Large Knee Joint Bone Defect Substitution with Hex-Based and Cable Techniques

Large knee joint bone defects (LKJBD) often lead to permanent dysfunction of the lower limb and disability (Oostenbroek and van Roermund, J Bone Joint Surg Br. 83(1):50–4, 2001). The presence LKJBD, of type IIIC, IVA, and IVB according to classification (Solomin et al., Traumatol Orthop Russ. 24(1):36–43, 2018), does not allow to provide an acute docking site procedure. Bifocal bone transport makes it possible to replace extended defects in a shorter time (Kinik, J Trauma Inj Infect Crit Care. 67(6):E213–9, 2009). The use of bone transport over the nail (BTON) and cable techniques minimizes the external fixation device: Rings are placed only on the lower leg. Using a hex-based bone transport eliminates the jamming of the transport fragment (Shchepkina et al. Med-Biol Soc-Psychol Probl Saf Emerg Situat 2:80–8, 2021). In the case under discussion, a defect of 8 cm was replaced: 4 cm due to the femur bone transport and 4 cm due to the tibia bone transport. The bone transport period was 55 days, and the external fixation period was 75 days. Patent had possibility for full weight-bearing after 4 months after frame dismantling, compensating for the residual shortening 10 cm with orthopedic shoes. The patient expects the next stage: elimination of the limb length discrepancy with a lengthening over the nail technique.