Abstract
Introduction
In total knee arthroplasty (TKA), the setting position of component and the angle influence surgical results. 3D matching evaluation method using the CT before and after operation was a useful method as a rating system after operation. The anterior femoral cortical line (AFCL) is an anatomical landmark for determining intraoperative femoral component rotation in total knee arthroplasty (Fig.1). Our aim in this study is to evaluate the effectiveness of the JIGEN (Jig Engaged 3D Pre-Operative Planning System for TKA) (LEXI, Japan) operation support system using AFCL.
Patients and methods
We performed TKA used GENUS MB (Adler, Italy) by January, 2015 from October, 2013. As for 5 male knees, 37 woman knees, the operation average age were 68 years old. The operation was based on each insertion parameter of the rod in marrow provided by a preoperative plan by the JIGEN system and at first installed a target device in the femoral front and manufactured a insertion point and inserted a rod in the marrow to plan insertion depth (Figure 1). We performed CT photography of the whole lower limbs after operation like preoperation and femoral component setting was located after operation using evaluation software (LEXI, Japan) and evaluated it.
Result
In the 3D evaluation, femoral components implanted less than 3 degrees were 98% in the coronal plane, 67% in the sagittal plane, and 79% in the axial plane (Figure 2). The rotational malposition of femoral component was found in the case that the distal femoral front was round.
Conclusion
The JIGEN system is useful for operation support in TKA. AFCL has the advantages of easy access and because of its extra-articular position is not affected by articular cartilage or processes that destroy the joint (such as degeneration or osteolysis). We considered that the JIGEN system using AFCL can be effective for determining intraoperative femoral component rotation in TKA.
