THE KNEE-JOINT. 345 



the interior of the articular cavity and a bursa which lies under cover of the medial 

 head of the gastrocnemius muscle. 



The epiphyseal line of the distal end of the femur is partly intra-capsular and 

 partly extra-capsular ; that of the proximal end of the tibia is extra-capsular. 



Ligamentum Patellae. The ligamentum patellae or anterior ligament (Fig. 

 318) is a powerful flattened band, attached proximally to the apex and adjoining 

 margins of the patella, and distally to the rough anterior tuberosity at the proximal 

 end of the shaft of the tibia. This ligament also serves as a tendon of insertion for 

 the quadriceps extensor muscle, and a certain number of the fibres of the tendon 

 may be observed to run distally as a thin fibrous covering for the anterior surface 

 of the patella. The deep surface of the tendon is separated from the front of the 

 head of the tibia by a synovial bursa, and proximal to this it rests upon the 

 infra-patellar pad of fat, which is placed between the tendon and the synovial 

 stratum of the joint. 



The ligamentum posterius posterior (ligament) (Fig. 318) is a compound structure 

 of unequal strength, and those portions by which it establishes continuity with 

 the lateral parts of the articular capsule are remarkably thin. It is attached 

 proximally to the popliteal surface of the femur, close to the intercondyloid notch, 

 with lateral extensions to the non-articular areas immediately proximal to the 

 posterior articular margins of the two condyles, where it is closely associated with 

 the origins of the gastrocnemius muscle. 



Distally it is attached to the rough non-articular posterior border of the head 

 of the tibia, where, to its fibular side, it presents an opening of exit for the tendon 

 of the popliteus muscle (Fig. 318). 



The tendon of insertion of the semi-membranosus muscle contributes an 

 important expansion which augments the posterior ligament on its superficial 

 aspect. This expansion lig. popliteum obliquum passes obliquely proximally and 

 laterally to Ipse itself in the general ligament, but it is most distinct in the region 

 between the femoral condyles, where it may present proximal and distal arcuate 

 borders (lig. popliteum arcuatum). A number of vessels and nerves perforate 

 this ligament, and hence it presents a number of apertures. 



Lig. Collaterale Tibiale. The tibial collateral ligament (O.T. internal lateral) 

 (Figs. 317 and 318) is a well-defined, strong, flat band which is applied to the* 

 medial side of the knee-joint, and is rather wider in the middle than at either end. 

 It is frequently regarded as consisting of two portions an anterior or long portion, 

 and a posterior or short one. The two parts arise close together from the medial 

 epicondyle, immediately distal to the adductor tubercle. The short or posterior 

 portion passes distally and slightly backwards, to be attached to the postero-medial 

 aspect of the medial part of the tibia proximal to the groove for the semi- 

 membranosus tendon. The long or anterior portion inclines somewhat forwards, 

 and extending distally superficial to the tendon of the semi-mernbranosus, it is 

 attached to the proximal part of the medial surface of the shaft of the tibia distal 

 to the level of the tuberosity. 



On its superficial aspect the tibial collateral ligament is augmented by pro- 

 longations from the tendons of the semi-membranosus and sartorius muscles, 

 but is separated by a bursa from the tendons of the gracilis, semi-tendinosus, 

 and sartorius. Its deep surface is adherent to the convex edge of the meniscus 

 medialis, but more distally the distal and medial articular vessels intervene 

 between the ligament and the shaft of the tibia. 



Lig. Collaterale Fibulare. The fibular collateral ligament (O.T. external lateral) 

 (Figs. 317 and 318) is a distinct rounded band which is under cover of the ordinary 

 capsule, and yet well separated from the articular cavity by intervening objects. It 

 is attached proximally to the lateral epicondyle, immediately proximal to the 

 groove occupied by the tendon of the popliteus muscle, superficial to which the 

 ligament extends distally to be attached to the lateral side of the head of the 

 fibula, in front of the styloid process. In its course it splits the tendon of 

 insertion of the biceps femoris (Fig. 317), the portions of which are fixed to the 

 head of the fibula on either side of the ligament, and a bursa may intervene 

 between the tendon and the ligament. The distal lateral articular vessels pass 



