ANTERIOR SHOULDER DISLOCATION

Reduce the patient’s dislocation immediately. If his injury is recent, reduction is usually easy.

INDICATIONS Anterior dislocations less than 3 weeks old. If the dislocation is older than this, see below.

Have you X–rayed him to make sure your diagnosis is correct? Check his axillary nerve (Fig. 55-6), and his radial pulse.

ANAESTHESIA If the patient’s injury is recent, he may not need an anaesthetic. Good relaxation is required if it is more than a few hours oId, or if he is very muscular. (1) General anaesthesia with a muscle relaxant. (2) Ketamine and diazepam (A 8.2).(3) intravenous pethidine with diazepam (A 8.8).

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Figure 71.6: TWO METHODS FOR REDUCING A DISLOCATED SHOULDER. A, the arm swinging method, and B, the Hippocratic method. The editor is on the floor; the sock belongs to Peter Bewes! A, kindly contributed by Gerald Hankins.

THE ARM SWINGING METHOD FOR A RECENT ANTERIOR DISLOCATION

Try this first, especially if the patient’s dislocation is very recent, using pethidine, preferably with diazepam.

Lie him on a table, face downwards, with his arm over its edge.

Ask him to relax his arm as much as he can. If the table is high enough, tie a 2 kg weight to his wrist. Dead weight traction of this kind is often more successful than manual traction, because it is easier for him to relax. Leave him alone for a while. When you return you may find the dislocation reduced.

If it is not reduced, bend his elbow and move his arm in all directions. At the same time pull on his arm. His shoulder will usually go back into its socket with a sudden spontaneous click.

THE HIPPOCRATIC METHOD FOR A RECENT ANTERIOR DISLOCATION

METHOD Lie the patient on the floor. If he has dislocated his right shoulder, remove your shoe and put your right foot in his axilla, lean backwards, and pull on his abducted arm. If you are agile, you can also use this method while he is on a table, by raising your foot and placing it in his axilla.

Pull gently and steadily for 5 minutes.

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Figure 71.7: SHOULDER EXERCISES are in two groups. EARLY EXERCISES should be done smoothly and rhythmically with gradually increasing amplitude. Here are the instructions to a patient. (1) Stoop forwards and circle your arm (’arm dangling’). (2) Put your arm against a wall. With your arm straight, move steadily closer to it (’wall crawling’). (3) Stand astride with your arms crossed and swing them sideways and upwards. (4) Stand astride and swing your arms forwards and upwards. (5) Lean against a wall with your arms bent, turn your arms to touch the backs of your hands against the wall. LATE EXERCISES should be done more vigorously. (6) Put one leg in front of the other, put your hand on your knee, and swing your arm. (7) Stand astride with your arms crossed, swing your arms sideways and upwards, and clap them above your head. (8) Lie on your back with your arm stretched and press downwards to touch the floor. (9) Stand astride; alternately touch the back of your neck and fold your hands behind your back. Kindly contributed by Michael Wood.

CAUTION! Don’t exert excessive force. You may injure his brachial plexus.

If this does not reduce the dislocation, ask an assistant to exert traction as above. While he does so, press the head of the patient’s humerus backwards with both your thumbs in the direction of its socket. Or, grasp his arm with both hands and pull laterally.

If you fail and are not using general anaesthesia, try again using it and a relaxant.

POSTOPERATIVE CARE (both methods) As soon as the patient is awake ask him to abduct his arm gently. Check that you have not injured his axillary or musculocutaneous nerves during reduction. Examine him to make sure that you have reduced his dislocation, and check with an X–ray.

Put his arm in a sling for 3 weeks, and start pendulum exercises in the sling immediately. Then start most of the other early exercises in Fig. 71-7. Avoid abduction and external rotation exercises, because they are dangerous and may redislocate his shoulder.

DIFFICULTIES WITH DISLOCATED SHOULDERS

If you suspect that a patient has a dislocation but you have NO X–RAYS, anaesthetize him and move his shoulder gently. A dislocation may reduce spontaneously, and you are unlikely to harm him.

