THE BONES OF THE LOWER LIMB 



241 



of the intercondylar fossa. At birth the shaft is ossified, and the lower epiphysis 

 is showing signs of ossification, but the three upper epiphyses are cartilaginous. 

 The centre for the head appears in the first year, that for the great trochanter 

 in the fourth year, and that for the small trochanter in the fourteenth year. 

 The small trochanter joins the shaft at seventeen, the great trochanter at 

 eighteen, the head at nineteen, and the lower epiphysis at twenty. The neck 

 is ossified from the centre for the shaft. The hne indicating the junction ot 

 the lower epiphj'sis and shaft cuts the adductor tubercle into two, one portion 

 belonging to the lower epiphysis, and the other to the shaft. 



The Patella. 



The patella, rotula, or knee-cap, is situated in front of the knee- 

 joint, where it articulates with the patellar surface of the femur. 

 It is originally a sesamoid cartilage developed in the tendon of 

 the quadriceps extensor cruris. The bone is triangular with the 

 apex downwards, and is compressed from before backwards. The 



SuperMM- Border 



External Border 



Vertical Femoral Facet 

 (ia extreme flexion) 



.,' Anterior Surface 



Upper Transverse 



Femoral Facet 



Middle do., do. 

 —Lower do., do. 



- Ligamentum Patelbe 



Fig. 142. — The Right Patella. 

 A, Anterior Surface ; B, Posterior Surface. 



superior border or base is broad, and its plane is inclined forwards 

 and slightly downwards. It gives insertion anteriorly to the 

 rectus femoris and crureus, in this order from before backwards, 

 and posteriorly it is covered by a portion of the s\movial mem- 

 brane of the knee-joint. The lateral borders are sloped towards 

 the apex, the outer being at first rather more prominent than the 

 inner. The outer border over its upper third gives insertion to a 

 portion of the vastus extemus, and the inner over its upper half to a 



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