286 



THE ARTICULATIONS 



of the patella into the ligament. It is an extremely strong, flat band, attached 

 above to the lower border of the patella; below, it is fixed to the lower part of the 

 tuberosity and upper part of the crest of the tibia, somewhat obliquely, being 

 prolonged dowoiward further on the lateral side, so that this border is fully 2.5 

 cm. (1 in.) longer than the medial, which measures 6.7 cm. (2^ in.) in length. 

 Behind, it is in contact with a mass of fat which separates it from the synovial 

 membrane, and a small bursa intervenes between it and the head of the tibia. 

 In front, a large bursa separates it from the subcutaneous tissue, and at the sides 

 it is continuous with the fibrous expansion of the extensors. 



The tibial (internal) collateral ligament (fig. 317) is a strong, flat band, which 

 extends from the depression on the tubercle on the medial side of the medial 



Fig. 317. — Posterior View of the Knee-joint. 



Plantaris 

 Lateral head of gastrocnemius 



Fibular collateral ligament: 

 anterior portion 



Posterior part of fibular 

 collateral ligament 

 Tendon of popliteus 



Tendon of biceps 



Superior posterior tibio- 

 fibular ligament 



Tendon of adductor magnus 



Medial head of gastrocnemius 



Tendon of semimembra- 

 nosus with its slip to 

 thicken the oblique pop- 

 liteal ligament 



Tibial collateral ligament 



epicondyle of the femur, to the medial border and medial surface of the shaft of 

 the tibia, 3.7 cm. (1| in.) below the condyle. It is 8.7 cm. (3| in.) long, well 

 defined anteriorly, where it blends with the expansion of the conjoined extensor 

 tendons; but not so well defined posteriorly, where it merges into the oblique 

 popliteal ligament. 



Some of the lower fibres blend with the descending portion of the semimembranosus tendon, 

 Its deep surface is firmly adherent to .the edge of the medial meniscus and coronary ligament. 

 while part of the semimembranosus tendon and inferior medial articular vessels and nerve pass 

 between it and the bone. Superficially, a bursa separates it from the tendons of the gracilis 

 and semitendinosus muscles and from the aponeurosis of the sartorius muscle. 



The fibular (external) collateral ligament (fig. 317) consists of two portions: 

 the anterior, which is the longer and better marked, is a strong, rounded cord, 

 about 5 cm. (2 in.) long, attached above to the tubercle on the lateral side of the 

 lateral epicondyle of the femur, just below and in front of the origin of the lateral 

 head of the gaslrocnemius, wliilst the tendon of the popliteus arises from the 

 groove below and in front of it. Below, it is fixed to the middle of the lateral 

 surface of the head of the fibula, 1.25 cm.(^) in. or more anterior to the apex. 



Supcrfifially is the tendon of the biceps, which splits to embrace its lower extremity; while 

 beneath it pass the popliteus tendon in its sheath, and the inferior lateral articular vessels and nerve. 



