FRACTURES OF THE SHAFT OF THE HUMERUS

INDICATIONS if the patient is ambulant, use this method for all fractures of the mid–shaft of the humerus, whether they are spiral, oblique, transverse, or comminuted.

CONTRAINDICATIONS if the patient is unable to sit or stand because of other injuries, treat him in traction as described later.

X–RAYS are not essential, unless there are signs which suggest that the patient’s shoulder may be dislocated also, or unless the fracture is so low in the shaft as to be supracondylar (72-11).

TREATMENT FOR FRACTURES OF THE SHAFT OF THE HUMERUS

Before starting, check the patient’s peripheral pulses, and test the function of his radial nerve and record it (Fig. 75-3). Can he dorsiflex his wrist or extend his fingers? If his radial nerve is injured and fails to recover, he will not be able to blame your treatment.

If the fracture is grossly angulated, reduce it under anaesthesia. Manipulate him carefully. His radial nerve is close to the fracture site. You can use local anaesthesia of the fracture haematoma, provided you do it in a sterile manner (A 5.6). Alternatively, wait for the bone ends to become sticky in about 10 to 20 days and then manipulate them.

Make the patient a sling 10 cm wide which supports only the distal part of his forearm. It must not include his elbow which must be at 90. Make it by folding a triangular bandage several times, as in Fig. 71-15.

CAUTION! The width of the sling is critical. Use a narrow wrist sling which supports only the distal half of the patient’s forearm. Don’t use: (1) an elbow sling which raises and supports his elbow, or (2) a collar and cuff, or (3) a bootlace or piece of bandage. If his elbow is supported in a full sling, the weight of his forearm cannot reduce the overlap. A collar and cuff will draw the lower fragment forwards and angulate the fracture. A bootlace or a single turn of bandage will be acutely uncomfortable.

If you decide to splint the patient’s arm: (1) ideally use a plastic splint with ’Velcro’ fastenings. Or, (2) pad his arm well with cotton wool, place some strips of bamboo (ideally sewn between two pieces of cloth) along it, and cover these with a crepe bandage. Or, (3) apply a light U–slab.

CAUTION ! If you decide to put a U–slab on his arm (and you will usually be wise not to), it must be as thin and light as possible. Apply it during the first few days only. It is unnecessary later, and may distract fragments undesirably.

Tell the patient that he may hear and feel crepitus for the first week or two, but that this is a good sign. He may think he needs a splint. Reassure him that he does not.

If he is to avoid a stiff shoulder, he MUST exercise it. If he has a transverse fracture, the only safe exercises are the rhythmical pendulum exercises shown in A, Fig. 71-7 and B, Fig. 71-15. Show him how to bend forwards, and to move his arm in all directions from his shoulder.

Tell him to use his hand actively, and to flex and extend the muscles of his elbow a little inside the sling, as in C, Fig. 71-15. He must not take off his sling until there is clinical union, or the bone may angulate at the fracture site, and break again. Passive movements are unnecessary and potentially dangerous. Supervise these exercises carefully, or the fracture may not unite. If he is 100% on your side and smiling (patient E), you have won. If he looks like patient F, expect failure.

CAUTION! (1) Exercises must start within a day or two of the injury, or the fracture will be slow to unite. (2) If he has a transverse fracture, warn him that he must not abduct his arm at the shoulder or let his forearm hang by his side until his fracture is solidly united. He should wait for you to tell him that it is safe for him to do this. Extending his arm when his elbow is stiff will cause forward bowing and may fracture the callus, or cause delayed union or malunion.

If you wish to correct the position, do it at about 15 days when the bone ends are sticky. This is seldom necessary, because almost any position is acceptable.

Good callus usually forms in 4 weeks. Wait for signs of consolidation (Fig. 69-4). These are: (1) No tenderness over the fracture site. (2) Attempts to angulate the bone at the fracture site fail, and do not cause pain.

When, and only when, there are definite signs of clinical union, cautiously remove the sling for longer periods each day, until the patient has good elbow movements.

Consolidation usually takes 2 months in spiral fractures and 3 months in transverse ones; it normally takes twice as long as clinical union. So, if consolidation takes 6 weeks, the patient should continue to wear his sling for 12 weeks. If there is any danger of his humerus refracturing, as in a crowded bus, he must wear his sling, but he can take it off at other times.

