1. Review the muscles which are closely related to the knee joint. Note the insertions of the sartorius, gracilis, semitendinosus and semimembranosus tendons into the upper part of the medial surface of the tibia. Identify the tendon of insertion of the adductor magnus. Now look for the tibial collateral ligament on the medial side of the knee joint and then find the cord-like fibular collateral ligament on the lateral side. Find the oblique popliteal ligament, an expansion from the semimembranosus tendon passing upwards and laterally on the posterior aspect of the joint. Note the attachments and relationships of the popliteus tendon to the capsule and joint cavity. Remember that the popliteus is important in unlocking of the knee joint (initiating flexion).

2. Note that the capsule is deficient anteriorly and is replaced by the tendon of the quadriceps, the patella, and the ligamentum patellae in front and by the expansions of the vastus medialis and lateralis on the sides. Open the joint by cutting transversely through the quadriceps tendon above the patella and by two cuts vertically one on either side of the patella. Draw the patella down and examine the synovial infrapatellar fold in the midline and alar folds on either side.

3. Examine the opposing articular surfaces of the patella and the femur. Note that it is the lower part of the patella which articulates with the femur in full extension. Observe that the patella and the medial femoral condyle articulate in full flexion.

4. Cut transversely across the rest of the capsule and examine the posterior and anterior cruciate ligaments. Divide the cruciate ligaments and note their attachments. Examine the medial and lateral menisci in situ. Note the attachment of the popliteus to the posterior aspect of the lateral meniscus. See whether the medial meniscus is attached to the tibial collateral ligament. Note that the anterior and posterior horns of the menisci are attached anterior and posterior to the intercondylar eminence of the tibia respectively, while the periphery of the menisci is connected to the tibia by coronary ligaments.

The muscles of the extensor and fibular compartments are supplied by the common fibular nerve which reaches the fibular compartment by winding round the neck of the fibula where it is liable to injury. It divides into the superficial fibular nerve supplying the lateral (fibular) compartment and the deep fibular nerve supplying the muscles of the anterior (extensor) compartment. The muscles of the fibular compartment are evertors. The muscles of the anterior compartment are dorsiflexors of the ankle. In addition, the tibialis anterior is an invertor of the foot while the fibularis tertius assists the fibular muscles in eversion. The anterior tibial artery reaches the anterior compartment by passing through the interosseous membrane while the deep fibular nerve, after piercing the extensor digitorum longus, comes to lie on the lateral side of the artery. The anterior tibial artery continues at the level of the ankle joint as the dorsalis pedis, whose pulsation can be felt on the dorsum of the foot. The knee joint is a modified hinge joint in which there is considerable freedom of movement. In spite of this, there is also a great degree of stability of the joint which is essential for transmitting the weight of the body. This is provided by strong ligaments and muscles which surround the joint and by the iliotibial tract. Therefore, the functions of the various ligaments and muscles in relation to the knee joint must be studied and understood thoroughly. The extra-articular area on the medial femoral condyle is used up in the terminal medial rotation of the femur in locking of the knee joint, which occurs in the final stage of extension. Which muscle is concerned with the unlocking of the knee joint? The synovial infrapatellar and alar folds are due to the invagination of the synovial membrane from the front. They attempt to divide the knee joint into three subdivisions: two between the condyles of the femur and the corresponding condyles of the tibia, and the third between the patella and the femur. However, all three joint cavities are continuous as the alar folds are not attached to the femur. The cruciate ligaments invaginate the synovial membrane from the back of the joint and consequently there is no synovial membrane lining the posterior part of the capsule. The attachment of some of the fibres of the popliteus muscle to the lateral meniscus and the attachment of the tibial collateral ligament to the medial meniscus have opposite effects on the mobility of the menisci.

SOLE OF FOOT

1. Make the following incisions: on the plantar surface of the foot:-

(a)a midline incision from the heel to the tip of the middle toe;

(b) a transverse incision across the roots of the toes; and

(c) longitudinal incisions along the middle of the remaining toes. Reflect the skin flaps.

2. Starting from the heel remove the superficial fascia on the plantar surface to expose the deep fascia. The deep fascia is thickened to form the plantar aponeurosis. Note that the plantar aponeurosis has medial, intermediate and lateral subdivisions. The intermediate (central) part of the plantar aponeurosis, which is strong, is attached behind to the medial process of the calcaneal tuberosity. Then follow its five distal processes passing to the fibrous flexor sheaths of the digits. Cut the central portion of the plantar aponeurosis transversely near the heel and carefully reflect it. Note the medial and lateral intermuscular septa passing deeply from this part of the aponeurosis.