Introduction
knee arthroplasty, fracture, TKA
SITE INFECTION, COMPLICATIONS, SECONDARY
Computer-assisted surgery (CAS) total knee arthroplasty (TKA) remains a controversial area of surgical practice. Several studies have demonstrated improved precision of alignment with the use of CAS, allowing the surgeon to reproducibly implant a knee replacement to their alignment of choice [The iNAV Electromagnetic (EM) navigation system used in this study was developed to avoid the line of site problems encountered with infra-red systems, and the recurring contamination of the reflector balls on the reference arrays from blood and saw aerosols. The system employs small reference frames attached to the femur and tibia which are incorporated within the primary surgical incision, thereby avoiding the need for additional pin sites in the tibia and femur as required for infra-red trackers. This removes the potential complications of pin site infection and periprosthetic fracture related to the use of such bone pins [The primary outcome of this randomised controlled trial (RCT) was to assess the precision of implantation of components comparing the iNAV electromagnetic system in TKA versus conventional TKA utilising standard instrumentation where the aim of implantation was for neutral mechanical alignment in all cases. The secondary outcome measures included PROMs, complications and all-cause revision. We have previously demonstrated that at one-year follow-up there was no statistically significant difference in the proportion of TKAs in either group implanted within 3° of the neutral mechanical axis, and no difference in component rotation in sagittal, coronal or axial planes as measured by computed tomography (CT) scan [