The role of three dimensional reconstruction and virtual operation after CT scanning in the treatment of slipped capital femoral epiphysis

Objective To evaluate the role of three dimensional reconstruction and virtual operation after CT scanning in the treatment of slipped capital femoral epiphysis(SCFE).Methods Twenty-nine cases of SCFE (31hips) were treated by screw fixation between 2004 and 2008.The Southwick angle and the lateral epiphyseal-shaft angle(LESA) were measured by hip anteroposterior and frog-lateral radiographs.All of them underwent to CT and three dimensional reconstruction.And then virtual operation with a screw was performed.The patients were divided into two groups by the results of X ray,CT and the virtual operation.Internal fixation might be successfully performed as group 1 based on the virtual operation.Otherwise,patients were allocated to the group 2.Results The cases of group 1 were 24 hips,and the cases of group 2 were 7 hips.The Southwick angle in group 1 was significant higher than that of group 2(128.8±9.3 vs 116.3±10.4).The LESA in group 1 was 37.4±6.9,which was significant less than that in group 2(56.1±7.7).In the 7 cases of group 2,the virtual operation results of 2 cases showed the screw fixation could not be performed.One case was treated conservatively,and another case was treated by physeal osteotomy and screw fixation.Conclusions The treatment of SCFE could be effectively directed by three dimensional reconstruction and virtual operation,especially in serious cases. Key words: Epiphyses,slipped; Imaging,three-dimensional