542 



APPLIED ANATOMY. 



the twenty-fourth. The epiphysis of the tibia runs transversely across the tibia about 

 1.5 cm. (fi in.) below the articular surface and anteriorly passes down to embrace 

 the tubercle (Fig. 554). 



These epiphyseal separations are produced either by direct violence, by force 

 applied laterally, or by twisting a common way is for the leg to be twisted by being 

 caught between the spokes of a revolving wheel. They never occur later than the 

 age of twenty years and usually occur several years before that age has been reached. 



Often the displacement is not serious 

 and is corrected before the patient is 

 seen by the surgeon. Occasionally, 

 especially when the lower epiphysis of 

 the femur is affected, displacement is 

 marked, and the fractured surface of 

 the fragment may lie on the anterior 

 surface of the shaft of the femur. 

 Sometimes the injury is compound 

 and the vessels so injured that ampu- 

 tation is required. 



In spite of the fact that the greater 

 part of the growth of the lower ex- 

 tremity occurs from the bones adja- 

 cent to the knee-joint epiphyseal sep- 

 arations almost never interfere with it. 

 This is so true that epiphysiolysis or 

 the deliberate separation of the lower 

 epiphysis of the femur by bending the 

 knee laterally over the hard edge of 

 a table is the preferred operation with 

 , External tuberosity some surgeons for the correction of 

 lateral deformities of the knee, espe- 

 cially knock-knee. The injury is 

 usually treated as a simple fracture 

 and heals without incident. 



Resection of the Knee. In 

 making the skin incision care should 

 be taken to carry it back sufficiently 

 far to allow of division of the lateral 

 ligaments; in so doing, however, one 

 should not divide the long saphenous 

 vein and nerve at the posterior edge 

 of the internal condyle. It is essen- 

 tial to recognize the joint-line; it is 

 just below the lower edge of the patella 

 and thence extends laterally about a 

 finger-breadth above the head of the 

 fibula. It is customary to carry the 

 incision from near the posterior edge 

 of the femur on the inner side to the 

 posterior edge on the outer side at 



the joint-line, passing over the middle of the tendo patellae so as to allow this latter 

 to be readily sutured later if desired. 



Care is to be taken to avoid wounding the popliteal artery. This lies close to 

 the posterior part of the capsule; hence the latter is not to be divided transversely 

 but is to be separated by keeping the knife close to the bone. Finally, inasmuch as 

 the bulk of the growth of the lower extremity occurs in the upper end of the tibia 

 and lower end of the femur, it is essential to avoid removing the entire epiphyseal 

 cartilages. For this reason formal resections have been abandoned in young children, 

 and in adolescents as little tissue as possible is removed. The epiphyseal line in the 

 femur runs transversely on a line with the adductor tubercle and passes close to the 



Line of epiphysis 



External condyle 



Patella 



Internal tuberosity 



Head of fibula 

 Line of epiphysis 



Tibial tubercle 



FIG. 554. Antero-external view of the bones of the knee, 

 showing the lines of the epiphyses. 



