Functional Outcomes of Primary Subtalar Arthrodesis versus Late Subtalar Arthrodesis in Sanders Type IV Calcaneal Fractures

Abstract Background Sanders type IV calcaneal fractures are challenging. They are more likely to result in painful subtalar arthritis and subsequent subtalar arthrodesis. There is no consensus about the best management, so our study was conducted to compare the functional outcomes of primary subtalar arthrodesis with those of late subtalar arthrodesis. Methods From 2019 till 2022, 34 patients with Sanders type IV calcaneal fractures were included. Seventeen patients were managed by open reduction and internal fixation plus primary subtalar arthrodesis, while the other seventeen patients were treated conservatively followed by calcaneoplasty and late subtalar arthrodesis. Outcomes were measured by two scores: (1) the American Orthopaedic Foot and Ankle Society’s Ankle-Hindfoot scale (AOFAS-AHS) and (2)Foot and Ankle Ability Measure - Activities of Daily Living sub scale (FAAM-ADL). We also documented the union rate at one year, the wound complications and the need for second surgeries. Results Twenty-nine patients were followed for at least two years. At one-year follow up, the mean AOFAS-AHS for group A and group B were 72.86 (SD 3.13) and 70.80 (SD 3.63) (P = .12) respectively, while the mean FAAM score for group A and B were, respectively, 57.29/84 (68.20%) (SD 2.27) and 55.27/84 (65.80%) (SD 2.74) (P = .04). At two-year follow up, the mean AOFAS-AHS for group A and group B were 74.42 (SD 1.95) and 73.80 (SD 1.9) (P = .88) respectively, while the mean FAAM score for group A and B were, respectively, 59.21/84 (70.49%) (SD 1.6) and 58.73/84 (69.92%) (SD 1.7) (P = .44). The complications were comparable. Conclusion Primary subtalar arthrodesis is a successful treatment option for these severe life-changing fractures. It may reduce the overall disability time. Level of Evidence Level II