ORIF Olecranon

Indications and Fixation Decision

Mayo Classification and Operative Indications

TBW vs Plate — Decision Summary

Tension Band Wiring is appropriate for:

• Simple transverse fractures (Mayo IIA) in good bone quality
• Fractures involving less than 80% of the articular surface
• Active patients with good bone stock
• Osteotomy fixation (as part of distal humerus ORIF approach)

Plate Fixation is preferred for:

• Comminuted fractures (Mayo IIB or IIIB)
• Oblique fracture patterns
• Fractures involving more than 80% articular surface
• Osteoporotic or elderly patients
• Mayo type III (any elbow instability)
• Very proximal fractures (fragment too small for K-wires)
• Fractures extending into the coronoid

Key Evidence

Wolfgang et al. (CORR, 1987; PMID 3665240): Landmark series of 45 displaced olecranon fractures treated by TBW over 13 years, with good or excellent results in 29 of 30 isolated fractures (97%). Established TBW as a reliable technique; true K-wire migration was uncommon and considered avoidable with correct technique.

Hume and Wiss (CORR, 1992; PMID 1446443): Prospective randomised trial of 41 displaced olecranon fractures comparing TBW versus plate fixation. Loss of reduction (significant articular step-off or gap) occurred in 53% after TBW versus 5% after plate; good clinical results in 37% (TBW) versus 63% (plate). Symptomatic metal prominence followed TBW in 42%. Concluded plate fixation should be carefully considered for displaced fractures.

Schliemann et al. (Acta Orthop Belg, 2014; PMID 24873093): Comparison of TBW versus precontoured locking compression plate in isolated Mayo type IIA fractures. No significant difference in DASH or Mayo Elbow Performance Score; locking plates did not improve functional or radiographic outcome and were more expensive. Implant-related irritation requiring removal was more frequent after TBW.

Carter, Duckworth et al. (JBJS Essent Surg Tech, 2018; PMID 30588367): Modern operative-technique reference reporting a prospective randomised trial of plate versus TBW in 67 active adults — no difference in patient- or surgeon-reported outcomes, but implant removal was required in roughly 1 in 2 patients after TBW. Notably, infection and revision surgery occurred exclusively after plate fixation.

Biomechanical Principles of Tension Band Wiring

The tension band principle is fundamental to orthopaedic surgery and applies to any fracture surface under eccentric loading:

• The axis of rotation of the elbow passes through the centre of the trochlea
• Triceps contraction applies a posterior (distracting) force to the olecranon
• A tension band wire positioned anterior to the axis of rotation converts this deforming force into compression at the fracture site
• This is only effective when the fracture surface is transverse (perpendicular to the long axis) and the posterior cortex is intact
• In an oblique fracture, the wire generates shear rather than compression — fixation fails

Why TBW fails in certain patterns:

• Comminuted fractures: no stable cortex to resist compression — fragments split
• Osteoporotic bone: K-wires pull out of soft bone — cannot maintain wire tension
• Very proximal fractures: insufficient bone in the proximal fragment for K-wire purchase

An evidence-based caveat: cadaveric cyclic-loading work (Hutchinson et al., JBJS Am 2003; PMID 12728033) showed that the AO K-wire tension band did not generate measurable compression across the osteotomy gap and that an intramedullary 7.3 mm cancellous screw with a tension band was roughly five times stiffer than the classic K-wire construct. The clinical implication for the exam is that the tension-band "compression" concept holds best as a model rather than a guaranteed mechanical fact — favour passive over aggressive active extension early, and consider screw-based or plate constructs where stiffness matters.

