Comparison of Femoral Component Rotational Axes in Computer-Assisted Total Knee Arthroplasty using the Gap Technique: A Retrospective Study
Thanaphot Channoom MD1, Pithinatt Mangklanontachai MD2, Patarawan Woratanarat MD, PhD1, Siwadol Wongsak MD1, Paphon Sa-ngasoongsong MD1, Viroj Kawinwonggowit MD1
Affiliation : 1 Department of Orthopedics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand 2 Surgery & Orthopedic Surgery Clinic, Thonburi 2 Hospital, Bangkok, Thailand
Objective : To compare the deviation of three femoral rotational axes in computer assisted surgery [CAS] total knee arthroplasty
[TKA] using the gap technique.
Materials and Methods : A retrospective cross-sectional study was conducted between 2004 and 2013 at the Department of
Orthopaedics, Ramathibodi Hospital of patients who had undergone computer-assisted total knee arthroplasty. All patients
were included with the exception of those who had had post-traumatic knee osteoarthritis, valgus knee, or trapezoidal
medial-lateral gap. Baseline characteristics and femoral rotational axes (Whiteside, posterior condyle, and transepicondyle)
were recorded. Comparison among the three axes was performed using analysis of variance.
Results : The study included 140 patients (114 women and 26 men) with an average age of 71.6+8.4 years, representing 140
total knee arthroplasties. The deviation of femoral component rotation axes were: Whiteside’s line 0.42+4.49 degrees,
posterior condylar line -1.43+4.82 degrees and transepicondylar line -3.93+5.00 (p<0.001).
Conclusion : Whiteside’s line showed the smallest deviation in femoral component rotation compared to the gap technique
in CAS TKA.
Keywords : Femoral component rotation, Computer-assisted, Total knee arthroplasty, Gap technique, Anatomical landmark
