THE LEG. 1461 



The proximal part of the medial surface of the medial condyle is overlapped by 

 the muscular prominency of the distal fibres of the vastus medialis. Leading 

 proximally from the medial condyle is a slight furrow, corresponding to the 

 interval between the distal part of the vastus medialis and the sartorius ; at the 

 bottom of the furrow the cord-like tendon of the adductor magnus may readily be 

 felt, and followed to its insertion into the adductor tubercle ; the latter, situated at 

 the junction of the medial supra-condylar ridge with the proximal and posterior 

 part of the medial condyle, marks the level of the epiphyseal cartilage. Anteriorly 

 and posteriorly the epiphyseal cartilage lies just proximal to the highest part of 

 the articular cartilage. 



Disease of the distal end of the body of the femur generally invades the popliteal surface 

 of the femur and the popliteal fossa rather than the cavity of the knee-joint. In Macewen's 

 operation for knock-knee, the incision (through which the osteotome is introduced to divide the 

 femur) is carried down to the bone through the vastus medialis a little proximal to the medial 

 condyle, a finger's breadth proximal to the summit of the trochlea, to avoid injury to the epi- 

 physeal cartilage, and the same distance in front of the adductor tendon, to avoid injury to the 

 musculo-articular branch of the arteria genu suprema. 



Distal to the medial condyle is the subcutaneous medial condyle of the tibia, 

 across which the tendons of the sartorius, gracilis, and semitendinosus pass to their 

 insertions. Between those tendons and the medial head of the gastrocnemius is 

 a groove which winds distally and forwards from the popliteal space ; an incision 

 along this groove will expose the great saphenous vein and saphenous nerve and the 

 superficial or saphenous branch of the arteria genu suprema. 



On the lateral side of the knee is the ilio-tibial tract, which, after crossing and 

 obscuring the line of the joint, is attached to the lateral condyle of the tibia. By 

 semiflexion of the knee the posterior border of the tract is thrown into relief, and a 

 well-marked furrow intervenes between it and the prominent tendon of the biceps ; 

 the distal part of the shaft of the femur and the popliteal surface may be reached 

 through an incision along this furrow. Under cover of the ilio-tibial tract, as it 

 crosses the line of the joint, are the lateral meniscus, the distal lateral genicular 

 artery, and the fibular collateral ligament. The head of the fibula, and the tendon 

 of the biceps passing to be inserted into it, are rendered distinctly visible by 

 semiflexing the knee ; the former lies on a level with the tuberosity of the tibia, 

 1J in. posterior and a little distal to the most prominent part of the lateral 

 condyle of the tibia. Immediately distal to the head of the fibula is the termina- 

 tion of the common peroneal nerve, which is liable to be contused from blows, and in 

 fractures of the neck of the fibula. 



The synovial layer of the knee-joint extends distally, anteriorly, as far as the level 

 of the proximal border of the tibia ; posteriorly, it dips distally for a short distance be- 

 hind the popliteal notch of the tibia, to form a small cul-de-sac, the close relation of 

 which to the popliteal artery must be borne in mind in performing the operation of 

 excision of the knee. Anteriorly, the synovial layer extends proximally beneath the 

 quadriceps in the form of a pouch, which reaches nearly two inches proximal to the 

 articular surface of the femur ; posteriorly, there is no extension of the synovial cavity 

 proximal to the condyles ; at the sides of the knee the synovial layer covers the anterior 

 third of the superficial surface of each condyle. 



In effusion into the knee-joint the hollows become obliterated, the patella is floated up, and 

 fluctuation may be obtained proximal, distal, and to either side of the patella. 



To pass a tube through the knee-joint for drainage, two short vertical incisions should 

 be made one on each side of the joint at the level of the proximal part of the patella, and 

 a finger's breadth behind its lateral edges. In arthrectomy of the knee for tubercular disease, the 

 subsynovial fat facilitates the separation of the supra-patellar pouch from the distal and anterior 

 part of the shaft of the femur ; to expose the pouches posterior to the condyles, the cruciate liga- 

 ments must be divided. 



THE LEG. 



The medial surface of the tibia is subcutaneous throughout ; hence the seat of a 

 fracture of the shaft is, as a rule, easily felt, and the distal extremity of the proximal 

 fragment is liable to perforate the skin. The skin over the distal half of this 



