102 



KNEE JOINT. 



Fig. 95.* 



and the cartilage being somewhat broader than the internal, nearly covers 

 the articular surface of the tibia. The external semilunar fibre-cartilage 

 besides giving off a fasciculus from its anterior border to constitute the 

 transverse ligament, is continuous by some of its fibres with the extremity 

 of the anterior crucial ligament ; posteriorly it divides into three slips ; 

 one, a strong cord, ascends obliquely forwards and is inserted into the 

 anterior part of the inner condyle in front of the posterior crucial ligament ; 

 another is the fasciculus of insertion into the fossa of the spinous process ; 

 and the third, of small size, is continuous with the posterior part of the 

 anterior crucial ligament. 



The ligamentum mucosum is a slender conical process of synovial 

 membrane enclosing a few ligamentous fibres which proceed from the 

 transverse ligament. It is connected, by its apex, with the anterior part 

 of the condyloid notch, and by its base is lost in the mass of fat which 

 projects into the joint beneath the patella. 



The alar ligaments are two fringed folds of sy- 

 novial membrane, extending from the ligamentum 

 mucosum, along the edges of the mass of fat to 

 the sides of the patella. 



The synovial membrane of the knee joint is by 

 far the most extensive in the skeleton. It invests 

 the cartilaginous surfaces of the condyles of the 

 femur, of the head of the tibia, and of the inner 

 surface of the patella ; it covers both surfaces of 

 the semilunar fibro-cartilages, and is reflected 

 upon the crucial ligaments, and upon the innei 

 surface of the ligaments which form the circumfe- 

 rence of the joint. On each side of the patella, it 

 lines the tendinous aponeuroses of the vastus inter- 

 nus and vastus externus muscles, and forms a 

 pouch of considerable size between the extensor 

 tendon and the front of the femur. It also forms 



ments. 1. The cartilaginous surface of the lower extremity of the femur with its two 

 condyLs; the figure 5 rests upon the external; the figure 3 upon the internal condyle. 

 2. The anterior crucial ligament. 3. The posterior crucial ligament. 4. The transverse 

 ligament. 5. The attachment of the ligamentum mucosum; the rest has been removed. 

 6. The internal semilunar fibro-cartilage. 7. The external fibre-cartilage. 8. A part of 

 the ligamentum patellae turned down. 9. The bursa, situated between the ligamentum 

 patellre and the head of the tibia; it has been laid open. 10. The anterior superior 

 tibio-fibular ligament. 11. The upper part of the interosseous membrane; the opening 

 above this membrane is for the passage of the anterior tibial artery. 



j- A longitudinal section of the left knee joint, showing the reflection of its synovial 

 membrane. 1. The cancellous structure of the lower part of the femur. 2. The tendon 

 of the extensor muscles of the leg. 3. The patella. 4. The ligamentum patell . 

 The cancellous structure of the head of the tibia. 6. A bursa situated between the 

 ligamentum patelhe and the head of the tibia. 7. The mass of fat projecting into the? 

 oavity of the joint below the patella. ** The ^synovial membrane. 8. The pouch 

 of synovial membrane which ascends between the tendon of the extensor muscles of 

 ihe leg, and the front of the lower extremity of the femur. 9. One of the alar liga- 

 ments : the other has been removed with the opposite section. 10. The ligamentum 

 mucosum 'left entire; the section being made to its inner side. 11. The anterior or 

 external crucial ligament. 12. The posterior ligament. The scheme of the synovial 

 membrane, which is here presented to the student, is divested of all unnecessary com- 

 plications. It may be traced from the sacculus (at 8), along the inner surface of the 

 patella; then over the adipose mass (7), from which it throws off the mucous liga 

 irent (10) ; then over the head of the tibia, forming a sheath to the crucial ligamencs; 

 ine*i upwards along the posterior ligament and condyles of the femur to the saceulus, 

 wncnoe its examination commenced. 



