Lateral Tibial Plateau Fracture: Open Reduction and Internal Fixation

The tibial plateau is composed of medial and lateral articular surfaces (Fig. 30-1).
The medial plateau is larger and is concave in the sagittal and coronal
axes. The lateral plateau extends higher and is convex in the sagittal
and coronal planes. The normal tibial plateau has a 10-degree
posteroinferior slope. The two plateaus are separated from one another
by the intercondylar eminence, which is nonarticular and serves as the
tibial attachment of the cruciate ligaments.

The most widely accepted classification has been that proposed by Schatzker (Fig. 30-2).
Type I is a wedge (split) fracture of the lateral tibial plateau. Type
II is a split depression fracture of the lateral plateau; the femoral
condyle first splits the condyle and then depresses the medial edge of
the remaining plateau. Type III is a pure central depression fracture
of the lateral plateau without an associated split. Type IV is a
fracture of the medial tibial plateau that usually involves the entire
condyle. Type V is a bicondylar fracture that typically consists of
split fractures of the medial and lateral plateaus without articular
depression. Type VI is a tibial plateau fracture with an associated
proximal shaft fracture.

Controversy exists regarding the specific indications
for open versus closed management of tibial plateau fractures. Some
surgeons advocate nonoperative treatment for fractures with up to 1 cm
of depression. Others accept only minimal displacement of the articular
surface. However, there is general agreement that instability of more
than 10 degrees (compared with the uninvolved knee) of the nearly
extended knee is an indication for operative intervention. Open tibial
plateau fractures or those associated with a compartment syndrome or
vascular insult require emergent care.

Initial radiographs should include an anteroposterior, a lateral, and two oblique views and the 15-degree caudal plateau view (Fig. 30-3). These five radiographs are known as the knee trauma series.
These films are analyzed for rim widening, articular depression, shaft
extension, and bony avulsions. The amount of condylar depression can be
measured from the remaining intact articular surface on the 10-degree
caudal plateau or lateral radiographs.

Comparison radiographs of the contralateral extremity
are useful for the preoperative plan. Tri-spiral and computed
tomography coupled with sagittal reconstructions are helpful in
evaluating the degree of articular displacement

(Fig. 30-4).
These studies are an excellent adjunct to plain x-ray films in the
preoperative planning for lag screw placement, particularly when
contemplating percutaneous fixation. Magnetic resonance imaging may
play a role in the future in the evaluation of meniscal and ligamentous
injuries associated with these fractures.

The exact nature of the fracture should be understood before attempting any form of surgical intervention (Fig. 30-5).
Although useful for simpler fractures, preoperative planning is
critical for more complex injuries. This forces the surgeon to
understand the “personality of the fracture” and mentally prepare an
operative plan. All aspects of the reduction and fixation should be
drawn out to help avoid technical pitfalls and ensure that all the
needed equipment is available.

Several basic instruments are necessary for open reduction and internal fixation of a tibial plateau fracture (Fig. 30-6):

Patients should be positioned supine with a bolster
under the knee or on a table that has the ability to flex the foot of
the table (Fig. 30-7). The ipsilateral iliac
crest should be prepared and draped if a need for autogenous bone graft
is contemplated. The patient’s position should take into account the
need for intraoperative image intensification, with the ability to
obtain anteroposterior, lateral, plateau, and oblique views. If
arthroscopy is to be used, a well-padded leg holder or post should be
available.

Fracture reduction can be aided by the use of
ligamentotaxis using a femoral distractor. This instrument be placed on
the ipsilateral side of the tibial plateau fracture, extending across
the knee joint, with one pin in the femoral condyle and the other pin
in the mid to distal tibia, well away from the anticipated distal end
of the implant (Fig. 30-8). In the event of bicondylar or type VI fractures, bilateral femoral distractors may be required.

