336 THE ARTICULATIONS, OR JOINTS 



posteriorly it gives off a strong fasciculus, the ligament of Wrisberg, which passes 

 obliquely upward and outward, to be inserted into the inner condyle of the femur, 

 close to the attachment of the posterior crucial ligament. Occasionally a small 

 fasciculus is given off which passes forward to be inserted into the back part 

 of the anterior crucial ligament. The external cartilage gives off from its anterior 

 convex margin a fasciculus which forms the transverse ligament. 



The transverse ligament (ligamentum transversum genu) (Fig. 269) is a 

 band of fibres which passes transversely from the anterior convex margin of the 

 external cartilage to the anterior convex margin of the internal cartilage; its 

 thickness varies considerably in different subjects, and it is sometimes absent 

 altogether. 



The coronary ligaments (ligamenta coronaria) are merely portions of the 

 capsular ligament, which connect the circumference of each of the semilunar 

 fibrocartilages with the margin of the head of the tibia. 



Synovial Membrane (Figs. 270 and 271). The synovial membrane encloses the articular 

 cavity (cavum articulare) of the knee-joint. It is the largest and most extensive synovial mem- 

 brane in the body. Commencing above the upper border of the patella, it forms, on the lower 

 part of the front of the shaft of the femur, a short cul-de-sac beneath the Quadriceps extensor 

 tendon of the thigh ; this communicates, by an orifice of variable size, with a synovial bursa inter- 

 posed between the tendon and the front of the femur (bursa suprapatellaris). On each side of the 

 patella the synovial membrane extends beneath the aponeurosis of the Vasti muscles, and more 

 especially beneath that of the Vastus internus. Below the patella it is separated from the anterior 

 ligament by the anterior part of the capsule and a considerable quantity of adipose tissue, known 

 as the infrapatellar pad (Fig. 270). In this situation the synovial membrane sends off a tri- 

 angular prolongation, containing a few ligamentous fibres, which extends from the anterior 

 part of the joint below the patella to the front of the intercondyloid notch. This fold has been 

 termed the ligamentum mucosum (plica synovialis patellaris). It also sends off two fringe- 

 like folds, called the ligamenta alaria (plicae alares) (Fig. 270), which extend from the sides of 

 the ligamentum mucosum, upward and laterally between the patella and femur. On either 

 side of the joint it passes downward from the femur, lining the capsule to its point of attach- 

 ment to the semilunar cartilages; it may then be traced over the upper surfaces of these 

 cartilages to their free borders, and from thence along their under surfaces to the tibia. 

 At the back part of the external one it forms a cul-de-sac between the groove on its surface 

 and the tendon of the Popliteus; it surrounds the crucial ligaments and lines the inner surface 

 of the ligaments which enclose the joint. The pouch of synovial membrane between the Quad- 

 riceps extensor tendon and the front of the femur is supported, during the movements of the 

 knee, by a small muscle, the Subcrureus, which is inserted into the upper part of the capsular 

 ligament. 



The folds of synovial membrane and the fatty processes contained in them act, as it seems, 

 mainly as a padding to fill up interspaces and obviate concussions. Sometimes the bursa beneath 

 the Quadriceps extensor is completely shut off from the rest of the synovial cavity, thus forming 

 a closed sac between the Quadriceps and the lower part of the front of the femur; sometimes it 

 communicates with the synovial cavity by a minute aperture; usually the two cavities are incom- 

 pletely separated by a synovial fold. 



Bursse. The bursse about the knee-joint are the following: In front there are/owr bursse; one 

 is interposed between the patella and the skin. It is known as the prepatellar bursa (bursa 

 praepatellaris subcutanea); another, of small size, between the upper part of the tuberosity of 

 the tibia and the ligamentum patellae is called the deep infrapatellar bursa (bursa infrapatellaris 

 prof undo)', and a third between the lower part of the tuberosity of the tibia and the skin, the 

 subcutaneous tibial bursa (bursa subcutanea tuberositalis tibiae). A fourth bursa exists in front, 

 the suprapatellar bursa (bursa suprapatellaris). It lies between the anterior surface of the 

 lower end of the femur and the posterior surface of the Quadriceps femoris. Spalteholz says that 

 the suprapatellar bursa is closely connected with the Quadriceps tendon and is usually incom- 

 pletely shut off from the cavity of the joint. 1 Occasionally there is a bursa between the ex- 

 pansion of the fascia lata and the Quadriceps and the patella (bursa praepatellaris subfascialis), 

 and sometimes one between the tendon of the Quadriceps and the anterior surface of the patella 

 (bursa praepatellaris subtendinea). On the outer side there are four bursse: (1) One (which some- 

 times communicates with the joint) beneath the outer head of the Gastrocnemius; (2) one above 

 the external lateral ligament between it and the tendon of the Biceps femoris; (3) one beneath the 



1 Spalteholz's Hand Atlas of Human Anatomy. Translated by Lewellys F. Barker. 



