The fragment is stabilized with headless screws depending on the fracture characteristics.
In a simple capitellar fracture, an anterior-to-posterior screw trajectory is often used and described in this procedure.
Involvement of the trochlea requires more central and medial exposure for fracture reduction and screw placement.
If there is posterior trochlear comminution of a posterior transverse fracture of the capitellum or trochlea, then a posterior approach extended into the olecranon fossa is recommended (eg, olecranon osteotomy).
The mechanical properties of the distal humerus are based on a triangle of stability, comprising the medial and lateral columns and the articular block (see also the anatomical concepts).
Screw fixation can be achieved with cannulated headless compression screws or traditional noncannulated screws.
Headless screws (2.4 or 3.0 mm) are used in the articular segments.
Insertion of a cannulated headless screw is described in this procedure.
This procedure is usually performed with the patient in a supine position.
For the treatment of a posterior fracture extension, a lateral decubitus or prone position is needed for a posterior approach.
The lateral approach is the most commonly used and is detailed here.
Elevate the origins of the extensor carpi radialis longus (ECRL) and extensor carpi radialis brevis (ECRB) from the anterior aspect of the humerus, along with the brachioradialis.
Split the interval between the ECRB and the extensor digitorum communis (EDC). Take care not to extend posteriorly to the midpoint of the radial head to protect the lateral collateral ligament.
Take care when extending the EDC split distally to protect the posterior interosseous nerve.
The anterior approach may be used if there is no posterior involvement.
For the treatment of a posterior fracture extension, a posterior approach with olecranon osteotomy or triceps-elevating approach can be used.
The fracture fragment should be apparent in the anterior aspect of the joint.
With trochlear fracture involvement, the brachioradialis also needs to be elevated.
Clear the fracture of any hematoma, loose pieces of bone, or interposed tissue.
Inspect the joint surfaces to ensure that there is no additional intraarticular fracture extension.
Align the fracture and maintain reduction with a small hook or pick.
Monitor fracture reduction by realigning the metaphyseal and articular fracture lines.
Insert K-wires in an AP direction across the fracture site to stabilize the reduction.
The guide wires for the cannulated headless screws may act as the provisional fixation wires.
If necessary, check the reduction and provisional fixation with image intensification.
The screw trajectory in a simple capitellar fracture is usually anterior to posterior perpendicular to the fracture plane, if possible.
The more lateral screw can be angled in a proximal direction to avoid the articular surface.
The headless screw needs to be below the articular surface and should not penetrate the posterior articular surface.
Complete the entire sequence of drilling and screw insertion for each screw before inserting the next screw.
Insert the guide wire.
Drill the pilot hole for the screw to the appropriate depth, using the cannulated drill bit placed over the guide wire.
Take care when removing the drill not to dislodge or remove the K-wire.
Insert the chosen screw over the wire, then remove the guide wire.
Insert the subsequent screws in the same way.
Posterior screw placement can be possible after elevation of the anconeus and the triceps from the humerus.
This allows for anterior and posterior screw placement.
Visually inspect the fixation and manually check for fracture stability.
Repeat the manual check under image intensification.
The rehabilitation protocol consists usually of three phases:
The arm is bandaged to support and protect the surgical wound.
The arm is rested on pillows in slight flexion of the elbow so that the hand is positioned above the level of the heart.
Short-term splinting may be applied for soft-tissue support.
Neurovascular observations are made frequently.
Hand pumping and forearm rotation exercises are started as soon as possible to reduce lymphedema and to improve venous return in the limb. This helps to reduce postoperative swelling.
Gravity-eliminated active assisted exercises of the elbow should be initiated as soon as possible, as the elbow is prone to stiffness:
Active patient-directed range-of -motion exercises should be encouraged without the routing use of splintage or immobilization.
Avoid forceful motion, repetitive loading, or weight-beating through the arm.
A simple compressive sleeve can provide proprioceptive feedback which can help regain motion and avoid cocontraction.
No load-bearing (ie, pushing, pulling, or carrying weights) or strengthening exercises are allowed until early fracture healing is established by x-ray and clinical examination.
This is usually a minimum of 8–12 weeks after injury. Weight-bearing on the arm should be avoided until bony union is assured.
The patient should avoid resisted extension activities, especially after a triceps-elevating approach or olecranon osteotomy.
When the fracture has united, a combination of active functional motion and kinetic chain rehabilitation can be initiated.
Active assisted elbow motion exercises are continued. The patient bends the elbow as much as possible using his/her muscles while simultaneously using the opposite arm to gently push the arm into further flexion. This effort should be sustained for several minutes; the longer, the better.
Next, a similar exercise is performed for extension.
If the patient finds it difficult to accomplish these exercises when seated, then performing the same exercises when lying supine can be helpful.
Generally, the implants are not removed. If symptomatic, hardware removal may be considered after consolidated bony healing, usually 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.