Reconstruction of massive tibial defects after resection of adamantinoma with double-level distraction osteogenesis

Abstract

Adamantinoma is an extremely rare disease that typically involves large portions of the tibial cortex requiring extensive resections, for which a myriad of complex reconstructions have been performed with varying success. Techniques of bone regeneration utilizing internal or external methods are used to manage bone defects in trauma, infection and congenital deformities, but less commonly used for oncological osseous defects. We present four cases of patients diagnosed between 2015 – 2018 with tibial adamantinoma in a background of osteofibrous dysplasia who underwent distraction osteogenesis reconstruction via a double level cable bone transport. In all cases wide resection of the adamantinoma was performed to achieve negative surgical margins and the defect reconstructed by double level bone transport using Ilizarov cables guiding distraction osteogenesis. Bone transport occurred at a combined mean rate of 2 mm per day: 1mm proximally and 1mm distally. Full weight-bearing and ambulation were encouraged immediately. The mean age at time of surgery was 18 years (14 – 25) and the mean size of tibial defect was 23 cm (17.5 – 26). The mean time in external fixation was 8.5 months (6 – 12 months), yielding a mean External-Fixation Index (EFI) of 0.44 month/cm (0.3 – 0.69). The average MSTS score at mean follow time of 20 months (13-27 months) is 28 (26 – 30). At last follow up all patients are infection free and without evidence of disease. Despite typical complications of prolonged external fixation, all four patients have excellent results with an average MSTS score of 28. The mean EFI of 0.44 month/cm is well below the standard EFI of 1 month/cm, suggesting this subset of patients may require less external fixation time than previously considered. The case series supports the hypothesis that double level D.