CHAPTER II. DISLOCATIONS OF THE STERNAL END OF THE CLAVICLE. Surgical Anatomy. — The articular end of the clavicle is much larger than the articular facet on the sternum, and the integrity of the joint is almost entirely dependent on the ligaments that surround the joint and bind the two bones together. The capsule is attached to the margins of the two articular surfaces and completely encloses the joint cavity. It is reinforced in front and behind by the anterior and posterior sterno-clavicular ligaments. To the inner side and above, it is overlaid by the interclavicular ligament which may be seen attached to the upper aspect of the inner end of the bone. Externally the rhomboid ligament, extending from the under surface of the clavicle to the cartilage of the first rib, greatly strengthens the articulation. This ligament is in relation posteriorly with the subclavian vein. The ends of the bones entering into this articulation are very poorly adapted to each other and when dislocation takes place recurrence of deformity is prompt, unless prevented by retentive dressings. The rhomboid ligament is seldom completely torn and will tend to limit the displacement.
Displacement of the sternal end is usually the result of indirect violence. If the long axis of the clavicle is continued inward it will pass in front of the sternum, and accordingly the most common type of luxation of the sternal end is forward. The displacement may be partial or complete and accordingly the condition is spoken of as either a luxation or a subluxation. Forced backward displacement of the shoulder may produce a luxation of the inner end of the clavicle by leverage against the first rib. Forward dislocation is by far the most common luxation seen at this joint, and is usually the result of the shoulder having been driven forcibly backward beyond the normal limitation of motion. If the shoulder be carried backward the inner end of the clavicle comes in contact with the first rib, and if forced still further backward this contact with the first rib acts as a fulcrum by means of which the inner end of the bone is torn away from the sternum and displaced forward.
<Callout type="important" title="Important">Forward dislocations are common due to shoulder being driven backward, often seen in accidents or falls.</Callout>
The trachea, oesophagus and the large vessels of the neck lie behind the inner end of the clavicle, and when a posterior displacement occurs any or all of these structures may be pressed upon. Upward luxation of the sternal end of the clavicle is extremely rare and is usually the result of violence which depresses the shoulder.
Symptoms. — Pain is more or less pronounced at the site of the lesion and is increased with motion of the shoulder. Loss of function varies with the completeness of the dislocation and the amount of pain suffered by the patient. There is more or less swelling about the inner end of the bone. The deformity varies with the direction of the luxation. In forward luxations the inner end of the bone is more prominent than normal and is often found displaced downward onto the anterior surface of the sternum, as well as forward. The lowered position of the inner end of the bone changes the axis of the clavicle, which deformity can often be recognized by inspection alone.
<Callout type="risk" title="Risk">Forward luxations may cause compression of vital structures behind the clavicle.</Callout>
Diagnosis. — The clavicle is subcutaneous throughout and the sternal notch may be palpated without difficulty. Accordingly displacements of the inner end of the bone are easily determined. Differentiation of fractures of the clavicle from luxations of the inner end presents no particular difficulty unless the swelling is pronounced. In fractures of this bone crepitus is almost invariably distinct, and the absence of this symptom in luxations is significant.
Treatment.— Reduction is, as a rule, easily accomplished but it is usually a difficult matter to retain the articular surfaces in their proper relations. Certain positions are known to be favorable in the prevention of the recurrence of deformity but the surgeon should determine for himself in each and every case just what position is most favorable in holding the articular surfaces in apposition.
<Callout type="tip" title="Tip">Forward luxations can often be reduced by applying outward traction on the shoulder with direct pressure on the end of the bone.</Callout>
Operative Treatment. — Operative intervention is, as a rule, indicated only in old cases with loss of function, and in cases of recurrent dislocation which have not responded to non-operative measures.
After-Treatment. — In simple cases the retentive dressings may be dispensed with at the end of a month, and pressure over the sternal end is seldom of use after ten days to two weeks.
Key Takeaways
- Forward dislocations are common due to shoulder being driven backward
- Pain and swelling are typical symptoms, with loss of function varying by severity
- Reduction is usually easily accomplished but maintaining the position can be difficult
Practical Tips
- Apply outward traction on the shoulder when reducing forward luxations.
- Use a figure-of-eight bandage to immobilize the shoulder effectively.
- Monitor for recurrence and adjust treatment as necessary.
Warnings & Risks
- Avoid pulling the shoulder too far backward during reduction, as this can cause further injury.
- Be cautious of compression risks behind the clavicle in posterior dislocations.
Modern Application
While the techniques described here are rooted in historical practices, understanding the anatomy and treatment of clavicle dislocations remains crucial for modern emergency responders. The principles of proper immobilization and reduction can be adapted to contemporary medical protocols, ensuring that survivors receive effective care.
Frequently Asked Questions
Q: What is the most common type of dislocation involving the sternoclavicular joint?
The most common type of dislocation seen at this joint is forward displacement, usually resulting from the shoulder being driven forcibly backward beyond its normal limitation of motion.
Q: How can a forward dislocation be reduced?
Forward dislocations can often be reduced by applying outward traction on the shoulder with direct pressure on the end of the bone. This method helps to reposition the inner end of the clavicle back into place.
Q: What are the typical symptoms of a sternoclavicular joint dislocation?
Typical symptoms include pain at the site of the lesion, which increases with shoulder motion. There is also swelling around the inner end of the bone and a change in the axis of the clavicle due to forward displacement.