Varus and valgus flexion laxity of total knee alignment methods in loaded cadaveric knees

José Romero, James F. Duronio, Afshin Sohrabi, Nicolas Alexander, Bruce A. MacWilliams, Lynne C Jones, David S. Hungerford

Research output: Contribution to journalArticle

Abstract

Both total knee alignment methods, the anatomic and classic, seek to achieve stability in flexion and extension. However, posterior femoral condyle referencing (anatomic alignment) combined with perpendicular tibial resection (classic alignment) results in a 3° relative internal rotation of the femoral component with lateral joint opening. The current cadaver study investigated the influence of total knee alignment methods and femoral component malrotation (3° and 6° internal and external malrotation) on femorotibial laxity. Varus and valgus excursion tests were done at 0°, 30°, 60°, and 90° knee flexion under vertical loading conditions of 150 N. None of the alignments produced increased laxity in extension. The largest laxity was found on the varus test at 60° flexion with the femoral component at 6° internal rotation. A 3° internal rotation of the femoral component showed increased varus laxity only for the combined alignment method. This finding shows that the femoral component position of the combined alignment method is a 3° relative internal malrotation and that an additional internal malrotation may compromise varus stability. Posterior femoral condyle referencing did not provide proper femoral component rotation. A ligament tensor may be helpful in determining femoral component rotation after soft tissue release in extension is performed.

Original languageEnglish (US)
Pages (from-to)243-253
Number of pages11
JournalClinical Orthopaedics and Related Research
Issue number394
Publication statusPublished - 2002

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ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine

Cite this

Romero, J., Duronio, J. F., Sohrabi, A., Alexander, N., MacWilliams, B. A., Jones, L. C., & Hungerford, D. S. (2002). Varus and valgus flexion laxity of total knee alignment methods in loaded cadaveric knees. Clinical Orthopaedics and Related Research, (394), 243-253.