184 



THE AETICULATIONS OF THE LOWER LIMB. 



The internal lateral ligament is derived from the tendon of the adductor magnus muscle ; 

 the external represents the detached femoral origin of the peroneus longus (Sutton). 



The posterior ligament is broad and membranous, and passes from the upper 

 edge of the intercondylar fossa of the femur to the posterior margin of the head of 

 the tibia. It is in great part formed by an expansion from the tendon of the semi- 

 membranosus, which is directed upwards and outwards towards the external condylc 

 of the femur and the outer head of the gastrocnemius muscle. 



The ligamentum patellae, or iufrapatellar tendon of the quadriceps extensor 

 cruris muscle, is a strong flat band, attached above to the apex and lower border of 



Fig. 208, A. RIGHT KNEE-JOINT, FROM THE INNER SIDE AND ANTERIORLY. (Allen Thomson.) 



1, tendon of the rectus muscle near its insertion into the patella ; 2, insertion of the vastus intern vis 

 into the rectus tendon and side of the patella ; 3, ligamentum patellae descending to the tubercle of the 

 tibia ; 4, capsular fibres forming a lateral ligament of the patella prolonged in part from the insertion 

 of the vastus internus downwards towards the inner tuberosity of the tibia ; 5, internal lateral ligament ; 

 6, tendon of the sernimernbranosus muscle. (After Arnold.) 



Fig. 208, B. RIGHT KNEE-JOINT FROM BEHIND. (Allen Thomson. ) 



1, insertion of the tendon of the adductor niagnus ; 2, origin of the inner head of the gastrocnemius- 

 muscle ; 3, outer head of the same ; 4, external lateral ligament ; 5, tendon of the popliteus muscle ;. 

 6, part of internal lateral ligament ; 7, tendon of the semimembranosus muscle ; 8, posterior ligament, 

 spreading outwards from the tendon ; 9, expansion of the popliteal fascia downwards from the same, 

 represented as cut short ; 10, on the head of the fibula, marks the posterior superior tibio-fibular 

 ligament ; 11, upper part of the interosseous membrane with the foramen at the upper end for the 

 anterior tibial vessels. 



the patella, and below to the tubercle of the tibia. Between the tibia and the liga- 

 ment, near its insertion, is placed a synovial bursa. 



The crucial ligaments, placed in the centre of the joint, pass from the sides of 

 the intercondylar fossa to the spaces in front of and behind the spine of the tibia. 

 They decussate somewhat like the lines of the letter X. The anterior or external 

 ligament is fixed by its lower extremity to the inner part of the depression before the 

 spine of the tibia, and by its upper extremity it is inserted into the inner and hinder 

 part of the external condyle of the femur ; hence its direction is upwards, back- 



