Jeremy P Zebroski ,Donald A Hackbarth Jr ,Mei Wang,Sean C Tracy ,
Torsional Stability of a Chevron Interface for Intercalary Allograft Fixation of the Femur
Journal of Surgical Oncology
2020
2674-3000
http://dx.doi.org/10.31487/j.JSO.2020.01.03
https://www.sciencerepository.org/torsional-stability-of-a-chevron-interface-for-intercalary_JSO-2020-1-103 
Abstract: Intercalary allografts are frequently used for diaphyseal long bone reconstruction following tumor resection.
Torsional stability between allograft and host bone is an important factor in achieving osseous union at the
interface and reducing fracture risk of the allograft. The purpose of this study was to evaluate the torsional
stability of an intercalary allograft construct using a new chevron type of osteotomy. The torsional load of
up to 4.0 Nm in both directions were applied to six matching pairs of fresh frozen cadaveric femurs,
reconstructed using either a 60-degree chevron or a modified step-cut interface. The torsional stiffness of
the construct and the interface rotation were compared between the two groups. The results showed that a
construct with a 60-degree chevron interface had comparable interface rotations and stiffness as those with
the modified step-cut interface. However, the large inter-specimen variations observed in rotation results of
the modified step-cut suggest higher technical requirements associated with this procedure. The study also
revealed a trend towards improved torsional stiffness with increased axial load of the chevron construct,
combined with its 55% more surface area across the graft-host interface over the modified step-cut, which
prove that 60-degree chevron interface may serve as a good alternative in intercalary allograft fixation.
Keywords: Intercalary allograft, torsional stability, implant fixation, tumor resection, limb-salvage