Custom Made Implant in Revision Knee Arthroplasty with AORI 3 Bone Defect: а Case Report

Background. Replacement of extensive bone defects during revision knee arthroplasty (RKA) is a certain problem. The development of additive technologies allows us to produce an individual titanium augment to restore the lost bone tissue. The aim of the study is to show the possibility of replacing extensive tibia defects with an custom made augment during revision knee artroplasty. Case presentation. The patient is 66 years old. At the age of 58, due to secondary knee osteoarthritis in 2 years interval, the patient underwent total knee arthroplasty: left — in 2012, right — in 2014. Subsequently, several revision interventions were required for early periprosthetic infection of the right knee joint. From 2015 to 2018, due to the infection remission, the function of the right knee joint was satisfactory. In 2018, the patient admitted to our clinic with the periprosthetic infection relapse. Due to the previous treatment, the patient had type 3 bone defect according to the AORI classification. A two-stage revision knee arthroplasty was performed. To compensate the extensive tibial defect, the individual tibial implant was manufactured using additive technologies, and a semiconstrained endoprosthesis was implanted. There was no relapse of infection during the observation. There is deficit of active extension, there are no radiological signs of the implant instability. Conclusion. In our case, we were able to achieve satisfactory results in patient with a complex anamnesis and extensive bone defects. The use of individual implant helped to avoid arthrodesis, preserve the weight-bearing of the lower limb and articulation in the knee joint. The use of implants made using 3D technologies is a promising solution for compensating defects of types 2B and 3 according to the AORI classification.