1 Principles topenlarge
Triangle of stability-concept
The mechanical properties of the distal humerus are based on a triangle of stability, comprising the medial and lateral columns, and the articular surface.
In complete articular fractures, all 3 columns have to be restored.
2 Opening the joint topenlarge
Cleaning of the fracture site
Clean out the fracture by removing blood clots, loose pieces of bone, and any interposed tissue.
3 Reduction and provisional fixation topenlarge
Fixation of small articular fragments
Assemble any small fragments covered by cartilage, even if they have no soft tissue connection. A headless screw, buried threaded wire, or absorbable pin is each a good option for fixing such fragments.
Although by definition, this is a simple articular fracture, in many instances, small articular fragments may be found.
In parallel plating it is customary to reduce and secure provisionally all of the fracture fragments, prior to plate application, using K-wires.
4 Definitive plate and screw fixation topenlarge
Plate selection and contouring
Contoured 3.5-millimeter reconstruction plates, or precontoured plates, are selected for direct lateral positioning on the lateral column and direct medial positioning on the medial column.
These are usually placed slightly posteriorly and are always placed on top of the soft tissues - do NOT strip the medial and lateral columns.
The plates should extend distally enough to engage all fracture fragments and proximally enough so that 2 or 3 screws through each plate engage the proximal (shaft) fragment.
Drilling for distal screws
As many screws as possible are placed in each distal fragment.
Each screw goes through a plate hole.
Smooth K-wires the same size as the appropriate drill (e.g. 2.0 mm wire for 2.7mm screw) can be inserted through the plate holes to ensure that the screws, once inserted do not conflict: this also allows the drilling stage to be skipped.
Distal screw application
Each of the smooth K-wires is exchanged for a self-tapping screw.
5 Proximal plate fixation topenlarge
When there is solid bony contact across the articular and proximal fragments, compression is applied with pointed reduction forceps and eccentrically placed load screws, one column at a time.
- When a column is comminuted, it should be bridged, and if necessary, because of missing fragments, bone grafted.
- When the reassembled condylar mass is short, and non-locking plates are used, long, distal-to-proximal, 3.5 mm column screws will enhance the stability of the fixation.