LUXATION. 



neck of the humerus, when the head of tlie bone lies deep in 

 the axilla beyond that procils. This liindrancc_to reduction 

 vill be increafed in proportion to the deprcihoii "of the acro- 

 mion ; if the extenfion is made in a horizontal direftion. 

 I'or in this cafe the edge of the jrlenoid cavity pitches againll 

 the neck of the humerus, .and, in fome degree, prevents the 

 head of the bone from advancing forward-. In order to re- 

 move this hindrance, ttie licad of the humerus mud be lowered 

 by elevating the arm, and the edge of the glenoid cavity 

 raifed from the neck of the humerus by reprcilinn- the acro- 

 mion." Mr. Hey then ftates that he has now, "for feveral 

 years, preferred the method rcconnnended by Mr. Broni- 

 iield, for repreffing the acromion during the extenfion, and lie 

 inlills on the propriety of bending the fore-;irm, before ap- 

 plying the means for extenfion, fo that the biceps may be re- 

 laxcil as iiiueh as iKifTibic, and not hinder the glenoid cavity 

 fio^being reprefled. See Practical Obfervations in Sur- 

 gery, p. 299, ^00. edit. 2. A defcription of Bromfield's 

 method may be found in this gentleman's Cliirurgical Ob- 

 ferv. and Cafes, vol. i. chap. 6. p. 269. 



J.uxations of the Elbow-joint, or of the Fore-arm from the 

 Humerus — Here authors have generally defcribed four kinds 

 of diflocation ; r/s;. backwards, forwards, outwards, and 

 inwards ; but all thefe cafes do not occur with equal fre- 

 quency, as experience proves, and the llrudture of the joint 

 might enable us to anticipate. 



The luxation of the bones of the fore -arm backwards are 

 by far the moll common ; the diflocation of them forwards 

 is very rare, was never obferved by Default or Petit, and 

 indeed cannot happen without a frafture of the olecranon. 

 I^uxations inwards or outwards are alfo not frequent, and 

 when they do happen they mult alnioll inevitably be incom- 

 plete, in confequence of the great extent of the articular 

 furfaces. The frequency of luxations backwards, compared 

 with that of lateral diflocations, is eftimated in Default's 

 vporks by Bichat as 10 to i. The luxation forward being 

 fo uncommon, no comparifon whatever is afligncd. The 

 coronoid procefs, forming only an inconhderable curvature, 

 cannot make any vaft relillance to the afcent of the olecra- 

 non and radius, up the poilerior part of the humerus. But 

 the kind of hook which the olecranon makes, effedually 

 hinders this procefs itfelf as well as the radius from flipping 

 forwards in front of the humerus. Indeed, as we have al- 

 ready oblerved, a luxation in this direction may be regarded 

 as impolhble, without a fradure of the olecranon. The 

 lateral ligaments, and the reciprocal manner in which the 

 irregular furfaiA-s of the articulation fit each other, are alfo 

 ftrong obftacles to lateral diflocations. Luxations back- 

 wards are, as we have faid, by far the moll frequent. 



In the luxation backwards, the radius and ulna may af- 

 cend more or lefs behind the humerus ; but the coronoid 

 proceis of the ulna is always carried above the articular 

 pulley, and is found lodged in the cavity deilined to receive 

 the olecranon. The head of the radius is placed behind 

 and above the external condyle of the humerus. The an- 

 nular ligament, which confines the fuperior extremity of the 

 radius to the ulna, may be lacerated; in whi h cafe, even 

 when the bones are reduced, it is difficult to keep them in 

 their proper places, as the radius tends conllantly to fepa- 

 rate from the ulna. 



