72 



ABNORMAL CONDITIONS OF THE KNEE-JOINT. 



of dislocation of the knee, to which we refer 

 for many observations we have not space for, 

 gives a case of luxation of the femur backwards 

 and of the tibia forward, which in some re- 

 spects differed from those adverted to by Sir 

 A. Cooper. He informs us that M. Lavalette 

 was called on the 6th of April, 1815, to visit a 

 man who had just before met with the accident 

 we are now describing under the denomination 

 of dislocation of the femur backwards and of 

 the tibia forwards at the knee-joint. The limb 

 was in a state of extension, somewhat inverted, 

 and much shortened ; it could, however, be 

 flexed and extended, although with much pain. 

 The extensor muscles of the leg were in a 

 relaxed condition, as were also the hamstring 

 muscles from the shortening of the whole limb. 

 A depression existed where the condyles of the 

 femur ought to present themselves anteriorly, 

 and below this space the superior extremity of 

 the condyles of the tibia could be felt. The 

 patella was placed horizontally on the upper 

 articular surface of these condyles ; its point, 

 which is normally placed downwards, was now 

 directed forwards, and its superior margin back- 

 wards; its anterior or cutaneous surface was 

 placed directly upwards, and its articular facet 

 downwards, resting, as already mentioned, on 

 the flat surface of the upper extremity of the 

 condyles of the tibia. Lavalette here knew 

 that he had to deal with a complete luxation, 

 which we have called a luxation of the femur 

 backwards and of the tibia forwards ; and he 

 was finally convinced of the real nature of the 

 case by placing his hand in the popliteal re- 

 gion, where he distinctly felt the two condyles 

 of the femur. 



Luxation of the lower extremity of the 

 femur forward. The lower extremity of the 

 femur is sometimes thrown forwards off the 

 condyles of the tibia, while the latter bone is 

 thrown backwards behind the condyles of the 

 femur, producing the following appearances : 

 the limb is shortened, the condyles of the os 

 femoris are seen projecting, the ligament of the 

 patella is depressed, and the leg is bent for- 

 wards. Sir A. Cooper gives a case in which 

 the condyles of the femur were completely dis- 

 located forwards, and the head of the tibia 

 passed so far backwards behind the condyles 

 as to fill up completely the popliteal space. 

 The tendinous connexion of the patella to the 

 rectus muscle was ruptured ; the external con- 

 dyle of the os femoris was very protuberant; 

 the leg was bent forward and shortened, and a 

 depression existed just above the patella. The 

 patient felt most excruciating pain when the 

 limb was moved, but when at rest there was 

 not any considerable suffering ; the luxation 

 was reduced, and in five months recovery was 

 complete. 



Lateral luxation of the femur at the knee- 

 joint. Although from the structure of the parts 

 it might at first be supposed that complete la- 

 teral luxation should be less resisted than the 

 luxation of the femur either forwards or back- 

 wards, still there is no case on record with 

 which we are acquainted of complete lateral 

 luxation of the femur from the tibia as the 



result of accident. We commonly see only 

 one of the condyles of the femur abandon the 

 tibia, while the other remains in the cavity the 

 first had left. The luxation is then what is 

 called incomplete. The reduction of this lux- 

 ation is easy in consequence of the rupture of 

 the ligaments.* 



Dislocation outwards of the femur at the 

 knee-joint. In the dislocation outwards of the 

 femur at the knee-joint, this bone is thrown 

 off the external condyle of the tibia, and this 

 latter bone projects on the inner side of the 

 joint so as at once to disclose the nature of the 

 injury. Sir A. Cooper once saw a case of this 

 kind at St. Thomas's Hospital, and stated he 

 was struck with three circumstances. The first 

 was the great deformity of the knee from the 

 projection of the tibia inwards ; the second, 

 the ease with which the bone was reduced by 

 gradual extension ; and the third, the little in- 

 flammation which followed upon what appeared 

 so serious an injury. The man was discharged 

 after a few weeks, having suffered little local or 

 constitutional irritation. 



Example of dislocation of the femur out- 

 wards. Mr. Bovill was thrown from a gig ; 

 the femur projected much externally at the 

 knee, and the tibia much (below the situation 

 of the inner condyle of the femur) to the inner 

 side of the condyle of the os femoris. The 

 limb was extended from the thigh-bone, in a 

 bent position ; the extension was a long time 

 continued, and force was employed by several 

 persons for half an hour before the luxation 

 was reduced. Sir A. Cooper saw him eighteen 

 months after the accident ; the patient could 

 not then bend the limb at right angles with the 

 thigh ; there was also an unnatural lateral mo- 

 tion of the joint from the injury which the 

 ligaments had sustained. 



Incomplete dislocation of the femur inwards 

 at the knee-joint. The femur is sometimes 

 thrown on the inner side of the knee-joint, the 

 condyles of the tibia being carried outwards. 

 The under surface of the inner condyle of the 

 femur may be felt through the skin, while the 

 outer condyle of this bone rests on the cup-like 

 cavity hollowed on the upper extremity of the 

 inner condyle of the tibia, or rather behind it. 

 A deformity is produced analogous to that in 

 the external dislocation, and may be easily con- 

 ceived. From the little experience had of such 

 cases, the reduction of the limb is stated to be 

 equally easy with the former, and the patient 

 recovers with little diminution of the powers of 

 the part. Sir A. Cooper states as his opinion 

 that in these cases the condyle of the os femoris 

 with respect to the tibia is thrown somewhat 

 backwards as well as outwards or inwards. An 

 alderman fell from his horse and partially dis- 

 located the condyle of the os femoris inwards, 

 and the tibia outwards; the femur was easily 

 replaced. He was perfectly recovered in twelve 

 months. 



To whichever side the tibia is luxated, it 

 always pulls with it the patella, which suffers 



* Blandin says : " Je 1'ai eprouve moi-meme line 

 fois a 1'Hopital de la Charite." Traite d'Anat. 

 Topog. Paris, 1826, p. 617. 



