Easy Identification of Mechanical Axis during Total Knee Arthroplasty.

Author: Jai Gon SEO ¹ ; Young Wan MOON ; Sang Min KIM ; Byung Chul JO ; Sang Hoon PARK
Author Information

1. Department of Orthopaedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Publication Type:Original Article
Keywords: Lower limb neutral mechanical axis; inter-femoral head center distance; extramedullary reference; total knee arthroplasty
MeSH: Arthroplasty, Replacement, Knee/*methods; Femur/surgery; Humans; Tibia/surgery
From:Yonsei Medical Journal 2013;54(6):1505-1510
CountryRepublic of Korea
Language:English
Abstract: PURPOSE: We devised an intraoperatively identifiable mechanical axis (IIMA) as a reference of alignment in total knee arthroplasty (TKA). MATERIALS AND METHODS: Between February 2010 and January 2011, primary TKAs were consecutively performed on 672 patients (1007 knees) using an IIMA as a reference in the coronal plane. RESULTS: The alignment of the lower extremity improved from a mean of 11.4+/-6.7degrees (-10.3-34.4degrees) of varus preop. to 0.7+/-3.5degrees (-5.2-8.6degrees) immediately after surgery. Mean alignment of the femoral component in the coronal plane was 89.3+/-2.3degrees (83.4-97.2degrees) postop. and mean alignment of the tibial component was 90.4+/-2.2degrees (85.1-94.2degrees) postop. CONCLUSION: This study showed that IIMA could be of considerable value as a new guider of alignment that is easily accessible and highly effective during total knee arthroplasty.