Functional Outcomes of Isolated Infrasyndesmotic Fibula Fractures

Abstract

Background: Ankle fractures are among the most common injuries encountered by orthopedic surgeons, with an incidence ranging from 71 to 187 per 100 000 people. Few studies have reliably investigated injuries involving isolated fractures of the distal fibula below the level of the ankle syndesmosis. Therefore, this study details on the patient-reported outcomes of nonoperatively managed isolated infrasyndesmotic fibula (ISF) fractures with a minimum 3-year follow-up.

Methods: A retrospective population-based cohort study was undertaken across all emergency departments serving a major urban population. Among 159 consecutive patients meeting inclusion criteria, 108 agreed to participate. Clinical information, functional outcomes, and radiographic measurements were collected from electronic medical records and 3 validated outcome measures: the American Academy of Orthopaedic Surgeons (AAOS) Foot & Ankle Scale (FAS), the AAOS Shoe-Comfort Scale (SCS), and a general questionnaire.

Results: An incidence of 22 ISF fractures per 100 000 people/year was found with FAS (91.2 ± 12.9) and SCS scores (76.8 ± 27.7), similar to reported population norms. Approximately 40% of patients (n = 43) reported continuing symptoms including pain (81.8%), stiffness (68.1%), and/or instability (39.0%). Less than 13% (n = 14) reported "severe" disabilities, and no patients required operative intervention within the follow-up period. Less-favorable outcomes were reported among work-related injuries, female patients, and "avulsion-type" fractures less than 10 mm in height (P < .01). No relationships were identified between age, degree of articular-incongruity, fracture-displacement, and self-reported outcomes.

Conclusions: The majority of patients with nonoperatively managed ISF fractures reported good-to-excellent early functional outcomes. Less-favorable outcomes were reported among work-related injuries, female patients, and "avulsion-type" fractures.

Level of evidence: Level III, comparative series.

Keywords: Weber-A fracture; ankle fracture; avulsion fracture; fibula; incidence; infrasyndesmotic fracture; lateral malleolus fracture; outcome assessment; prognosis; shoes.

Figure 1.

(A) Mortise-view ankle plain radiographs demonstrating a larger malleolar-type fracture with approximately 1.5 mm of articular incongruity, and (B) an avulsion-type fracture with no displacement.

Figure 2.

Graphic illustration of subjective responses to various survey questions. Likert-type 5-point scale responses transformed into 4 symptom categories for illustration purposes: none (1), mild (2), moderate (3) and severe (4 and 5).

Figure 3.

Graphic illustration of subjective responses to various survey questions. Likert-type 5-point scale responses transformed into 4 symptom categories for illustration purposes: none (1), mild (2), moderate (3) and severe (4 and 5).