Manual of Surgery Volume Second: Extremities—Head—Neck. Sixth Edition.

by Alexis Thomson; Alexander Miles

Prognosis.—In cases with little displacement, if the fragments have been kept in perfect apposition, osseous union may take place, but in the great majority of cases the union is fibrous. The shortening of the quadriceps and the gradual stretching and thinning of the connecting fibrous band may allow of further separation of the fragments ([Fig. 88]), which to a variable extent interferes with the stability and functions of the limb. The proximal fragment sometimes becomes attached to the front of the femur, and moves with it, and the fibrous band between the two fragments gradually becomes stretched. After bony union has occurred, it is not uncommon for the patella to be fractured again by a fall within a month or two of the original accident.

Treatment.—It is probably true that the best functional results are most speedily obtained by operative measures. The laceration of the aponeurosis of the quadriceps, the tilting of the fragments, and the interposition of the torn periosteum between them, can in no other way be rectified with certainty. The operation, however, should only be undertaken by those who are familiar with wound technique, and who have the means at their disposal for carrying it out. Operative treatment is specially indicated in young subjects who lead an active life, and in labouring men, particularly those who follow dangerous employments necessitating stability of the knee.

As soon as the wound is healed,—in a week or ten days,—massage and movement of the limb are commenced, and the patient is encouraged to move his limb in bed. At the end of another week he may be allowed up with sticks or crutches.

Non-operative Treatment.—In the majority of cases occurring in patients who do not follow a laborious occupation or otherwise lead an active life, a satisfactory result can be obtained without having recourse to operation. We have reason to be satisfied with the following method: the patient is kept in bed for a few days, the injured region being supported on a pillow and massaged daily, and the patella moved from side to side as a whole to prevent adhesion to the femur. About the fourth day he is allowed to get about with crutches. As osseous union of the fragments is not essential to a good functional result, and as fibrous union does not necessarily entail any material interference with the usefulness of the limb, no attempt need be made to approximate the fragments, but every effort must be made to maintain the function of the quadriceps muscle and the mobility of the joint.

If it is desired to bring the fragments into contact and to secure osseous union, the limb should be placed upon an inclined plane to relax the quadriceps muscle, and means taken to arrest effusion and to diminish the swelling by systematic massage and a supporting bandage. When, in the course of a few days, this has been accomplished, the attempt is made to approximate the fragments, by fixing a large horseshoe-shaped piece of adhesive plaster to the front of the thigh, embracing the proximal fragment. Extension is made upon this by means of rubber tubing, which is fixed to the foot-piece of the splint. The bandage which binds the limb to the splint should make upward pressure on the distal fragment, or this may be done by a special piece of adhesive plaster with elastic tubing pulling in an upward direction.

The retentive apparatus is kept on for about three weeks, and a rigid, but easily removable, apparatus is thereafter applied, and the patient allowed up on crutches, the limb being massaged and exercised daily to improve the tone of the muscles.

When the fracture is caused by direct violence, such as a fall on the knee or the kick of a horse, it may be transverse, oblique, or vertical, but in many cases it is stellate, the bone being broken into several irregular pieces. These comminuted fractures are frequently compound. In transverse and oblique fractures, the displacement depends upon the same causes as in fracture by muscular action. In vertical and stellate fractures, unless the knee has been forcibly flexed after the bone has been broken, there is little or no displacement. The treatment is governed by the same considerations as in fractures by muscular action.

Old-standing Fracture.—As fibrous union, even with an interval of several inches between the fragments, is not incompatible with a useful limb, it is not often necessary to operate for this condition, but when the usefulness of the limb is seriously impaired, operative treatment is indicated. The operation is carried out on the same lines as for recent fracture, the ends of the bones being rawed and adhesions divided. When the proximal fragment has become attached to the femur, it should be separated and a layer of fascia interposed; it is sometimes necessary to lengthen the quadriceps muscle by making a number of V-shaped incisions through its substance; or a flap may be turned down from the rectus and stitched to the patella and the ligamentum patellæ.

When operative treatment is contra-indicated, the patient should be fitted with a firm apparatus which will limit flexion of the knee and support the fragments.

Dislocation of the patella is rare. It results from exaggerated muscular movements when the limb is in the fully extended position, or from a blow on one or other edge of the bone. Laxity of the ligaments and knock-knee are predisposing factors. It is sometimes associated with fracture of the edge of the trochlear surface, which renders retention in position difficult.