ABNORMAL CONDITION OF THE ANKLE-JOINT. 



157 



the dead subject, they resist more powerfully 

 than the structure of the bones themselves. 



It was as a consequence of the fracture of 

 the fibula and a rupture of these ligaments, 

 that, in the case alluded to, the astragalus was 

 seen dislocated outwards, and then drawn up 

 on the outer side of the tibia. In short, the 

 astragalus, the malleolus externus, and the foot, 

 which formed but one system of parts firmly 

 connected, were drawn first to the outer side of 

 the leg, and then two inches upwards on the 

 tibia. 



A carpenter, aged fifty-four years, was ad- 

 mitted into the Hotel Dieu, in February, 1816. 

 His right leg presented all the signs of fracture 

 of the fibula at its inferior part, such as devia- 

 tion and rotation of the foot outwards, promi- 

 nence of the tibia, and of the internal malleolus 

 inwards, depression and crepitation above the 

 outer ankle ; but that which most attracted the 

 attention was, 1st, the shortening of the limb, 

 and, 2dly, the enormous increase in breadth of 

 the space which should naturally intervene be- 

 tween the two malleoli. The sinking down of 

 the lowest part of the tibia, even to the level of 

 the sole of the foot, where the projection of the 

 internal malleolus could be felt, the elevation of 

 the astragalus, of the peroneal malleolus, and the 

 whole of the foot along the external surface of 

 the tibia, even to two inches, were all symp- 

 toms quite unusual in fracture of the fibula, 

 and left no doubt that the ligaments which 

 stretched inferiorly from this bone to the tibia 

 had been lacerated, and that the foot, yielding 

 to a violent effort from within outwards, and 

 from below upwards, had been luxated in these 

 directions, and had carried with it the peroneal 

 malleolus. This then is evidently a case of 

 complete dislocation of the tibia inwards, or, 

 as the French writers would call it, a luxation 

 of the foot outwards and upwards. 



Although this species of luxation has not 

 been specially described in any of our English 

 works, I doubt not but such an accident has 

 been observed, although it is possible that its 

 nature was not always clearly understood. Sir 

 A. Cooper, in his valuable work on Disloca- 

 tions and Fractures, states that the foot has also 

 been known to be thrown upwards, between 

 the tibia and fibula, by the giving way of the 

 ligament which unites these bones; but he 

 adds that this accident is only an aggravated 

 form of an internal dislocation. 



We find but little difficulty in comprehend- 

 ing how the accident described by Dupuytren 

 may occur, because, the fibula having been 

 first fractured, the broken bone and ruptured 

 ligaments permit the foot to yield to the 

 powerful action of the muscles on the back 

 part and outside of the leg, which draw it at 

 first outwards, and then upwards ; but on the 

 contrary, it is not easy to imagine any force 

 capable of overcoming the resistance of the 

 many inter-osseous ligaments which exist, and 

 of the fasciae and annular membranes which 

 surround the bones of the leg : a force must be 

 great indeed which can overcome the muscles 

 also, and cause a divarication of the bones of the 

 leg sufficient to permit the astragalus and rest 



Fig. 53. 



Fig. 54. 



Complete luxation of tlie 

 tibia inwards or of the foot 

 outwards and upwards. 

 (Dupuytren.) 



Dissection of a case of 

 the same class as fig. 53, 

 from the museum of St. 

 Thomas's Hospital. 



of the foot to be thrown upwards between the 

 tibia and fibula. Supposing this last case pos- 

 sible, the shortening of the limb and its newly- 

 acquired breadth between the malleoli might 

 lead to error, and the two cases here alluded to 

 be at first sight confounded ; but in Dupuy- 

 tren's case, the fracture of the fibula, the over- 

 lapping of its fragments, and above all the 

 ascent of the external malleolus, so much above 

 the level of the internal, will always constitute 

 such characteristic marks, that when such an 

 accident presents itself, we conceive it cannot 

 be confounded with any other injury of this 

 articulation. 



What are the anatomical characters of this 

 complete luxation of the tibia inwards, with 

 displacement of the foot and outer malleolus 

 upwards and outwards? It is evident that 

 there must be very extensive injury done in 

 such cases to the ligaments and bones ; the fibula 

 must be fractured near the ankle, and it is 

 probable that some fragments of the tibia may 

 be carried off with the fibula, for such is the 

 strength of the ligaments between the lower part 

 of the tibia and fibula, where these unite for 

 the reception of the astragal us (vid.fg. 61), that 

 there is reason to believe that the bone itself 

 would break before the ligaments would yield. 

 If a portion of the tibia, however, is not broken 

 off and carried with the fibula, these transverse 

 fibrous bands must be torn, as well as those 



