3D templating and patient-specific cutting guides (Knee-Plan®) in total knee arthroplasty: Postoperative CT-based assessment of implant positioning

IntroductionThe precision of bone cuts and the positioning of components influence the functionality and longevity of total knee arthroplasty (TKA). The objective of this study was to evaluate the results of TKA, performed after 3D preoperative templating, with the prosthesis implanted using custom cutting guides (Knee-Plan® system, Symbios Orthopédie SA).Material and methodsThis prospective study investigated 107 TKAs. Three-dimensional preoperative templating was carried out on the surface views and CT views to analyze the deformation of the lower limb and plan the implantation. The components were positioned in an individualized manner to realign the lower limb and provide ligament balance based on bone landmarks. Final component positioning was analyzed in the three planes with a postoperative CT scan. The preoperative and 1 year follow-up IKS and WOMAC scores were collected and compared.ResultsAll the cutting guides were stable and functional. Femoral component planning was reproduced with 0 ± 2 precision in the frontal plane (94% ± 3), 2 ± 3 in the sagittal plane, and 0 ± 2 in the transverse plane. The precision of the tibial component was reproduced with 0 ± 2 precision in the frontal plane (93% ± 3) and 0 ± 4 in the sagittal plane. The HKA angle increased from 177 ± 7 preoperatively to 180 ± 3 at 1 year of follow-up. The IKS and WOMAC scores were significantly improved at 1 year (P < 0.0001).ConclusionThe Knee-Plan® system can be a realistic, simple, and reliable alternative to conventional cutting guides and to computer-assisted surgery for TKA implantation.Level of evidenceIV; prospective cohort study.