A surgeon should be familiar with several approaches to the knee
region since each exposure has advantages and disadvantages. Adequate
exposure, a minimum of retraction and intraoperative X-rays are
important. Current techniques recommend early mobilization of
the knee which means that soft tissue damage should be minimized,
muscle splitting avoided wherever possible with accurate, strong
repair of all tissues.
LATERAL
APPROACH TO THE DISTAL FEMUR AND KNEE
This approach is most useful for internal fixation of
supracondylar and transcondylar fractures permitting wide exposure
of the distal femur in spite of limited exposure of the femoral
condyles.
The patient is supine on a regular operating table with a roll
under the ipsilateral buttock permitting up to 90° knee flexion.
A sterile tourniquet may be used.
The skin is incised laterally along the anterior margin of the
iliotibial band as far proximal as necessary, extending distally
beyond the knee joint and curving anteriorly towards the tibial
tubercle (Fig. 10-1 a).
The fascia is split along the anterior border of the iliotibial
band down to its attachment to Gerdys tubercle. The fibres,
which form the patellar retinaculum, are thus cut and can be retracted
anteriorly (Fig . 10-1 b).
The intermuscular septum is identified and the vastus lateralis,
detached and retracted anteromedially, ligating the blood vessels
which penetrate the septum (Fig. 10-1 c and d).
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Lateral
approach to the distal femur and knee
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Fig.
10-1.
- Lateral approach to the distal femur and knee.
a) Distal lateral skin incision.
b) Skin incision held apart by retractors. The enveloping
fascia of the thigh and iliotibial band are shown.
c) Cross section through lower thigh.
d) Exposure of distal femur and knee capsule; division and
ligation of vessels.
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Retraction of the vastus lateralis and intermedius exposes the
supracondylar region. The capsule of the knee joint is incised
anterior down to the femoral attachment of the collateral ligament.
The superior lateral geniculate vessels are identified and ligated.
Self retaining retractors are useful to provide adequate exposure
for insertion of internal fixation devices for uncomplicated supra
and intercondylar fractures.
Closure of the capsule and fascia restores the deep anatomical
relationships and permits early mobilization of the knee.
EXTENSILE
LATERAL APPROACH
TO
THE DISTAL FEMUR,
FEMORAL
CONDYLES
AND
KNEE JOINT
This approach, although infrequently needed, is most useful
for internal fixation of comminuted distal femoral fractures with
extensive femoral condylar disruption. It permits a complete and
comprehensive view of the entire distal femur as well as of both
femoral condyles.
The patient is positioned with a tourniquet in place and a large
roll under the thigh to permit 90° of knee flexion. The skin is
incised along the anterior border of the iliotibial band, oriented
anteriorly over the femoral condyle and extending over the tibial
crest just distal to the tibial tubercle (Fig. 10-2 a).
The fascia is split along the anterior border of the iliotibial
band from Gerdys tubercle as far proximally as needed. Identify
the intermuscular septum, dissect the vastus lateralis from it
and then retract the vastus anteriorly exposing the distal femoral
shaft, after ligating perforating vessels as encountered (Fig.
10-2 b).
Open the knee joint capsule and synovium laterally as far down
as the tibial tubercle. Expose the tubercle and the patellar tendon.
By freeing proximally and distally, it is sometimes possible
to gain adequate exposure by dislocating the patella medially.
If not, it is necessary to osteotomize the tibial tubercle (Fig.
10-2 c).
If more complete exposure is needed, especially of the medial
femoral condyle, make small drill holes at the margins of the
tibial tubercle. Overdrill the center hole for later lag screw
fixation (Fig. 10-2 d).
Join the outer drill holes inserting a small osteotome rather
deeply, in order to remove a substantial block of bone along with
the tibial tubercle. When this is removed, free the tendon from
the infrapatellar fat pad and make a medial parapatellar capsular
incision to retract the patellar mechanism proximally and medially
(Fig. 10-2 e).
Closure is effected by replacing the tubercle block and fixing
it with a single cortical screw (usually with a washer) which
engages the posterior cortex. Soft tissue closure is achieved
with interrupted sutures and early mobilization of the knee is
recommended (Fig. 10-2 f).