Before
inflation of the tourniquet, the knee should be flexed to allow the
quadriceps muscle to stretch distally. Exposure of the tibial plateau
can be gained through a variety of approaches. The surgical approach
should provide maximum visualization, combined with preservation of all
vital structures and minimal soft tissue and osseous devitalization.
Skin incisions for tibial plateau fractures should be longitudinal (Fig. 30-9).
Midline skin incisions are favored in bicondylar fractures to allow
access to both knee compartments and facilitate any future
reconstructive procedures. Because most plateau fractures involve the
lateral compartment, a lateral parapatellar incision and arthrotomy are
often used. Medial fractures use a medial parapatellar approach. Flaps
that are raised should be full thickness down to the crural fascia and
retinaculum and include the subcutaneous fat (Fig. 30-10). Excessive
soft tissue dissection can result in osseous devascularization and
increase the risk for soft tissue complications, including skin slough.

After the level of the capsule has been reached, an arthrotomy is performed. The arthrotomy can be submeniscal (Fig. 30-11) or vertical with division of the anterior horn of the lateral meniscus. When
using a submeniscal arthrotomy, the surgeon should leave a soft tissue
cuff on the proximal tibia for capsular reattachment or prepare to use
Mitek anchors. With either approach, the split fracture component can
be displaced open and depressed fracture fragments elevated. The joint
must be examined for evidence of meniscal pathology, because meniscal
tears have been reported in up to 50% of tibial plateau fractures. Lesions
that are not appropriate for repair should be excised at this time.
Peripheral tears should have a suture repair at closure. Posteromedial
fractures of the plateau can be approached through a separate incision
between the medial gastrocnemius and semitendinosus and then between
the medial collateral ligament and the posterior oblique ligament.

The split fracture line is identified (Fig. 30-12).
Exposure of the depressed articular fragment is accomplished by opening
the metaphysis like a book at the split fracture line and hinging the
peripheral fragments outward, preserving their soft tissue attachments (Fig. 30-13).
Reduction of the depressed articular surface fragment should start by
recognizing the area of uninvolved articular surface. Depressed
articular fragments should be elevated en mass from below as large cancellous blocks to prevent articular surface fragmentation (Fig. 30-14). This can be achieved with the use of a bone tamp or elevator working through the split component.

Once elevated, provisional stabilization of the articular fragments to the medial or lateral condyle using Kirschner

wires (K-wires) is performed (Fig. 30-15).
These K-wires should be placed to avoid interfering with reduction of
the split fragment. At this point, the metaphyseal defect should be
bone grafted and the split fragment reduced and provisionally stabilized (Fig. 30-16).

Once satisfied with the fracture reduction, definitive
stabilization is performed. Definitive stabilization requires the
insertion of two 6.5- or 7.0-mm cancellous lag screws parallel to the
joint (Fig. 30-17), followed by metaphyseal buttress plating (Fig. 30-18).
This buttress must be located at the distal extent of the fracture line
and serves to prevent shear forces from causing late collapse. The
choice of plates depends on the degree of cortical comminution and may
be as simple as a washer (i.e., one-hole plate), two-hole plate, T- or
L- buttress plate, or Burri plate. The surgeon should select that plate that offers stable fixation but minimizes bulk to prevent complications with wound closure.

After definitive fracture stabilization, the incision is
irrigated and the wound closed. The coronary ligament of the knee
capsule is reattached using sutures or Mitek anchors, or both (Fig. 30-19). Wound closure is performed over suction drains. If the wound cannot be closed without tension, it is

preferable to leave the incision partially open and covered with a
sterile dressing. Wound closure may then be performed at a later date.

Postoperatively, the knee should be protected in a
hinged knee brace and started on continuous passive motion with a range
of motion of 0 to 30 degrees and advanced as tolerated. The machine is
kept on as much as possible during waking hours; early motion has been
clearly demonstrated to promote cartilage healing. Physical therapy for
active assisted range-of-motion exercises and touch-down weight bearing
is initiated and continued until the patient is independent with
ambulatory aids. Full weight bearing is permitted

by 12 weeks based on radiographic evidence of consolidation.