Augmented plate causes bone resorption in reconstruction of large segmental femur defects with induced membrane technique

Abstract Purposes: Large segmental femur bone defect is a serious clinical problem. Limited study have been reported to optimize the fixation during the second stage of induced membrane technique. We would like to report our new findings in two different fixation method with this technique. Methods: We retrospectively analyzed 56 cases with large segmental femur defects and treated with induced membrane technique from January 2013 to December 2017. Patients were separated into two groups according to different fixation method during the second stage and followed at least 2 years. Bacteria culture, treatment outcome, and complication were collected and analysed. Results: Patients with an average age of 41.8 years old had an average of 2.6 surgical history. Bone defects were 8.93 cm in average ( 4-16.8 cm). Though 20 complications were noticed in this series, 85.7% (48/56) of the cases acquired bone union during their final follow up. However, 57.6%(15/26) of the cases observed obvious bone resorption near the plate in augmented plate group. And this resulted to lower bone union rate was calculated when compared with intramedullary nail group (P = 0.019). Insufficient bone grafting material is another main reason resulted nonunion and verified in 5 cases. Conclusions: Augmented plate will resulted bone resorption and leads to nonunion in induced membrane technique. The plate should be fixated outside the membrane if necessary. Insufficient bone grafting material when grafting is a easily neglectful problem, and proper measures should be taken with cautious.