Alternately, Henry recommended to approach the distal femur and
femoral condyles by dissecting between the vastus lateralis (which
is reflected posteriorly) and the quadriceps tendon to facilitate
medial patellar dislocation without osteotomizing the tibial tubercle.
LATERAL
APPROACH TO THE KNEE
AND
PROXIMAL TIBIA
This approach is used for open reduction of the lateral tibial
plateau and for repair or reconstruction of lateral collateral
and capsular ligaments.
The patient is supine with a roll under the ipsilateral buttock
and the knee flexed to 90° with a tourniquet in place. The skin
incision starts at the lateral femoral condyle, extends obliquely
distal and anterior, curves posteriorly 1 cm behind the patellar
tendon, for a distance of 5 cm. When required, the distal
limb can be extended (Fig. 10-3 a).
The retinaculum is opened in the line of skin incision. Flexion
of the knee to 90° may permit preservation of the iliotibial band
attachment to Gerdys tubercle. More complete visualization
is possible by dividing this attachment. Elevate the muscles from
the flare of the upper tibia taking care not to injure the anterior
tibial artery which passes from posterior to anterior between
the proximal tibia and fibula (Fig. 10-3 b).
Intra-articular visualization is possible by transversely dividing
the meniscotibial ligament from anterior to posterior as far posterior
as the lateral collateral ligament. Varus stress on the knee provides
good articular visualization (Fig. 10-3 c).
Should posterior articular exposure be insufficient, the lateral
collateral ligament can be divided obliquely and later resutured
(Fig. 10-3 d).
At closure, the lateral meniscus is first resutured to the tibia;
all of the divided structures must then be firmly reapproximated
with interrupted sutures.
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Fig.
10-3.
- Lateral approach to the knee and proximal tibia.
a) Skin incision.
b) Muscles and periosteum elevated from proximal tibia preserving
the iliotibial band attachment to Gerdy's tubercule.
c) Varus stress to open the knee joint after the meniscotibial
ligament has been cut. Lateral meniscus is reflected proximally
with lateral femoral condyle. Lateral tibial plateau is thus
exposed.
d) Wider posterior exposure following section of the lateral
collateral ligament. |
ANTEROMEDIAL APPROACH
TO
THE DISTAL FEMUR AND KNEE
This approach is most frequently used for knee arthroplasty
or tumor resection.
The patient is positioned to permit at least 90° of knee flexion
during the procedure. A tourniquet is usually applied to expedite
the procedure and is deflated prior to closure.
The skin is incised at the anterior midline from about 12 cm
above the patella curving slightly medially around the patella
and extending to below the tibial tubercle (Fig. 10-4 a),
exposing the quadriceps tendon and fascia (Fig. 10-4 b).
Alternately the skin incision is straight and midline.
The vastus medialis is separated from the quadriceps tendon
and the patellar retinaculum is divided near the patella leaving
enough tissue for later re-attachment. Make certain that the retinaculum
and capsule are divided distally as far as the tibial tubercle
(Fig. 10-4 c).
Open the synovial membrane to expose the joint (Fig. 10-4 d).
Dislocate the patella laterally with the knee extended and flex
the knee to 90°. This provides a comprehensive view of the femoral
condyles and tibial plateau (Fig. 10-4 e).
For access to the femoral shaft, the vastus intermedius is also
split.
Closure is by interrupted sutures, preferably with the knee
partially flexed, testing the suture lines at 90° of flexion after
closure of the fascial planes.
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Anteromedial
approach to the distal femur and knee
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Fig.
10-4. -
Anteromedial approach to the distal femur and knee.
a) Skin incision.
b) Exposure of the patella, quadriceps tendon, vastus medialis,
knee capsule. Incision line of the deep structures.
c) Cut between quadriceps tendon and vastus medialis then
of the retinaculum, one centemetre from patella, as far distal
as the tibial tubercle. Synovial membrane incision.
d) Exposure of femoral condyles, distal femur and proximal
tibia after incision of the synovial membrane.
e) Knee bent to 90° with patella dislocated to the lateral
side of the lateral femoral condyle. |
MEDIAL
UTILITY APPROACH
TO
THE KNEE
This is a useful approach for the repair of medial ligament
injuries and fractures of the medial tibial plateau.
