髌骨骨折(英文版)-PPT.ppt

It is important to fully evaluate patella fractures on the AP x-ray as well asthe 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.It is important to fully evaluate patella fractures on the AP x-ray as well asthe 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.Lateral radiograph demonstrating complete separation ofthe patella with loss of extensor mechanism.A vertical midline incision is performed over the patella.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.The articular surface of the patella and trochlear groove areevident upon flexion of the knee.PATELLA ARTICULARSURFACETROCHLEARGROOVEPROXIMALDISTALRETINACULAR TEARWith displaced patella fractures there are concomitant retinacular tears medially and laterally.TROCHLEAPATELLA ARTICULARSURFACEAfter complete debridement and cleaning of the fractures,acannulated screw guidewire can be placed retrograde throughthe fracture site,close and parallel to the articular surface.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.Using a clamp,the fracture is reduced.Using a clamp,the fracture is reduced.FRACTUREREDUCTIONA second clamp is necessary in this case to maintain the reduction.Closeup of the complete reduction,using several clamps.After the reduction is complete,the K-wires are visualized in thelateral and AP planes,which are used to evaluate not only theguidewire placement but also the reduction.Lateral and AP views.Notice that the lag screw is placedbetween the inferior lateral and inferior central fragment,but does not extend into the fragment on the medial side,asthis would interfere with the placement of the K-wire.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 thatthe 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 thebone.This is to avoid the cable or wire system from being injuredby the sharp threaded end of the screw.The cable system is introduced through one screw looped aroundanteriorly,then placed in the same direction through the secondscrew.The two ends are pulled through a connector and underneaththe clamp,which remains in place during the tightening.In this case the Dahl-Miles system is used and the tighteneris connected to the two free ends after a fastener is attached.Lateral X-RayAP 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 themedial and lateral sides to afford stability and additionalsupport to the reconstruction.Closeup of the final reconstruction.Lateral radiograph demonstrating the reduction.Notice that thescrew tips are shy of the cartilage on the patella.The cable gripsystem wraps around the bone and is not making a sharp angleat the tip of the screw.AP x-ray demonstrating the reconstruction using the cannulatedscrews to fix the central distal fragment and the medial distal fragmentback to the proximal fragment.The distal lateral fragment is held witha lag screw.After fixation,the knee is brought to a complete range of motion to confirm stability and repeat radiographs are obtained.