164 TOPOGRAPHIC AND APPLIED ANATOMY. 



condylea, the linea intercondylea, and the facies patellaris; at the upper end of the tibia, the 

 tuberosities with their articular surfaces, the eminentia intercondylea, the tuberculum intercon- 

 dyleum anterius and posterius, and the fossa intercondylea anterior and posterior. The head 

 of the fibula is connected to the tibia by an articulation which does not communicate with the 

 knee-joint. The posterior surface of the patella is covered by hyaline cartilage and forms the 

 immediate anterior boundary of the articular cavity; during flexion and extension of the joint 

 it slides up and down upon the facies patellaris of the femur. The incongruity of the articular 

 surfaces of the tibia and of the femur is partly compensated for by the interposition of the in- 

 ternal and external semilunar cartilages (meniscus lateralis and medialis). The external meniscus 

 is the more sharply curved and its ends are attached immediately in front of and behind the 

 spine of the tibia (eminentia intercondylea tibiae). The internal meniscus is more semilunar in 

 shape ; it commences in front at the margin of the articular surface of the tibia and ends behind 

 at the posterior intercondyloid fossa. 



The capsular ligament is in very intimate relation with muscle- insertions which help to 

 strengthen it. Anteriorly the tendon of the quadriceps encloses the patella and ends in the 

 patellar ligament running to the tubercle of the tibia. Posteriorly are the popliteus, the origins 

 of the gastrocnemius, and the insertion of the sermmembranosus, externally the biceps runs to 

 the head of the fibula, and internally are the three tendons of the sartorius, semitendinosus, and 

 gracilis, forming the "pes anserinus." The capsular ligament passes from the posterior surface 

 of the tendon of the quadriceps to the anterior surface of the end of the femur somewhat above 

 its cartilaginous surface and excludes the epicondyles from the articular cavity. Posteriorly it 

 is attached to the intercondyloid line. At the tibia the capsular ligament runs from the edge of 

 the cartilaginous surface to the outer borders of the menisci, and to the inferior margin of the 

 patella. At the upper and anterior portion of the articular cavity the large suprapatellar bursa 

 is situated between the femur and the quadriceps tendon and communicates directly with the 

 joint (Fig. 84). This bursa extends upward a distance of four to eight centimeters above the 

 upper margin of the patella with the leg in the extended position. 



The ligaments consist of internal, lateral, and posterior bands of connective tissue. The 

 internal ligaments are the ligamenta cruciata, and they check excessive pronation. The anterior 

 crucial ligament passes from the inner surface of the external condyle of the femur to the anterior 

 intercondyloid fossa of the tibia; the posterior crucial ligament runs from the outer surface of 

 the internal condyle to the posterior intercondyloid fossa. Both ligaments are united to each 

 other by connective tissue, project into the interior of the joint from the posterior portion of the 

 capsular ligament, and are incompletely covered by the synovial membrane. The lateral liga- 

 ments are the ligamentum collaterale fibulare (the long external lateral ligament), which runs 

 from the external condyle of the femur to the head of the fibula as a comparatively independent 

 structure, and the ligamentum collaterale tibiale (the internal lateral ligament), a broad fibrous 

 radiation in the capsular ligament extending from the internal condyle of the femur to the margin 

 of the cartilaginous surface of the tibia. Posteriorly there are two ligaments: (i) The liga- 

 mentum popliteum obliquum, running from the external condyle of the femur obliquely down- 

 ward and inward, where it becomes adherent to the tendon of insertion of the semimembranosus 

 muscle; (2) the ligamentum popliteum arcuatum, a curved fibrous band radiating from the ex- 



