Computer-assisted surgery versus manual total knee arthroplasty: A case-controlled study

Background: Restoration of neutral alignment of the leg is an important factor affecting the long-term results of total knee arthroplasty. Despite the use of modern instruments in total knee arthroplasty, component malalignment remains a problem. Computer-assisted systems have been developed in order to improve alignment of components. The objective of this study was to determine whether the computer-assisted total knee arthroplasty is superior to the conventional surgical method with regard to the precision of implant positioning. Patients and methods: A total of 44 patients were included in the study. Twenty-three patients underwent surgery using a computer-assisted navigation system. The control group included 21 patients, who were operated on using the conventional technique. The groups were similar with regard to age, gender, diagnosis, body mass index, side of the operated limb, implants and preoperative value of IKSKS. The two methods were compared for alignment of the leg and the orientation of components on post-operative long-leg coronal and lateral films. Results: The groups were not significantly different with regard to the accuracy of component positioning as compared to that achived by conventional total knee arthroplasty (p > 0,05). Postoperative range of motion of the knees and postoperative value of IKSKS were similar in both groups. The operating time was longer in the computer-assisted total knee arthroplasty, by 30 minutes on average. The blood loss was greater in the computer-assisted total knee arthroplasty, by approximately 70 mL on average. Conclusions: Computer-assisted total knee arthroplasty yields better correction of leg alignment and orientation of the components compared with the conventional technique. However, these results were not statisticaly significant. Potential benefits in the long-term outcome and functional improvement require further investigation.