Annual Report

Executive Editor: Rick Buckley, Chris Colton

Authors: Florian Gebhard, Phil Kregor, Chris Oliver

Patella Complete articular, frontal/coronal multifragmentary fracture

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Glossary

1 Principles top

The patello-femoral 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 patellar fractures to strive for anatomical reduction of the joint surface and stable fixation.

An additional treatment goal is restoration of function of the knee extensor mechanism and allow early range of motion of the knee.


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Debridement

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

2 Patient preparation and approach top

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Patient preparation

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


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Approach

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

3 Reduction and fixation top

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Reduction and temporary fixation

The reduction of this fracture requires careful planning.

The largest fragments are reduced and temporary fixed with K-wires.

In frontal/coronal (transverse) fractures, reduction is easier with the knee extended. 

Sagittal fractures are more easily reduced with the knee flexed.


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Frequently, the use of several K-wires is required to hold smaller fragments to the larger fragments.


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Verify the reduction by palpation of the retropatellar surface.


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Plate application

Non-locking 2.4 and 2.7 plates are typically used for the patella. They are small and very malleable which facilitates contouring to the patella surface.

The plates can be used circumferentially around the patella, in a similar fashion to a cerclage wire, or across the surface to resist distraction forces.

Each piece of the comminuted patella will require at least one point of fixation if not more.

The resulting construct should be strong enough for early motion to be started.

Care should be taken to prevent screw penetration into the joint.

Reduction should be verified by careful intraoperative X-ray and finger palpation.


Additional stability

To achieve a satisfactory stability, the combination with multiple techniques including lag screws, lag screws through a plate, and K-wire fixation with or without cerclage may be needed.

4 Case top

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These are preoperative X-rays in a 25-year-old female injured in a motorcycle crash.

Note the extensive multifragmentary fracture pattern on the AP.


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The multifragmentary pattern can also be seen in the lateral view.


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This clinical picture is in the middle of the operating procedure. Note the stellate fracture pattern on the undersurface of the patella as this fracture is approached from the lateral parapatellar approach.


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AP postoperative X-ray image demonstrating dorsal and circumferential plating of the multifragmentary patella fracture.


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The same patient with the lateral image demonstrating multiple plates and the best possible articular reconstruction for this multifragmentary fracture.


Clinical video of 25-year-old patient three months after patellar plating, demonstrating excellent function of the extensor mechanism.

v2.0 2019-03-21