Limb salvage in multiple revision total knee arthroplasty using customised implants: When sleeves and cones are no longer an option.

Purpose: Multiple revision total knee arthroplasty (rTKA) remains highly challenging due to severe bone defects, which often render standard implants unsuitable. This study aimed to evaluate the clinical outcomes, survivorship and complication rates of customised knee implants used in aseptic one-stage rTKA for patients with severe bone defects. Methods: This study included 16 patients who underwent 18 one-stage rTKAs using custom-made implants due to aseptic loosening between 2016 and 2023. Conventional revision systems failed to provide appropriate femoral or tibial fixation due to severe conical longitudinal bone defects classified as Anderson Orthopaedic Research Institute (AORI) type III. Clinical outcomes were assessed using the knee injury and osteoarthritis outcome score (KOOS), Oxford knee score (OKS), visual analogue scale (VAS) for pain, range of motion (ROM), walking time and procedure-related complications. Implant costs were compared between customised and standard implants. Results: Mean follow-up was 51 months (range, 24-100), with patients having an average of five previous surgeries (range, 2-8). During follow-up, three patients (17%) reported complications: one periprosthetic fracture, one periprosthetic joint infection and one failure of the modular stem component. Mean KOOS improved from 31 to 80 ( Conclusions: Customised implants for one-stage rTKA present a promising cementless fit-and-fill fixation option for patients with severe longitudinal bone defects, particularly when standard knee revision implants, including cones and sleeves, are no longer suitable. Yet, these results are just midterm and small sample size-based and therefore long-term results in larger patient numbers need to be awaited before a final conclusion can be made. Level of Evidence: Level IV.