1 Principles topenlarge
Triangle of stability
Stability of the distal humerus is based on 3 columns: Medial, lateral, and the articular surface.
In complete articular fractures, all 3 columns have to be restored.
2 Patient preparation top
3 Approaches topenlarge
For this procedure a posterior approach is normally used:
4 Identification of the bony fragments topenlarge
Take your time to identify all bony fragments, and compare them to the x-rays.
Mobilize the fragment
Some displaced fragments are not immediately seen after osteotomy. Be sure
to account for all fragments. Mobilize the fragments and bring them into the
Clean out the fracture by removing blood clots, loose pieces of bone, and interposed tissue. Inspect the joint to ensure that no intraarticular fracture component was missed when examining the imaging.
5 Reduction and provisional fixation topenlarge
Fixation of small articular fragments
Assemble all small fragments covered by cartilage, even if they have no soft tissue connections. A headless screw, or buried threaded wire, or absorbable pin are options for fixing these fragments.
In parallel plating it is customary to reduce and provisional by secure all of the fracture fragments prior to plate application.
6 Distal 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 in each plate engage the proximal (shaft) fragment.
Drilling for distal screws
As many screws as possible are placed in the distal fragments.
Each screw goes through a plate hole.
Smooth K-wires the same diameter 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 allows the drilling stage to be skipped.
Distal screw application
Each of the smooth K-wires is exchanged for a self-tapping screw.
7 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 this should be bridged and if necessary, because of missing bone, 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. These need to be inserted with great care in the presence of comminution of a column.