AUGUST 2022 | The Surgical Technologist | 351 Kostretzis et al. Kinematic Alignment Total Knee Revision FIGURE 1 | Vendittoli’s restricted kinematic alignment protocol. Analysis of Failure to Plan rKA Reconstruction Patients’ preoperative clinical and radiographic assessments are crucial for determining the cause of failure, especially for patients with well-fixed implants, and planning the rKA reconstruction. Knees were examined for range of motion limitations and ligamentous instability. Implant size, position, orientation, and joint-line were compared with preoperative radiographic images when available or with the contralateral side. Computed tomography scans were performed to evaluate the axial rotation of the components when malrotation was suspected (17, 18). The coronal alignment was planned preoperatively using the restricted rKA protocol (Figure 1). As TKA revision systems were designed for MA with fixed coronal implant-stem angle (6◦ valgus on the femur and 0◦ on the tibia for most systems), stem relation to the meta-diaphyseal region is templated. In most cases, to achieve the proper rKA coronal alignment, short-cemented stems are planned without interfering with the meta-diaphyseal cortex. Distal augments or bone resections needed to achieve the correct coronal angle for components was estimated. The amount of angulation achieved depends on the thickness of the augment and the size of the component (Figure 2). The approximate angular correction at the tibia for the 5- and 10-mm augments for each tibial component size are provided in Table 1. The approximate angular correction at the distal femur for the 5-, 10-, and 15-mm augments for Frontiers in Surgery | www.frontiersin.org 3 August 2021 | Volume 8 | Article 721379
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