Proximal Ulna/Olecranon — Tension Band Wiring (TBW)

Olecranon fractures are common injuries involving the proximal ulna at the elbow joint. They account for approximately 10% of upper extremity fractures and often occur following a fall onto the elbow or due to a sudden contraction of the triceps muscle. Because the olecranon forms part of the articular surface of the elbow, fractures frequently disrupt the extensor mechanism and compromise joint stability.

One of the most widely used surgical techniques for displaced olecranon fractures is tension band wiring (TBW). This method converts tensile forces generated by the triceps muscle into compressive forces at the fracture site during elbow motion. Proper application of the tension band principle allows stable fixation and early mobilization, which is essential for preventing elbow stiffness.

Although tension band wiring is considered the standard technique for simple transverse olecranon fractures, other fixation methods such as plate fixation are often used for comminuted or unstable fracture patterns.

The olecranon is the proximal bony prominence of the ulna and forms the posterior portion of the elbow joint. It articulates with the trochlea of the humerus and serves as the insertion point for the triceps tendon.

• Forms the posterior aspect of the elbow joint
• Provides insertion for the triceps muscle
• Acts as a lever arm for elbow extension
• Contains a large articular cartilage surface

The proximity of the olecranon to the elbow joint means that most fractures are intra-articular. Preservation of articular congruity is therefore essential to maintain normal elbow function.

Olecranon fractures occur through two principal mechanisms: direct trauma and indirect trauma.

• Direct blow to the posterior elbow
• Fall onto a flexed elbow
• Indirect force from sudden contraction of triceps
• High-energy trauma such as road accidents

Indirect injuries typically produce transverse fractures, while direct trauma often results in comminuted fractures.

Several classification systems exist for olecranon fractures. The Mayo classification is the most commonly used and is based on displacement and stability of the elbow joint.

• Pain over posterior elbow
• Swelling and bruising
• Loss of active elbow extension
• Tenderness over olecranon
• Visible deformity in displaced fractures

Patients often present with inability to actively extend the elbow against gravity because the triceps mechanism is disrupted.

• AP and lateral radiographs of elbow
• CT scan in comminuted fractures
• 3D CT for surgical planning

Radiographs usually demonstrate a transverse fracture line across the olecranon with displacement caused by the pull of the triceps muscle.

The tension band technique converts tensile forces generated by the triceps muscle into compressive forces across the fracture during elbow flexion. This principle allows stable fixation even with relatively simple hardware.

• Two parallel Kirschner wires inserted across fracture
• Figure-of-eight stainless steel wire loop
• Compression generated during elbow motion
• Stable fixation allowing early mobilization

1. Posterior approach to the elbow
2. Anatomic reduction of fracture
3. Insertion of two parallel K-wires
4. Placement of figure-of-eight tension band wire
5. Tightening of wire to achieve compression
6. Confirmation of stability under fluoroscopy

Early mobilization is encouraged once stable fixation is achieved.

• Hardware irritation
• Loss of fixation
• Nonunion
• Elbow stiffness
• Post-traumatic arthritis

Hardware prominence is a common complaint following tension band wiring and may require later removal.

• Olecranon fractures disrupt the extensor mechanism
• Tension band converts tensile forces into compression
• TBW best for simple transverse fractures
• Plate fixation preferred for comminuted fractures