4 i6 THE INFERIOR EXTREMITY 



ments of the joint. Each meniscus presents two fibrous 

 extremities, or horns, which are attached to the rough inter- 

 mediate surface on the proximal end of the tibia. They are 

 thick towards the circumference of the joint, but thin away to a 

 fine free concave edge in the opposite direction. Both surfaces 

 are smooth and covered with the synovial layer. They do not 

 cover the entire extent of the condylar surfaces of the tibia. 

 The central parts of the latter, as well as the sloping surfaces 

 of the tubercles of the intercondyloid eminence, are free. 

 When the cartilages are raised from the surface upon which 

 they rest, distinct impressions, similar in shape and extent, 

 are seen on the subjacent encrusting cartilage of the tibia. 



Dissection. Carefully define the attachments of the fibrous 

 horns of the menisci. 



The lateral meniscus is usually somewhat thicker around 

 its circumference than the medial meniscus. It forms the 

 segment of a smaller circle, and its horns being fixed to the 

 tibia close together, a very nearly complete circle is formed. 

 The anterior fibrous horn is attached, immediately in front of 

 the intercondylar eminence, to the lateral side of and partly 

 under cover of the attachment of the anterior cruciate ligament. 

 The posterior horn is fixed to the summit of the inter- 

 condylar eminence in the interval between the two tubercles. 

 It gives a strong slip also to the posterior cruciate ligament. 

 The fibular collateral ligament is separated from the lateral 

 meniscus by the lateral part of the articular capsule and also 

 by the tendon of the popliteus which lies inside the fibrous 

 stratum of the lateral part of the capsule. The tendon of 

 the popliteus grooves the posterior part of the lateral border 

 of the lateral meniscus, but behind and in front of the groove 

 the peripheral margin of the lateral meniscus is blended with 

 the internal surface of the fibrous stratum of the articular 

 capsule. 



The medial meniscus is semicircular in outline, and forms 

 the segment of a much larger circle than the lateral meniscus. 

 Its anterior fibrous horn is fixed to the anterior part of the 

 anterior intercondylar fossa of the tibia, in front of the attach- 

 ment of the anterior cruciate ligament ; its posterior horn is 

 attached in the posterior intercondylar fossa of the tibia, 

 behind the intercondylar eminence and in front of the 

 attachment of the posterior cruciate ligament. The greater 



