ABNORMAL CONDITIONS OF THE KNEE-JOINT. 



71 



which had been broken exceeded by about six 

 times the same diameter of that of the opposite 

 side. The fracture did not represent a straight 

 transverse line, but was somewhat undulated. 

 At the two extremities of the line of junction of 

 the fracture it was quite evident that the union 

 of the broken bone was immediate, and by the 

 intervention of a true bony callus. Lallement 

 presented Boyer with the patella thus solidly 

 united, and he has given an engraving of it in 

 his valuable work. 



In the collection of Dr. William Hunter, there 

 is a well-marked instance of bony union of a 

 transverse fracture of the patella, and other 

 examples have been seen in the dead subject 

 by Mr. Wilson. In Sir Charles Bell's museum 

 were likewise similar specimens, one or two of 

 which are now in the Museum of University 

 College.* 



Dislocations of the femur from the tibia at 

 the k?tce-joint. The articular surfaces of the 

 head of the tibia for the reception of the femoral 

 condyles are very superficial ; and although the 

 semilunar cartilages are superadded to them 

 for the reception of the condyles of the femur, 

 they have no direct tendency to resist luxations 

 of the femur at the knee-joint. On the other 

 hand it is to be recollected that the surfaces by 

 which the tibia and femur are articulated 

 together are broad, and that the number and 

 strength of the ligaments which unite these 

 bones is considerable. The solidity of the arti- 

 culation is further augmented by numerous and 

 powerful tendons which surround the joint. 

 Although therefore the knee-joint from its situa- 

 tion and functions must be subjected to nume- 

 rous injuries, dislocations are very seldom wit- 

 nessed as the result of accident. Dislocations, 

 however, occur in four different directions ; two 

 of them are incomplete and lateral while the 

 others are perfect luxations, the femur being 

 thrown either backwards or forwards. The 

 lateral luxations are the rarest. 



The lower extremity of the femur is now and 

 then dislocated backwards : the signs of the 

 accident are the following. The thigh-bone is 

 somewhat displaced to the side as well as back- 

 wards, and the tibia is advanced before the 

 condyles of the femur. The lower dislocated 

 extremity of the osfemoris makes such pressure 

 on the popliteal artery as to prevent the pulsa- 

 tion of the anterior tibial artery on the foot. 

 The patella and tibia are drawn by the rectus 

 muscle forwards ; such, Sir A. Cooper tells us, 

 are the appearances the knee-joint presented in 

 a man brought into St. George's Hospital in the 

 year 1802. The limb in this case was easily 

 reduced by extending the thigh from above the 

 knee, and by drawing the leg from the thigh and 

 inclining the tibia a little backwards. As soon 

 as it was reduced, the popliteal artery ceased to 

 be compressed, and the pulsation in the anterior 

 tibial artery was restored. We will quote the 

 following abstract, of a case of dislocation of the 

 lower extremity of the femur backwards ;f the 



* Prof. Cooper. 



t London Medical Gazette, May 14, 1836, given 

 by Mr. Thomas Brittan, House Surgeon, Chester 

 Infirmary. 



subject of the accident, besides other injuries, 

 was brought into the Chester Infirmary with a 

 very complete dislocation of the lower extremity 

 of the femur backwards. The whole limb was 

 shortened four or five inches, and the condyles 

 of the femur could be felt plainly among the 

 muscles of the calf of the leg, while the tibia 

 was in advance of the femur and drawn up- 

 wards on the anterior part of this bone. The 

 leg and foot were swollen and cold ; all circu- 

 lation below the knee was stopped ; there were 

 no marks of external contusion. It appears 

 that although the pulleys were used to reduce 

 the luxation, it was easily effected by gradual 

 extension of the limb. It became necessary 

 after about five weeks had passed from the time 

 of the accident, to amputate the limb in conse- 

 quence of an extensive abscess which formed in 

 the ham and calf of the leg. Upon examining 

 the amputated limb, it was found that the pop- 

 liteal abscess was very extensive and commu- 

 nicated with the knee-joint. On tracing the 

 course of the artery, which had been previously 

 injected, it was found to be obliterated from 

 just below the point where it gives off the 

 superior articular artery, exactly to its bifurcation 

 into the anterior and posterior tibial arteries. 

 The nerve also for this distance was slightly 

 enlarged and firmer than natural, having a cord- 

 like feel ; the whole being so closely connected 

 by dense cellular tissue as to be scarcely sepa- 

 rable. The attachments of the muscles were all 

 perfect and did not appear to have been lace- 

 rated. With respect to the joint the lateral 

 ligaments on both sides were perfect ; the ante- 

 rior crucial ligament had been absorbed, but 

 the posterior crucial ligament and the posterior 

 ligament of Winslow were united into one 

 band ; the synovial membrane was healthy or 

 but very little altered ; the semilunar cartilages, 

 as well as those on the ends of the bones, were 

 sound ; there was no fluid in the joint. 



Case of dislocation of the femur backwards 

 from the tibia. Sir A. Cooper remarks that 

 cases of dislocation of the knee-joint are so 

 rare that every instance of this accident is 

 worthy of recital. He adduces the following 

 example from the experience of Mr. Too- 

 good, of Bridgewater. Francis Newton, a 

 strong athletic man thirty years old, fell from 

 the fore part of a waggon, and was dragged a 

 great distance before he was disentangled from 

 the framework of the shafts. In two hours 

 after the accident the left knee was observed to 

 be very much swollen; the os femoris was dis- 

 located backwards, and its lower extremity 

 occupied the upper part of the calf of the leg, 

 the internal condyle of the femur being nearly 

 through the skin; the tibia, fibula, and patella 

 were driven up in front of the thigh. The 

 appearances of the limb were so dreadful that 

 Mr. Toogood despaired at first sight of being 

 able to reduce it, but to his surprise the reduc- 

 tion was easy. The limb was placed in splints; 

 the strictest antiphlogistic treatment with rest 

 was prescribed ; the symptoms were mild, and 

 he suffered little from pain or inflammation. 



Malgaigne, in a letter to Velpeau in the Ar- 

 chives Medicates, June 1837, upon the subject 



