458 THE INFERIOR EXTREMITY 



when the leg is flexed the more convex posterior surface of the 

 femoral condyle is only in contact with the broader posterior 

 part of the medial meniscus, and in medial rotation of the 

 femur on the tibia the curve of this part is accentuated, while 

 the anterior part becomes correspondingly straighter. If the 

 violence of the rotatory movement is sufficient to tear its anterior 

 attachment, the meniscus resumes its semilunar outline, with 

 the result that its torn extremity projects into the centre of the 

 joint (Fig. 134). Subsequent extension of the joint catches the 

 meniscus between the two articular surfaces. 



The Surgical Approach to the menisci is carried out with 

 the knee-joint flexed (Jones) in order to obtain good exposure. 

 The incision, which is convex forwards and extends for two inches 

 on each side of the line of the joint, does not quite reach the 

 margin of the patella, and a curved flap of skin and fascia is 

 reflected backwards. A vertical incision is made in the capsule 

 midway between the patella and the margin of the femoral 

 condyle, and the anterior extremity of the meniscus can then be 

 dragged forwards out of the wound. After it has been dealt with 

 the capsule is closed and the skin margins are reunited. As 

 the incision through the skin does not immediately overlie the 

 incision through the capsule, leakage of the synovial fluid is 

 hindered, while there is no subsequent weakening of the capsule 

 in flexion and extension, such as occurs when the incision 

 through it is made in a transverse direction. 



The Cruciate Ligaments extend from the intercondylar 

 fossa of the femur to the intercondylar area on the top of the 

 tibia. They cross one another in the centre of the joint and are 

 therefore iritra-capsular, but they are excluded from the synovial 

 cavity by the synovial membrane. The anterior cruciate ligament 

 is attached to the top of the tibia in front of the intercondylar 

 eminence, and passes upwards and backwards to reach the 

 posterior part of the medial aspect of the lateral femoral condyle. 

 These two bony points are farthest from one another when the 

 knee-joint is fully extended, and in this position of the limb, 

 therefore, the ligament is tense. Aided by the collateral 

 ligaments and the thickened posterior part of the capsule, the 

 anterior cruciate ligament is sufficiently strong to prevent 

 hyper-extension of the joint unless excessive force is applied. 

 The posterior cruciate ligament is attached to the posterior part 

 of the non-articular area on the top of the tibia, and extends 

 upwards and forwards to the anterior part of the lateral aspect 



