Abstract
BACKGROUND
Computer navigation system offers an inherent advantage to surgeons improving the surgical technique of total knee arthroplasty (TKA) in that it provides constant visual and numerical feedback throughout the procedure.
On this basis, this study was designed to explore the chronologic change of surgical outcomes in TKA by a single surgeon with experience of over 50 Imageless navigation-assisted TKA procedures before.
METHODS
Surgical outcomes were analyzed in 295 consecutive total knee arthroplasties treated in period 1 (2011.1–2012.12) in which both navigation (53 knees, P1-NAVI) and conventional technique (106 knees, P1-CON) were used and in period 2 (2013.1–2013.12) in which conventional technique (136 knees, P2-CON) was only used.
The study parameters were implantation accuracy, clinical outcome, operation time and complications.
Coronal femoral component and tibial component angle, and hip–knee–ankle mechanical axis alignment were evaluated.
Results
A statistically significant superior result was achieved in final mechanical axis and coronal tibial component angle during P1-NAVI to P1-CON (p=0.00 and p=0.047).
However, comparisons between P1-NAVI and P2-CON did not reveal the statistical significant differences in mechanical axis (p=0.08). Additionally during P2-CON, the result of mechanical axis alignment was superior to P1-CON (p=0.009).
However, a statistically significant inferior result in coronal tibial component angle during P2-CON was shown in comparison with P1-NAVI (p=0.00) as well as P1-CON (p=0.02).
In terms of coronal femoral component alignment, the statistically inferior result during P1-CON was shown in comparison with P1-NAVI (p=0.00) as well as P2-CON (p=0.01). There was no statistically significant differences between P1-NAVI and P2-CON (P=0.08).
A statistically significant increase in operating time was found in P1-NAVI compared to P1-CON as well as P2-CON (p=0.01, p=0.00). Additionally, P1-CON has shown the increased operating time compared to P2-CON (p=0.02).
There was no statistically significant differences in complications between P1-NAVI and P1-CON. However, the overall number of complication was decreased from period 1 (P1) to period 2 (P2).
Conclusions
After stop using imageless navigation system, the mechanical axis and frontal femoral component angle was well maintained. But, surgeon could not maintain the coronal tibial component alignment. The operating time and number of complications were decreased over time. Based on this single surgeon's chronologic change of surgical outcomes, the continuing use for real time feedback such like navigation is needed to maintain the consistency of TKA.
