Unsatisfactory Accuracy as Determined by Computer Navigation of VISIONAIRE Patient-Specific Instrumentation for Total Knee Arthroplasty

This investigation evaluated the Smith and Nephew VISIONAIRE patient-specific cutting block (PSCB) system for total knee arthroplasty. A consecutive series of 60 patients was recruited. Intraoperative computer navigation was used to evaluate the accuracy of the cutting blocks in the coronal and sagittal planes for the tibia, as well as rotational plane for the femur. The PSCB would have placed 79.3% of the sample within ±3° of the preoperative plan in the coronal plane, while the rotational and sagittal alignment results within ±3° were 77.2% and 54.5% respectively. The VISIONAIRE PSCB system achieved unacceptable accuracy when assessed by computer navigation. There might be many sources of error, but caution is recommended before using this system routinely without objective verification of alignment.