- Discussion:
- note that type II fractures may often not be amenable to percutaneous fixation because an acceptable reduction of the depressed
fragment can be difficult to obtain;
- part of the difficult lies in the fact that the depressed fragment is buried w/ in the plateau and is obsured by the frx lines of the split
fragment;
- hence the patient should be forewarned about the need for open reduction;
- Reduction:
- if the split fragment is depressed, it needs to be brought out to length with use of a femoral distraction;
- the distractor is placed on the same side as the fracture;
- once the fracture fragment has been elevated w/ ligamentotaxis, then the medial or lateral displacement can be corrected;
- reduction is achieved w/ percutaneous applied reduction forceps w/ flourscopic assistance;
- consider applying the reduction forceps eccentrically, and then torque the reduction forceps to achieve reduction;
- adequate reduction implies less than 1-2 mm step off;
- depressed fragments:
- make a small window in the metaphyseal cortex and elevate the depressed fragment with a bone tamp;
- Fixation Methods:
- percutaneous screws:
- wedge of type I frx of lateral plateau can usually be fixed w/ only cancellous percutaneous lag screws and washers (plates are
usually not necessary);
- consider 6.5 mm cancellous screws (over washers) which are placed in a triangular position;
anti-glide screw:
- antiglide screws are typically placed after 1-2 percutaneous lag screws are placed thru the frx fragment;
- antigluide screws (over washers) are placed just distal to the frx edge to prevent distal displacement;
- 4.5 mm cortical screws over washers are typically used