1 Introduction topenlarge
It is not uncommon for an elbow dislocation in a skeletally immature patient to be associated with a medial epicondylar fracture.
In rare cases, the fragment is incarcerated in the humero-ulnar joint (A1.3).
One or two screws will provide sufficient fixation.
It can be useful to incorporate the soft-tissue attachments to the medial epicondyle by using a washer.
Screw fixation is straightforward using cannulated screws, but can also be performed with non-cannulated screws.
2 Open reduction topenlarge
Mobilize the fragment and clean the fracture site
Identify and protect the ulnar nerve.
Open the fracture site by gently retracting the fragment anteriorly.
Clean out the fracture by removing blood clots, loose pieces of bone or interposed tissue. Inspect the joint to ensure that no intraarticular fracture component was missed when examining the imaging.
Realign the fracture and hold reduced with a small hook.
Monitor fracture reduction by realigning the metaphyseal fracture lines.
Depending on the extent of exposure, you can check the anterior and posterior fracture lines, including the articular surface.
3 Provisional fixation topenlarge
Planning for screws
The screws must avoid the olecranon fossa and the articular surface. Generally there is room for one screw down the articular part, and one screw up the lateral column.
Insertion of K-wires
Secure the fracture with 2 or more K-wires crossing the fracture site. Take care to avoid the planned screw track.
Use smooth K-wires at least 1.5 mm in diameter.
Check fracture alignment using an image intensifier.
Alternative K-wire placement
Alternatively, use a K-wire the size of the drill and place the K-wires in
the planned screw tracks.
Using this technique, each wire can be exchanged for its screw, skipping the drilling step.
4 Drilling topenlarge
Position screw technique
For a partially threaded screw, drill both fragments with a 2.5 mm drill.
Alternative lag screw technique
For lag screw technique using a fully threaded screw, drill the near fragment with a 3.5 mm drill to create a gliding hole, and the far fragment with a 2.5 mm drill.
Be careful using lag screw technique in metaphyseal bone, particularly when osteoporotic. It may be preferable to obtain thread purchase in both the near and far fragments (a position screw).
5 Definitive fixation topenlarge
Insertion of screw
When using a non-selftapping screw, tap the screw track prior to screw insertion.
For poor bone quality it may be helpful to use a washer with the screw, and to avoid tapping the far condylar fragment.
Pediatric case: result
This illustrates the more common pediatric manifestation of the A1.3 incarcerated fracture, after reduction and single screw fixation.
Insertion of further screws in adult cases
Insert two or more screws. Complete the entire sequence for each screw
before inserting the next screw.
Remove provisional K-wires.