74 



ABNORMAL CONDITION OF THE ELBOW-JOINT. 



returned back to its proper situation, but habi- 

 tually remained dislocated completely forwards 

 in front of the external condyle. The liga- 

 ments seemed to have been so lacerated, and 

 the joint felt so weak, that I was in constant 

 terror lest the bone should be further luxated 

 as formerly, and that it should again slip over 

 the external condyle of the humerus. I could 

 extend my arm, but not fully, and could rotate 

 it, but could not flex it sufficiently to use my 

 fork at dinner. In this state I remained for six 

 years, and in the winter of 1834-5 the radius 

 was again luxated laterally over the external 

 condyle of the humerus by a fall from my bed. 

 Now the difficulty experienced in bringing the 

 bone back to the situation it had so long occu- 

 pied in front of the external condyle, was ex- 

 treme. I went to the hospital, and two sur- 

 geons, assisted by six of my brother pupils, 

 could not, with all their force, reduce the bone. 

 The pulleys were also now used, but without suc- 

 cess. Dr. O'Beirne and the late Dr. JVTDowel 

 were called into consultation ; they placed me 

 sitting on my bed, and fixing the hollow angle 

 at the bend of the elbow against one of the 

 bed-posts, they used great force to straighten 

 it, in which they succeeded; that is to say, 

 they replaced the bone, not into its original 

 berth, but back to the new socket, which had 

 been formed for it in front of the external con- 

 dyle, where it had been lodged for six years 

 previously to the last accident, and where it 

 now remains. At this moment it presents all 

 the characters assigned to the luxation of the 

 radius forwards ; the rounded head of this bone 

 is quite prominent in front of the external con- 

 dyle of the humerus, in which situation it 

 seems to have worked for itself a socket, and 

 behind the head of the radius a deep depres- 

 sion exists. The arm has a rounded appear- 

 ance, and the fore-arm is much wasted." 



This case seems to us important as proving 

 three circumstances : 1. that a partial luxation 

 forwards of the radius can exist from relaxation 

 or elongation of ligaments ; 2. that this partial 

 luxation or weakness of the joint is readily 

 convertible into the true luxation forwards ; 

 and, 3. that in the case of unreduced luxation 

 of the radius forwards the patient is still in 

 danger of further luxation of this bone laterally, 

 or above the capitulum and outer condyle of 

 the humerus. 



c. Luxation of the upper extremity of the 

 radius backwards. This luxation would appear 

 to be the most frequent the upper extremity of 

 the radius is liable to, although it cannot be 

 considered a common accident. When, how- 

 ever, we consider the functions of this joint 

 and its form, we shall not be surprised to find 

 the luxation backwards more usual than that 

 forwards. The articulation is less sustained 

 posteriorly by muscular parts than in front, 

 when the fleshy bellies of the supinators cover 

 and support it. There is also much latitude 

 given to the movement of pronation, and the 

 pronators are very powerful muscles. During 

 a forced pronation, the radius becomes very 

 oblique, and its upper extremity has a strong 



tendency to pass behind the axis of the hu- 

 merus. 



The motion of supination, on the contrary, 

 is not so frequent, the muscles to effect it are 

 not so powerful, arid the oblique and interos- 

 seous ligaments, which afford no restraint in 

 the motion of pronation, are, on the contrary, 

 soon rendered tense, and oppose a forced 

 supination, which is the movement most likely 

 to be followed by the luxation forwards. We 

 think, therefore, we have physiological grounds 

 for our belief that the luxation of the radius 

 backwards ought to be the most frequent lux- 

 ation of the radius at the elbow-joint. When 

 the luxation of the upper extremity of the 

 radius backward has occurred, the patient 

 feels at the moment a severe pain in the region 

 of the joint. The fore-arm is flexed, and the 

 hand remains fixed in a state of pronation. 

 Supination cannot be effected either by the 

 voluntary action of muscles or by force ap- 

 plied, and each effort, tending to produce this 

 effect, is attended with a considerable augmen- 

 tation of pain. The hand and fingers are held 

 in a moderate state of flexion. Finally, the 

 superior extremity of the radius forms a mani- 

 fest prominence behind the capitulum or small 

 head of the humerus. 



When the bone is left unreduced, many of 

 the motions of the fore-arm are rendered im- 

 perfect, particularly supination ; but the shoul- 

 der articulation becomes somewhat more free, 

 and in some degree this circumstance makes 

 up for the deficiency. 



Sir A. Cooper, who has not seen any example 

 of this luxation of the radius backwards in the 

 living subject, has given us an account of a dis- 

 section of this injury. He informs us that in 

 the winter of 1821 a subject was brought for dis- 

 section into the theatre of St. Thomas's Hos- 

 pital, in which was found this luxation, which 

 had never been reduced. The head of the 

 radius was thrown behind the external condyle 

 of the humerus, and rather to the lower extre- 

 mity of that bone. When the arm was ex- 

 tended, the head of the radius could be seen as 

 well as felt behind the external condyle of the 

 humerus. On dissecting the ligaments, the 

 coronary ligament was found to be torn through 

 at its fore part, and the oblique ligament had 

 also given way. The capsular ligament was 

 partially torn, and the head of .the radius 

 would have receded much more had it not 

 been supported by the fascia which extends 

 over the muscles of the fore-arm. 



d. Sub-luxation of the upper extremity of 

 the radius, with elongation of the coronary 

 ligament. While Boyer denies the possibility 

 of any partial luxation of the upper extremity 

 of the radius, he describes very clearly an 

 abnormal condition of the radio-humeral joint, 

 of which we have seen many examples, and 

 which perhaps we may call a sub-luxation. 

 The ligaments which connect the head of the 

 radius to the ulna, in the cases above alluded 

 to, undergo a gradual relaxation and elonga- 

 tion, so that whenever an unusual effort is 

 made to produce a strong pronation of the 



