Abstract
The combination of obesity and malalignment may result in increased revision rates following total knee arthroplasty (TKA). The purpose of this retrospective matched-pair study was to compare the accuracy of limb and component alignment after TKA using conventional versus computer-assisted technique in obese patients. Radiographic data regarding limb alignment, coronal and sagittal component alignment of 72 conventional TKAs (52 patients) were compared with data of a matched group of 72 computer-assisted TKAs. All procedures were performed by a single surgeon, using a single approach and a cruciate-substituting design.
The mean postoperative limb alignment in the conventional group was 177.2° ± 2.5° compared to 179.3°± 1° in the computer-assisted group (p=0.0001). The coronal and sagittal alignment of both femoral and tibial components in the computer-assisted group was significantly accurate compared to the conventional group. In the conventional group, 40.2% of limbs (29 out of 72) had a postoperative HKA angle > ±3° from the neutral compared to 1.3% of the limbs (1 out of 72) in the computer-assisted group (p=0.0001).
Computer-assisted total knee arthroplasty performed in obese patients showed excellent limb and component alignment with very few outliers when compared to conventional total knee arthroplasty. Obesity is an appropriate indication for the use of computer navigation during TKA where use of conventional techniques may result in significant limb and component malalignment.
