Plating with precontoured periarticular locking plates provides angular-stable fixation and is the most commonly used method of distal humeral fracture fixation.
This fracture pattern with a wedge on either side is fixed with a combination of a lateral and a medial plate. In this procedure, the fixation of a fracture with a comminuted wedge on the medial side is shown.
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).
In principle, for extraarticular fractures, the side of the triangle with the simplest fracture is fixed first.
In these fractures, two modes of plate application are used:
Precontoured anatomical plates have been designed. If these are not available, a reconstruction plate is used both on the medial and the lateral sides. If a stronger plate is required, a small-fragment compression plate may be used, but this is more difficult to contour.
Since the distal fragment is short and the bone quality usually poor, fixation with conventional implants is difficult and anatomical plates with locking head screws are strongly recommended.
This procedure is normally performed with the patient either in a prone position or lateral decubitus position.
For this procedure, a posterior approach may be used:
For very low fractures, a triceps-elevating approach or an olecranon osteotomy may be preferable.
In principle, preserve all fracture fragments attached to soft tissue in situ if possible.
Preserve loose bone fragment for later use as bone graft. Keep removal of hematoma to the minimum necessary to facilitate the exposure of the fracture.
Reduction of the articular block to the shaft is easier on the side without metaphyseal comminution.
Manually reduce the distal fragment to the radial and ulnar columns.
Hold the reduction with the insertion of an axial K-wire.
With the more stable column temporarily stabilized, align the comminuted column.
Ensure an accurate alignment of the articular block to the shaft (see also the anatomical concepts).
Insert a K-wire to secure the alignment temporarily.
If necessary, check the reduction and provisional fixation with image intensification.
The basic technique for application of anatomical plates is described in:
If precontoured anatomical plates are not available, see the basic technique for application of reconstruction plates.
Start fixation in compression mode with the noncomminuted column.
When the plate is securely in place, remove the lateral K-wire.
Bridge the metaphyseal comminution. No compression should be exerted.
In fractures with very short distal segments, additional stability can be gained by inserting a long, distal-to-proximal, 3.5 mm column screw in the column with solid bony contact across the fracture.
Take care of potential conflict between screw tracks.
Visually inspect the fixation and manually check for fracture stability.
Repeat the manual check under image intensification.
Ensure the ulnar nerve is not unstable or tethered on implants throughout a full range of motion.
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 routine use of splintage or immobilization.
Avoid forceful motion, repetitive loading, or weight-bearing 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.