To assess whether delaying operative fixation through the sinus tarsi approach resulted in a decreased wound complications rate or could hinder the quality of reduction in subjects with Sanders type II and III displaced intra-articular calcaneus fractures. From January 2015 to December 2019, all polytrauma patients were screened for eligibility. We divided patients into two groups: Group A, treated within 21 days after injury; Group B, treated more than 21 days after injury. Wound infections were recorded. Radiographic assessment consisted of serial radiographs and CT scans: postoperatively (T0) and at 12 weeks (T1) and at 12 months after surgery (T2). The quality of reduction of the posterior subtalar joint facet and calcaneal cuboid joint (CCJ) was classified as anatomical and non-anatomical. A post hoc power calculation was performed. A total of 54 subjects were enrolled. Four wound complications (three superficial, one deep) were identified in Group A; two wound complications (one superficial one deep) were identified in Group B. According to "mean interval between trauma and surgery" and "duration of intervention", there was a significant difference between the groups (p < 0.001). There were no significant differences between Groups A and B in terms of wound complications or quality of reduction. The sinus tarsi approach is a valuable approach for the surgical treatment of closed displaced intra-articular calcaneus fractures in major trauma patients who need delayed surgery. The timing of surgery did not negatively influence the quality of the reduction and the wound complication rate. level II, prospective comparative study.