The patient is positioned with a roll under the opposite buttock
and a tourniquet in place. The skin incision starts proximal to
the medial femoral condyle, extends distally 2 to 3 cm medial
to the patella and curves posteriorly at the level of the tibial
tubercle (Fig. 10-5 a).
The retinaculum is incised creating a definite angle proximally
(for more accurate closure). (Fig. 10-5 b).
Retraction exposes the superficial medial collateral ligament,
the posterior oblique ligament (posterior capsule) and the pes
anserinus tendons (Fig. 10-5 c).
Arthrotomy may be performed through an anteromedial capsular
incision. If desired, the medial plateau may be exposed anteriorly.
Knee flexion moves the collateral ligament posteriorly and facilitates
the preservation of the semimembranosus attachments (Fig. 10-5
d).
The posterior aspect of the joint may be exposed by incising
the attachments of the posterior oblique ligament to the medial
collateral ligament. This exposes the posteromedial corner and
the posterior aspect of the medial meniscus (Fig. 10-5 e).
Closure of the capsular structures should be with interrupted
sutures taking special care to approximate the posterior oblique
ligament to the medial collateral ligament.
POSTERIOR
APPROACH
TO
THE KNEE
This approach is used for the removal of popliteal cysts or
neoplasms, as well as for the repair or reconstruction of posterior
cruciate ligament injuries.
The patient is positioned prone with a tourniquet in place.
The skin is incised beginning a few centimetres proximal to the
popliteal skin crease, along the semitendinosus tendon, then curves
across the popliteal space and turns distally over the lateral
gastrocnemius (Fig. 10-6 a).
Incise the fascia in the line of skin incision (Fig. 10-6
b).
Identify the medial sural nerve as it passes in the midline,
superficial to the fascia (Fig. 10-6 c).
Trace the nerve proximally until it is seen to join the medial
popliteal nerve. Then trace the medial popliteal nerve distally,
across the back of the knee, until it becomes the tibial nerve.
The popliteal artery and vein lie anterior and slightly medial
to the tibial nerve (Fig. 10-6 c).
Retract these structures medially, and the lateral popliteal
nerve, laterally to expose the posterior capsule of the knee and
the two heads of the gastrocnemius muscle (Fig. 10-6 d).
Closure of the popliteal fascia, subcutaneous tissue and skin
is with interrupted sutures.
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Posterior
approach to the knee
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Fig.
10.6. -
Posterior approach to the knee.
a) Skin incision.
b) Fascial incision.
c) Exposure of sural nerve (1) superficial to fascia, and
of popliteal vessels (3) with medial popliteal nerve (4),
slightly posterior and lateral, between medial (5) and lateral
(6) heads of of gastrocnemius.
d) Sural nerve (1), medial popliteal nerve (4) and popliteal
vessels (3) retracted medially and lateral popliteal nerve
(7) retracted laterally to expose medial and lateral heads
of gastrocnemius and posterior capsule (8) of knee joint. |
ANTERIOR,
TRANSVERSE APPROACH
TO
THE PATELLA AND KNEE
The approach may be used for reduction of patellar fractures,
for patellectomy or for knee fusion. Many surgeons prefer a longitudinal
incision.
The skin is incised transversely from the medial to the lateral
femoral epicondyles curving distally at either end (Fig. 10-7
a).
The subcutaneous tissue is dissected widely from the retinaculum
exposing the patellar tendon, patella and quadriceps tendon (Fig.
10-7 b).
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Anterior,
transverse approach to the patella and knee
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Fig.
10-7. -
Anterior, transverse approach to the patella and knee joint.
a) Line of skin incision.
b) Subcutaneous tissues dissected and retracted to expose
patella, quadriceps tendon, patellar tendon and patellar retinaculum.
c) Patellar tendon divided and retracted proximally exposing
the femoral condyles and menisci. |
The patella is retracted superiorly and the patellar tendon is
divided inferiorly cutting the expansions to gain wider exposure
(Fig. 10-7 c).
Closure requires suture of the patellar tendon and its expansions.