The risk of notching the anterior femoral cortex with the use of navigation systems in total knee arthroplasty

Abstract

Use of navigation systems has recently been introduced in total knee arthroplasty (TKA) to achieve more reliable prosthetic alignment. In the sagittal plane, there are two important requirements for navigation systems: (1) perpendicular cut to the femoral mechanical axis and (2) prevention of notching of anterior femoral cortex. These two requirements, however, may conflict. The angles between the line of the anterior femoral cortex and four sagittal femoral mechanical axes for navigation systems using radiographs of the entire lower extremity, while standing were measured and compared. These four sagittal axes simulated on the radiographs in navigation systems were in extension relative to the line of the anterior femoral cortex in 40-85% of cases in male and 65-100% in elderly female. The present study showed that navigation systems have the potential risk for notching of anterior femoral cortex.

Clinical Faceoff: Do We Need Special Strategies for Asian Patients with TKA?

“…We should make an adequate bone bed for the anterior flange of the femoral component with proper cementing technique. Furthermore, caution should be taken to avoid anterior notching in knees with severe femoral anterior bowing, particularly when using computer assisted navigation [4,13,17]. Postoperative rehabilitation is also impo rtant.…”

Kinematic analysis of leg alignment during conventional versus navigated total knee arthroplasty: Initial results of a prospective study

“…Thus, the inherent guiding designs and according concepts of IM guide and mechanical-axis-based navigation programs account mostly for the differences. In addition, common anatomical variations involved in the operative field, such as anterior femoral bowing, are expected to enhance the surgical discrepancy in the sagittal plane [18]. However, there were only a few deformed femurs involved in the present study (1 in the IM group vs. 2 in the NA group), and we believe that the anatomical factors affect the measured alignment to a lesser extent.…”

“…However, anatomical variations, such as inherent bony bowing or traumatic deformities, should be taken into consideration even in the navigated TKAs. These anatomical factors may either alter accurate registration in image‐based navigation, or induce undesirable anterior femoral notching [18] or oversized femoral components [22] in image‐free kinematic‐based models without preoperative planning.…”

Total knee arthroplasty using a hybrid navigation technique

“…Computer navigation has the disadvantages of a protracted learning curve and increased surgical time [11] In addition, several investigators have suggested that navigation might increase the risks of notching of the anterior femoral cortex and oversizing of the femoral component. In particular, Minoda et al [3] found that 40-85% male cases and 65-100% of elderly female cases treated with navigation showed anterior notching. Matsumoto et al [2] suggested that surgeons should be aware of the potential for oversizing when determining the size of the femoral component, particularly when the femoral bone is anteriorly bowed.…”