OLECRANON FRACTURES Zeus (or Poseidon ), in bronze, c 460 BC, National Archaeological Museum of Athens.
The figure has the potential for violence, is concentrating, poised to throw, but the action is just beginning, and we are left to contemplate the coming demonstration of strength. Carol Mattusch, Greek Bronze Statuary: From the Beginnings Through the Fifth Century B.C. (Ithaca Cornell University Press) 1988. In 1926 a magnificent ancient Greek Bronze statue was discovered by divers and recovered from the Aegean Sea off Cape Artemision. It has been dated to the Fifth Century B.C, and now stands in the National Archaeological Museum of Athens. Academics and historians agree that the statue is of a god, but controversy exists as to whether it is Zeus or Poseidon, though the current consensus seems to favour Zeus. The figure is poised majestically at the moment of being about to hurl a weapon with its right arm, its left stretched outward to guide the god s line of sight toward the intended victim. The actual weapon however unfortunately has not survived the millennia, and hence the confusion as to which god the statue represents. Traditionally Zeus would be portrayed hurling a lightning bolt, whist Poseidon, a trident. A key element of any of throwing action is the forceful and explosive contraction of the triceps muscle acting on the olecranon process. A rare, though well recognized, mechanism of fracture of the olecranon is this movement when the action is violent and sudden enough. Fortunately for posterity however the great bronze s olecranon was discovered intact, thus preserving the grace, power and athletic poise of the ancient masterpiece!
OLECRANON FRACTURES Introduction Olecranon fractures occur relatively frequently. They may occur in isolation or as part of a more complex injury involving the elbow joint. The ability to extend the arm against gravity is an important part of the assessment of these injuries. Displaced fractures will usually require ORIF. Mechanism of injury Olecranon fractures may occur as a result of: The most common mechanism of injury for an olecranon fracture is a fall on the semiflexed supinated forearm. The next most frequent mechanism is direct trauma, as in falls on, or direct blows to, the point of the elbow. Occasionally, the olecranon may be fractured by hyperextension injuries, such as those resulting in elbow dislocation in adults or supracondylar fractures in children. Very rarely the olecranon may be broken by extreme muscular contraction, as in throwing. The anatomic integrity of the olecranon is essential for normal triceps strength and function of the elbow, just as intact patella function is necessary for extension of the knee. Classification There is no universally accepted classification for olecranon fractures. One system is the Mayo classification: Mayo Type 1: These are undisplaced fractures, sometimes further sub-divided into: Type I A: Not comminuted Type I B: Comminuted.
Mayo type I Olecranon fracture Mayo Type II: These are displaced fractures, which can be further sub classified as: Type II A: Not comminuted Type II B Comminuted. Mayo Type III: Mayo type II Olecranon fracture These are displaced (> 2 mm) fractures, with accompanying injuries which can be further sub classified as: Type III A: Not comminuted Type III B: Comminuted.
Mayo type III Olecranon fracture The triceps aponeurosis is intact in Mayo I fractures and this is a stable fracture. The triceps aponeurosis may be disrupted in Mayo II fractures. The triceps aponeurosis disrupted in Mayo III fractures, and these are unstable fractures. Complications Possible complications of olecranon fractures include: Usual bony union complications may occur, delayed union, non-union, mal union Osteomyelitis, if compound. Ulna nerve injury Myositis ossificans Elbow joint instability, if not correctly treated Secondary osteoarthritic changes. Clinical Features Olecranon fractures generally are isolated injuries, however if the mechanism of injury is forceful a high index of suspicion must be maintained for associated fractures. 1. Olecranon fractures will have the usual signs of a bony fracture at the site of injury, including: Pain, Swelling, bruising and tenderness.
2. A bony defect may be felt at the site of fracture 3. Inability to extend the elbow actively against gravity is a key finding. This sign indicates a disruption in the triceps mechanism, which clinically indicates an unstable Mayo II or III fracture. 4. Distal neurovascular compromise should always be checked for, in particular, ulna nerve function. Investigations Ulna nerve injury is usually due to contusion which resolves spontaneously with time. Plain radiology: Plain A-P and lateral radiographs are sufficient to diagnose olecranon fractures in most cases. The degree of fracture displacement is judged when the elbow is in the 90 degree flexed position. Fracture displacement is predominantly due to the pull of the triceps muscle, which tends to displace the separated fragment upward. This upward movement however is resisted by the strong fibrous capsule surrounding the elbow joint. If the capsule remains intact, there will be minimal or no displacement, even in the presence of comminution. CT scan: CT scanning may be required when: Plain radiography is equivocal, but clinical suspicion remains high Injuries are complex and require further delineation to assess the extent of injury as well as to plan possible surgical intervention. Management 1. Analgesia: Give as clinically indicated. 2. Conservative treatment:
3. ORIF: In general terms, non-displaced fractures with intact extensor mechanisms may be treated non-operatively. Three weeks immobilization in a plaster cast is usually sufficient. Serial follow-up films should be done however to ensure that displacement does not subsequently occur. Range of motion exercises under the supervision of a physiotherapist may be begun at about 3 weeks Displaced (>2 mm) and/ or comminuted Mayo II and III type fractures are generally treated with ORIF References 1. Wheeless Textbook of Orthopaedics Online, www.wheelessonline.com/ 2. Olecranon fractures, in Rosen s Emergency Medicine, Mosby 5 th ed 2002, p. 570-71. Dr. J. Hayes 1 August 2009