[Computer aid designed operation of complicated calcaneal fracture by 3D simulation].

OBJECTIVE: To precisely treat complicated calcaneal fracture by 3D simulation through computer aid designed operation. METHODS: From November 2007 to March 2008, 38 patients of calcaneal fracture were treated. There were 29 males and 9 females aged 14-69 years old (average 29.8 years old). According to Sanders classification, there were 4 patients of type I, 14 of type II, 12 of type III, and 8 of type IV. The time between injury and surgery was 3 hours to 5 days. The CT images of calcaneal fracture of 38 patients were put into computer for 3D reconstruction, then the Böhler angles were measured and bone grafting angles were designed. According to the angle surveyed by the computer, the individual-oriented operation program was made, and then the operation was done under C-arm X-ray machine. RESULTS: The preoperative Böhler angel was (34.58 +/- 4.38) degrees in the normal side and (8.33 +/- 12.62) degrees in the injured side, indicating there was significant difference (P < 0.05). During the process of the poking reduction by 3D simulation, when the bone rotating angle was (28.84 +/- 6.51) degrees, the Böhler angel was restored to (32.86 +/- 1.72) degrees, indicating there was no significant difference when compared with the normal side before operation (P > 0.05), and significant difference compared with the injured side before operation (P < 0.05). Twenty-eight patients were followed up for 12-22 months (average 18 months). The Böhler angel was restored to (32.41 +/- 1.42) degrees 1 year after operation. According to the foot function scoring system made by American Ankle Surgery Association, 16 cases were graded as excellent, 10 as good, 1 as fair, 1 as poor, and the excellent and good rate was 92.9%. CONCLUSION: Computer aid designed operation of complicated calcaneal fracture by 3D simulation technique can restore the Böhler angel and subtalar joint precisely. It is an effective supplementary treatment method for calcaneal fracture.