228 ANATOMY OF THE KNEE-JOINT. 



lateral ligament, although the posterior external lateral 

 ligament gives off a peculiar arrangement to support its 

 posterior limb. The internal semilunar fibro-cartilage, again, 

 must be regarded as an appendage to the internal condyle of 

 the tibia, to which it is fixed by the two internal lateral 

 ligaments. It resembles a curved, yielding, but elastic railway 

 on the upper surface of the inner condyle of the tibia, along 

 which the corresponding condyle of the femur rolls backwards 

 and forwards. 



The term of synovial pad may be applied to the mass of 

 vascular fat covered by the synovial membrane, and usually 

 called a Haversian gland, or synovial vascular fringe. Some 

 years ago, I directed attention to the structure and rela- 

 tions of these bodies, as corroborating the opinion of Havers 

 regarding their function (Anat. and Pathological Observations, 

 p. 42*), and have now ascertained that, in addition to their 

 probable function in supplying synovia, they act undoubtedly 

 as movable stuffing-pads, which not only smear the synovia 

 over the opposite cartilaginous surfaces, but steady the move- 

 ments of the joints by passing into the spaces left between 

 the surfaces during action. These pads are so constant in 

 their form and relations as to indicate the general character 

 of the movements the joint is capable of. 



The principal structure of this kind in the knee-joint is 

 the great infra-patellar pad the mass in connection with the 

 so-called alar and mucous ligaments. It presents a posterior 

 free surface of a quadrilateral form, which is applied against 

 the cartilaginous surface of the femur, principally in the 

 extended condition of the joint ; a superior free margin cut 

 into two lobes, which fill up the variable angular space 

 between the femur and patella, being forced upwards from 

 below by the so-called flabelliform ligaments of the patella ; 

 an inferior free margin, also divided into two lobes, separated 



* No. XXVII. of this volume. 



