Executive Editor: Rick Buckley, Chris Colton

Authors: Florian Gebhard, Phil Kregor, Chris Oliver

Patella Partial articular, medial sagittal simple fracture

back to skeleton


1 Principles top

Treatment goal

The patellofemoral joint is biomechanically very stressed when the knee is loaded. Any compromise of the joint surface is likely to lead to degenerative joint disease. It is, therefore, highly desirable, in vertical patellar fractures to strive for anatomical reduction of the joint surface and stable fixation with interfragmentary compression.


Combination of techniques

In simple partial articular sagittal fractures, lag screw fixation alone, following anatomical reduction, provides absolute stability.

The addition of a tension band is not necessary as the longitudinal integrity of the extensor mechanism is not disrupted.

Screw size

Historically 4.5 screws were used but have been found to be too large. Now it is more common to use 3.5 or 2.7 screws.


Verification of reduction

Anatomical reduction of the articular surface is monitored by palpating the joint from inside, as neither inspection nor the x-ray will reveal a minor step off. This will require creation of a small arthrotomy.

Nevertheless, an image intensifier or X-ray should always be available, so that the reduction can be checked in the AP and lateral planes if needed.

2 Patient preparation and approach top


Patient preparation

This procedure is normally performed with the patient in a supine position with the knee flexed 30°.



For this procedure a mid-axial longitudinal approach is used.

3 Reduction and fixation top


Fracture debridement

The knee joint and fracture lines must be irrigated and cleared of blood clot and small debris, to allow exact reconstruction.



With the knee in flexion, reduce the fracture using a pointed bone reduction forceps or tenaculum.


Temporary fixation

Two K-wires are inserted through the planned screw trajectory with the fracture reduced



Insert two partially threaded cannulated lag screws over the K-wires.

Alternatively, a fully threaded screw may be inserted using the appropriate technique.

Anatomical restoration of the articular surface is verified by palpation if possible.

v2.0 2019-03-21