# Posterior Malleolus Fixation in Trimalleolar Ankle Fractures: Outcomes From a Single-Centre Retrospective Cohort

## TL;DR

This study examines outcomes of posterior malleolus fixation in ankle fractures, finding high functional scores and manageable complications.

## Contribution

The study provides real-world data on morphology-guided posterior malleolus fixation outcomes in UK NHS hospitals.

## Key findings

- Median OMAS score was 85, indicating high functional outcomes.
- Minor complications occurred in 25.6% of patients.
- No deep infections or permanent neurological deficits were recorded.

## Abstract

Background: Fixation of the posterior malleolus in ankle fractures has evolved from simple size-based criteria to morphology-guided indications informed by computed tomography (CT). Direct posterior approaches now permit anatomic reduction of the posterior tibial plafond and restoration of syndesmotic stability. However, real-world functional outcomes and complication data from United Kingdom (UK) centres remain limited.

Objective: To describe patient-reported outcomes and complication patterns following morphology-guided posterior malleolus fixation for trimalleolar ankle fractures in a single National Health Service (NHS) teaching hospital.

Methods: We conducted a retrospective cohort study of patients with trimalleolar ankle fractures who underwent posterior malleolus fixation between 2020 and 2022. Functional outcome was assessed using the Olerud-Molander Ankle Score (OMAS). Scores were categorised as poor (<30), fair (30-59), good (60-79), very good (80-99), and excellent (≥100). Complications and reoperations were identified from electronic records. All summary data are reported as frequency (n) and percentage (%), and figures were generated directly from the clinical dataset.

Results: Thirty-nine patients contributed OMAS data. The median OMAS was 85, with an interquartile range of 27.5, indicating a distribution skewed towards higher function. Category distribution was poor in 2/39 (5.1%) patients, fair in 6/39 (15.4%), good in 8/39 (20.5%), very good in 16/39 (41.0%), and excellent in 7/39 (17.9%). Minor complications occurred in 10/39 patients (25.6%), most commonly pain in 2/39 (5.1%), post-traumatic arthritis requiring steroid injection in 2/39 (5.1%), and issues related to syndesmotic screws in 2/39 (5.1%). Seven patients (17.9%) underwent removal of metalwork. No deep infections or permanent neurological deficits were recorded.

Conclusion: Morphology-guided posterior malleolus fixation in trimalleolar ankle fractures was associated with high functional scores and an acceptable complication profile in this single-centre series. These findings support contemporary practice that emphasises CT-based assessment and direct posterior fixation when morphology or instability indicates, while highlighting the need for further prospective studies with standardised reporting and long-term follow-up.