Comminuted Suprasyndesmotic Ankle Fractures Are Associated With a High Rate of Anterolateral Plafond Involvement.

OBJECTIVES

The aim of this study was to identify the rate at which the anterolateral (AL) tibial plafond is affected in comminuted suprasyndesmotic ankle fractures (OTA/AO 44C2) and to assess how its involvement affects clinical outcomes.

DESIGN

Retrospective review.

SETTING

Level 1 Trauma Center.

PATIENT SELECTION CRITERIA

Patients with a preoperative computed tomography treated surgically for OTA/AO 44C2 fractures from January 2005 to December 2021.

OUTCOME MEASURES AND COMPARISONS

The primary outcome measure was the prevalence of AL plafond impaction or a displaced Tillaux-Chaput fracture. Secondary outcome measures included reoperation rate (excluding hardware removal), rate of new-onset ankle osteoarthritis, rate of ankle osteoarthritis progression, Single Assessment Numeric Evaluation score, and the Olerud Molander Ankle Score.

RESULTS

Fifty-three patients met inclusion criteria. The average age was 50 years (range 18-100), and 53% were female. The AL plafond was involved in 26 patients (49%), with AL plafond impaction in 11 patients (21%) and a displaced Tillaux-Chaput fragment in 15 patients (28%). Five patients (19%) received independent fixation of the AL plafond, and 3 of these patients had AL plafond impaction addressed. Thirty-eight patients (72%) had clinical follow-up of at least 6 months. Patients with AL plafond impaction had a higher rate of reoperation (excluding hardware removal) compared with those without any AL plafond involvement (hazard of reoperation = 8.3, 95% confidence interval, 1.4-15.3, P = 0.022) and a higher rate of new-onset ankle osteoarthritis (83% vs. 23%, P = 0.013). There was no difference in the rate of reoperation (11% vs. 9%, P = 0.748) or new-onset osteoarthritis (63% vs. 23%, P = 0.078) when comparing those with a displaced Tillaux-Chaput fracture to those without AL plafond involvement. There were no differences in Single Assessment Numeric Evaluation (75% vs. 78% vs. 85%, P = 0.661) or Olerud Molander Ankle Score (70 points vs. 69 points vs. 81 points, P = 0.517) scores when comparing those with AL plafond impaction, those with Tillaux-Chaput fragments, and those with no AL plafond involvement.

CONCLUSIONS

Computed tomography evaluation is recommended in patients with comminuted suprasyndesmotic fibula fractures (OTA/AO 44C2) given their high association with AL plafond impaction and Tillaux-Chaput fracture. Patients with AL plafond impaction have a higher reoperation rate and new-onset ankle osteoarthritis compared with those without AL plafond involvement.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.