Plating with precontoured periarticular locking plates provides angular-stable fixation and is the most commonly used method of distal humeral fracture fixation.
In this fracture, both columns are fractured with either a simple wedge or comminution on each side.
Therefore, each column should be stabilized with an individual plate.
The fracture zone in relation to the olecranon fossa can be variable, ie, there are high and low variants.
If the size of the fragments and bone quality permit independent lag screw fixation, place these screws before plate application. This is typically the case when the fracture is above the olecranon fossa.
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:
Bridge plating for the comminuted column(s)
Compression plating for the column with a simple wedge, intrinsically stable after reduction
Reduction and fixation principle for extensive comminution
There is no intrinsic guide to the length and rotational alignment of the distal humerus. In these cases, an external fixator or distractor to gain provisional alignment can be used.
For many comminuted fractures, it is preferable to bridge the comminution without reducing and securing each fragment individually.
This approach preserves the blood supply and healing capacity of the fragments while relying on the implants for relative stability until early healing is established.
Precontoured anatomical plates have been designed. If these are not available, at least one column (usually the lateral column) should be fixed with a small-fragment LCP in bridging mode. The other column can also be fixed with a small-fragment LCP or a reconstruction plate in bridging mode.
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.
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).
Use an external fixator or distractor to facilitate and provisionally stabilize the angular and rotational alignment, although in most cases, manual traction is sufficient.
Distraction may be performed by transarticular or periarticular pin placement depending on the available bone stock of the articular segment.
Note: Plan the pin insertion to avoid interference of the distractor with later plate application.
Note: The radial nerve is at risk during proximal pin insertion.
Ensure an accurate alignment of the articular block to the shaft (see also the anatomical concepts).
4. Plate fixation
The basic technique for application of anatomical plates is described in:
Manipulate the fracture fragments as little as possible, and preserve their soft-tissue attachments. Once length and alignment are restored, plates alone provide relative stability, and no screws are used in the intervening fracture fragments.
Start fixation of the less complex fragmented column in bridge mode. No compression should be exerted.
Then bridge the other column accordingly.
Option: compression of the column with a simple wedge
If one column comprises a simple wedge fragment, which can be reduced and is then intrinsically stable, apply a plate in compression mode.
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.