[Individualized molds for alignment of primary knee arthroplasty]. / Moldes individualizados para alineación de la artroplastía primaria de rodilla.

ABSTRACT

INTRODUCTION: Patient-specific cutting blocks (PSCB) have been proposed as an interesting option to achieve appropriate alignment in knee arthroplasty. However, there is no information as to which of the available planning methods is the right one. MATERIAL AND METHODS: A prospective study was designed to compare two, PSCB systems using different planning methods (Signature with CAT scan + teleradiography; Visionaire with MRI) with the standard alignment method. Radiographic and functional pre- and postoperative parameters were analyzed, together with hospital stay, blood transfusion needs, operative time and associated complications. RESULTS: A total of 10 patients per group were operated on. No statistically significant differences were observed between both of the patient-specific alignment systems and the standard system (p > 0.05). However, greater precision was achieved with the former systems and the Signature system was slightly more accurate. Operative time was shorter in patients in whom PSCBs were used, and it was still slightly shorter in those in whom the Visionaire system was used (p > 0.05). CONCLUSIONS: The new PSCB systems may be useful to improve alignment in knee arthroplasty and reduce the operative time. While larger case series confirming these data become available, the authors recommend using these systems in cases in which the standard systems do not work properly.