Non-operative Management (Mayo Type I)

Mayo type I fractures (less than 2 mm displacement, intact extensor mechanism) may be managed non-operatively:

• Posterior splint or collar-and-cuff in 45–90 degrees flexion for 2–3 weeks
• Begin early active ROM at 2–3 weeks; avoid passive extension
• Serial radiographs at 1 and 3 weeks to confirm no secondary displacement
• Failure — secondary displacement of greater than 2 mm — requires operative intervention
• Outcomes comparable to operative management in undisplaced fractures (Duckworth et al., JBJS 2014)

Surgical Anatomy of the Olecranon

Olecranon Bony Anatomy

The olecranon is the proximal posterior process of the ulna. Key anatomical features:

• Trochlear notch (semilunar notch): Articulates with the trochlea of the distal humerus; spans approximately 180 degrees. The articular surface is divided by a transverse ridge.
• Bare area: A transverse non-articular zone crossing the trochlear notch — the optimal site for olecranon osteotomy.
• Olecranon tip: Posterior bony apex; insertion point for the triceps tendon at the posterior surface.
• Coronoid process: Anterior projection of the proximal ulna; not part of the olecranon fracture zone but may be injured in Mayo III patterns.
• Proximal radioulnar joint: The radial head articulates with the lesser sigmoid notch of the proximal ulna — disruption here (associated radial head fracture) indicates a more complex injury.

Triceps Insertion Footprint

The triceps brachii inserts as a broad tendon across the posterior olecranon. The insertion is not confined to the tip — it extends 2–3 cm distally along the posterior ulna. This broad insertion means:

• Fractures through the olecranon always carry periosteum and partial triceps attachment
• Reducing and fixing the olecranon fragment re-tensions the extensor mechanism
• The figure-of-8 tension band wire must be placed through the triceps tendon substance, not superficially

Ulnar Nerve Course

• Passes posterior to the medial epicondyle in the cubital tunnel (osseofibrous canal)
• Enters between the two heads of FCU approximately 1–2 cm distal to the epicondyle
• The nerve runs medially, approximately 1–2 cm medial to the olecranon
• At risk during medial soft-tissue retraction and medial plate application
• Motor branches enter FCU and then FDP (ring and little) within 3–5 cm of the tunnel

Medial Collateral Ligament (MCL)

• Anterior bundle: medial epicondyle to sublime tubercle of coronoid — primary valgus restraint
• At risk in Mayo III fractures with associated elbow dislocation
• Must be assessed intraoperatively once the olecranon fracture is fixed — valgus stress test and fluoroscopic assessment

Posterior Interosseous Nerve Proximity

• Relevant only if the approach is extended laterally
• Enters the supinator 10–20 mm distal to the radial head
• Maintain full forearm supination if any lateral dissection is required

Operative Technique

Positioning

Patient positioned lateral decubitus (elbow uppermost) or prone with arm on chest rolls, or supine with arm across chest on hand table. Lateral decubitus with the arm over a padded bolster allows full elbow extension and is widely preferred. Apply a tourniquet to the proximal arm. Fluoroscopy unit positioned for AP and lateral elbow views.

(A) Tension Band Wiring — 10 Steps

Step 1 — Skin Incision: Posterior midline incision, approximately 10–12 cm, centred over the olecranon tip. Curve slightly to one side of the tip to avoid a scar directly over the bony prominence. Raise full-thickness skin flaps medially and laterally. Identify and protect the medial cutaneous nerve of the forearm in the subcutaneous tissue.

Step 2 — Fracture Exposure: Open the fracture haematoma. Identify the fracture plane and confirm the pattern (transverse, simple). Irrigate and remove loose clot and small bony debris. Preserve all viable periosteum and soft-tissue attachments to the fracture fragment — this maintains the blood supply.

Step 3 — Ulnar Nerve Identification: Before any reduction attempt, identify the ulnar nerve behind the medial epicondyle. Protect it with a vessel loop throughout the procedure. Do not retract medially without confirming nerve position.

Step 4 — Fracture Reduction: Anatomically reduce the fracture under direct vision. Use a pointed reduction clamp across the fracture site. Confirm anatomical articular congruity — any step-off is unacceptable. Provisionally hold with a Kirschner wire or bone clamp while definitive fixation is applied.

Step 5 — K-wire Placement (2 parallel wires): Insert two parallel 1.6 mm (18-gauge) Kirschner wires from the posterior olecranon tip, angled 45 degrees into the intramedullary canal. Both wires must penetrate and engage the anterior cortex of the ulna — confirm on lateral fluoroscopy. The wires should exit the anterior cortex by 2–3 mm. Divergent or convergent K-wires do not provide adequate rotational stability.

