Olecranon Fracture: Mayo Classification, Clinical Features, Treatment and Complications

Olecranon fractures are common injuries affecting the elbow joint due to olecranon located subcutaneously where it is vulnerable to injury
These fractures are diagnosed clinically and by elbow X rays
Treatment is operative in most cases

Mechanism of injury

Olecranon fractures are caused by Multiple mechanisms, those include:
1. Low energy trauma (e.g. a fall on the outstretched hand, fall on the elbow)
2. High energy trauma to the elbow (e.g. road traffic accidents)
3. Stress fracture due to long periods of stress on the bone in athletes

Ulna is medial and longer forearm bone
Ulna has a big proximal end (compared to the radius which has a smaller one), ulna proximal end articulate with the humerus proximally and the head of the radius laterally
Ulna articulates with the humerus with two processes (projections), which include the coronoid process and the olecranon process
The anterior process is the coronoid process which projects anteriorly and insert into the coronoid fossa during full elbow flexion
The posterior process is the olecranon, which serves as a short lever for extension of the elbow
The olecranon and coronoid processes form the walls of the trochlear notch which articulate with the trochlea of the humerus
On the lateral side of the coronoid process is a smooth rounded concavity which is called the radial notch and it is where the radial head articulates with the ulna
The triceps tendon inserts into the olecranon
Inferior to the coronoid process is the tuberosity of the ulna which is the insertion of the brachialis tendon
The shaft of the ulna is thick proximally but its diameter diminishes as it continue distally

Mayo classification is the most commonly used classification for olecranon fractures, and it classify these fractures according to displacement, comminution and elbow joint stability
Mayo classification on three types:
- Type 1
- Type 2
- Type 3
Type 1: undisplaced
- A: Non comminuted
- B: Comminuted

Type 2: Displaced > 3mm olecranon fractures with a stable elbow joint
- A: Non comminuted
- B: Comminuted

Type 3: Displaced > 3mm olecranon fractures with dislocated elbow joint
- A: Non comminuted
- B: Comminuted

Symptoms
- Patient present with elbow pain and patient can localize the pain to posterior elbow
- Think of olecranon stress fracture if the patient gives a history of a pain during a long period of time
Physical examination
- Look
  - Elbow swelling
  - Ecchymosis on posterior elbow
  - Deformity if there is associated elbow dislocation
- Feel
  - there is tenderness on pressure over posterior elbow
  - Displaced fragment can be felt
- Move
  - Patient can’t extend elbow against gravity

X-rays
- AP and lateral elbow X rays are ordered
- Note the fracture pattern, fracture comminution, presence of displacement and elbow joint condition (dislocated or not)
CT helpful in preoperative planning

Pain management
In Injuries associated with elbow dislocation (Mayo III), the elbow should be reduced
An above elbow backslab and collar and cuff is provided to Mayo I and II injuries and Mayo III after reduction

Indications:
- Mayo 1: elbow X rays should be taken when the elbow in flexion to make sure no displacement
- Mayo 2 in elderly patients > 70 years old only. as a result, patient lose some of the elbow extension power but that is much better than experiencing the operative complications at this age
Non operative treatment consist of cast immobilization at 45-90 and exercises are started at 1 week

Indications
- Mayo 2 in patients younger than 70 years old
- All Mayo 3 fractures
Mayo 2 A treated with tension band wiring, Mayo 2 B and Mayo 3 treated with olecranon plating
Immediate post operative mobilization is recommended to prevent stiffness

Fixation hardware irritation to the subcutaneous border of olecranon (common)
Elbow stiffness: occur in 50% of patients and minimized by early mobilization
Non union: due to inadequate reduction and fixation. Treated with ORIF if elbow function is bad
Ulnar nerve symptoms: resolve spontaneously in most cases
Osteoarthritis: late complication, occur in 20% of patients and treated with analgesia
Wound infection