218 THE ARTICULATIONS. 



b. Tlie interna] patellar ligament also forms a flattened band, longer, but not 

 80 wide or thick as the preceding. Its inferior extremity is attached to the inner 

 side of the anterior tuberosity of the tibia. Its superior extremity becomes much 

 thickened and fibro-cartilaginous, and is inserted into a prominence inside the 

 patella. This fibro-cartilaginous portion (Fig. Ii2, 3) of the ligament ghdes on 

 the internal border of the femoral trochlea, and may justly be considered as a 

 complementary apparatus of the patellar surface. The ligament, joined to the 

 preceding by the hbrous fascia ab-eady mentioned, is confounded, inwardly, with 

 the aponeurosis of the adductor muscles of the leg. 



c. The middle patellar ligament is a round cord, situated, as its name indicates, 

 between the other two, concealed beneath the aponeurosis which unites these, and 

 in the middle of the adipose tissue protecting the synovial capsules in front. It 

 leaves the anterior face of the patella, and descends vertically to the tibia, to be 

 lodged in the fossa in the middle of the anterior tuberosity, where a small synovial 

 bursa facilitates its movements. Its inferior extremity is inserted into the most 

 decUvitous part of this excavation. 



B. Ligaments which attach the leg and thigh hones. — These are six in number : 



1. A femoro-patellar capsule maintaining the patella against the femoral trochlea. 



2. Five femoro-tibial ligaments, as follows : two lateral, two external and 

 internal ; a posterior ; and two interarticular, distinguished with reference to 

 their inferior insertion into anterior and posterior. 



1. T\\Q femoro-patellar capsule is a membranous expansion which covers, above 

 and laterally, the superior synovial membrane. This capsule is attached by its 

 borders around the femoral trochlea and the periphery of the patellar surface. 

 It is extremely thin in its superior part ; but laterally it is thicker, and consti- 

 tutes two wide fibrous fasciculi which bind the patella to the eccentric sides of 

 the two condyles, and is described in several works as two special ligaments. Its 

 external face is covered by the insertion of the superficial gluteus and the triceps 

 cruralis. 



2. Femoro-tibicd ligaments. — a. The lateral ligammts are two ribbon-shaped 

 cords situated at the extremities of the transversal axis of the articulation, more 

 behind than before ; they are relaxed during flexion, and very tense in ex- 

 tension. 



The external, the shortest and strongest, proceeds from one of the hollow 

 facets on the external condyle of the femur, and is inserted into the head of the 

 fibula by its inferior extremity, after gliding over the external tuberosity of the 

 tibia by means of a special synovial bursa. It is covered by the crural or tibial 

 aponeurosis, and covers the tendon of the popliteus, from which it is sometimes 

 separated by a vesicular synovial membrane. 



The internal is attached, superiorly, to the eminence of insertion that sur- 

 mounts the eccentric face of the internal condyle, and descends vertically to the 

 tibia, gliding over the margin of its articular surface by means of a small facet 

 covered with cartilage, and a nd-de-sac prolongation of the internal synovial 

 membrane. It is fixed by its inferior extremity to the imprints which cover the 

 internal tibial tuberosity. 



Its fil)res are disposed in two layers, which slightly intercross in X fashion ; 

 those passing downwards and forwards adhere to the border of the internal 

 meniscus. Covered by the aponeurosis of the adductor muscles of the leg, this 

 ligament adheres by its deep face to the internal meniscus. 



b. The posterior ligament belongs to the class of membranous or capsular 



