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JRPMS Vol 4, No 3, September 2020, p.60-67

doi: 10.22540/JRPMS-04-060


Original Article

A CT Based assessment of femoral component external rotation in TKA for osteoarthritic varus knees

Chetan Sood, Ankur Deshwal

  • Department Of Orthopaedics, Base Hospital Lucknow, Uttar Pradesh, India

Keywords: Osteoarthritis (OA), Posterior Condylar Axis (PCA), Surgical Trans-epicondylar Axis (sTEA), Total Knee Arthroplasty (TKA)


Objectives: A CT based comparative assessment of the femoral component axial rotation (FCAR) achieved in two different design rationales compared to desired distal femoral axial rotation in balanced knees. Methods: 19 males and 31 females randomized in 02 groups of 25 patients each underwent unilateral TKA using two different implant designs (Genesis II & PFC). Posterior Condylar Axis (PCA) Trans-epicondylar Axis (TEA) open angle used to assess axial placement of femoral components per-operatively. CT based evaluation of the TKA done at 06 weeks to assess the FCAR achieved compared to desired value. Results: Mean FCAR for Genesis II group was 3.63 degrees with no difference among the males and females. In PFC group the mean FCAR achieved was 4.07 degrees the mean value was lower in males 3.95 degrees (2.8-6.5) and higher in females 4.16 (2.5-5.2). Mean achieved FCAR achieved in the study is 3.85 degrees. Conclusion: Mean achieved FCAR for the two design rationales showed no statistically significant difference. Mean FCAR in Genesis II group was more than inbuilt 3 degrees and is statistically significant. In a well-balanced knee the mean achieved FCAR in the study is significantly higher (3.85 degrees) than conventional desired 3 degrees.