Abstract：Objective To investigate the application value of three-dimensional morphological measurement in the treatment of displaced intra-articular calcaneal fractures in the elderly. Methods A retrospective case series study was conducted to analyze the clinical data of 44 patients with displaced intra-articular calcaneal fractures admitted to East Hospital Affiliated to Tongji University from January 2015 to January 2018. There were 33 males and 11 females, aged 60-88 years (mean, 67.2 years). According to Sanders classification, 35 patients were with type II fractures and 9 with type III fractures. All patients were evaluated with digital technology and received open reduction and internal fixation. The operation time, intraoperative blood loss, intraoperative fluoroscopy frequency and complications were recorded. Three-dimensional morphological parameters of calcaneal fractures were compared before and at latest follow-up, including horizontal length of the calcaneus, height of the posterior articular facet, height and length of the anterior process,Gissane angle, and Böhler angle. The visual analogue scale (VAS) and American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind foot function score were also compared. Results All patients were followed up for 12.30 months (mean, 17.1 months). There were 31 patients with posterior articular facet depression more than 2 mm, and 13 patients showed the back shift of the whole or part of posterior articular facet more than 3 mm and varying degree of fracture of the upper or lateral wall part of calcaneus body. The operative time was 55-105 minutes (mean, 85.1 minutes).The intraoperative blood loss was 30-130 ml (mean, 74.9 ml). The intraoperative fluoroscopy frequency was 5-8 times (mean, 6.5 times). During the operation, the internal fixation was not changed. Two patients suffered from skin incision infection after operation. At latest follow-up, the horizontal length of the calcaneus, height of the posterior articular facet, Gissane angle and Böhler angle were significantly improved from that before operation ［(76.9±4.1)mm vs. (75.5±5.2)mm, (24.2±2.1)mm vs. (22.5±2.9)mm, (29.0±6.2)° vs. (18.3±5.5)°, (124.8±7.2)° vs. (107.6±8.5)°, respectively］(P<0.01). No significance was found in the height and length of the anterior process (P>0.05). At latest follow-up, the VAS and AOFAS ankle-hind foot function score were also significantly improved compared to preoperation ［(1.1±0.9)points vs. (4.4±0.9)points, (86.4±6.2)points vs. (49.9±6.3)points, respectively］ (P<0.01). AOFAS ankle-hind foot function score was excellent in 13 patients, good in 26, fair in 5, with the excellent and good rate of 87%. Conclusion Three-dimensional morphological measurement can fully evaluate the damage of calcaneal fractures and provide data reference for the preoperative planning of open reduction and internal fixation in the elderly, so as to restore the calcaneus structure, relieve pain and improve ankle function.
