Fig. i8i. Transverse Section through the Knee-joint. 



Frozen Section. 



This frozen section shews the Prepatellar Bursa (Subcutaneous and Subfascial Com- 

 partments), the lateral ligaments and anterior to these, the Retinacula of the Patella, which 

 strengthen the Capsule. These Retmacula become of importance in Fracture of the Patella. 

 When the Patella is broken transversely, the functional impairment of the Extensor Apparatus 

 will depend on the extent of the destruction of these Retinacula. 



Figs. i8a and 183. Lymphatics of the Popliteal Space. 



Fig. 1^2. From a man aged 41 years. — Fig. 183. From a -woman aged 60 rears. 



Normally there occur in the Popliteal Space more Lymphatic Glands than are usually 

 stated (3—5); they are easily overlooked on account of their small size and the difficulty of 

 their dissection in fat subjects. They ma}' be divided into three groups (of at least one gland 

 each'i : a Superficial group between the External Saphenous Vein and External Popliteal Nerve, 

 separated from the latter by a thin fascia — the Superficial Popliteal Gland. The greater 

 number lie close to the Popliteal Vessels under cover of the Internal Popliteal Nerve — the 

 Deep Popliteal Glands. Variable in position is a gland below the vessels which receives the 

 bulk of the lymphatics of this space; whereas the Afferent Lymphatic Vessels to the different 

 groups of glands are fairly constant, there is much variation in the Efferent Vessels. Therefore 

 different cases are depicted. 



In Fig. 182, large Lymphatics, accompanying the Short Saphenous Vein, join the 

 Superficial Gland; one Efferent Lymphatic extends upwards with the Femoro-popliteal Vein, 

 another Efferent Lymphatic divides and joins the Articular Gland, which thus becomes a second- 

 ary gland to the Superficial as well as to the Deep Gland and the Lymphatics of the 

 Joint. The large Efferent Vessel opened, in this instance, into the Efferent Tract (first mentioned), 

 of the Superficial Gland and extended upwards as a stray vessel, to 4 inches beyond the figure, 

 under cover of the fascia. After piercing the fascia it divided into 5 branches, and after a 

 curved course opened into the Lower Internal Group of the Superficial Inguinal Glands. 



The arrangement of the Lymphatics in Fig. 183 is similar. The Afferent Vessels join, 

 in this case, to form a thick trunk which passes with the Popliteal Vein through the opening 

 in the Adductor Magnus. Between these two extremes there are endless variations, both paths 

 being used in equal or unequal proportions at the same time. We are not satisfied of the 

 presence of a third path; if such were emploj'ed it would, theoretically, lead along the Great 

 Sciatic Nerve to the Pelvic Glands. The Lymphatics of the lower extremity begin at the foot 

 and follow, in front and on the inner side, the Long Saphenous Vein; on the posterior aspect 

 they partly pass over the Popliteal Space and go to the inner side; partly, as shewn in the 

 figure, to the Popliteal Space, under the fascia, accompanying the Short Saphenous Vein. 



So that these Lymphatics may reach the Deep Inguinal Gland by following the 

 Popliteal and Femoral Vessels, or join the Superficial Inguinal Glands after having pierced 

 the fascia. 



In Fig. 183, the Bursa in connection with the Semimembranosus Muscle has been 

 opened and the Bursa under the Inner Head of the Gastrocnemius is shewn projected through 

 that Muscle. Both communicate at the red spot which is marked by a f. We were unable 

 in these cases and in 8 others, to shew any communication between these Bursae and the 

 Knee-joint. 



It, therefore, seems doubtful whether this Bursa communicates (in "j.^rd or '/., of all 

 cases), with the Joint as is stated in the books. 



Weak spots in the Capsule favour the perforation backwards in pathological cases; 

 in the removal of Hygromata, the joint is frequently opened on account of the tenuity 

 of its wall. 