I'his luxation always takes place from a fall on the hand ; 

 for, when we are falling, we are led by a mechanical in- 

 llincl to bring our hands forwards to protect the body. If 

 in this cafe tlie fuperior extremity, inllead of relling verti- 

 cally on the ground, be placed obliquely with the hand 

 nearly in a ftate of iupinatio;i, the repulfiou which it receives 

 from the ground will caufe the two bones of the fore- arm 



to afccnd behind the humerus, whilft the weight of the 

 body prefllng on the humerus, directed obUquely down- 

 wards, forces its extremity to pafs down before the coronoid 

 procefs of the ulna. 



The fore-arm, in this luxation, is in a ftate of half-flexion, 

 and every attempt to extend it occafions acute pain. The 

 fituation of the olecranon, with refpcct to the ccmdyles of 

 the humerus, is changed. The olecranon, which in the 

 natural Rate is placed on a level with the external condyle, 

 which is itfelf fituated lower than the internal, is even higher 

 than the latter. 



This luxation may be millaken for a frafture of the ole- 

 cranon, of the head of the radius, or even of the inferior 

 extremity of the humerus. Such a millake is attended with 

 very bad confequences ; for it the reduttion be not effefted 

 before the end of fifteen or twenty days, it is often im- 

 poflible to accomplifh it afterwards. The fwelling, which 

 iupervenes in twenty-four hours after the accident, renders 

 a diagnofis more difficult ; but the olecranon and internal 

 condyle are never fo obfcured, that the dillance between 

 tliem cannot be found to be increafed,. though Boyer makes 

 a contrary affertion. It is true, that tiie rubbing of the 

 coronoid procefs and olecranon againil the humerus, may 

 caufe a grating nolle, fimilar to that of a fraiilure ; and fome 

 attention is certainly requilite to eftablifli a diagnofis be- 

 tween a frafture of the head of the radius, and a difloca- 

 tion of the fore-arm backwards.. 



The following method of reducing the cafe is advifed by 

 Boyer : — The patient being firmly feated, an affiftant is to 

 ^ake hold of the middle part of the humerus, and make the 

 counter-extcnfion, while another affiftant makes extenfion at 

 the inferior part of the fore-arm. The furgeon, feated on 

 the outfide, grafps the elbow with his two hands, by apply- 

 ing the fore-fingers of each to the anterior part of the hu- 

 merus, and the thumbs to the poilerior, with wliich he 

 preiTes on the olecranon, in a diredtion downwards and for- 

 wards. This method will be in general fuccefsful. If the 

 ilrength of the patient, or the long continuance of the luxa- 

 tion, render it neceffary to employ a greater force, a fillet is 

 to be applied on the wriil, to make extenfion, and a cuffiion 

 is to be placed in the ax-illa, and the arm and trunk fixed, as 

 is done in cafes of luxation of the humerus. 



A bandage may afterwards be applied, in the form of a 

 figure of 8, and the arm is to be kept in a fling. The lace- 

 ration which always takes place, is always followed by moi-e 

 or lefs fwelling, which is to be combated by antiphlogilUc 

 means. 



At the end of fevcn or eight days, when the inflamma- 

 tory fym.ptoms are nearly gone, the articulation is to be 

 gently moved, and the motion is to be increafed every day, 

 in order to prevent an anchylofis, to which there is a great 

 tendency. 



In this luxation, the annular ligament which confines the 

 head of the radius to the extremity of the ulna, is fome- 

 times torn, and the radius palles before the ulna. In fin h 

 cafes, pronation and fupination are difficult and painful, 

 though the principal luxation has been reduced. The head 

 of the radius may be eafily replaced, by preffing it from 

 before backwards, and it is to be kept in its place by a com- 

 prefs, applied to the fuperior and extei-nal part of the fore- 

 arm. The bandage and compreffes are to be taken off every 

 two or three days, and re-applied. This is neceffary, on 

 account of the neceffity of moving the articulation to pre- 

 vent an anchylofis. 



If the luxation be not foon reduced, it becomes irreduci- 

 ble ; the heads of the radius and ulna grow to the back part 

 of the humerus, and the patient can neither bend nor ex- 

 tend 



