Ernest L. Sink
SURGICAL MANAGEMENT
Plate osteosynthesis of pediatric femur fractures allows stable fixation with good results.2,3,5,7,12
This traditionally requires a large exposure with soft tissue disruption.
Submuscular bridge plating results in stable fixation while minimizing soft tissue dissection.
In unstable fractures, it reliably maintains length and alignment that may be difficult to maintain with either immediate spica casting or elastic intramedullary nails.
Minimally invasive plating techniques avoid a large dissection and leave the soft tissues intact, allowing rapid “biologic healing.” This has led to more appeal for plating.
The technique of femoral shaft plating has evolved with a better understanding of plate mechanics.9
The indications for this technique are unstable comminuted or oblique femur fractures in ages 6 to skeletal maturity.
TECHNIQUES
PROVISIONAL REDUCTION
Patients are positioned on a fracture table, and a provisional reduction is obtained with boot traction.
The well leg is extended if the fracture table allows. Thus, the legs are scissored in an anteroposterior (AP) direction (TECH FIG 1).
The well leg can also be positioned on a well-leg holder.
This allows the fluoroscopy to be aimed perpendicular to the fractured leg to get a good lateral image for percutaneous screw placement.
A radiolucent table can also be used if there is enough assistance for traction.
The goal of the provisional reduction is to restore length and rotation.
TECH FIG 1 • Patient positioning in boot traction with the legs scissored in the AP direction.
IMPLANT SELECTION AND PREPARATION
The final reduction, particularly in the AP plane, can be done with the plate and screws.
A 4.5-mm narrow low-contact dynamic compression plate (LC-DCP) is chosen for most patients.
Locking plates may be used in osteopenic patients or in proximal or distal fractures in which the amount of available room for screws is compromised.
Given the percutaneous nature of screw placement, self-tapping screws are used to facilitate insertion.
The usual plate length is from 10 to 16 holes, depending on the fracture location and patient size.
Plate length is determined by placing the plate over the anterior thigh and using imaging to confirm the appropriate length.
As a general rule, the plate spans from the trochanteric apophysis to the distal femoral metaphysis.
If possible, length should allow six screw holes proximal and distal to the fracture.
Some fracture locations may allow for only two or three holes.
A table plate bender is used to contour the plate.
This usually involves a small bend to accommodate both the proximal femur and the distal metaphysis.
It is important to contour the plate as close to anatomic as possible, as the femur will reduce to the contour of the plate with screw placement.
After the plate is contoured, it is again placed on the anterior thigh, and imaging is used to “shadow” the lateral aspect of the femur to confirm the contour (TECH FIG 2).
It is not necessary to contour the plate to fit the normal anterior bow of the femur.
In our experience, there has been no misalignment secondary to a poorly contoured plate.
TECH FIG 2 • The plate on the anterior thigh shadowing the lateral femur with fluoroscopy to evaluate plate contour and length.
INTERNAL FIXATION
Plate Placement
A small incision (about 4 to 7 cm) is made over the distal lateral femur and through the tensor fascia to expose the obliquely oriented distal fibers of the vastus lateralis.
Blunt dissection is performed deep to the distal aspect of the vastus lateralis to enter the plane between the lateral femoral periosteum and vastus lateralis, which is easily defined.
The plate is then tunneled proximally along the lateral femoral periosteum (TECH FIG 3A–C).
Slow advancement of the plate allows the surgeon to feel the plate contact against the lateral femur.
Fluoroscopy may assist the surgeon in guiding the plate past the fracture (TECH FIG 3D).
Once the plate is fully advanced, AP and lateral views are obtained with fluoroscopy to confirm the plate position.
A Kirschner wire in then placed percutaneously in the most proximal and distal holes using fluoroscopy to secure the plate position (TECH FIG 3E,F).
Occasionally, adjustments need to be made to the plate position on the lateral view before Kirschner wire placement.
TECH FIG 3 • A–C. The plate is tunneled proximally under the distal vastus lateralis. D. Fluoroscopic view of the plate being guided proximally. E,F. Kirschner wires secure the plate in position before screw placement.
Screw Placement
The principles of external fixation are used to guide the surgeon in screw placement.
Three screws are placed proximal and three screws distal to the fracture (rarely there is room for only two screws).
The screws should be spaced as far apart as possible on each side of the fracture.
One of the screws should be placed near the proximal and distal margins of the fracture (TECH FIG 4A).
No lag screws are used as the fracture region is bridged.
Freehand “perfect circle” technique is used for percutaneous screw placement.
With fluoroscopy in the lateral position, the holes in the plate are visualized as a “perfect circle” to guide the drill.
A stab incision is made over the “perfect circle” and the knife blade is directed horizontal to the fluoroscopic beam through the iliotibial band and vastus lateralis to the desired hole.
The 3.2-mm drill bit is then placed into the desired hole and the surgeon drills perpendicular to the plate through both cortices.
The fluoroscopic image is rotated to the AP view.
The depth gauge is placed on the anterior thigh, and fluoroscopic imaging is used to obtain the appropriate screw length.
A Vicryl suture is tied over the screw head so the screw capture into the screwdriver is not lost during percutaneous screw placement (TECH FIG 4B–E).
The decision as to which percutaneous screw to place first is determined by where the femur is furthest from the plate and closest to the fracture.
The screw will act as a reduction screw, reducing the femur to the plate contour (TECH FIG 4F,G).
The second screw is placed on the opposite side of the fracture.
The remaining screws are then placed, attempting to achieve the greatest screw spread possible to achieve maximal stability.
Once the plate has been fixed to the femur, final radiographs are obtained to ensure adequate alignment and length (TECH FIG 4H,I).
