Approach for Lateral Meniscectomy
Approach for Lateral Meniscectomy
A lateral meniscectomy can be performed through several types of incisions. Longitudinal and oblique incisions provide better access to other structures within the joint, whereas a transverse incision provides limited access to the knee, but excellent exposure of the meniscus itself. All incisions enter the lateral compartment of the knee anterior to the superficial lateral ligament.
Open surgical approaches for lateral meniscectomy are now confined to parts of the world where arthroscopic equipment is not available.
The approach is used for the following:
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Removal of loose bodies
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Removal of foreign bodies
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Treatment of osteochondritis of the lateral femoral condyle
Position of the Patient
Two positions can be used. For both positions, exsanguinate the limb either by elevating it for 2 minutes or by applying a soft rubber bandage. Next, inflate a tourniquet.
Table-Bent Position
The table-bent position is identical to that used for medial meniscectomy. Two points are critical:
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The sandbag must be placed under the thigh, not under the knee, to keep the popliteal artery and the posterior capsule from being compressed against the back of the femur and tibia.
Crossed Leg Position
Place the patient supine on the operating table. Drop the end of the table so the knees can flex. Then, place the calf of the affected side over the opposite thigh to flex the affected knee and abduct and externally rotate the hip. Now, place the table in 45 degrees of Trendelenburg to bring the lateral side of the knee up to eye level. Finally, flex the head of the table up so that the patient does not slide backward (Fig. 10-42).
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Figure 10-41 Position for the lateral approach to the knee.
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Figure 10-42 With the patient supine on the operating table, drop the end of the table so the knee can flex. The crossed leg position allows a direct approach to the
lateral aspect of the knee.
Landmarks and Incision
Landmarks
Palpate the smooth anterior border of the lateral femoral condyle as far as the joint line.
The head of the fibula is situated at about the same level as the tibial tubercle. From the lateral femoral epicondyle, move a thumb inferiorly and posteriorly across the joint line to find it.
Palpate the lateral border of the patella.
To find the lateral joint line, flex and extend the knee; palpate the area with a thumb to feel the movement of the femur and the tibia.
To palpate the superficial lateral ligament (fibular collateral ligament, lateral collateral ligament), cross the patient’s leg so that his or her ankle rests on the opposite knee. When the knee is flexed to 90 degrees and the hip is abducted and externally rotated, the iliotibial tract relaxes and makes the superficial lateral ligament easier to isolate. The ligament stands away from the joint itself, stretching from the fibular head to the lateral femoral condyle. It is easily palpable and usually visible.
Incision
Of all the skin incisions made around the knee, the oblique incision offers the most leeway, both for meniscectomy and for other intra-articular procedures, should they prove necessary. To make the incision, start at the inferolateral corner of the patella and continue downward and backward for about 5 cm. The incision should remain considerably anterior to the superficial lateral ligament, which lies under a line drawn vertically up from the head of the fibula to the lateral femoral condyle (Fig. 10-43A).
Internervous Plane
There is no internervous plane in this approach, which consists of incisions of the lateral patellar retinaculum and the joint capsule. No major nerves are located in or near the area.
Superficial Surgical Dissection
Open the anterolateral aspect of the knee capsule in line with the incision (see Fig. 10-43B).
Deep Surgical Dissection
Incise the synovium and extrasynovial fat of the knee joint in line with the incision to open the anterolateral portion of the joint. To avoid damaging the underlying meniscus, begin the incision well above the joint line and cut down carefully (Fig. 10-44; see Fig. 10-43C).
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Figure 10-43 A: Incision for the lateral approach to the knee. The incision should remain considerably anterior to the superficial lateral (fibular collateral) ligament. B: Incise the knee joint capsule in line with the skin incision. C: Incise the synovium and extrasynovial fat pad to enter the joint. Avoid damaging the
underlying meniscus.
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Figure 10-44 Expose the meniscus. Place retractors to allow maximum exposure of the joint.
Dang
Vessels
The lateral inferior genicular artery runs around the upper part of the tibia. The artery lies next to the peripheral attachment of the lateral meniscus; it may be damaged if the meniscus is detached along with a portion of the capsule during meniscectomy, leading to massive postoperative hemarthrosis. It is not in danger during the approach (see Fig. 10-50).
Muscles and Ligaments
The superficial lateral ligament (fibular collateral ligament) limits posterior extension at the incision. If it is cut and not repaired, it may affect lateral stability. Its position may be estimated by a line drawn from
the head of the fibula to the lateral femoral condyle (see Fig. 10-50).
Special Problems
The lateral meniscus may be damaged if the synovium is incised too close to the joint line.
How to Enlarge the Approach
This particular approach restricts the view of the inside of the joint because of the relative immobility of the structures that are incised and the difficulty in retracting them. The exposure may be improved in three ways without extending the incision:
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Retraction. Retractors should be readjusted frequently to allow the best possible view.
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Position of the joint. An inward stress opens up the lateral side of the joint (one advantage of the crossed leg position), which automatically puts an inward stress on the knee. Flexion of the knee allows better access to the back of the lateral side of the joint. If the very back of the joint must be seen, however, the best view may be obtained by putting the knee into extension and applying distraction and inward force.
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Lights. The direction of the light should be adjusted frequently so that it shines into the depths of the wound. A headlamp can be used to advantage for lateral meniscectomy.
Extensile Measures
Posterior Extension. The incision cannot be extended posteriorly because of the presence of the superficial lateral ligament.
Superior Extension. To extend the incision superiorly, incise the skin and lateral patellar retinaculum along the lateral border of the patella, increasing access to the back of the patella. To widen the exposure still further, extend the incision superiorly and open the plane between the posterior border of the vastus lateralis muscle and the lateral intramuscular septum. Extending this approach into a posterolateral approach to the femur offers the theoretic possibility of extending the exposure as far as the greater trochanter (see Posterolateral Approach in Chapter 9). This extended exposure is very useful in the treatment of supracondylar fractures of the femur with intra-articular components.
Inferior Extension. To extend the incision inferiorly, incise the skin
vertically downward, staying lateral to the tibial tubercle and running vertically down the leg about 1 cm from the subcutaneous border of the tibia. Incise the lateral patellar retinaculum, then carefully detach part of the origin of the tibialis anterior muscle from the lateral border of the tibia. This will allow access to the upper third of the tibia and good visualization of the inside of the joint. This extension can be used for the internal fixation of lateral tibial plateau fractures although the anterolateral approach to the lateral tibial plateau is most commonly used for treatment of these pathologies (see pages 585-588). In these fractures, it is critically important to achieve good visualization of the articular surface of the lateral tibial condyle to allow anatomic reconstruction of this surface.