Compound Gustilo-type III intra-articular calcaneus fractures are challenging to treat. Anatomical reduction of the subtalar joint increases the chances of a better functional outcome and is traditionally achieved by an open reduction and plating. Conversely, ORIF is associated with a high risk of infection and even amputation. In our case study, we present the treatment of a Gustilo-type III intra-articular calcaneus fracture with a circular external fixator and a temporary antibiotic cement spacer for fracture reduction and stabilization. Active bio-glass was implanted to fill bone loss and to prevent infection. A closing-wedge calcaneal tuberosity osteotomy was used to facilitate wound closure. We paid special attention to reducing the posterior facet. The patient returned to work and full ambulation five months post-injury.