The Vicryl ties are cut and the incisions are closed.
TECH FIG 4 • A. Fluoroscopic image of two screws bridging the fracture. These are commonly the first two screws placed. They are on the proximal and distal margin of the fracture. B–E. Percutaneous screw placement using fluoroscopic guidance and “perfect circle” freehand technique. B. The scalpel localizing the position and forming a percutaneous incision to the desired screw hole. C. Drilling a bicortical screw hole. D. An absorbable suture is tied around the screw head. E. Percutaneous screw placement. F,G. Reduction of the femur to the precontoured plate using the screw for reduction. H,I.Postoperative AP radiographs of the long oblique proximal-third femur fracture managed with the submuscular plate.
POSTOPERATIVE CARE
A soft dressing is applied.
A knee immobilizer can be used for postoperative comfort with mobilization.
No bracing or casting is required in the postoperative period.
Patients are then allowed to perform hip and knee range of motion as tolerated.
Touch-down weight bearing is encouraged until fracture callus is seen (about 6 to 8 weeks).
Full activity, including sports, is allowed when a bridging callus is present on at least three of the four cortices.
Plate removal is at the discretion of the surgeon and family.
Removal is often recommended in the younger child with the potential for bony overgrowth of the plate.
If plate removal is chosen, it is recommended at 6 to 8 months.
If the plate is removed at a later date it will be more difficult to remove in a percutaneous manner secondary to tissue overgrowth.
The plate can be removed through the same percutaneous incisions.
A Cobb elevator is advanced proximally along the lateral aspect of the plate to free the soft tissue.
The screws are then percutaneously removed using fluoroscopy.
A Cobb elevator is then placed between the plate and bone to free the plate to allow removal through the distal incision.
OUTCOMES
Over the past 30 years, femur fracture plating has evolved in terms of the use of longer plates, indirect reduction techniques, fewer plate screws, and fewer lag screws.
The best predictor of success is the length of the plate.9.
In comminuted and long oblique fractures treated with submuscular plating, the longer plate results in less strain on the plate and screws as the working length of the plate increases.
Since the comminuted fracture is spanned with a long plate, the strain on the healing fracture is less.
With the soft tissues intact around the fracture, the more rapid callus formation results in earlier load-sharing of the bone with the plate.
This limits the period of the load carried by the plate and the potential for failure.
The longer plate also requires fewer screws for optimal plate fixation.
There is a subgroup of pediatric femur fractures in which the options for treatment are complex.
This encompasses the comminuted and long oblique length unstable fracture, the larger adolescent, and more proximal and distal fractures.
Complications have been reported while treating these complex fractures with other methods of fixation, such as titanium elastic nails or external fixation.4,8,11
In comparison, the published results of submuscular plating are very successful, with minimal reported complications.1,6,10
Submuscular bridge plating is a reliable and predictable method to stabilize the more complicated pediatric femur fracture.
COMPLICATIONS
Reported complications are rare, and there are only two currently reported: refracture after early plate removal and a 3.5-mm plate that bent.6
These reported complications can be avoided by waiting for complete healing before plate removal and using a 4.5-mm plate in all but the smallest femurs.
Since the fracture is secured out to length, there is the potential for postfracture femoral overgrowth.
In our experience, this potential overgrowth does not become clinically relevant.
There is a loss of anterior bow or a few degrees of recurvatum in many fractures after union, but again this has not been proved to be clinically relevant.
Appropriate plate bending can help prevent malunion.
REFERENCES
1. Agus H, Kalenderer Ö, Eryanilmaz G, et al. Biological internal fixation of comminuted femur shaft fractures by bridge plating in children. J Pediatr Orthop 2003;23:184–189.
2. Caird MS, Mueller KA, Puyear A, et al. Compression plating of pediatric femoral shaft fractures. J Pediatr Orthop 2003;23:448–452.
3. Eren OT, Kucukkaya M, Kockesen C, et al. Open reduction and plate fixation of femoral shaft fractures in children aged 4 to 10. J Pediatr Orthop 2003;23:190–193.
4. Flynn JM, Hresko T, Reynolds RA, et al. Titanium elastic nails for pediatric femur fractures: a multicenter study of early results with analysis of complications. J Pediatr Orthop 2001;21:4–8.
5. Fyodorov I, Sturm PF, Robertson WW Jr. Compression-plate fixation of femoral shaft fractures in children aged 8 to 12 years. J Pediatr Orthop 1999;19:578–581.
6. Kanlic EM, Anglen JO, Smith DG, et al. Advantages of submuscular bridge plating for complex femur fractures. Clin Orthop 2004; 426:244–251.
7. Kregor PJ, Song KM, Routt ML, et al. Plate fixation of femoral shaft fractures in multiply injured children. J Bone Joint Surg Am 1993; 75A:1774–1780.
8. Luhmann SJ, Schootman M, Schoenecker PL, et al. Complications of titanium elastic nails for pediatric femoral shaft fractures. J Pediatr Orthop 2003;23:443–447.
9. Rozbruch SR, Müller U, Gautier E, et al. The evolution of femoral shaft plating technique. Clin Orthop 1998;354:195–208.
10. Sink EL, Hedequist D, Morgan SJ, et al. Results and technique of unstable pediatric femoral fractures treated with submuscular bridge plating. J Pediatr Orthop 2006;26:26:177–181.
11. Sink EL, Gralla J, Repine M. Complications of pediatric femur fractures treated with titanium elastic nails. J Pediatr Orthop 2005; 25:577–580.
12. Ward WT, Levy J, Kayne A. Compression plating for child and adolescent femur fractures. J Pediatr Orthop 1992;12:626–632.