The Locking Plate for Supracondylar Femur Fractures

Don Weber M.D., FRCSC
Associate Clinical Professor
University of Alberta
Edmonton, AB

Considering the widely accepted principles of anatomic articular reduction, stable fixation, minimal soft tissue dissection, and early mobilization - the locking plate delivers in all areas. It does, however, come at a significantly higher monetary cost than more traditional fixation devices and does require some expertise to avoid documented complications.

Supracondylar femur fractures constitute up to seven percent of all femur fractures and have a bimodal age distribution. That is, they occur with high-energy trauma in younger patients, and with low energy insults in the elderly. These fractures can lead to knee stiffness and have a tendency to collapse into varus. Up to fifty percent are intra-articular, are open and require anatomic reduction. Both high and low energy injuries can cause significant metaphyseal comminution depending upon bone quality.

In choosing a treatment method, one needs to consider a number of factors including bone quality, joint involvement, and the soft tissue envelope. Patient factors such as age, co-morbidities, and mobilization demand attention. Finally, surgeon factors such as experience and available resources come into play.

weberfigure_1.jpg
Figure 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Minimally invasive surgical techniques have gained wide acceptance in trauma circles. The locking plate has a low profile and is designed to be inserted with limited dissection so as to preserve fracture hematoma and limit iatrogenic devascularization. This application is probably most important in the setting of comminution and osteoporosis. Minimally invasive techniques have been shown to reduce non-union rates and to decrease the requirement for acute bone grafting as well as, potentially, lead to fewer soft tissue complications. Some expertise is required to carry out this procedure, as there are well-documented complications from malreduction. The most common deformities induced with the locking plate are medialization and external rotation of the distal fragment. These plates are extremely stable and the initial reduction is usually maintained. Therefore a malreduction invariably leads to a malunion. One location where minimal exposure is generally not used is in reconstruction of intra-articular fractures.

Locking plates are of great value in the setting of intra-articular comminution. Open joint reconstruction is the norm but shaft fixation can generally be achieved percutaneously. Distal locking screws are inserted at multiple angles and have adequate spacing to allow capture of various joint fragments. They have stronger fixation than conventional screws in the face of osteoporosis, and can provide excellent control of the distal fragment in a periprosthetic fracture above a stable total knee replacement. They do not remove a large amount of bone from the distal femur in contrast to the dynamic condylar screw. Locked unicortical fixation allows for some bone purchase up to the stems of long total hip components or stemmed total knee implants.

Metaphyseal comminution also demands treatment with a fixed angle device or a locked intramedullary nail and is therefore amenable to locking plate treatment.

Rigid fixation allows early mobilization of the knee. One situation in which this is extremely useful is in the high-energy open supracondylar fracture. This is illustrated by the following case.

weberfigure_2.jpg
Figure 2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A 45-year-old motorcyclist collides with the flat deck of a semi-trailer at highway speed. Figure 1 displays a radiograph of the presenting open supracondylar femur fracture. Initial stabilization is achieved with a spanning external fixator. This is followed by repeat debridement, articular reconstruction, and rigid fixation (Figure 2). A staged bone grafting is performed six weeks post-injury and repeated at five months post-injury. Because the fixation was stable up to the final bone grafting, continuous range of motion was allowed and an excellent clinical and radiographic result was achieved. Even though the femur became osteoporotic from the extended period of non-weight bearing, the fixation held. This likely reduced secondary soft tissue compromise, increased the ultimate range of motion achieved, and probably reduced the risk of infection.

Even though locking plates can be used in all supracondylar fractures, perfectly acceptable results can be achieved with standard devices in most instances. It must be remembered that locking plates are expensive.

A ten-hole distal femoral locking plate with screws will cost about $1800. This can be compared to a locked retrograde intramedullary nail at $850, or a condylar buttress plate and screws costing $600.

weberfigure_3.jpg
Figure 3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

There are two other things to be wary of with the use of locking plates. Fixing a simple fracture rigidly with a gap can lead to a non-union. Secondly, because of the "sense" that the fixation is strong, weight bearing allowed too early can lead to hardware failure.

Every fracture is unique when you consider the myriad of tissue, patient, and surgeon variables. Locking plates can be an invaluable part of a trauma surgeon's armamentarium, especially in the face of comminution, osteoporosis, and periprosthetic fractures.

References

  1. Higgins T., Pittman G., Hines J., Bachus K N. Biomechanical Analysis of Distal Femur Fracture Fixation: Fixed-Angle Screw-Plate Construct Versus Condylar Blade Plate. Journal of Orthopaedic Trauma Jan. 2007. Vol. 21:43-46.
  2. Sommer C., Babst R., Muller M., Hanson B. Locking Compression Plate Loosening and Plate Breakage: A Report of Four Cases. J Orthop Trauma. 2004 Sept:18(8): 571-7.
  3. Gautier E., Sommer C., Guidelines for the Clinical Application of the LCP. Injury. 2003 Nov: 34 Suppl 2: B63-76.
  4. Bolhofner B.R., Carmen B., Clifford P. The Results of Open Reduction and Internal Fixation of Distal Femur Fractures Using a Biologic (Indirect) Reduction Technique. J Orthop Trauma. 1996; 10(6): 372-7.
  5. Ziowodzki M., et. al. Biomechical Evaluation of the Less Invasive Stabilization System, Angled Blade Plate, and Retrograde Intramedullary Nail for the Internal Fixation of Distal Femur Fractures. J Orthop Trauma. 2004 Sep; 18(8): 494-502.
  6. Kegor P.J., Stannard J.A., Ziowodzki M., Cole P.A., Treatment of Distal Femur Fractures Using the Less Invasive Stabilization System: Surgical Experience and Early Clinical Results in 103 Fractures. J Orthop Trauma. 2004 Sep; 18(8): 509-20.
  7. Weight M., Collinge C., Early Results of the Less Invasive Stabilization System for Mechanically Unstable Fractures of the Distal Femur (AO/OTA types A2, A3, C2, and C3). J Orthop Trauma. 2004 Sep; 18(8): 503-8.

Submit Community Content

If you have orthopedic information that you would like to share with the Orthogate Community, please register/login and submit your news, event, job, article, case or workshop from the Submit Content menu under the My Account area. Learn more!