Supracondylar Femur Fractures: Open Reduction Internal Fixation

Temporary, spanning, external fixation can be helpful in
multiply injured patients and in patients with complex fracture
patterns. It usually consists of a knee joint–spanning external fixator
with pins placed into the tibia and the femur. Femoral pin placement
can be directly anterior, directly lateral, or anterolateral.
Regardless of their entry orientation, pins should be placed proximal
to the anticipated surgical incision(s) for definitive fixation. Some
knee flexion (10 to 20 degrees) is recommended and improves the
commonly observed extension deformity of the distal femoral segment.

The primary focus of this chapter is on the fixation of
combined supracondylar and intercondylar (AO/OTA 33C) distal femoral
fractures. However, because of the versatility and number of implants
appropriate for fractures of the distal femur, other fracture patterns
will be mentioned. Fractures without articular involvement (33A
fractures) can be treated with antegrade nails, retrograde nails, and
lateral plate constructs. The choice of implant in these injuries is
largely dependent upon the surgeon’s comfort, the patient’s associated
injuries, and the predicted management of any potential complications
due to the injury or the treatment. Fractures with partial articular
involvement (lateral condyle fractures, medial condyle fractures, or
tangential fractures of the posterior condyle) can be treated with lag
screws, conventional plates, or a combination of both. For fractures
with both supracondylar and intercondylar involvement, effective
implants include conventional lateral plates (condylar buttress plate,
precontoured lateral plates specific for the distal femur), lateral
plates with a fixed angle (95-degree angled blade plate, dynamic
condylar screw), and lateral locking plates (Fig. 23.3). In general, the surgical tactic and reduction are more important than the implant.

Conventional lateral plates are inexpensive and easy to
apply. Angulation of the screws in the distal segment may be
advantageous in fractures where multiple lag screws are required to
stabilize any articular-surface comminution. The biggest disadvantage
is the inability of these implants to prevent postoperative varus
deformation due to screw loosening, especially in the distal articular
block. This may be most significant in open fractures, patients with
osteopenia, and fractures with associated bone loss.

Fixed-angled lateral implants include the 95-degree
angled blade plate, the 95-degree condylar screw, and the lateral
fixed-angled screw-plate devices. All of these implants have the
advantage of minimizing varus deformation by eliminating screw toggling
in the distal metaphyseal bone. Blade plates can be placed quite
distally and do not remove significant bone from the distal articular
segment. However, these implants are technically difficult to place and
require a single perfect entry location. This is especially important
in distal

femoral
fractures with associated articular comminution that require a prior
surgical stabilization of the multiple articular fragments. These
implants may prevent ideal placement of the condylar blade distally.
The dynamic condylar screw is easier to implant and allows submuscular
implantation. However, this device removes a significant amount of bone
and cannot be placed as distally as an angled blade plate. Locking
plates, in addition to maintaining the coronal plane reduction, allow
for placement of multiple fixed implants (screws) into the distal
segment. Thus, they allow for some flexibility in screw location and
may be more forgiving. These implants have the further advantage of
having specifically designed surgical jigs that enhance submuscular
implantation.

The patient is positioned supine on a radiolucent table
that allows unimpeded fluoroscopic imaging in both planes. A small bump
placed beneath the ipsilateral hip should be sized to ensure that the
femur is in neutral rotation, assisting with the intraoperative
assessment of extremity rotation during and after reduction. The knee
is placed in slight flexion over a custom ramp or folded blankets with
an additional small rolled bump at the fracture site (Fig. 23.4).
This improves the sagittal plane reduction of the fracture by relaxing
the primary deforming force of the gastrocnemius. In addition, this
position facilitates intraoperative, lateral, fluoroscopic imaging of
the proximal thigh without obstruction from the contralateral extremity.

The entire limb is prepped and draped from the
ipsilateral pelvis to the toes, allowing intraoperative manipulation of
the leg and access to the femur proximally as needed. If traction
radiographs in the AP and lateral planes have not been obtained
previously, these can be obtained at this time. A sterile tourniquet
can be applied proximally if desired.

