Epidemiology and outcomes of ankle fractures

Abstract

Ankle fractures are common injuries which can have major effects on the lives of patients. Recent detailed investigation into the epidemiology of ankle fractures is lacking, particularly work on the effect of social deprivation and open injuries. Assessment of outcomes is key to selecting the optimal treatment for individual patients. Outcomes of the investigations used in assessing ankle fractures, and their surgical management, post injury rehabilitation and post injury thromboprophylaxis require further investigation.

A database was collated prospectively of 1,262 consecutive ankle fractures presenting to the RIE over a 21-month period from 8/9/10 to 29/6/12. Data were collected on several variables including age, gender, mechanism of injury, fracture classification, past medical history, drug history, body mass index (BMI), measures of social deprivation and date of injury. Some studies used additional datasets including a database of open fractures and a retrospectively collated cohort of patients managed with the use of the fibular nail.

Investigation into the epidemiology of ankle fractures found the majority were low energy injuries (65.2% due to a fall from a standing height) with a mean age of 48.5 years. There was a significantly higher incidence in women than in men (p<0.001) and the women sustaining ankle fractures were significantly older than the men (p=0.007). Social deprivation was shown to be related to ankle fractures with a significantly higher incidence in patients in the most deprived quintile of society (p<0.001).

The subgroup of open ankle fractures were also predominantly low energy injuries with 48.9% due to a fall from a standing height. The mean age was higher than that of ankle fractures as a whole at 55 years. The modal Gustillo Anderson type was IIIa with 82% of injuries being isolated with a median ISS of 13.

Investigation into the outcomes of gravity stress radiographs found a high rate of false positives with the risk of over-treatment of patients with stable ankle fractures if gravity stress radiographs were used for surgical decision making. A total of 79% of patients with stable ankle fractures had gravity stress radiographs with an MCS of greater than 4 mm.

The fibular nail was found to be a good treatment method for unstable ankle fracture management with good clinical and radiographic outcomes. A retrospective review of 105 patients, 79% with comorbidities, treated with the fibular nail found good outcomes particularly once the technique for fixation to the bone had been refined.

Weight bearing after ankle fractures was found to be safe in the majority of patients, whether treated operatively or non-operatively. Of 847 patients with ankle fractures 99.7% had good radiographic and clinical outcomes following a protocol of early weight-bearing post injury.

Investigation into current venous thromboembolic prophylaxis protocols found low rates of VTEs when patients did not routinely receive chemoprophylaxis after discharge from hospital. The incidence of VTEs among non-operatively managed ankle fractures within 30 and 90 days was 0.12% and 0.35% respectively.

Operatively treated fractures were at greater risk, at 0.48% within 30 days and 0.72% at 90 days.

In conclusion, ankle fractures remain common injuries affecting large numbers of patients. Gravity stress radiographs have not been shown to be a useful tool in assessing their stability whilst fibular nailing, early weight bearing and current VTE prophylaxis all have been found to have good outcomes for patients.