ABSTRACT
Objective To investigate the value of 3D rapid prototype technology in therapy of complex pilon fractures.Methods In this study,60 patients with pilon fracture who had been hospitalized during January 2013 to May 2014 were randomly and equally divided into a 3D group and a control group according to their hospitalization order.The 3D group:21 males and 9 females,an average age of 34.8 ±6.0 years,13 cases of AO type C2 and 17 ones of AO type C3.The control group:21 males and 9 females,an average age of 35.8 ±6.2 years,12 cases of AO type C2 and 18 ones of AO type C3.The 3D group received surgery aided by rapid prototype and 3D printing while the control group underwent conventional surgery with open reduction and internal fixation.In the 3D group,the distal tibia models were manufactured by 3D rapid prototyping technology based on the 3D reconstructions which were accomplished by computer aided technology.The diagnosis,classification and preoperative plan were then conducted using the models.The 2 groups were compared in terms of operation time,postoperative skin necrosis and infection,and Maryland foot function scoring at the last follow-up.The 2 groups were compatible in preoperative demographic data (P ＞ 0.05).Results There were significant differences between the 3D and control groups in operation time (65.1 ±4.8 minutes versus 80.5 ± 3.6 minutes) and rate of postoperative complications [6.7％ (2/30) versus 16.7％ (5/30)] (P ＜0.05).There was no significant difference between the 2 groups in the excellent to good rate by Maryland foot function scoring at the last follow-up [76.7％ (23/30) versus 73.3％ (22/30)] (P ＞ 0.05).Conclusion Since rapid prototype and 3D printing technology can display the morphology of pilon fracture intuitively and stereoscopically,it helps surgeons with accurate assessment of the fracture.3D printed models of the pilon fracture pre-operatively raise the accuracy of reduction,reduce both operation time and incision complications,and facilitate functional recovery.
ABSTRACT
Objective To introduce calcaneal osteotomy without subtalar fusion for calcaneal malunion and to discuss its indications, advantages and disadvantages. Methods From November 1998 to May 2003, 24 cases with 26 calcaneal malunion for 1 to 9 months were treated by calcaneal osteotomy without subtalar fusion. The average age was 32.6 years (range, 28 to 42 years). All patients underwent radiography including plain, axial and lateral views for calcaneus, oblique view for foot and three-dimensional CT imaging reconstruction. According to Sanders classification, 13 cases were of type Ⅱ(9Ⅱb, 4Ⅱc), 13 of type Ⅲ(8 Ⅲac, 5 Ⅲbc). Through the modified lateral L-shaped approach, the protruding lateral wall of calcaneus was resected and the posterior subtalar facet was reduced by elevating the fragment of the posterior subtalar facet upwards and backwards. The defect of calcaneus was filled with bone autografts. Iliac crest bone graft was used in 19 feet and the bone graft resected from the extruding lateral wall of calcaneus in 7 feet. The calcaneus was fixed with plate and screw. Results 21 feet were followed up for an average of 14.5 months (range, 9 to 22 months). No complications such as wound infection, screw breakage and calcaneum varus were found postoperatively. The average time for bone healing was 11.2 weeks (range, 10.5 to 13.3 weeks). The postoperative functional evaluation by Maryland foot score system revealed excellent result in 8 feet, good in 10, fair in 3. The rate of excellent to good results was 86%. Plain radiographs showed the nearly complete restoration of Bhler angle, Gissane angle, talus inclining angle, calcaneal width and height of the calcaneal thalamus. Conclusion Calcaneal osteotomy without subtalar fusion is an effective method for calcaneal malunion with advantages of correcting deformity markedly, restoring the function and the outer aspect of hindfoot satisfactorily.