The choice of surgical approach is determined by the
fracture location and pattern, any associated comminution, the primary
reduction techniques, and the implant. In general, an

extensile lateral approach can be used for most supracondylar and intercondylar distal femoral fractures (Fig. 23.5).
This approach allows access to the lateral femoral condyle, the
intercondylar region, and the entire lateral femur. This approach can
be useful for both open plating techniques and minimally invasive
techniques. The lateral exposure can be limited to that necessary for
reduction of the articular surface in cases where submuscular
techniques are chosen for stabilization of the articular segment to the
femoral diaphysis. A lateral parapatellar approach may be used in
fracture patterns with significant intercondylar comminution, coronal
plane fractures, or both. Although this approach allows access to
intercondylar comminution, trochlear comminution, and most medial and
lateral coronal condylar fractures, it is not as easily extended
proximally to allow a lateral plate application on the femoral
diaphysis. This approach may be most useful is cases where minimally
invasive or percutaneous methods are anticipated for plate application
proximally (Figs. 23.6 and 23.7).
Infrequently, a medial subvastus approach may be required in
conjunction with a lateral approach. This approach should be limited to
the articular segment, respecting the more proximal, medial,
soft-tissue attachments. In all surgical approaches, the posterior and
medial soft-tissue attachments to any metaphyseal bone segments should
be left intact.

In open, distal, femoral fractures, as with any open
fracture, a thorough debridement of any devitalized tissue is necessary
prior to reduction and definitive fixation. The ideal incision for the
surgical approach necessary for fracture fixation should first be
marked on the skin. The open wound can be incorporated into the
incision if appropriate. However, an extensile approach that allows
exposure and debridement of the open fracture as well as reduction of
the distal femur should be a priority over an objective to minimize the
number of scars around the knee. This is particularly true in patients
with traumatic open wounds located medially.

In general, any bone fragments without soft tissue
attachments should be discarded. However, every attempt should be made
to retain any articular fracture fragments. If definitive fixation is
delayed (either due to the need for a second debridement or due to the
combination of fracture complexity and surgical timing), consideration
should be given to placing a spanning external fixator as previously
described. Antibiotic beads can be placed into any metaphyseal defect
that may exist after debridement.

By avoiding dissection of the medial soft tissues in the
distal-femoral metaphyseal region, healing should proceed predictably
in most supracondylar/intercondylar fractures. Therefore, most lateral
plate devices will be effective in the majority of fracture patterns.
Because of the tendency for these fractures to collapse into varus
prior to healing, a fixed-angled implant (angled blade plate or dynamic
condylar screw) or a locking implant can be considered for most
fracture patterns. The location and severity of articular comminution
combined with the implants necessary to reduced them may make the use
of certain implants difficult. The use of minimally invasive and
percutaneous techniques, which attach the distal, femoral, articular
component to the femoral shaft, helps to maintain the blood supply to
the metaphyseal fracture fragments (Fig. 23.8).
However, an open technique can also be performed in which soft-tissue
attachments are respected. As a general rule, the distal, femoral,
articular surface is first anatomically reduced and stabilized with
multiple lag screws and then the articular block can be reduced and
fixed to the femoral diaphysis.

Typically, coronal plane fractures are reduced and
stabilized prior to reduction of the intercondylar component. For
coronal plane fractures of the lateral femoral condyle, the articular
surface can be reduced and compressed with a pointed clamp, followed by
placement of lag screws (Fig. 23.9). The
location and angulation of the fracture plane determine the direction
and location of the screws. Usually, 3.5-mm lag screws can be placed
from anterior to posterior, perpendicular to the fracture, and
angulated approximately 10 degrees from medial to lateral. The screw
heads should be countersunk beneath the patellofemoral articular
surface when necessary.

For coronal fractures of the medial femoral condyle,
angulation of up to 25 degrees from lateral to medial may be required.
Two screws are usually adequate for simple coronal plane fractures. The
intercondylar fracture can then be reduced and stabilized. All hematoma
and loose osseous fragments should be removed from the intercondylar
fracture prior to attempting a reduction. Joysticks (2.0-mm to 2.4-mm
wires) placed into each femoral condyle can assist with reducing the
flexion/extension deformities seen with each condyle. A clamp can then
be placed across the fracture, securing the two condyles and
compressing the intercondylar fracture. Depending on the location and
size of the surgical approach, this clamp may be placed either within
the surgical arthrotomy or through small percutaneous stab incisions.
The intercondylar fracture can then be secured with multiple 3.5-mm lag
screws placed from lateral to medial. These screws should be placed
strategically in anticipation of a lateral plate. For fracture patterns
with more extensive comminution, 2.0-mm, 2.4-mm, and 2.7-mm screws may
be necessary. Intraosseous screws and those placed through the
articular surface should be adequately countersunk.

