The Ankle Joint. 381 



of the internal ligament, by the anterior and middle fibres 

 of the external ligament, by the anterior ligament and by 

 the astragalus meeting the tibia behind. 



Disease. Synovitis. In synovitis, the effusion dis- 

 tends the capsule and causes a swelling, slight on either 

 side of the tendo Achilles, but marked over the front of the 

 joint. On the inner aspect of the front of the joint, this 

 swelling is most pronounced between the tendon of the 

 tibialis anticus and the internal lateral ligament ; whereas, 

 on the outer side, it is most in evidence between the per- 

 oneus brevis and the external lateral ligament. Inflam- 

 mation of the bursa lying between the lower part of the 

 tendo Achilles and the upper part of the posterior surface 

 of the os calcis might be confounded with the swelling 

 found posteriorly in synovitis of the ankle joint, but may 

 be diagnosed by the fact, that, in bursitis, the fluctuation 

 from one side of the tendon to the other is more super- 

 ficial and is situated lower down, i.e., nearer the os calcis 

 than in synovitis, and further, that, in the latter disease, the 

 swelling is evident on the front of the articulation as well. 

 Tubercular disease, occurring in the ankle joint may be- 

 gin in either the bone or in the synovial membrane of the 

 joint, and, in connection with tuberculosis of this joint, it 

 is interesting to note the ease with which the disease can 

 spread to most of the surfaces of the astragalus. In 

 tubercular synovitis, Barwell states that a point of special 

 tenderness is located in front of the outer malleolus, just 

 about where the peroneus tertius crosses the joint. Rela- 

 tive position of the structures surrounding the joint. In 

 front. From within outwards, are: (1) The tibialis anti- 

 cus; (2) the extensor proprius hallucis; (3) the termina- 

 tion of the anterior tibial artery with its venae comites; 

 (4) the anterior tibial nerve; (5) the extensor communis 

 digitorum, and (6) the peroneus tertius. In the super- 



