72.11 Fracture of the medial epicondyle of the humerus

Between the ages of 5 and 20 the centre of ossification of the medial epicondyle is a separate piece of bone. The flexor muscles of the forearm are attached to it, and if these are pulled on hard enough by a fall on an outstretched hand, they can pull it away from a patient’s humerus. His detached medial epicondyle may remain outside his elbow joint or go inside the joint and lock it. Closed methods may succeed in removing it, but if they fail, an open operation is necessary Removing the detached medial epicondyle would not be a difficult operation, if his ulnar nerve were not so close. Sometimes, his elbow is dislocated also (72.4).

After a fall an older child or youth complains of a painful elbow. The contour of his arm is normal, but his medial epicondyle is tender and swollen. Rotation is normal and some flexion and extension is usually possible. Compare the X–rays of both his elbows.

Figure 72.16: FRACTURE OF THE MEDIAL EPICONDYLE. If the child is over 5, the age at which the centre of ossification appears, you will be able to see if it is in its normal position A or not. If it is displaced, it may not prevent his elbow moving (B), or it may be inside his elbow and locking it (C). From Perkins with kind permission.

FRACTURE OF THE MEDIAL EPICONDYLE

IF THE PATIENT CAN MOVE HIS ELBOW ADEQUATELY, put his arm in a collar and cuff for a week. Then give him a sling and encourage active movements. Full movements may not return for a year.

IF HE CANNOT MOVE HiS ELBOW ADEQUATELY, anaesthetize him. Extend his wrist to tension his flexor mucles. Flex, abduct, and supinate his elbow, then suddenly extend it. The fragment may reduce with a sudden clunk. X–ray his elbow, and repeat the manoeuvre twice if necessary.

If you can move his elbow through its full range of movement and it is stable, apply a collar and cuff as above.

If you cannot move his elbow through most of its full range, refer him for open reduction.

OPERATION If you cannot refer him, and are familiar with the procedures, consider operating. This is not an operation for the beginner, because the child’s ulnar nerve will not be in its normal position and may be kinked into the joint with his medial epicondyle. Make all incisions in the line of the nerve, not across it.

Make a 5 cm longitudinal incision 1 cm anterior to his medial epicondyle. Find his ulnar nerve and take care not to injure it. You will see the fibres of the common flexor origin emerging from the joint cavity. Pull on these fibres with a hook or forceps, and pull the epicondyle out of the joint.

Find the rough place on the medial side of his elbow from which the epicondyle broke off. Either suture it in place by drilling a small hole in it and in the neighbouring bone, or, anchor it in place with two short pieces of Kirschner wire with their ends bent over subcutaneously. Remove them 4 to 6 weeks later. If fixing the epicondyle is difficult, and the fragment is small, excise it. His flexor muscles will quickly find new attachments.

Figure 72.17: FRACTURE OF THE LATERAL CONDYLE is a serious Salter Harris Type IV epiphyseal injury; it occurs at a younger age than injuries of the medial condyle, and the fragment is larger. Kindly contributed by John Stewart.

DIFFICULTIES WITH FRACTURES OF THE MEDIAL EPICONDYLE

If the patient’s ULNAR NERVE IS INJURED, paralysis may be due to stretching and only be temporary. If recovery is delayed more than 6 weeks, refer him for transfer of the nerve to the front of his elbow.

If the FRAGMENT HAS BEEN LEFT INSIDE THE JOINT, and you discover It some time later, refer the child. If you cannot refer him, warn him that full movement may not return.