Executive Editor: Chris Colton

Authors: Peter V Giannoudis, Hans Christoph Pape, Michael Sch├╝tz

Femur shaft 32-B2 ORIF subtrochanteric

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Glossary

1 Principles top

Principles enlarge

Important module-wide statement

Where appropriate, a “generic” fracture zone will be illustrated and not necessarily the specific fracture morphology under consideration. Where the fracture morphology determines the fixation technique, the specific morphology will be shown.


Principles enlarge

Bridge plating

Bridge plating uses the plate as an extramedullary splint, fixed to the two main fragments, leaving the intermediate fracture zone untouched. Anatomical reduction of intermediate fragments is not necessary. Furthermore, their direct manipulation would risk disturbing their blood supply. If the soft tissue attachments are preserved, and the fragments are relatively well aligned, healing is enhanced.

Alignment of the main shaft fragments can be achieved indirectly with the use of traction and the support of indirect reduction tools, or indirectly via the implant.

Mechanical stability, provided by the bridging plate, is adequate for gentle functional rehabilitation and results in satisfactory indirect healing (callus formation). Occasionally, a larger wedge fragment needs to be approximated to the main fragments with a lag screw.

Note: choice of implants

Implants that can be considered for this technique include the DCS, proximal femoral locking plate and the 95° angled blade plate.

The use of a 95° angled blade plate is possible but technically very demanding. It should therefore only be considered for acute fractures if no other implant is available. It is a valuable technique for nonunions and corrective osteotomies.


Reduction

It is important to restore axial alignment, length, and rotation.

Reduction can be performed with a single reduction tool (eg, large distractor) or by combining several steps (for example fracture table +/- external fixator, +/- reduction via the implant, etc.) to achieve the final reduction.

The preferred method depends on the fracture and soft-tissue injury patterns, the chosen fixation device, and the experience and skills of the surgeon.

If a large fragment has separated from the fracture and impaled the adjacent muscle, direct reduction may be required through a separate limited approach.

2 Preliminary reduction top

Preliminary reduction enlarge

General considerations

Subtrochanteric fractures present a particular problem in terms of fracture reduction and alignment. Due to the strong pull of the iliopsoas muscle, the proximal fragment is flexed and externally rotated and therefore difficult to control.

Preliminary reduction should be undertaken before the plate is applied. Once the plate is attached to the proximal fragment the definitive reduction with respect to length, rotation and axis can then be achieved.


Preliminary reduction enlarge

The iliopsoas muscle flexes and externally rotates the proximal fragment.


Preliminary reduction enlarge

Use of reduction clamps

Reduction clamps are often required to achieve proper alignment. Pointed reduction forceps may be used, but may not provide enough force.


Preliminary reduction enlarge

Use of large distractor

After the placement of two pins - one in the greater trochanter and the second one in the shaft - the large distractor is attached.

Attention has to be paid so that the pins do not conflict with the later plate position.

The preliminary reduction is held by tightening the clamps of the large distractor.

Please refer to an AO-video for the application of the large distractor.

3 Preoperative planning top

Preoperative planning enlarge

Plate length and number of screws

Depending on the extent of the zone of fracture comminution and the underlying bone stock (osteoporosis), the appropriate plate length is chosen. Sufficient bicortical screws (a minimum of three up to six) should be inserted in each fracture fragment. The relative stability results from leaving plate holes empty over the fracture zone.

4 Plate fixation to proximal fragment top

Plate fixation to proximal fragment enlarge

Guide wire insertion and verification of trajectories

The proximal femoral plate is anatomically shaped to match the profile of the upper femur. First, the plate is adjusted optimally to fit the proximal fragment. Through the two attached wire guides, the proximal 2.5 mm guide wires are inserted into the proximal fragment.


Plate fixation to proximal fragment enlarge

The positions of the guide wires are verified under image intensification in both planes (AP and lateral).


Plate fixation to proximal fragment enlarge

Screw length measurement

The correct screw lengths are determined by measuring the remaining guide wire length, using the dedicated measuring device.


Plate fixation to proximal fragment enlarge

Proximal 7.3 mm screw insertion

Cannulated 7.3 mm screws (locking or non-locking) are inserted over the guide wires into the proximal fragment.

5 Plate fixation to distal fragment top

Plate fixation to distal fragment enlarge

Verification of reduction

Under image intensifier control, the preliminary reduction is again checked in respect to axial alignment and length and, to a degree the rotation (in more complex fractures the clinical judgment of the rotation becomes more important while the radiological findings in that respect is challenging to interpret).


Plate fixation to distal fragment enlarge

The illustration shows the fracture incompletely reduced.


Plate fixation to distal fragment enlarge

Insertion of first screw into distal fragment

Two blunt Hohmann retractors placed ventrally and dorsally around the femoral shaft can help to control the lateral position of the plate.

If the overall reduction is found to be satisfactor the first cortical non-locking screw in the distal fragment is inserted. This screw helps to reduce the bone to the anatomically shaped implant. Nevertheless, this screw should not fully be tightened, still allowing fine tuning of the plate position on the lateral surface of the femur.


Plate fixation to distal fragment enlarge

Insertion of second screw into distal fragment

Once the most distal screw has been inserted, the first screw is now fully tightened.


Plate fixation to distal fragment enlarge

Pearl: final reduction

In case the lateral position, prior to the placement of the second screw, is not correct the use of sterile bolsters is helpful.


Pearl: osteoporotic bone

In case of osteoporotic bone the usage of locking screws is advantageous.

6 Additional screw placement top

Additional screw placement enlarge

In accordance with preoperative planning, additional screws are inserted into the proximal and distal main fragments.

v1.0 2007-12-02