Conventional Versus Patient-specific Instruments in Total Knee Arthroplasty

Total knee arthroplasty (TKA) has a high success rate for addressing pain and improving function. However, in instances where incorrect positioning and malignment of the TKA components are observed, patients can experience a range of negative postoperative outcomes such as loss of thickness of polyethylene tibial bearings, eccentric loading, implant loosening, and eventual early revision. To avoid these complications, achieving a postoperative alignment within the range of 0°±3° of the mechanical axis is recommended. Manual intramedullary/extramedullary guides are not thought to be capable of consistently achieving axes in this range, and though computer-assisted navigation has shown superior results in comparison with conventional instrumentation, it is also limited by increased surgical times and no clear superiority in improving short-term clinical outcomes. Thus, there has been in a push in the orthopaedic community to create more precise technologies to aid in the reconstruction of the knee's mechanical axis. Patient-specific instrumentation (PSI), which uses anatomical data obtained primarily from pre-operative axial computed tomography (CT) or magnetic resonance imaging (MRI) to create disposable cutting jigs individualized to the patient's unique anatomy, was created with this goal. This study aims to compare the clinical results of conventional and patient-specific instruments in total knee arthroplasty.