LIVRE JDG 2010

spreader is used to open the osteotomy site

until the desired correction is achieved. The

intra-articular correction is performed through

the opening wedge osteotomy as visualized

through a lateral arthrotomy [2-5]. The depres-

sion of the tibial plateau can best be identified

and approached with the knee in 100° of

flexion. This position is facilitated by suppor-

ting the foot of the patient on a sandbag moun-

ted onto the operating table. Further approach

to the knee joint depends on the location of the

joint incongruency. With a standard lateral

arthrotomy, the anterior 50 to 60% of the late-

ral plateau can easily be visualized and

approached. To expose more posteriorly situa-

ted depressions, an osteotomy of the Gerdy

tubercle and reflection of the attached iliotibial

tract allow visualization of approximately 80%

of the lateral plateau. Finally, an additional

osteotomy of the fibular head after release of

the peroneal nerve allows full anterior disloca-

tion of the lateral tibial plateau. This extended

approach is necessary for reconstruction of a

posterolateral malunion. Through the lateral

arthrotomy, the lateral meniscus, if it is still

present, can be temporarily detached to assess

the tibial plateau and provide direct visualiza-

tion during the elevation of the depression.

Damaged regions of the meniscus are removed

while the peripheral meniscal remnants are

preserved. The depressed cartilage zone is then

marked circumferentially with a 2-mm drill-

bit. With these drillholes used for guidance,

the depressed zone is osteotomized in the ver-

tical plane with a small osteotome. The intra-

articular osteotomy [2-5] can also be perfor-

med through the openingwedge tibial plateau

osteotomy with a small bone distractor

in situ

For this approach, including the elevation of

the depressed lateral tibial plateau, it is helpful

to create a small metaphyseal cortical window

at the site of the tibial plateau osteotomy. It

allows better access to the subchondral site

and free handling of curved osteotomes and

impactors. The intra-articular malunion may

consist of one large or multiple small osteo-

chondral fragments. With a curved impactor

inserted through the window, the depressed

area of the plateau is elevated to conform to

the lateral femoral condyle in both extension

and flexion, creating an overcorrection of

1mm. The correction is maintained by impac-

ting cancellous autograft bone beneath the ele-

vated segment. The lower extremity alignment

is evaluated clinically by adjusting the bone

spreader, and then the intra-articular correc-

tion, the ligamentous stability, and the weight-

bearing position of the knee are all checked. A

further important step in the procedure is

dynamic testing of the knee from full flexion

to full extension to verify that articular

congruence is optimal and that any osseous

pivot shift has disappeared. The technique is

shown in. The operation is completed with the

impaction of wedged corticocancellous auto-

graft bone into the open gap and internal fixa-

tion with an L or a T-plate [2-5]. After exten-

ding the approaches, the tibial plate is usually

sufficient to be used to fix both the Gerdy

tubercle and the proximal tibial varus osteoto-

my at the same time. Finally, a lag screw is

sufficient to secure the osteotomy of the fibu-

lar head. The only indication to approach the

tibial plateau by arthrotomy and an osteotomy

of the tibial tuberosity is when there is a com-

bination of medial and lateral malunions. This

approach allows full visualization, evaluation,

and intra-articular correction of both knee

compartments, whereas an approach with use

of separate medial and lateral incisions makes

intra-operative orientation more difficult.

Wound closure: The anterior tibial fascia is

reattached, and a lateral fasciotomy is perfor-

med to prevent an anterior compartment syn-

drome. In the presence of a lateralized patella,

closing the iliotibial tract is unnecessary.

POSTOPERATIVE

MANAGEMENT

Activity is restricted to functional passive

motion until reduction of postoperative swel-

ling and restoration of range of motion of the

knee is accomplished. Brace protection is pro-

vided, and only toe-touch weight-bearing with

crutches is allowed for eight weeks. Thereafter,

an increase to full weight-bearing is allowed as

tolerated. Physiotherapy is recommended

JOURNÉES LYONNAISES DE CHIRURGIE DU GENOU