Cadaveric results of an accelerometer based, extramedullary navigation system for the tibial resection in total knee arthroplasty

IntroductionIn total knee arthroplasty, the accuracy and precision of the tibial resection must be improved. The purpose of this study was to determine the accuracy and time associated with the use of an accelerometer based, extramedullary surgical navigation system for performing the tibial resection.Materials and methodsFour orthopedic surgeons performed a tibial resection utilizing the KneeAlign? system, each on five separate, cadaveric tibiae. Each surgeon was assigned a preoperative “target” of varus/valgus alignment and posterior slope prior to each resection. The alignment of each resection was measured using both plain radiographs and computed tomography, along with the time required to use the device.ResultsRegarding coronal alignment, the mean absolute difference between the preoperative “target” and tibial resection alignment was 0.77° ± 0.64° using plain radiograph, and 0.68° ± 0.46° using CT scan measurements. Regarding the posterior slope, the mean absolute difference between the preoperative “target” and the tibial resection was 1.06° ± 0.59° using plain radiograph, and 0.70° ± 0.47° using CT scan measurements. The time to use the KneeAlign? for the fifth specimen was less than 300 s for all four orthopedic surgeons in this study.DiscussionThis cadaveric study demonstrates that the KneeAlign? system is able to accurately align the tibial resection in both the coronal and sagittal planes.Level of evidenceCadaveric study.