156 



ARTICULATIONS OF THE LOWER LIMB. 



articular surface of the tibia; its posterior end is attached to the inner 

 edge of the hollow behind the spine, and is in relation with the posterior 

 crucial ligament. 



The external semilunar cartilage forms nearly a complete circle ; its two 

 cornua, fixed, one before, the other between the points of the spine of the 

 tibia, are so close at their insertion that they may be said to be interposed 

 between the attachments of the internal semilunar plate. Its external 

 border is in contact behind with the tendon of the popliteus muscle, and is 

 therefore separated by this from the fibrous capsule. From this fibro- 

 cartilage a ligamentous band ascends, to be attached to the inner condyle of 

 the femur in connection either in front or behind with the posterior crucial 

 ligament (accessory band of the posterior crucial ligament). 



Transverse ligament. Towards the front of the joint the convex borders 

 of the interarticular fibro- cartilages are connected by a slight transverse 

 band, which receives this name. Its thickness varies much in different 

 bodies. 



Capsular membrane. Under this name is described the fibrous tissue 

 which invests the joint in the intervals between the stronger bands which 

 have been named ligaments. It is incomplete, not extending underneath 

 the tendons of the extensor muscles. Between the sides of the patella and 

 the femur it consists of fibres connected with the insertion of the vasti 

 muscles and with the fascia lata, and thus forms the structures, uniting the 

 patella to the tibia, which have been called lateral patellar ligaments ; 



posteriorly it covers the condyles of the 



Fig- 143. femur beneath the gastrocnemius muscle. 



In this last situation it is thin, and a 

 sesamoid bone is often found in connection 

 with it in the outer, less frequently in the 

 inner head of the muscle. 



Fig. 143. VERTICAL ANTERO-POSTERIOB SECTION 

 OF THE LEFT KNEE-JOINT, SEEN FROM THE 

 OUTER OR LEFT SIDE. ^ 



The section is made somewhat obliquely a little 

 to the outside of the middle, so as to preserve entire 

 the crucial ligaments with their attachments : it is 

 from a young subject of eighteen or nineteen years. 

 1, 1, the upper portion of the synovial cavity of 

 the joint, showing in the part above the patella the 

 synovial pouch which extends upwards between the 

 extensor tendons and the femur ; 1', an aperture 

 made into the posterior portion of the synovial 

 cavity ; 2, 2', ligamentum mucosum ; 3, ligamen- 

 tum patellae ; 2', 3, the subpatellar synovial fatty 

 cushion ; 4, bursa above the insertion of the liga- 

 mentum patellae into the anterior tibial tuberosity ; 



5, 5', the anterior crucial ligament ; 5', points also 

 to the internal semilunar cartilage within the joint; 



6, lower part of the posterior crucial ligament, the 

 upper part of which is towards 2 ; 6', the accessory 

 band joining the external semiluuar cartilage, 

 which is cut short ; 7, the spine of the tibia. 



The synovial membrane is the largest in 

 the body. Traced downwards from the 

 femur on either side of the joint, it may 



be followed from the capsule to the upper surface of the semi-lunar 

 cartilages, round the free borders of those structures to their inferior surfaces 