Step 6 — Tension Band Wire Loop: Drill a transverse hole through the ulna approximately 3–4 cm distal to the fracture, at the level of the ulnar crest. Pass a 18-gauge (1.25 mm) stainless steel wire through this hole. Pass the same wire through the substance of the triceps tendon (not superficially around it) at the olecranon tip, crossing in a figure-of-8 pattern around the K-wire tips.

Step 7 — Wire Tightening: Tighten both limbs of the figure-of-8 wire symmetrically using a wire twister. Confirm that tightening compresses the fracture site — check with fluoroscopy. Avoid asymmetric tightening that tilts the fragment. The completed loop must lie anterior to the K-wire tips, ensuring the tension band sits anterior to the axis of rotation and generates compression with elbow extension.

Step 8 — K-wire Bending and Burial: Bend the protruding K-wire tips 180 degrees (shepherd's hook) using a wire bender and bury them into the posterior cortex or triceps tendon. This reduces hardware prominence and prevents proximal migration. Confirm K-wire tips are not prominent on fluoroscopy.

Step 9 — Intraoperative ROM and Stability: Take the elbow through full ROM under fluoroscopy. Confirm anatomical reduction is maintained through the arc. Ensure the tension band mechanism generates compression in extension. Assess for any impingement or articular step-off. Test extensor mechanism — patient should be able to extend against gravity.

Step 10 — Wound Closure: Irrigate the wound copiously. Close the periosteum and deep fascia over the hardware. Subcutaneous tissue then skin. Apply a posterior plaster splint at 45–90 degrees flexion. Elevate the limb.

(B) Plate Fixation — Technique

Positioning and exposure as above. Following fracture reduction and provisional K-wire fixation:

Dorsal plate application: Apply a pre-contoured dorsal or lateral (90-degree) locking plate to the posterior surface of the olecranon, spanning the fracture. Locking screws provide angular stability — particularly important in osteoporotic bone. Proximal screws must engage the olecranon fragment with at least 3–4 cortices of purchase. Distal screws anchor into the diaphyseal ulna — aim for 3–4 bicortical screws distally.

Lateral plate option: A 90-degree lateral plate (placed along the lateral column of the proximal ulna) avoids direct prominence over the posterior subcutaneous surface and may reduce hardware symptomatic removal rates.

Locking screws in proximal fragment: In comminuted or osteoporotic fractures, locking screws prevent toggling and loss of reduction. Confirm articular congruity with fluoroscopy before fully tightening.

Comminuted fragments: Bridge plating technique spanning comminuted zones; avoid over-compression of comminuted fragments. Small articular fragments may require lag screws perpendicular to the fracture before plate application.

Intraoperative Fluoroscopy Checkpoints

Fluoroscopy is mandatory at the following steps:

Equipment Checklist

Complications and Management

Post-operative Protocol

Immobilisation

Apply a posterior plaster splint at 45–90 degrees elbow flexion immediately post-operatively. Elevation of the limb is essential in the first 48 hours to reduce swelling. The splint is worn for comfort only — it is removed at 1–2 weeks.

Early ROM (Weeks 1–2)

• Remove splint at 2 weeks (or earlier if fixation is stable and patient cooperative)
• Commence active-assisted elbow flexion and extension as well as forearm rotation
• Avoid passive stretching in the first 6 weeks (increases heterotopic ossification risk)
• Overhead elevation exercises to reduce swelling
• Target: 30–120 degrees ROM by 6 weeks

Physiotherapy Protocol

Hardware Removal Timing

• Confirm radiographic union before considering removal (usually 12–18 months)
• TBW hardware removal rate: 70–80% (symptomatic prominence)
• Plate removal rate: 15–25% (symptomatic or patient preference)
• After hardware removal: protect from heavy lifting for 6 weeks (re-fracture risk through screw holes)
• Day-case procedure under general anaesthesia or sedation; fluoroscopic guidance for wire removal

Extensor Mechanism Assessment

Test active elbow extension against gravity before discharge and at first follow-up. Any extension lag warrants investigation. Physiotherapy should include triceps strengthening exercises from week 6 onward.