The entire articular block can then be reduced to the
femoral shaft, spanning any areas of metaphyseal comminution. If the
metaphyseal fracture component is simple, then a direct, open, lateral
reduction can be used. No attempt should be made to reduce the medial
metaphyseal components of the fracture. Similarly, if multiple
intercalary fracture fragments exist, the temptation to directly reduce
and stabilize these components should be avoided. The distal, femoral,
articular segment is usually in an extended position relative to the
shaft due to the attachment of the gastrocnemius. With increasing
longitudinal traction applied to the limb, this deformity frequently
increases. A bump placed at the distal femur will allow flexion of the
fracture, reducing the extension deformity. If some deformity

persists,
joysticks placed from anterior to posterior in the distal segment can
be used to restore the proper flexion. The coronal plane alignment can
usually be corrected with manual angulation of the extremity.

If a fixed-angled device (such as a 95-degree angled
blade plate, a dynamic condylar screw, or a locking condylar plate) is
used, the implant is typically fixed to the distal articular block and
indirect techniques are used to align this segment with the shaft. The
insertion

angle,
location, and angulation of the implant in the articular segment
determine the final reduction of the distal femur. The usual location
for insertion is 1.5 cm (angled-blade plate) or 2.0 cm (dynamic
condylar screw) proximal to the articular surface and in the middle
third of the anterior half of the distal femoral as viewed from the
lateral surface. The angle of insertion is parallel to the distal,
femoral, articular surface and perpendicular to the lateral femoral
metaphysis. Implants placed horizontal relative to the lateral,
femoral, distal surface lead to medial displacement and internal
rotation deformities.

The shaft can then be reduced to the plate while
alignment is maintained. The plate should be of sufficient length such
that at least five screw holes are entirely proximal to the fracture.
Proximal plate length is more important than the number of screws in
the proximal segment. Limb length can be restored using a femoral
distractor, the articulated tensioning device, a push screw with a
lamina spreader, or with manual traction. When the length is properly
obtained, the plate can be secured to the lateral femoral shaft with a
reduction clamp. In noncomminuted fractures, the fracture can be
compressed using the articulated tensioning device. In most cases,
supracondylar comminution exists and the plate is statically fixed to
the lateral femur after the proper length is obtained. Three or four
bicortical screws maximally spread in the shaft component should be
placed. If a long plate is used, the mismatch between the sagittal
plane bows that are between the bone and the plate will be accentuated,
necessitating a more posterior plate application to ensure that the
implant is not off the bone proximally.

An accurate articular reduction through an open approach
is necessary prior to stabilization of the distal articular block to
the shaft (Fig. 23.10). Minimally invasive
techniques are useful primarily for reduction of the articular block to
the femoral shaft. Virtually all implants can be fixed to the femoral
shaft using minimally invasive techniques. Proper length, translation,
and alignment should be accurately restored or an open approach is
required. Length is best accomplished with either manual traction or a
femoral distractor placed anteriorly from the femoral diaphysis to the
proximal tibia. Translational and angulatory deformities are best
corrected manually with joysticks, mallets, pushers, or bumps. Prior to
fixing the implant to the distal articular segment, the plate is slid
in a submuscular fashion along the lateral aspect of the femur using a
combination of tactile feedback and visual clues from the fluoroscopic
imaging. It is important to ensure that the implant is fixed to the
midlateral aspect of the femur along its entire length. Frequently,
lateral implants are angulated at least 10 degrees posteriorly to
ensure proper position in the distal fragment. As a result,
fluoroscopic confirmation of proper plate placement on the lateral
femur requires limb external rotation.

For isolated unicondylar medial or lateral condyle
fractures, the surgical approach is dictated by the fracture location.
Most lateral condyle fractures (AO/OTA 33B1) can be approached from an
extensile lateral approach to the distal femur, similar to that for
many supracondylar-intercondylar fractures. However, if extensive
involvement of the intercondylar notch is noted on the CT scan,
consideration can be given to using a lateral parapatellar approach to
better visualize this articular reduction. In medial condyle fractures
(AO/OTA 33B2), a medial subvastus approach is extensile proximally and
allows excellent visualization of the articular reduction.In either
case, the sagittal plane rotation of the condyle must be reduced
perfectly at both the proximal cortical exit and the intercondylar
articular surface. If significant articular comminution is present,
this must be accurately reduced prior to reduction of the major
condylar fragment. Temporary Kirschner (K) wire fixations are useful
for maintaining these reductions. If visualization is difficult, a
knee-spanning femoral distractor can be of assistance. Fixation can
usually be accomplished with a combination of lag screws placed
perpendicular to the fracture line and an antiglide plate placed
proximally (Fig. 23.11).