CAUTION! (1) A hanging cast, as in A, Fig. 71-15 is the most common cause of non–union. (2) Forced movements of his elbow may refracture his humerus. So, be careful!

DIFFICULTIES WITH FRACTURES OF THE SHAFT OF THE HUMERUS

If the patient’s ARM IS PULSELESS AND COLD, reduce it and apply gentle traction. If this does not restore his circulation immediate exploration of his artery is indicated (55.3). Meanwhile keep his arm cold. If its circulation is not restored, his arm may need amputating.

If his SHOULDER OR ELBOW IS STIFF, he may complain about it long after his arm has healed. But, provided it has not been injured, his shoulder should not become stiff, if he does his dangling exercises properly. A stiff shoulder is a serious disability.

Loss of movement is less serious in the elbow, because people commonly use only a limited range of elbow movements.

If UNION IS DELAYED, or fails, assist it by encouraging him to contract his arm muscles vigorously, so that he can hear the bone ends grating! Unless there is vigorous muscular action, little callus will be formed, and union will be poor. Be patient if it is slow. Keep his arm in a sling and make him use the flexors and extensors of his elbow. These cross the fracture site and their action will encourage union.

Delayed union or non–union can be the result of: (1) Removing the sling too early, so causing posterior angulation of the fracture. (2) Using a sling which supports the elbow. (3) Other injures which confine the patient to bed, (4) Applying a heavy cast which distracts the fragments. (The more plaster you apply to these fractures, the less likely they are to unite.) (5) Unskilled internal fixation, as in Fig. 69-2.(6) Traction. (7) Soft tissue between the bone ends.

When non–union has occurred, if the patient is painfree, encourage him to accept the disability, as in D, Fig. 71-15 and continue his daily activities- if he cannot accept his pain and disability, consider referring him for internal fixation and a bone graft. This may fail, even in the best hands.

If he CANNOT DORSIFLEX HIS WRIST after a fracture of his humerus, he has injured his radial nerve. He can do this in various ways: (1) it can be bruised or stretched at the time of the injury and slowly recover. (2) it can be torn at the time of the injury and not recover. Or, (3) a radial nerve paralysis can develop during treatment, as the result of fibrosis and constriction of the radial nerve tunnel. Whatever the cause, he will probably recover. Refer him for exploration of his radial nerve if: (1) it shows no signs of recovery in 6 months, or (2) the paralysis develops some weeks after the injury.

Meanwhile, use a cock–up splint to support his wrist in dorsiflexion and prevent a contracture, as in Fig. 69-2. Sometimes passive exercises are enough. Ask him to extend his fingers several times a day with his other hand.

If he has FRACTURED THE SHAFT OF HIS HUMERUS AND DISLOCATED ITS HEAD, the dislocation will be almost impossible to reduce, because traction on his arm will not move the head of his humerus. So refer him rapidly for open reduction and internal fixation.

If he has fractured the shaft of his humerus and has OTHER iNJURIES WHICH PREVENT HIM SITTING OR STANDING, you can treat his fracture in a sling as usual, if he can sit. If his other injuries prevent this, you will have to use traction instead.

Figure 71.16: TRACTION FOR FRACTURES OF THE SHAFT OF THE HUMERUS when a patient is confined to bed. Use skin traction to suspend his forearm with his elbow flexed to 90 and his humerus slightly abducted. Kindly contributed by John Stewart.

Either apply skin traction, as in Fig. 71-16, or drill a Kirschner wire through the thick part of his olecranon, and hold it in a Gissane stirrup, as in Fig. 70-13. Pass a cord from the stirrup over the foot of his bed. Use skin traction to suspend his forearm with his elbow flexed at 90 and his humerus slightly abducted.

CAUTION! Start with 2 kg in an adult, and check reduction with X–rays once or twice during the first week. Adjust the weight so as not to distract the fragments. As soon as he can sit up, change to the sling method of treatment.

Alternatively, make a light plaster gaiter (Fig. 81-6) round the shaft of his humerus, and encourage early active movements.