A Study on limb alignment in computer navigated total knee arthroplasty in patient with Osteoarthritis

Author(s): Dr. Raju Akkimaradi and Dr. EG Mohan Kumar

Abstract: The success of total knee replacement depends on several factors, including patient selection, prosthesis design, soft tissue balancing, and alignment of the limb. Proper rotational and translational alignment of the prosthetic components and of the limb are important factors that influence the outcome of knee replacement. All cases of Total knee replacement done using computer. 65 patients with 72 knee were available for the follow-up with their previous records, annual x-rays and follow-up papers. Pre-operative deformities and its values were recorded for the study from the hospital case sheets and discharge summaries. For the 72 knees in our study the average mechanical axis angle was 1.25 degree varus. 1 knee (1.38) had -4 varus, 2 knee (2.77%)had -3 degrees varus, 4knees (5.55%) had -2 degrees varus, and 2 knee(2.77%) had -1 degrees varus. 9 knees (12.5%) had +2 degrees of valgus, 8(11.1) knee had +3 degrees valgus, 5knees (6.9%) had degrees +4 valgus and 1 knees (1.38%) had +5 degrees valgus. Overall the mechanical axis radiological score excellent in 65 knees (90.27%) and 7 knees (9.72%) had good radiological score. Furthermore, all systems depend on the reflective trackers remaining stationary relative to their respective bones during the surgical procedure. If a pin loosens in osteopenic bone or if it is forcibly bumped during the operative procedure, the accuracy of the system is lost. The long term benefits of Computer navigated TKA over Convention jig based TKA is yet to be known.

DOI: https://doi.org/10.22271/ortho.2020.v6.i2n.2152