246 



OSTEOLOGY. 



LATERAL ARTICULAR FACET 



Surface for the ligamentum patellae 

 FIG. 245, THE RIGHT PATELLA. 

 A. Anterior Surface. B. Posterior Surface. 



usually plane, or somewhat convex transversely. Occasionally, in the macerated 

 bone, indications of a third vertical area are to be noted along the medial edge of 

 the posterior aspect. This defines the part of the articular surface which rests on 



the lateral border of 

 the medial condyle in 

 extreme flexion. In 

 the recent condition, 

 when the femoral sur- 

 face is coated with 

 cartilage, a more com- 

 plex arrangement of 

 facets may be in some 

 cases displayed (as in- 

 dicated in Fig. 244). 

 Lament (Journal of 

 Anat. and PhysioL, 

 1910, vol. xliv. p. 149) 

 has shown that these 

 areas undergo con- 

 siderable variation in 

 their arrangement in races who habitually adopt the squatting posture. 



Distal to the femoral articular area the posterior surface of the apex is rough 

 and irregular ; the greater part of this is covered with synovial membrane, the liga- 

 mentum patellae being attached to its summit and margins, reaching some little 

 distance round the borders on to the anterior aspect of this part of the bone. 



Ossification. The patella is laid down in cartilage about the third month of foetal 

 life. At birth it is cartilaginous, and the tendon of the quadriceps is continuous with the 

 ligamentum patellae over its anterior surface, and can easily be dissected off. About the 

 third year an ossific centre appears in it and spreads more particularly over its deeper surface. 

 Two centres, vertically disposed, have also been described. Ossification is usually com- 

 pleted by the age of puberty. 



The Tibia. 



The tibia is the medial bone of the leg. It is much stouter and stronger than its 

 neighbour the fibula, with which it is united proximally and distally. By its 

 proximal expanded ex- 



rrprmfv it qnivnnrtq thp Surface for attachment of anterior TUBEROSITY (O.T. Tubercle) 



Llty It Supports tne extremity of medial meniscus ^^ Sn f , 



condyles of the femur, * " I Ijjmk /""-t ^enSy of 



While distally it Shares EMINENTIA ^**&A i$&*^L lateral meniscus 



, -. f. J . n . , INTERCONDYLOIDEA X 



m the formation ol the 

 ankle-joint, articulat- 

 ing with the proximal 

 surface and medial side 

 of the talus. 



The proximal ex- 

 tremity comprises the 

 medial and lateral con- 

 dyles (O.T.tuberosities), 

 the intercondyloid emi- 

 nence (O.T. spine), and 

 the tuberosity. 



Each condyle is 



provided on its proximal aspect with an articular surface (facies articularis 

 superior), which supports the corresponding femoral condyle, as well as the 

 interposed meniscus. Of these two condylic surfaces the medial is the larger. Of 

 oval shape, its long axis is placed antero-posteriorly ; slightly concave from before 

 backwards and from side to side, its circumference rises in the form of a sharp and 

 well-defined edge. The lateral condylic surface is smaller and rounder. Slightly 

 concave from side to side, and gently convex from before backwards, its circumfer- 



Surface for attach, of 



SYNOVIAL COVERED ^M 1^T\ ^B^^" ^post. extremity of 



SURFACE ^BS^y POSTERIOR INTER- la teral meniscus 



Surface for attach, of post. / CONDYLOID FOSSA 

 extrem. of medial meniscus Post, cruciate ligament 



FIG. 246. THE PROXIMAL SURFACE OF THE PROXIMAL EXTREMITY 

 OF THE RIGHT TIBIA.' 



