THE LOWER LIMB 53i 



it pierces the tendon of the biceps femoris, being there provided with 

 a synovial investment. The inferior external articular vessels and 

 nerve pass beneath it. The long external lateral ligament repre- 

 sents the original tendon of origin of the peroneus longus from the 

 femur. The posterior division of the hgament, which is known as 

 the short external laterals ligament, lies a little behind the long, and is 

 not weU defined. If distinct, it is attached above to the external 

 condyle close to the outer head of the gastrocnemius, where it blends 

 with the posterior ligament, its inferior attachment being to the 

 styloid process of the fibula. Its direction is downwards and 

 forwards, and it is to be regarded as an expansion in that direction 

 of the posterior ligament. 



The internal lateral ligament is a long, flat, strong band of 

 unequal width, being broader at the centre than at either end. 

 It is attached superiorly to the internal tuberosity of the femur, 

 and inferiorly to the internal border and adjacent part of the 

 internal surface of the shaft of the tibia, extending from the 

 internal tuberosity downwards for fully 3 inches. Its posterior 

 border covers the chief part of the tendon of the semimembranosus, 

 and blends with the posterior ligament. As the ligament passes 

 over the inner side of the knee-joint it is closely adherent to the 

 internal semilunar fibro-cartilage, and, lower down, the inferior 

 articular vessels and nerve pass beneath it. The internal lateral 

 ligament represents the original insertion of the adductor magnus 

 into the tibia. 



The capsular ligament is formed to a large extent by expansions 

 derived from the tendons of the vastus extemus, vastus intemus, 

 sartorius, and semimembranosus, and from the fascia lata. It 

 surrounds the joint except above the patella, where its place is 

 taken by the suprapatellar tendon. The posterior part of the 

 capsule, which forms the posterior ligament, is specially strong, 

 being reinforced by the ligamentum posticum Winslowii. In other 

 situations it is comparatively thin. It furnishes a thin expansion 

 over the ligamentum patellae, and on either side of the patella it 

 forms the lateral patellar ligaments. ExtemaUy, where it is closely 

 incorporated with the ilio- tibial band of the fascia lata, it covers 

 the long external lateral hgament. Internally, where it receives 

 accessions of fibres from the sartorius and semimembranosus, it 

 ; blends with the internal lateral hgament. 



;' The lateral patellar ligaments are two in number, external 



and internal, and they take the form of flat membranous bands, 



:;jometimes called the retinacula. The external extends between the 



i!Outer border of the patella and the anterior margin of the outer 



r Tuberosity of the tibia. It is intimatel}^ connected with, and in 



ipart formed by, the iho-tibial band of the fascia lata. The internal 



-xtends between the inner border of the patella and the anterior 



nargin of the inner tuberosity of the tibia. 



2. Internal Ligaments. — The internal hgaments, properly so 



ailed, are as follows : the two crucial ligaments ; the two 



