髌骨骨折(英文版)

Using a clamp, the fracture is reduced.
FRACTURE REDUCTION
Using a clamp, the fracture is reduced.
in this case to maintain the reduction.
AP x-ray demonstrating the reconstruction using the cannulated screws to fix the central distal fragment and the medial distal fragment back to the proximal fragment. The distal lateral fragment is held with a lag screw. After fixation, the knee is brought to a complete range of motion to confirm stability and repeat radiographs are obtained.
Lateral and AP views. Notice that the lag screw is placed between the inferior lateral and inferior central fragment, but does not extend into the fragment on the medial side, as this would interfere with the placement of the K-wire.
Closeup of the complete reduction, using several clamps.
After the reduction is complete, the K-wires are visualized in the lateral and AP planes, which are used to evaluate not only the guidewire placement but also the reduction.
The two cannulated screws are placed over the guidewires. These screws must be large enough to enable the tension band to be placed through them.
Each manufacturer is different; the surgeon must be confident that the cannulation of the screw will accommodate the cable or wire system.
The screw should be placed such that it is short of the end of the bone. This is to avoid the cable or wire system from being injured by the sharp threaded end of the screw.
Closeup of the final reconstruction.
Lateral radiograph demonstrating the reduction. Notice that the screw tips are shy of the cartilage on the patella. The cable grip system wraps around the bone and is not making a sharp angle at the tip of the screw.
It is important to fully evaluate patella fractures on the AP x-ray as well as the lateral x-ray. The AP x-ray demonstrates the number of fragments and vertical splits in the sagittal plane that are not visible on the lateral x-ray.
After coming through subcutaneous tissue, the patella fracture is immediately evident. The clot and cancellous bone edges are cleaned.
A lamina spreader demonstrates the fracture site.
Lateral radiograph demonstrating complete separation of the patella with loss of extensor mechanism.
A vertical midline incision is performed over the patella.
The drill is then used also in a retrograde fashion.
The saggital plane split is seen when the distal fragment is flexed. This fracture is fixed with a transverse lag screw that will not interfere with the cannulated screws.
The cable system is introduced through one screw looped around anteriorly, then placed in the same direction through the second screw.
The two ends are pulled through a connector and underneath the clamp, which remains in place during the tightening.
In this case the Dahl-Miles system is used and the tightener is connected to the two free ends after a fastener is attached.
Lateral X-Ray
AP x-ray demonstrating the tightening of the cable grip system.
After the wire is sufficiently tightened and crimped in place, it is trimmed very close to the sleeve.
The retinaculum is then carefully repaired on both the medial and lateral sides to afford stability and additional support to the reconstruction.
It is important to fully evaluate patella fractures on the AP x-ray as well as the lateral x-ray. The AP x-ray demonstrates the number of fragments and vertical splits in the sagittal plane that are not visible on the lateral x-ray.
PATELLA ARTICULAR SURFACE
TROCHLEAR GROOVE
PROXIMAL
DISTAL
The articular surface of the patella and trochlear groove are evident upon flexion of the knee.
RETINACULAR TEAR
With displaced patella fractures there are concomitant retinacular tears medially and laterally.
PATELLA ARTICULAR SURFACE
TROCHLEA
After complete debridement and cleaning of the fractures, a cannulated screw guidewire can be placed retrograde through the fracture site, close and parallel to the articular surface.