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:
Compression plating for the noncomminuted column
Bridge plating for the comminuted column
Note: In a simple wedge fracture, fixation with compression can be applied if the wedge has intrinsic stability in the column after reduction.
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.
Note: ulnar nerve at risk
On the medial side, the ulnar nerve is at risk and needs to be exposed, released, and protected before inserting a medial column K-wire (see also neurological protection and handling).
Note: radial nerve at risk
For balanced fixation, it may be necessary to use a longer lateral plate, putting the radial nerve at risk.
For very low fractures, a triceps-elevating approach or an olecranon osteotomy may be preferable.
3. Reduction and temporary fixation
Preparing the fracture site
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.
Note: The more distal the transcondylar fracture line and the more complex the articular fracture pattern, the greater the risk to fragmental perfusion. Soft-tissue attachments are vital to fracture healing and should be respected (see additional material on vascularization).
Reduction of noncomminuted column
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.
Reduction of comminuted column
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.
It may be difficult to align the fracture correctly in the sagittal plane.
A K-wire introduced into the trochlea can be used as a joystick to rotate the distal fragment and restore the angle of anterior inclination of the lateral condylar mass in relation to the humeral shaft axis.
4. Plate fixation
The basic technique for application of anatomical plates is described in:
Start fixation in compression mode with the noncomminuted column.
When the plate is securely in place, remove the lateral K-wire.
Comminuted column: bridging
Bridge the metaphyseal comminution. No compression should be exerted.
Column screw insertion
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.
Pitfall: If the column is unstable, the column screw should be inserted as a position screw only. Take care not to create malalignment through inaccurate overcompression.
5. Final assessment
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:
Rehabilitation until wound healing
Rehabilitation until bone healing
Functional rehabilitation after bone healing
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.
Mobilization until wound healing
Gravity-eliminated active assisted exercises of the elbow should be initiated as soon as possible, as the elbow is prone to stiffness:
The bandages are removed, and the arm rested on a side table
Flexion/extension of the arm at the elbow is encouraged in a gentle sweeping movement on the tabletop as far as comfort permits (as illustrated)
Full pronation and supination in protected arm position is encouraged
Exercises are performed hourly in repetitions, the number of which is governed by comfort
Between periods of exercise, the elbow is rested in the elevated position for at least the first 48 hours postoperatively
Keep the arm elevated between periods of exercise until the wound has healed
Rehabilitation until bone healing
Note: Close surveillance by the clinician during this rehabilitation period has a tremendous impact on the patient outcome.
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.
Rehabilitation after bone healing
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.
Note: When a damaged joint is rehabilitated in this way, the risk of “co-contraction” is reduced, and the incidence of chronic regional pain syndrome is also reduced.
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.