Minimally Invasive Robotic-Arm-Guided Unicompartmental Knee Arthroplasty

Abstract

Unicompartmental knee arthroplasty is an underused procedure in orthopaedic surgery due to its level of difficulty and the unpredictability of results, which can be related to component malalignment. New robotic arm technology has been developed to assist the surgeon in accurately and reproducibly preparing the femur and the tibia for a minimally invasive bone-sparing unicompartmental knee arthroplasty. This new procedure provides comprehensive three-dimensional planning of unicompartmental knee arthroplasty components, including soft-tissue balancing, followed by accurate resection of the femur and the tibia. This paper reviews this new technology.

Preoperative Mapping in Unicompartmental Knee Arthroplasty Using Computed Tomography Scans Is Associated with Radiation Exposure and Carries High Cost

“…Increasingly, CT scans are being used for preoperative mapping in computer navigation, robotic assistance, or customization of cutting guides in TKA and UKA [1,2,[20][21][22][23]. Preoperative CT for knee arthroplasty requires special consideration given the non-diagnostic nature of the study, particularly with the availability of alternatives, such as conventional techniques, MRI-based methods for cutting guide customization, or image-free robotic technologies [5,6,24].…”

“…Robotic assistance enhances the accuracy of bone preparation, implant component alignment, and soft tissue balance in unicompartmental knee arthroplasty (UKA) [1][2][3][4][5][6]. Such precision relies on patient-specific preoperative and/or intraoperative mapping, which depending on the system utilized, may require a three-dimensional computed topography (CT) scan of the involved knee and ipsilateral hip and ankle.…”

Robotic-arm assisted total knee arthroplasty is associated with improved early functional recovery and reduced time to hospital discharge compared with conventional jig-based total knee arthroplasty

“…This patient-specific model is then used to calculate a haptic window for bone resection, and select optimal implant sizing and positioning for the desired postoperative bone coverage and limb alignment. [4][5][6] An interactive robotic-arm with visual, audio and tactile resistive feedback then guides intraoperative bone resection within this predefined haptic window. Saw blade action outside of this stereotactic window is limited, which conceptually helps to preserve native bone stock and minimize periarticular soft-tissue injury.…”

Patients Unicondylar Knee Replacement vs. Total Knee Replacement

“…The widespread performance of UKA has been limited by the technical difficulty of performing the procedure. In particular, UKA has less tolerance for acceptable component positioning when compared to TKA, as improper component positioning, by as little as 2 o , can result in UKA failure (Figure 3) [13][14][15][16][17][18] . Failures of UKA occur when there is medial-lateral mismatch, inadequate stability of the components, heterogeneous polyethylene wear, improper patient selection (such as performing UKA for bilateral osteoarthritis), aseptic loosening, and tibial Subsidence ( Figure 4A and 4B) [19] .…”