Effect of sustentaculum screw placement on outcomes of intra-articular calcaneal fracture osteosynthesis: A prospective cohort study using 3D CT.

INTRODUCTION

Correct placement of the sustentacular screw is an important component during the open reduction and internal fixation of calcaneal fractures. The hypothesis of this study is that certain 3D-CT images would help detect the real placement of the sustentaculum screw. The aims of the study are to investigate the postoperative status of the sustentacular screw and to evaluate the effect of the sustentaculum screw placement on the treatment of intra-articular calcaneal fractures.

PATIENTS AND METHODS

119 patients with intra-articular calcaneal fractures meeting the inclusion criteria were included in this prospective study. The postoperative sustentaculum screw was detected via radiographs and CT scans. According to the placement of the screw, the patients were divided into three groups: the sustentaculum screw with accurate fixation (group A), marginal fixation (group B), and non-fixation (group C). The perioperative parameters and the change of Böhler's angles on the postoperative and final follow-up radiographs were analyzed. The clinical outcomes were evaluated by the AOFAS ankle-hindfoot score and Short Form-36 questionnaire.

RESULTS

Eighty-five patients were followed up with an average time of 26 (range, 12-48) months. 3D-CT confirmed that 18 cases were in group A, 33 in group B, and 34 in group C. Except the length of stay, significant difference in the operating time and blood loss existed among three groups (P < 0.05). The mean decrease in Böhler's angle of group C was the greatest (P < 0.05). No significant difference could be detected in the AOFAS or SF-36 scores among the three groups either at the one-year follow-up or the final follow-up (P > 0.05).

CONCLUSION

The sustentaculum screw with non-fixation may cause the decrease of Böhler's angle throughout the follow-up. The clinical outcomes were similar whether the screw was accurately placed within the sustentaculum or not.