Abstract
There is still want of evidence in the current literature of any significant improvement in clinical outcome when comparing computer-assisted total knee arthroplasty (CA-TKA) with conventional implantation. Analysis of alignment and of component orientation have shown both significant and non-significant differences between the two methods. Not much work has been reported on clinical evidence of stability of the joint.
We compared computer-assisted and conventional surgery for TKA at 5.4 years follow-up for patients with varus osteoarthritic knees with deformity of more than 15∗. Our goal was to assess clinical outcome, stability and restoration of normal limb alignment.
We used CT and Cine video X ray techniques to analysize our results in Computer navigated and conventional TKRs. A three dimentional CT scan of the whole extremity was performed and evaluation was done in three planes; saggital, coronal and transverse views. CT scan was done between 10 to 14 days postoperative. Mean deviations in the mechanical axis, femoral and tibial plateau angles, and in transverse view, the trans-epicondylar axis vs posterior condylar axis were measured. The prospective randomized study comprised of 98 patients with surgery done on knees, one side navigated and other side conventional. Mean deviation in the mechanical axis was 2.2∗ in conventional knees and 1.8∗ in navigated knees. In 5 % of cases retinacular release was needed and CT analysis showed TEA in deviation of more than 2 ∗ in these cases. We analysed intraoperative data (surgical time and intraoperative complications), postoperative complications, lower limb alignment, radiographic complication on X-ray imaging, and clinical outcome throughknee and function score, range of motion and joint stability.
Our results showed that CAS had greater consistency and accuracy in implant placement and stability of joint in full extension and 90∗ flexion. In the coronal view, 93.3% in the CAS group had better outcomes compared with EM (73.4%). In the sagittal axis, 90.0% CAS also had better outcomes compared with EM (63.3%). Computer-navigated total knee arthroplasty helps increase accuracy and reduce “outliers” for implant placement.
