Fractures of the anterior process of the calcaneus (APC) are easily overlooked in clinical practice. Most patients have good to excellent clinical outcome after conservative treatment, while some patients may have persisting symptoms and unfavorable functional outcomes. The aim of this study was to identify the risk factors associated with unfavorable functional outcome after conservative treatment in APC fractures.

All patients presenting with APC fractures and receiving conservative treatment from April 2019 to April 2020 were retrospectively assessed. The primary outcome measurement was the ankle joint function assessed using Karlsson Scoring System at 2 years post-injury. The risk factors associated with unfavorable functional outcomes (Karlsson score ≤ 80) were evaluated by logistic regression analysis.

In total, 84 patients were included with a mean age of 40 years. 26 (31%) patients presented with unfavorable functional outcome at 2 years post-injury. In multivariate logistic regression, concomitant fractures of talonavicular (TN) joints and older age were significantly associated with unfavorable functional outcome (p<0.05). Patients with concomitant fractures of TN joints had an odds ratio of 3.623 for unfavorable functional outcome. The optimal cutoff age for an unfavorable outcome was ≥ 47.5 years, with an odds ratio of 5.010.

Most patients with APC fractures achieved good to excellent results when treated conservatively. Attention should be paid to those with concomitant fractures of TN joints and with age ≥ 47.5 years, which might lead to unfavorable functional recovery.

IV; case series.