Objective: The purpose of the present study was to report the results of radiographic comparisons made between CAS-TKA and conventional TKA.
Material and method: The authors retrospectively compared 102 knee radiographs from conventional TKA to 84 knees from CAS-TKA.
Results: The mean mechanical axis deviation was 2.77 degrees for conventional TKA and 1.80 degrees for CAS-TKA (p = 0.0002). For conventional TKA 42.2% of the results were considered to be outliers versus only 14.3% outlier frequency among the CAS-TKA procedures (p < 0.0001). Only 54.4% of scanograms were proper for the presented analysis due to improper anterior-posterior positioning. Implementation of a corrective standing block eliminated this issue.
Conclusion: CAS-TKA significantly reduces both margins of error in knee alignment and frequency of outlier compared with conventional TKA. Further investigation to compare long-term results of CAS-TKA with conventional TKA is recommended.