INFLAMMATION OF THE FLEXOR TENDONS. 841 



after neurectomy of the tibial nerve while the tendons were 

 inflamed. 



Course. The strain always occurs suddenly, and the anatomical 

 structure of the tendons explains its subsequent chronic course. 



Excessive tension of a tendon causes partial rupture with 

 retraction of fasciculi, laceration of the peritendinous covering and 

 inter-fascicular septa, extravasation, and sero-sanguineous exuda- 

 tion. The exudate fills the interfascicular spaces and distends the 

 areolar septa, the hitherto quiescent tendon cells increase in size 



Fig. 479. — Excessive " knuckling" in a horse (from a photograph). 



and become active, while the damaged fibres are partially con- 

 verted into a structureless hyaline pulp. Inflammatory reaction is 

 set up and in the reparative process the breach in the tendon is 

 made good by granulation tissue, which is formed by the agency 

 of the tendon cells and the fibroblasts of the connective tissue 

 adjacent to the lesion. On section the parts display greyish white, 

 sometimes greyish red, masses of connective tissue. In consequence 

 of the formation of new fibrous tissue thickening results, which may 

 lead to shortening of the tendon from cicatricial contraction, whilst 

 the paratendinitis leads to adhesion with neighbouring tissues. The 

 tendon gradually becomes permeated with blood-vessels ; ossifica- 

 tion has sometimes been seen in inflamed tendons. 



