1 Principles topenlarge
Note on illustrations
Throughout this treatment option illustrations of generic fracture patterns are shown, as four different types:
A) Unreduced fracture
B) Reduced fracture
C) Fracture reduced and fixed provisionally
D) Fracture fixed definitively
Plating in the distal humeral shaft
Depending on the fracture morphology it may be appropriate to obtain stable fixation with lag screws and then secure this with a neutralization plate. Alternatively, it may be better not to interfere with the fracture zone, and simply apply a bridge plate.
For stable plate fixation, typically three bicortical screws (6 cortical holds) would be used in each main segment. If locking head screws are used fewer screws may be sufficient.
The use of standard LCP in the treatment of distal third shaft fractures is limited by the number of fixation points needed in the distal segment. More distal fixation may be obtained by placing the plate onto the lateral column. This is easier if precontoured (ie anatomic) extraarticular distal humerus LCP are used.
To illustrate the principles of plating a shaft fracture with distal extension, the posterior application of an anatomic plate (extraarticular distal humerus LCP) through a distal posterior approach (triceps-on) is described.
The application of a lateral or anterior plate follows the same principles.
Approach and patient positioning
For fractures extending distally the distal posterior or lateral approaches are recommended, as they provide access to more fixation points in the lateral column of the humerus.
The distal posterior approach may be performed with the patient either in a lateral or prone position.
The lateral approach, with the patient in a supine position, provides good access to the radial nerve alongside the intermuscular septum which is necessary in cases of radial nerve injuries.
For plate application on the anterior aspect of the distal humerus the approach uses the distal part of the extended anterolateral approach with the patient in a supine position.
2 Plate positioning topenlarge
The choice of plate position depends on the fracture morphology, the radial nerve pathology and the surgeon’s preference. The lateral, anterior, and posterior surfaces of the distal humeral shaft are all possible choices.
Choose a plate long enough to achieve secure fixation in each main segment.
If the fracture extents distally to less than 6 cm proximal to the olecranon fossa, a standard plate (eg 4.5 mm LCP narrow) must be bent and/or twisted to obtain fixation on the lateral column of the distal humerus.
Alternatively, anatomic, extraarticular distal humeral plates may be used in fixation of these fractures.
Lateral plating is recommended if a radial nerve injury is apparent and requires further exploration/treatment (ie Holstein-Lewis fracture).
Typically, a straight LCP requires bending to fit the lateral aspect properly. Alternatively, anatomic, lateral distal humeral plates (VA-LCP) may be used.
The anterior plate position is appropriate for those fractures which extend distally up to 6 cm above the coronoid fossa allowing for 6 cortical fixation points in the distal segment.
Typically, straight 4.5 mm LCP narrow can be used. Anatomic plates are not available for this region.
3 Reduction and lag screw fixation top
It is important to restore axial alignment and rotation.
In osteoporotic bone anatomic reduction should be achieved as callus formation is poor.
Anatomic reduction and internal fixation follows the principle of reducing the numbers of fragments from 3 to 2 and 2 to 1 starting distally.
Alternatively, a bridging technique may be used.
Lag screw fixation
If the fragments are big enough and the fracture planes are suitable, the fragments may be reduced and held with lag screws or cerclage.
Reduce the wedge to the distal humerus, hold it with a pointed reduction forceps and fix it with a lag screw.
Then reduce the distal fragment to the proximal shaft segment using a pointed reduction forceps. Take care of proper rotation.
Option: A second lag screw from the proximal segment into the wedge may be used but typically it is not necessary.
4 Plate contouring topenlarge
Anatomic plates may not need contouring, but sometimes they need some fine adjustment.
If a standard LCP plate will be positioned over the lateral column of the distal humerus bending of the plate is necessary. In-plane bending is not possible except with reconstruction plates. The plate must be twisted, and also bent to allow for the physiological antecurvature of the lateral column.
The screw application follows the same order as for the precontoured plate described below.
5 Plate application topenlarge
Position the plate on the posterior aspect of the humerus.
Adjust the distal end of the plate to the lateral column of the distal humerus. Take care that the plate does not cause an impingement with the olecranon.
Check the correct plate position proximally in line with the humerus.
Placement under radial nerve
Frequently the posterior plate is longer than expected and requires a proximal placement under the radial nerve which must be identified and mobilized. In these cases, proper documentation of the relation between the radial nerve and the plate should be recorded in the operation note.
Insert first distal screw
Fix the plate to the distal humeral segment by using a bicortical cortical screw.
Check the fracture reduction and plate position again.
Insert first proximal screw
Fix the plate to the humerus proximal to the fracture by using a second bicortical cortical screw.
Check the fracture reduction and plate position again.
Final screw insertion
Insert the remaining locking screws through the plate distal and proximal to the fracture. Typically, one should look for 6 cortical holds each proximal and distal to the fracture.
6 Application of a lateral plate topenlarge
The application of the lateral plate follows the same sequence as with the posterior plate.
Slide the plate underneath the radial nerve which runs through the intermuscular septum towards the anterior compartment of the distal humerus.
Proper documentation of the relation between the radial nerve and the plate should be noted in the operation note.
7 Final radiological assessment top
Check for proper reduction and implant position with image intensification in AP and lateral views.
Also confirm correct torsional alignment of the humerus.