1 Preliminary remarks topenlarge
The group A3 intertrochanteric fractures are classified according to the
fracture pattern. The subgroup A3.1 represents the simple reverse oblique
fractures. The subgroup A3.2 are the transverse fractures and the subgroup A3.3
are the multifragmentary reverse oblique fractures with a detached medial
fragment including the lesser trochanter.
One should always attempt a closed reduction. If unsuccessful, a limited open reduction is necessary. It is done on a fracture table and subsequently, an appropriate fixation device is chosen. In most instances it will be an intramedullary device.
Only stable proximal femoral fractures can be treated with the DCS (dynamic condylar screw) plate. The DCS plate does not allow for controlled collapse and compression.
2 Reduction topenlarge
The use of a traction table depends on the surgeon’s preference. In fresh
cases, a traction table might not be necessary and the procedure can be done on
a translucent table designed for use with image intensification.
If a traction table is used, the patient should be positioned as indicated in the drawing with his ipsilateral arm elevated in a sling while the contralateral uninjured leg is placed on a leg holder.
Reduction will be achieved by first pulling on the leg in order to distract the fragments and regain length. This should be controlled under image intensification.
The second step is internal rotation of the leg. Again it has to be checked under image intensification in 2 planes as the reduction determines the degree of internal rotation.
A straight 10 cm skin incision is made starting at the greater trochanter
and carrying it downwards, parallel to the femoral axis. The fascia lata is
incised in line with the skin incision and in line with its fibers. The vastus
lateralis muscle is elevated from the intermuscular septum just enough to
expose the fracture. To avoid bleeding, tie off the perforating vessels. If
necessary use a small Hohmann in order to visualize the bone.
A pointed reduction clamp is used to reduce the fracture and maintain reduction.
3 Insertion of the dynamic condylar screw top
Technique of insertion
Lateral approach between the vastus lateralis muscle and intermuscular septum.
Application of the aiming device
The aiming device for the DCS is chosen. It is placed against the lateral cortex. Its position should be checked using image intensification in an AP view, according to the anticipated position of the guide wire.
Insertion of a guide wire for the screw
The guide wire is inserted through the aiming device. In the AP view it should be in the lower or caudal half of the femoral head. On the axial view it should be parallel to the axis of the neck and in the middle of the neck. The guide wire is advanced into the subchondral bone and its tip should lie 10 mm off the joint.
Determination of the length of the DCS screw
Determine the length of the DCS screw with help of the measuring device. Select a screw which is the same length as measured.
Adjust the cannulated triple reamer to the chosen length of the screw. Drill the hole for the screw and the plate sleeve.
The selected screw is mounted on a handle and inserted over the guide
When the screw has reached its final position, the T-handle has to be in line with the longitudinal axis of the femur to guarantee that the plate will come to lie on the femoral shaft.
Remove handle and leave guide wire in place.
4 Fixation of the DCS plate topenlarge
Application of the DCS plate
The length of the plate is determined by the extent of the fracture. One
should aim to have at least five screw holes distal to the fracture since one
needs eight cortices of screw purchase to ensure adequate fixation. In
osteoporotic bone, five screws (10 cortices) are advised.
The DCS plate is now inserted and seated with the impactor. Compression of the fracture might be achieved if the cortical screws are inserted in a load position starting with the most distal screw. One might also use the articulated tension device if indicated. If the fracture pattern allows, additional cortical screws should be inserted into the proximal fragment to augment the fixation.
Insertion of holding screws
The plate is fixed to the femoral shaft with an appropriate number and size
of plate holding cortical screws.
If possible insert lag screw(s) through the plate to compress the fracture.