For lateral condyle Hoffa fractures (AO/OTA 33B3), a
lateral approach with a lateral arthrotomy allows visualization of the
articular reduction as well as clamp applications for compression and
stabilization. For medial condyle Hoffa fractures, a medial subvastus

approach
allows visualization and reduction. These fractures are usually reduced
directly at the articular surface and indirectly at the posterior
cortical-fracture exit point. The fracture reduction can then be held
with K wires placed perpendicular to the fracture line as seen on the
lateral fluoroscopic image. The distal, femoral, condylar anatomy
suggests that implants for lateral condyle fractures should be
angulated approximately

10
degrees laterally in the coronal plane whereas implants for medial
condyle fractures should be angulated approximately 25 degrees medially
in the coronal plane. Two 3.5-mm lag screws directed from anterior to
posterior is usually adequate in uncomplicated fracture patterns.

The most common intraoperative complication related to
ORIF is a malreduction of either the articular surface or the
mechanical axis. An accurate reduction requires an appreciation for the
anatomy of the distal femoral articular surface as well as the
relationship between the distal femoral inclination and the femoral
shaft. Restoration of the limb axes as well as the entire articular
surface are among the operative goals. Small-fragment and mini-fragment
fixations may be required to fix small osteochondral fragments. The
relative rotation of the medial and lateral femoral condyles should be
accurately restored. Failure to achieve an accurate reduction in a
patient with a closed injury is an avoidable complication.

Nonunion can occur at any of the original fracture
locations and may be extra-articular (supracondylar) or intra-articular
(intercondylar or coronal). Supracondylar nonunions occur more commonly
than intra-articular nonunions. If indirect reduction techniques are
used, the incidence of supracondylar nonunion is low even when
bone-grafting materials are not used. Nonunion is associated with
certain injury factors, such as open traumatic wounds or bone loss, as
well as patient factors, such as smoking or steroid use. Large defects
due to open fractures with associated bone loss should be treated with
bone grafting at a minimum of 6 to 8 weeks from the time of the initial
stabilization. Supracondylar nonunions may be associated with deformity
depending on the time from injury and the durability of the implants
used to stabilize the distal femur. If no deformity exists, the
nonunion can be compressed using a lateral fixed-angled implant. The
articulated tensioning device is useful for compressing the nonunion
after the implant if fixed to the distal segment. Bone grafting should
be used according to the basic principles of nonunion treatment.

Intra-articular nonunions are uncommon and can be
minimized with compression at the time of the original fixation. If a
nonunion exists and secondary displacement has occurred, an
intra-articular osteotomy followed by fixation with compression is
required. Bone grafting may be necessary if any bone is lost. However,
nonunion is usually due to inadequate fixation at the time of the
initial operative procedure. Malunion occurs if the implants are
improperly placed (i.e., reduced with deformity) or if the fracture
position changes prior to healing. The usual late deformities
associated with distal femoral fractures are varus and extension.
Locked- or fixed-angled implants may minimize the development of
angular deformities in the distal femur. Depending on the amount of
angulation and shortening as well as location of the deformity, an
osteotomy is usually required for correction.

Loss of flexion may occur following distal femoral
fractures. Early and aggressive knee range-of-motion exercises usually
prevent this complication. If an extension contracture persists,
several options are available. Early contractures may be treated with a
combination of a knee manipulation and/or an arthroscopic lysis of
adhesions. Care must be taken to gently manipulate the knee to avoid an
iatrogenic fracture, especially an avulsion of the

tibial
tubercle. Most knee contractures require an extensile lateral approach
with meticulous dissection of the vastus musculature from the anterior
aspect of the femoral shaft. In ideal situations, the periosteum is
left attached to the femoral shaft as the quadriceps musculature is
dissected. A quadricepsplasty is typically combined with an open
arthrotomy with removal of all intra-articular adhesions. Frequent
locations of adhesions include the suprapatellar pouch and the medial
gutter of the knee. Infrequently, a release of the rectus origin or a
v-y quadriceps lengthening may be required to regain knee flexion.