It is impossible to feel the cup-shaped depression on the head of the radius as shown in Fig. 229. The backward displacement is usually less prominent in fractures, and the deformity is, as a rule, perceptibly higher. The relation of the three bony prominences is disturbed in vertical fractures of the lower end of the humerus, in dislocations of the elbow and in fractures of the olecranon, but not in transverse fractures of the lower end of the humerus. (See Figs. 233 to 235 and compare the deformities.) Dislocations of the upper end of the ulna alone are differentiated from luxations of the elbow by the position of the head of the radius which remains in its proper relation with the capitellum. To avoid mistakes it is well to identify the ulna at its lower end and trace the posterior subcutaneous border up to the olecranon; the head of the radius may next be identified and rotated by supinating and pronating the forearm. After these two points have been positively identified there will usually be little difficulty in recognizing the other landmarks of the elbow. When the case is seen early a tentative diagnosis can, as a rule, be made by inspection alone, but if first seen after swelling has developed it may be quite difficult to examine and determine the condition. Gentle, firm and continued pressure with the fingers in the region of the condyles and olecranon will usually displace the fluids within the tissues sufficiently to allow the surgeon to determine the positions and conditions of the three bony prominences. An anesthetic is often advisable if the traumatic reaction is pronounced at the time of the examination. <Callout type="important" title="Critical for Diagnosis">An even better procedure under these circumstances (provided the deformity is not great and the X-ray is promptly available) is to leave the parts undisturbed and determine the nature of the injury from a Rontgenogram.</Callout> Fig. 239 shows an anterior luxation of the elbow with fracture of the olecranon, while Fig. 240 illustrates a not uncommon complication of backward dislocations where the coronoid process has been broken off and displaced upward by the brachialis anticus muscle. Fracture of the coronoid is often difficult to recognize because of swelling, making palpation impossible. Complications are fortunately rare yet they do occasionally occur and should be recognized before reduction if possible. The diagnosis of these conditions is often made only after reduction has been attempted or accomplished, and many cases would go unrecognized without an X-ray. <Callout type="risk" title="Potential Risks">The condition of the reflexes and circulation below the level of the lesion should be determined both before and after reduction.</Callout> Treatment involves returning the ulna and radius to their normal relations with the humerus, followed by immobilization for healing.
Key Takeaways
- Identify the three bony prominences to diagnose elbow dislocations accurately.
- Use X-rays for definitive diagnosis if physical examination is inconclusive.
- Reduce backward luxations through traction and counter-traction with hyper-extension followed by flexion.
Practical Tips
- Supinate and pronate the forearm to identify the head of the radius properly.
- Apply gentle pressure in the region of condyles and olecranon to displace fluids for better examination.
- Use an X-ray if physical examination is difficult due to swelling or trauma.
Warnings & Risks
- Avoid unnecessary manipulation that could further injure ligaments already torn by the dislocation.
- Be cautious when reducing forward luxations as there's a risk of injury to the ulnar nerve.
Modern Application
While this chapter provides detailed historical methods for diagnosing and treating elbow dislocations, modern medical practices have advanced diagnostic tools like MRI and CT scans. However, understanding these traditional techniques is still valuable for situations where such technology isn't available or in emergency settings.
Frequently Asked Questions
Q: What are the key landmarks to identify when diagnosing an elbow dislocation?
The three bony prominences (the olecranon and the heads of the radius and ulna) should be identified. Proper identification helps differentiate between fractures, dislocations, and other injuries.
Q: Why is it important to use an X-ray for diagnosis?
An X-ray provides a definitive diagnosis when physical examination due to swelling or trauma is difficult. It can reveal fractures or complications that might be missed otherwise.
Q: What are the risks associated with reducing forward luxations of the elbow?
There's a risk of injury to the ulnar nerve during reduction, especially if the olecranon lies on and not in front of the trochlea. The arm should be adducted until the olecranon has passed the trochlea.