1 he Region of the Knee Joint. 36 1 



nerves are stretched, while all the ligaments of the joint, 

 with the exception, possibly, of the patellar, are tense 

 or torn. Forward displacement. The condyles of the 

 femur are felt behind, while the patella, the tibia and the 

 fibula are prominent in front, and the soft parts are in- 

 jured as in the preceding dislocation, the patellar ligament, 

 however, being torn as well as the other ligaments. 



Dslocation of the patella is very rare, but, should it 

 occur, the bone is generally displaced outwards. This is 

 due to a sudden, severe strain being put on the quadriceps 

 extensor, and, especially, on the external portion of it, as 

 for instance, in suddenly twisting the thigh, inwards, 

 while the weight of the body rests on the foot. Most fre- 

 quently, however, the dislocation is only partial, the inner 

 half of the patella resting on the articular surface of the 

 outer condyle. 



Operative Work on the knee joint. Excision of 

 the knee joint may be either partial or complete. Partial 

 excision is termed anthrectomy, and may be employed in 

 even the advanced stages of the disease, so that, 

 complete excision of the articulation is very rare- 

 ly performed. Partial excision, or arthrectomy, 

 means the scraping away of all diseased structures, 

 especially the synovial membrane, and the best incision to 

 employ, is one starting on each side of the lower portion 

 of the patella and running towards the respective condyle. 

 Should it be found that more room is required, then a 

 cross incision may be added over the front of the patella, 

 and this bone divided, transversely, so that, after the re- 

 moval of the diseased tissues, it may be united again 

 thus preserving the function of the quadriceps extensor 

 muscle. Complete excision. Should it be found advis- 

 able to do the complete operation, the above incisions may 

 be utilized if the alttempt has first been made to do a par- 



