These fractures can be repaired with buried headless screws, or alternatively, with screws that are inserted from posterior to anterior.

Screw fixation is straightforward using cannulated screws, but can also be undertaken with non-cannulated screws if cannulated screws are not available.

If non-cannulated screws are being used, provisional fixation should be achieved with K-wires which are then exchanged carefully, one at a time, for the definitive screws.

This procedure is normally performed with the patient in a supine position for lateral approach.

For this procedure a lateral approach is normally used.

The origins of the extensor carpi radialis longus and extensor carpi radialis brevis (ECRB) are elevated from of the anterior aspect of the humerus, along with the brachialis.

The interval between the ECRB and the extensor digitorum communis (EDC) is split distally. Care is taken not to go posterior to the midpoint of the radial head, in order to protect the lateral collateral ligament.

The capsule is incised, if not already ruptured.

The fracture fragment should be apparent in the anterior aspect of the joint.

Clean out the fracture by removing blood clots, loose pieces of bone, and any interposed tissue. Inspect the joint to ensure that no additional intraarticular fracture component was missed when examining the imaging.

Reduce the fracture. If the anterior exposure is in any way limited and digital reduction is not possible, a K-wire "joystick" and small pointed reduction forceps can be used.

Monitor fracture reduction by realigning the metaphyseal and articular fracture lines.

Insert the guide wires across the fracture site, where the planned screw tracks will be. Be sure to use the correct diameter guide wires for the chosen screw size.

Measure the screw length of the guide wire, using the appropriate depth measuring device.

Insert the wire deeper so that it is not dislodged during drilling.

Drill the pilot hole for the screw to the appropriate depth, using the cannulated drill bit placed over the guide wire.

Insert the chosen screw over the wire, then remove the guide wire. Complete the insertion of the first screw, before inserting the second screw.

The muscle interval is then closed.

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.