Ankle Fracture ORIF - Trimalleolar

Indication. Operative fixation of a trimalleolar ankle fracture is indicated when the mortise is disrupted — a displaced bimalleolar or trimalleolar injury with talar shift or mortise incongruity, a Weber B or C fibula fracture with medial clear space widening greater than 4mm, a posterior malleolus greater than 25 percent of the tibial plafond (or greater than 2mm of articular step-off), an open fracture, or an irreducible fracture-dislocation with interposed soft tissue. The goal is an anatomic, stable mortise that allows early motion. Absolute indications

• Displaced trimalleolar fracture with talar shift or mortise incongruity
• Weber B or C fibula fracture with medial clear space widening greater than 4mm
• Posterior malleolus greater than 25 percent of the articular surface on CT (some argue greater than 2mm displacement at any size)
• Open fracture — emergency debridement and stabilisation
• Irreducible fracture-dislocation with interposed soft tissue Relative indications
• Posterior malleolus 20-25 percent with step-off greater than 2mm
• Syndesmotic instability persisting after fibula fixation
• Young, active patient with any displacement
• Bilateral fractures needing early mobilisation Defer immediate ORIF when
• Severe soft-tissue swelling — wait for the wrinkle sign (typically 7-14 days), or temporarily span a fracture-dislocation with an external fixator
• Fracture blisters over the planned approach — wait for re-epithelialisation
• Active infection or significant medical instability
• Peripheral vascular disease with non-healing potential, or a non-ambulatory patient with minimal symptoms (relative) Three principles frame the whole operation:

Consent. Discuss the procedure-specific risks: post-traumatic arthritis (10-30 percent, higher with cartilage damage or residual displacement), symptomatic hardware needing removal (20-40 percent, especially medial screws), wound complications (5-10 percent), nerve injury — usually a neuropraxia that recovers (5-15 percent), syndesmotic stiffness if over-tightened or malreduced, DVT/PE (2-10 percent), nonunion (less than 5 percent with sound technique) and malunion (5-15 percent). With anatomic reduction, 80-90 percent achieve good to excellent results; patients return to walking without aids at 3-4 months and to sport or heavy labour at 6-12 months, with some permanent stiffness common but usually functional. Alternatives are non-operative care (only for stable, minimally displaced fractures), temporary external fixation for severe soft-tissue compromise, and — very rarely, for severe comminution in the low-demand elderly — primary arthrodesis. Setup. Position the patient supine with a bump under the ipsilateral hip to give 15-20 degrees of internal rotation, which brings the fibula into profile; a radiolucent triangle under the knee helps, and a lateral decubitus position is used if a direct posterior approach to the posterior malleolus is planned. Apply a thigh tourniquet at 350mmHg, exsanguinating by elevation (avoid Esmarch compression over the fracture), and free-drape the whole leg for manipulation. Position the image intensifier perpendicular to the table and confirm you can obtain AP, lateral and mortise views before prepping — the mortise view needs 15-20 degrees of internal rotation of the leg or external rotation of the C-arm. Typical instrument set | Category | Items | |----------|-------| | Reduction | Pointed reduction clamps, Weber clamp, dental pick, K-wires | | Fibula | One-third tubular plate (7-8 hole) or precontoured locking fibular plate | | Screws | 3.5mm cortical, 2.7mm cortical for lag, 4.0mm partially threaded cancellous | | Medial malleolus | 4.0mm partially threaded cancellous screws, medial malleolar plate | | Posterior malleolus | 3.5mm cortical screws, mini-fragment plate if needed | | Syndesmosis | Long 3.5mm cortical screw, suture button device (TightRope) | | General | Periosteal elevator, bone clamps, drill guide, depth gauge |

The goal is to restore an anatomic, stable mortise through three incisions — lateral over the fibula, anteromedial at the medial malleolus, and posterolateral when the posterior malleolus needs open reduction — fixing the fibula first, then the posterior malleolus, then the medial malleolus, and finally assessing the syndesmosis. The exposure is laid out step by step below (and in depth on the posterolateral approach to the ankle and medial approach to the ankle pages).

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Rehabilitation timeline | Timeframe | Activity | Goals | |-----------|----------|-------| | Day 1-14 | Non-weight-bearing in a backslab, elevation, ankle pumps | Wound healing, swelling control | | 2 weeks | Suture removal, transition to a CAM boot | Begin gentle range-of-motion exercises | | 2-6 weeks | Non-weight-bearing in a CAM boot, active ROM | Regain dorsiflexion and plantarflexion | | 6-8 weeks | Progressive weight-bearing if healing | Confirm radiographic union | | 8-12 weeks | Full weight-bearing, intensive physiotherapy | Strengthening and proprioception | | 3-4 months | Return to driving and light activities | Functional recovery | | 6-12 months | Return to sport or heavy labour | Full recovery | Syndesmotic screw management. A quadricortical screw is considered for removal at 3-4 months if symptomatic or before high-demand activity; a tricortical screw is often left in situ and may break with weight-bearing (acceptable). A suture button needs no removal. Modern evidence does not mandate routine screw removal if the patient is asymptomatic. Follow-up. 2 weeks (wound check, suture removal, X-ray), 6 weeks (clinical and radiographic assessment, advance weight-bearing), 3 months (assess union, consider screw removal), 6 months (functional assessment), 1 year (long-term assessment, screen for arthritis).

Epidemiology. Ankle fractures are among the most common operatively treated fractures, and their incidence in adults is rising — Court-Brown and colleagues documented a sustained increase through the 1990s, driven largely by low-energy falls in an ageing population. Trimalleolar injuries sit at the unstable, rotationally displaced end of that spectrum and almost always warrant ORIF; supination-external rotation is the commonest underlying mechanism. Two classifications frame the injury. The Weber (AO) system is defined by the level of the fibula fracture relative to the syndesmosis and is the one that drives the operative decision:

Critical radiographic measurements. Plain X-rays underestimate posterior malleolus size, so a CT is essential to measure the fragment as a percentage of the tibial plafond and to assess impaction, comminution and the syndesmosis.

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