If PART OF HIS GREATER TUBEROSITY HAS BROKEN OFF, it will probably return to its bed as you reduce his dislocation. If it does so, well and good. But if it fails to do so, and prevents him abducting his arm, try the methods in Section 71.10. A quarter of all acute dislocations are associated with a fracture, most commonly a fracture of the greater tuberosity. You can easily see this in routine X–ray views of a patient’s shoulder. The external rotator muscles of his shoulder pull a piece of bone away from the head of his humerus as his shoulder dislocates.

If you FAIL TO REDUCE HIS DISLOCATION under diazepam or ketamine, try general anaesthesia with a relaxant. This usually succeeds. If it fails don’t try again using more force. Instead, refer him for open reduction.

If his DISLOCATION RECURS after 6 weeks, it will probably continue to do so, so refer him for an operative reoair. A dislocated shoulder is usually stable after you have reduced it. But, if it dislocated after only a very minor injury, it probably did so because the labrum separated from the glenoid ring. Adult cartilage does not usually unite with bone, so his shoulder may continue to dislocate with increasing ease. Finally, it may dislocate even when he sneezes or turns over in bed.

If the HEAD OF HIS HUMERUS DROPS OUT OF HIS GLENOID because his axillary nerve has been paralysed, support his arm in a sling for several months until his nerve recovers. Tighten the sling regularly so as to keep the contour of his shoulder normal, and show his spouse how to do the same. This is not the same condition as recurrent dislocation of the shoulder. Suspect it when a patient is anaesthesic over his deltoid, and is totally unable to abduct his arm.

If his SHOULDER REMAINS STIFF after a dislocation, explain that movements will eventually return. Active exercises are safer and more effective than passive ones. Avoid excessive force, because this will only make the stiffness worse. His shoulder is more likely to become stiff if he fails to move it early.

If a patient’s BRACHIAL PLEXUS IS INJURED, it will probably recover in a year. Meanwhile, put his shoulder through a safe range of movements to prevent contractures. Some nerve injury is common after a dislocation, and may involve any of the three cords of his brachial plexus. His axillary and musculocutaneous nerves are commonly involved. Sometimes his whole brachial plexus is torn from his spinal cord, paralysis is permanent, and his useless aneasthetic arm has to be amputated (71.3).

If his AXILLA RAPIDLY SWELLS after a shoulder injury, his axillary artery has been torn- This is a very rare disaster in an old patient with hard arteries, and may follow a fracture dislocation. It is more likely to occur if you are trying to reduce a fracture dislocation, particularly an oId one, or if you use greater force than the original injury. The patient’s torn artery bleeds and forms a large arterial haematoma (55.5) round his shoulder. Suspect this disaster if a rapidly increasing swelling in a patient’s axilla follows a shoulder injury. If you don’t diagnose a torn axillary artery, and it is not repaired (55.6), he may bleed to death. Tying it is a desperate operation, but you will not have time to refer him. Firm axillary pressure may stop the bleeding, so try it. If this fails, you may have to clamp or tie his subclavian artery (3.4).

If the CIRCULATION IN HIS ARM IS POOR before his dislocation is reduced, reduce it gently. If this does not restore his circulation, his axillary vessels should be explored and his axillary artery repaired, if necessary. So, refer this rare complication quickly.

If a patient with a DISLOCATED SHOULDER PRE­SENTS LATE (more than 3 weeks after the dislocation), refer him. A difficult open operation may be justified, especially if pressure on the structures in his axilla causes symptoms, but the results may be poor. If you cannot refer him, movement between his scapula and his chest may give him a useful range of painless movement. Ask him to do active exercises, so that he can preserve as much movement as possible in his other joints.

Reduction becomes increasingly difficult and dangerous as time passes. Initially, every hour is important, and after 6 weeks reduction may be impossible. Using force may break the neck of a patient’s humerus, or tear his axillary vessels or nerves.

A PATIENT WHO CANNOT MOVE HIS SHOULDER AFTER AN INJURY HAS A DISLOCATION UNTIL PROVED OTHERWISE
REDUCE ALL DISLOCATIONS IMMEDIATELY
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Figure 71.8: POSTERIOR DISLOCATIONS OF THE SHOULDER are often missed because the AP view looks almost normal. The closeness of the head to the film does however make it look abnormally small. The head also looks flask shaped. You will not miss a posterior dislocation if you always take an oblique or a lateral view whenever you X–ray an injured shoulder. An axillary view (ifyou can move the patient’s arm far enough from his side to get the tube into his axilla) shows the dislocation best.