Primary Surgery Vol.2 – Trauma: EXAMINING THE ELBOW

EXAMINING THE ELBOW

First, check the patient’s median, ulnar, and radial nerves and his radial pulse, and record your findings (Fig. 75-3).

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Figure 72.1: INJURIES AROUND THE ELBOW have a characteristic age incidence. You will see dislocations at all ages. Supracondylar fractures are the most common elbow injuries with a modal age of about 7. They are much less common in adults, and when they do occur are more often T–shaped or comminuted. The medial epicondyle is injured in teenagers, and the lateral condyle in young children. Fracture of the capitulum is a rare adult injury. The neck of the radius fractures in children, and its head in adults.

If his elbow is normal he can: (1) flex it by putting his hand on his shoulder, (2) extend it by holding his arm out straight, and (3) pronate and supinate it 90 $\ensuremath{^\circ }$ in either direction, as in Fig. 69-1. Limitation of any movement suggests disease.

Is the contour of the posterior of his arm abnormal? If so, he may have a supracondylar fracture or a dislocation. If very little movement is possible, he has a dislocation, or supracondylar fracture, or a T–shaped fracture. If his elbow is fixed in 45 $\ensuremath{^\circ }$ of flexion with almost no movement, he almost certainly has a dislocation.

Does the head of his radius move normally? Bend his elbow to 90 $\ensuremath{^\circ }$ . If he can rotate his forearm, the head and neck of his radius are probably normal. Place your middle finger on his lateral epicondyle, and your index beside it over the head of his radius. Pronate and supinate his arm. If the head of his radius is intact, you can feel it moving under your index finger.

Can you feel the 3 bony points, as in A, in Fig. 72-2? Are they in their normal position in relation to the tower end of his humerus? If his elbow is severely swollen, you will not be able to feel them.

If the 3 bony points are displaced in relation to one another he may have a dislocation. If his olecranon is displaced, has it moved medially or laterally in relation to an imaginary line down the back of his arm? You will need to know this when you come to reduce a supracondylar fracture or a dislocation.

If his 3 bony points are their correct relation to one another but are displaced in relation to the lower end of his humerus as in D, Fig. 72-2, he may have a supracondylar fracture. This is a critically important sign in very young children before much ossification has taken place in the lower end of the humerus so making the x–rays difficult to interpret.

Where is the greatest tenderness? Just above the patient’s elbow? (supracondylar fracture). On the medial side of his elbow? (fracture of the medial epicondyle). Over his lateral condyle and the outer part of his antecubital fossa? (fracture of the lateral condyle, or epicondylitis). Over the head of his radius? (fractured head of radius). If the tenderness is over his olecranon, can you feel a gap in it, or move it in relation to the shaft of his ulna? These are signs that it may be fractured.

Can you move the end of his humerus or its condyles on the shaft? Use your finger and thumb to feel the bony ridges running up from his medial and lateral epicondyles. Steady his arm with your other hand. Then very gently try to move the lower end of his humerus sideways, and backwards and forwards on the shaft. If it moves, he has a supracondylar fracture. This is painful, so only do it if it is absolutely necessary.

If his elbow is obviously broadened, can you move one condyle in relation to the other, perhaps with crepitus? (T–shaped fracture).

Can he extend his elbow as in Fig. 72-23? If he can, his extensor mechanism is intact.

Is there an effusion? You can rarely diagnose an effusion because of swelling of the soft tissues. Look at his elbow from the back. Are the normal hollows on either side of his olecranon obliterated or bulging? If they are, he has an effusion. You may be able to observe fluctuation between these swellings, or between them and the fullness on the anterior surface of his elbow. When compared with the other side, does his ulnar nerve feel abnormally superficial in its groove behind the medial epicondyle, or even displaced from it by the effusion?

SUMMARY OF THF MAJOR FEATURES IN ELBOW INJURIES

Dislocated elbow

Any age. Contour abnormal. Severe swelling. Elbow fixed at 45 $\ensuremath{^\circ }$ . The 3 bony points are not in their normal relation to one another. Olecranon displaced posterior to the epicondyles. Lower end of humerus not abnormally mobile, no crepitus. Distance between lateral epicondyle and radial styloid abnormal.

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Figure 72.2: SOME PHYSICAL SIGNS IN THE ELBOW. A, the 3 bony points on the back of the elbow. B, and C, the contour of a normal arm and a dislocation compared. D, in a supracondylar fracture the 3 bony points are correctly related to one another, but are posteriorly displaced in relation to the shaft of the humerus. E, in a dislocation their normal relationship to one another is disturbed. Kindly contributed by John Stewart.

Supracondylar fracture

Common in children. Contour abnormal. Severe swelling. Some movement possible. Olecranon not displaced above the epicondyles. The 3 bony points are in their correct places in relation to one another, but they lie posteriorly to the shaft of the humerus. Abnormal mobility of the lower humeral fragment with crepitus. Distance between lateral epicondyle and radial styloid normal.

T–shaped fracture

Adults. Severe swelling. Contour abnormal. Condyles move in relation to one another. Some movements of the elbow still possible. Crepitus. Swelling obscures the 3 bony points.

Fractured medial epicondyle

Older children and youths. Contour normal. Medial epicondyle tender and swollen. Some flexion and extension possible. Rotation normal.

Fractured lateral condyle

Children. Contour normal. Lateral condyle tender and swollen.

Fractured capitulum

Rare. Adults. Very little flexion or extension. Some rotation possible. The 3 bony points are normal. Tenderness difficult to localize.

Fractured neck of radius

Common. Children under 4 years. Contour normal. Flexion and extension less painful than rotation. No rotation. The head of the radius may be tender.

Pulled elbow

Young child. Contour normal. The child refuses to use his arm. No rotation.

Fractured head of radius

Adults. Contour normal. Moderate swelling. Some flexion and extension possible but no rotation. The 3 bony points are normal. Head of the radius tender.

Fractured olecranon

All ages. Contour normal. Moderate swelling. The olecranon is tender, and a gap may be palpable. There are two varieties of fracture depending on whether active extension is possible or not (72.18).

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Figure 72.3: AN X–RAY OF THE ELBOW OF A CHILD OF 10 YEARS. Six centres of ossification can be seen in an AP view, but they are not always present at the same time. A large centre for the capitulum appears in the first year. A smaller one for the medial part of the trochka appears at about 9 years. A centre for the medial epicondyle appears about the fifth year. It is entirely outside the capsule and unites with the shaft at 20. The lateral epicondyle starts to ossify at about 12. The centres for the capitulum, the trochlea and the lateral condyle join one another and the shaft at puberty. A centre for the head of the radius appears in the fourth or fifth year, and unites with the shaft at puberty. There is also a centre of ossification for the olecranon, and another centre for the trochlea (not shown). These appear at about 9 years and unite at puberty.In a lateral view, the shaft of the humerus and its lower epiphysis overlap one another and obscure most of the epiphyseal space, which is wider behind than it is in front. A normal epiphysis lies in front of the lower end of the shaft, so that a line AB drawn down the anterior border of the shaft, meets the epiphysis at its middle. A supracondylar fracture disturbs these relationships. After Perkins with kind permission.