Computer assisted navigation in knee arthroplasty

Abstract

Computer assisted surgery (CAS) was used to improve the positioning of implants during total knee arthroplasty (TKA). Most studies have reported that computer assisted navigation reduced the outliers of alignment and component malpositioning. However, additional sophisticated studies are necessary to determine if the improvement of alignment will improve long-term clinical results and increase the survival rate of the implant. Knowledge of CAS-TKA technology and understanding the advantages and limitations of navigation are crucial to the successful application of the CAS technique in TKA. In this article, we review the components of navigation, classification of the system, surgical method, potential error, clinical results, advantages, and disadvantages.

Keywords: Arthroplasty; Computer assisted navigation; Knee.

Fig. 1

Application of a computer assisted navigation in total knee arthroplasty for a patient with extra-articular deformity. A 74-year-old man had malunion after fracture of the femoral shaft. In the preoperative roentgenogram, the mechanical axis was varus 29.3°.

Fig. 2

Soft tissue balancing under navigation guide in total knee arthroplasty. Navigation helps to check the balance of extension gap (A) and flexion gap (B).

Fig. 3

Accuracy of postoperative limb alignment in total knee arthroplasty (TKA) using a computer assisted navigation. In the postoperative 2 year roentgenogram of the same patient shown in Figs. 1 and 2, the mechanical axis was valgus 0.5° after TKA using the computer assisted navigation.

Fig. 4

Application of computer assisted surgery technique in revision total knee arthroplasty. Preoperative weight-bearing roentgenogram shows a varus deformity due to severe polyethylene wear.

Fig. 5

Soft tissue balancing under navigation guide in revision total knee arthroplasty (TKA). Navigation helps to check the balance of extension gap (A) and flexion gap (B) in revision TKA.

Fig. 6

Accuracy of postoperative limb alignment in revision total knee arthroplasty (TKA) using computer assisted surgery (CAS) technique. At 5.2 years after CAS-revision TKA of the same patient shown in Figs. 4 and 5, neutral limb alignment and stable implant position were maintained.