if failure to unite persists after treatment for some weeks, the condition becomes ununited fracture.

What is the pathology?

The "bony-cicatrical tissue" referred to under Repair of Fractures has failed to ossify, and exists only as fibrous tissue, which may enclose bony nodules, and whose length varies according to

Displacement of the vertebræ causing compression of the spinal cord.

the amount of separation of the fragments. Sometimes this fibrous union is only around the circumference, forming a kind of capsular ligament. The ends of the fragments in such cases have become smooth and hard, and move freely on each other. This variety of ununited fracture is called pseudarthrosis or false joint.

What is the treatment for these varieties of fibrous union?

Delayed union: moderate use of the part. If in the lower extremity, locomotion with some kind of orthopedic apparatus is indicated.

Ununited fracture: forcible bending of the limb at the site of the fracture, or drilling holes through the fibrous union and the con

tiguous portions of the bone; incision with removal of the fibrous tissue, and sawing off a layer of bone from each fragment with wiring or not; in all cases to be followed by careful immobilization.

Pseudarthrosis: regular excision of the false joint and immobili

zation.

What are some of the causes of fibrous union?

Tubercular or syphilitic inflammation; interposition of too much periosteum or fascia, etc. between the fragments; excessive comminution; too great loss of substance in compound fractures; improper treatment, such as faulty immobilization, or too early use of the part.

DISLOCATIONS.

What is a dislocation?

A dislocation or luxation is a complete separation from each other of those portions of bones which go to make up the constitution of a joint. An incomplete dislocation is often called a subluxation. A compound dislocation is one which is complicated by the presence of a wound. A sprain is a laceration, of greater or less extent, of the ligaments of a joint.

What are the causes of dislocations?

They are the same as those of fractures (which see). Muscular action rarely produces dislocation in healthy people, except in professional contortionists. Joints which are diseased are those which are usually dislocated by muscular action, such dislocations being called pathological. Congenital dislocations are those caused by muscular action or lack of development in utero.

What are the symptoms of a dislocation?

Displacement: the ends of the bones occupy an abnormal position with respect to each other.

Shortening to be estimated by measurement from some point above the joint to any point on the side of the lower bone opposite to the dislocation. Thus, if the dislocation of the end of the bone is inward, the point should be taken on the outer side, and vice versa.

Immobility: As a rule, a joint which has been dislocated is much restricted in motion. Should all the ligaments be torn-a

rare and severe form-there would be abnormal mobility. In addition to these symptoms there are also pain, swelling, and loss of function.

What is the treatment of dislocations?

Restoration of the ends of the bones to their normal position. As a rule, ether should be given. The two methods resorted to are traction and manipulation. The latter should be used first. If it fails, then traction may be tried. The general rules of procedure in manipulation are

(a) Increase the deformity: this loosens up the head of the bone;

then

(b) Reverse quickly the motions by which the deformity was increased this will effect the desired reduction.

FIG. 60.

High Dorsal Dislocation.

The after-treatment is rest until the rent in the ligaments is healed. This usually requires from four to six weeks. When necessary, pads and bandages should be used to retain the bones

in place. Manipulation of course is available only for the common typical dislocations-i. e. those in which there is only a rent or tear of the ligaments through which the head of the bone has slipped.

SPECIAL DISLOCATIONS.

Space will not permit the discussion of all the dislocations. Sufficient has already been said in a general way as regards diagnosis and treatment which will apply to those dislocations which are omitted.

Describe dislocation of the hip.

This means separation of the head of the femur from the acetabulum. There are three main varieties: 1. Dorsal, in which the head of the femur points backward, and may be situated on the dorsum of the ilium (Fig. 60), or lower down just posterior to the acetabulum (Fig. 61); 2. Thyroid (Fig. 62), in which the head is in the thyroid foramen. 3. Suprapubic (Fig. 63) in which the

FIG. 61.

FIG. 62.

head looks inward, and is placed on the horizontal ramus of the pubes. In all these varieties the ilio-femoral or Y-ligament is supposed to be intact.

What are the symptoms of these dislocations?

The special symptoms are as follows:

Dorsal: the limb is rotated in, flexed, and adducted.

It is also shortened. The head of the femur may be felt in its abnormal position.

Thyroid: slight outward rotation, abduction, and flexion are the attitude of the limb. There is some lengthening.

Suprapubic position; slight abduction, some extension, and marked outward rotation.