Rapid prototyping used in diagnosis and operation design for complex fractures of proximal humerus

Abstract

Objective To explore the auxiliary role of rapid prototyping (RP) technique in diagnosis and operation design for complex fractures of proximal humerus. Methods A retrospective study was conducted to analyze the 18 patients with complex fracture of proximal humerus who had been treated by authors from January 2010 to January 2014. They were 7 men and 11 women, aged from 39 to 78 years (average, 62 years). All fractures were fresh and closed. Ten patients underwent three-dimensional CT scan and RP was used to prepare their fracture models which were used to guide their operation design (3D group). By Neer classification, 7 of them had three-part fractures and 3 four-part fractures. Another 8 patients received conventional open reduction and internal fixation (control group). By Neer classification, 6 of them had three-part fractures and 2 four-part fractures. The 2 groups were compared in terms of operation time and intraoperative bleeding. Their outcomes were assessed using Neer evaluation criteria 6 months postoperation. Results The RP fracture models of 1:1 ratio facilitated classification of the fractures and the following operation design. The 3D group incurred less operation time (1.1 hours on average) and bleeding (190 mL on average) than the control group (1.5 hours and 240 mL). All the patients were followed up for 7 to 23 months (16 months on average). Fractures healed after 3 to 5 months (4.3 months on average). Neer evaluation 6 months postoperation showed 5 excellent cases, 4 good cases and one fair case in the 3D group while 3 excellent cases, 4 good cases and one fair case in the control group. Conclusions The fracture models of 1: 1 ratio manufactured by RP technique may help surgeons to gain accurate and visualized knowledge of the fracture to be treated. Consequently their surgical plan can be more specific and more individualized with the aid of RP models. Therefore, operation time and bleeding can be reduced to improve the curative effect. Key words: Shoulder joint; Early diagnosis; Computer simulation; Rapid prototyping