FREE BOOKS

Author's List




PREV.   NEXT  
|<   86   87   88   89   90   91   92   93   94   95   96   97   98   99   100   101   102   103   104   105   106   107   108   109   110  
111   112   113   114   115   116   117   118   119   120   121   122   123   124   125   126   127   128   129   130   131   132   133   134   135   >>   >|  
that is, deviation towards the radial side; but it may follow a direct blow on the back of the humerus, a fall on the elbow, or a twist of the forearm. [Illustration: FIG. 36.--Backward Dislocation of Elbow, in a boy aet. 10, caused by a fall off a wall, landing on the elbow.] _Morbid Anatomy._--All the ligaments of the elbow, except the annular (orbicular), are torn or stretched. The radius and ulna pass backward, the coronoid process coming to rest opposite the olecranon fossa behind the humerus, and the head of the radius behind the lateral condyle. The condyles of the humerus bear their normal relations to one another. The olecranon and the triceps tendon form a marked prominence on the back of the elbow, the tip of the olecranon lying above and behind the condyles. The lower end of the humerus lies in the flexure of the joint with the biceps tendon tightly stretched over it. The coronoid process is often broken, or the tendon of the brachialis torn. The median and ulnar nerves may be stretched or torn. Not infrequently the bones of the forearm are displaced towards the medial side as well as backward. Occasionally, as a sequel to the dislocation, processes of bone develop in relation to the insertion of the brachialis and interfere with the movements of the joint. These outgrowths are due to displacement of bone-forming elements, either at the time of the original injury or as a result of forcible efforts at reduction. According to D. M. Greig, they do not develop in the tendon of the brachialis, but under it, and are not of the nature of myositis ossificans. In from four to six weeks after reduction of the dislocation, the movements begin to be restricted, and a hard mass can be felt in the cubital fossa, which with the X-rays is seen to be a bony outgrowth springing from the quadrilateral space on the front of the elbow below the coronoid process (Fig. 37). This gradually increases in size and leads to fixation of the joint. In most cases the effects reach their maximum in about six months, and then reabsorption of the mass begins. [Illustration: FIG. 37.--Bony Outgrowth in relation to insertion of Brachialis Muscle, following Backward Dislocation of Elbow. (Sir Robert Jones' case. Radiogram by Dr. D. Morgan.)] If the disability shows no sign of abatement within a year, or if the bony outgrowth is producing pressure effects on the median nerve, it should be removed by operation. It is important no
PREV.   NEXT  
|<   86   87   88   89   90   91   92   93   94   95   96   97   98   99   100   101   102   103   104   105   106   107   108   109   110  
111   112   113   114   115   116   117   118   119   120   121   122   123   124   125   126   127   128   129   130   131   132   133   134   135   >>   >|  



Top keywords:

humerus

 

tendon

 

olecranon

 

coronoid

 

brachialis

 

process

 

stretched

 

backward

 
radius
 

relation


develop

 

dislocation

 

median

 

outgrowth

 

insertion

 

condyles

 

effects

 
movements
 

Illustration

 

forearm


Backward
 

reduction

 

Dislocation

 

springing

 

quadrilateral

 

restricted

 

ossificans

 

myositis

 

nature

 

cubital


disability

 

abatement

 

Morgan

 
Radiogram
 

removed

 
operation
 

important

 

producing

 

pressure

 

Robert


fixation

 
gradually
 
increases
 
maximum
 

Outgrowth

 

Brachialis

 
Muscle
 

begins

 

months

 

reabsorption