Reconstructive Challenges of Distal Tibia Bone Tumors: Extracorporeally Irradiated Autograft Combined with a Nonvascularized Autograft Fibula for Superior Reconstruction and Functional Outcomes When Compared to Ipsilateral Pedicled Fibula Transfer Alone.

Abstract

Introduction: Traditionally, centralization of the fibula with fusion across the tibiotalar joint has been used to reconstruct distal tibial defects. Although effective, it requires long periods of protected weight-bearing. The fibula or the fixation often fails before fibular hypertrophy necessitating multiple additional surgeries. A method of using ECRT with the available ipsilateral fibula (nonvascularized) to reconstruct the distal tibia defect with the aim of early return to weight-bearing was evolved. This paper documents our early experience. Patients and Methods. Four patients; with the diagnosis of osteosarcoma in 3 patients and recurrent giant cell tumor of the bone in 1 patient, underwent resection of the distal tibia for tumors between 2017 and 2019. Extracorporeally irradiated (50 Gy) distal tibia along with ipsilateral nonvascularized fibula was used to bridge the defect and fuse the tibiotalar joint. A plate was used to rigidly hold the construct. The final outcome was compared to the historical control group that underwent only pedicled ipsilateral fibula transposition and ankle arthrodesis without recycled autograft or allograft between 2009 and 2017. Oncological reconstruction and functional outcomes were compared for each group. Patient reported outcomes on the acceptability of ankle fusion; cosmesis and function were analyzed and compared between the two groups.

Results: The mean resection length in the study group (4 patients) was 7.75 cm (7 to 8.5 cm). As compared to the historical cohort of 7 patients, the study population showed statistically superior results in all reconstruction, functional, and patient-reported outcomes except time to proximal junction union (p=0.068). There were no reconstruction failures, infection, or nonunions in the study group, whereas the control comparative group had 2 proximal junction nonunions and a mean time to fibular hypertrophy of 143 weeks (82 to 430 weeks) with fibula centralization. Earlier weight-bearing was allowed (mean 26.75 weeks; median 27 weeks) compared to (mean 80.75 weeks; median 80 weeks) in the control group.

Conclusion: We think that ECRT with ipsilateral vascularized fibula is a promising method of reconstructing the distal tibia. The recycled autograft tibia added strength to the distal tibia construct in our study and aided the anatomical reconstruction of the distal tibia. The patient-reported outcomes for cosmesis and acceptability add to the benefits of performing this procedure. Consistent early union across the proximal junction and earlier weight-bearing were clear advantages of this method.