Surgical Anatomy. — Much that has already been said concerning the anatomy of 'Fractures of the Lower End of the Humerus' (page 120) and 'Dislocations of the Elbow' (page 154) is equally important in fractures of the upper end of the ulna since the region is the same. Fractures of the upper extremity of this bone may be of the olecranon, the coronoid or just below the latter process in the upper thickened portion of the shaft. Occasionally the nature of the break or its position is atypical.
<Callout type="important" title="Important">The triceps tendon insertion into the olecranon makes avulsion rare.</Callout>
The most important and at the same time the most common fracture occurring in the upper end of the ulna is of the olecranon process. This process is large, thick and curved, and projects upward behind the lower end of the humerus when the elbow is extended. Its upper surface is roughly quadrilateral and affords attachment to the tendon of the triceps. A portion of this tendon is continued through a heavy aponeurosis onto the posterior surface of the process, and thus the pull of the triceps may be exerted on the lower fragment in fractures of the olecranon, when the aponeu- rosis is not torn.
The upper epiphysis of the ulna consists of a thin layer or scale of bone at the top of the olecranon which first shows ossification in the tenth year, and joins the shaft during the sixteenth or seventeenth year. The fact that the triceps is attached not only to the upper end of the olecranon but to the posterior surface, <Callout type="gear" title="Gear">accounts for the comparative rarity of avulsion and separation of this epiphysis.</Callout>
The line of the epiphyseal cartilage has been mistaken for fracture. As previously stated the powerful triceps is inserted into the olecranon process of the ulna, but its antagonist the biceps is at- tached to the bicipital tuberosity of the radius. Thus it will be noted that the heavy extensor and flexor muscles of the forearm are able to balance each other only because the two bones of the forearm are firmly bound together.
Fracture of the olecranon, or fracture below the level of the sigmoid cavity with separation of the fragments, destroys the balance between the biceps and triceps. The brachialis anticus attached to the coronoid process is a flexor, and in fractures below the process this muscle tends to <Callout type="risk" title="Risk">counteract the pull of the triceps, but its relative weakness results in the upper fragment being carried into extension if the aponeu- roses have been torn sufftciently to allow deformity.</Callout>
The mechanism of fracture of the olecranon has been the subject of considerable discussion ; suffice it to say that most fractures of the olecranon are probably the result of a combination of direct violence and muscular action. Thus when a person falls heavily <Callout type="tip" title="Tip">on the outstretched hand, the triceps is firmly fixed in anticipation of the blow.</Callout>
Symptoms. — Immediately following the injury the patient finds that he is unable to actively extend the forearm, though motion may be accomplished passively or by the action of gravity. Motion is painful and the patient usually supports the forearm in a semi- flexed position with the uninjured member. When separation is present the deformity is characteristic if seen early before the elbow is much swollen. The point of the elbow is gone ; the pos- terior aspect of the joint has a rounded effect instead of its normal angularity, and in some cases the position of the displaced frag- ment may be determined by inspection alone.
Diagnosis cannot be made by inspection alone. The posterior border of the ulna is subcutaneous throughout and by tracing it upward from below the position of the fracture and the displaced fragment can as a rule be felt. Even where there is no displacement it is often possible to detect some loss of alignment on the posterior border of the olecranon and by grasping the process laterally, motion and crepitus may be elicited.
Treatment. — The methods of treatment employed will depend entirely on the conditions present. Where there is no separation the right angle splint will meet the requirements of the case, in addition diagonal strips of zinc oxide adhesive should be so placed as to bind down the olecranon and relieve the nupper fragment of the displacing action of the triceps.
<Callout type="warning" title="Warning">When displacement exists, a straight splint is indicated. The elbow should not be treated in extreme extension because it becomes intolerable to the patient.</Callout>
Operative Treatment. — Of late years operation has, to a great extent, supplanted the ordinary methods, and there has been a great deal of discussion on the subject, pro and con. There is a large proportion of cases which make excellent functional recoveries without operation, and it is unwise to resort to the open method in all cases.
<Callout type="important" title="Important">Fibrous union, when the fragments are close and the mass of fibrous tissue heavy, is usually accompanied by excellent results.</Callout>
Key Takeaways
- The triceps tendon insertion into the olecranon makes avulsion rare.
- Fractures of the olecranon are common and can be diagnosed by characteristic deformity.
- Treatment depends on whether there is separation; splints or surgery may be required.
Practical Tips
- Always support the forearm in a semi-flexed position to reduce pain after an injury.
- Use zinc oxide adhesive strips to bind down the olecranon and relieve displacement of the upper fragment.
- Consider the patient's age, condition, and occupation when deciding between non-operative and operative treatment.
Warnings & Risks
- Avoid treating the elbow in extreme extension as it can become intolerable to the patient.
- Be cautious with internal fixation; it may stretch before fibrous union is firm enough.
- Do not assume that all fractures will benefit from surgery; some recover well without it.
Modern Application
While the techniques described here are rooted in historical practices, they still provide valuable insights into managing upper limb injuries. Modern medical advancements have improved diagnostic tools and surgical techniques, but the principles of fracture management remain relevant for survival situations where immediate access to advanced care may be limited.
Frequently Asked Questions
Q: How can I tell if a patient has a fractured olecranon?
Look for characteristic deformity such as the point of the elbow disappearing and the posterior aspect of the joint having a rounded effect. The position of the displaced fragment might also be visible by inspection.
Q: What is the best way to treat an uncomplicated fracture of the olecranon?
Use a right angle splint with diagonal strips of zinc oxide adhesive to bind down the olecranon and relieve the upper fragment of displacing action from the triceps.
Q: When should surgery be considered for a fractured olecranon?
Surgery is recommended when there is displacement that cannot be perfectly corrected or in compound cases where internal fixation is necessary to maintain reduction.