THE LOWER LIMB 609 



be dissected, and the following ligaments studied : interosseous, internal 

 astragalo-calcaneal, and external or superior calcaneo-navicular. It is to 

 be noted that the synovial membrane of this joint is continuous with that 

 of the astragalo - navicular articulation. The bony articular surfaces 

 of the astragalo-calcaneal joints cannot be studied until the astragalus is 

 removed, which should presently be done. Meanwhile, by removing all the 

 Ugaments, except the interosseous, and dividing the synovial membranes, the 

 movements between the astragalus and os calcis are to be studied. 



The astragalo-navicular joint should now be examined. Inasmuch as this 

 is one of the most important joints of the foot, it should receive careful study. 

 The Ugaments to be dissected are as follows : astragalo-navicular, dorsally 

 placed ; external or superior calcaneo - navicular ; and internal or inferior 

 calcaneo-navicular, a most important Ugament, commonly spoken of as the 

 spring hgament. The last-named Ugament is to be studied from two points 

 of view, namely, from below, by removing the tendon of the tibiaUs posticus, 

 and from above, by removing the astragalus. In performing the latter dissec- 

 tion the interosseous astragalo-calcaneal Ugament is to be studied, and it is 

 to be observed that, whilst it is the anterior Ugament of the posterior 

 astragalo-calcaneal joint, it is the posterior Ugament of the anterior astragalo- 

 calcaneal joint. An exceUent view is obtained from above of how the spring 

 Ugament supports and forms a part of the socket for the under aspect of the 

 head of the astragalus, and from below it can be well seen how the tendon of 

 the tibiaUs posticus serves as an important strengthening adjunct to the 

 Ugament. It is to be noted that the synovial membrane of the astragalo- 

 navicular joint is continuous behind with that of the anterior astragalo- 

 calcaneal. The movements at the astragalo-navicular articulation are to be 

 carefully studied, and the manner in which pes planus may be brought about 

 is to be observed. Attention should also be directed to the support which 

 the spring Ugament, aided by the tendon of the tibiaUs posticus, gives to the 

 inner longitudinal arch of the foot. The bony articulcir surfaces are also 

 to receive attention. 



The calcaneo-cuboid joint is next to be studied. The Ugaments to be dis- 

 sected are dorsal, internal or interosseous, long plantar, and short plantar. 

 On opening the joint the sjTiovial membrane wiU be found to be pecuUar to 

 it, and the movements of which the £U"ticulation is capable are to be studied. 

 Attention is also to be given to the bony articular surfaces. The naviculo- 

 cuboid joint is next to be attended to, the Ugaments being dorsal, plantar, 

 and interosseous. The remaining tarsal articulations are to be studied in 

 the foUowing order : naviculo-cuneiform, intercuneiform, and cubo-cuneiform, 

 and the compUcated synovial membrane of these articulations should be 

 examined. The bony articular surfaces and movements are cilso to be studied. 



The dissector should next direct his attention to the tarso-metatarsal 

 articulations, which should be studied in the following order: (i) internal 

 tarso-metatarsal, (2) middle tarso-metatarsal, and (3) external tarso-meta- 

 tarsal. Special notice should be taken of the internal inteirosseous Ugament 

 of the middle tarso-metatarsal joint. It wiU be found extending between 

 the outer surface of the internal cuneiform and the inner surface of the base 

 of the second metatarsal bone. The synovial membranes, bony articular 

 surfaces, and movements of these articulations are to be attended to, and 

 their surgery is to be caret uUy studied in connection with Lisfranc's operation. 



The intermetatarsal articulations are to be studied next, attention being 

 directed to the basal intermetatarsal joints, and the union between the 

 heads of the metatarsal bones. The tarsal and tarso-metatarsal synovial 

 membranes should be reviewed at this stage. The metatarso-phalangeal 

 articulations are now to be dissected, the Ugaments being two lateral and an 

 inferior or plantar fibrous plate. The synovial membranes, bony articular 

 surfaces, and movements are to be studied. Lastly, the interphalangeal 

 articulations are to be dissected in a similar manner and to a Uke extent. 



39 



