Varus and Valgus Deformities of the Knee Joint: Disease Specific or Biomechanical?

160 patients (231 knees) with an angulation deformity of the knee have been examined. Varus deformity was uncommon except in patients with osteoarthritis. Osteoarthritis subsets, such as pyrophosphate arthropathy tend to cause a valgus deformity, as does rheumatoid disease. An analysis of 50 consecutive patients presenting with idiopathic knee osteoarthritis supports the impression that focal disease of the medial (common) or lateral (uncommon) compartment can occur. Different disease processes, with different associations, may be responsible. The biomechanics of the knee joint in relation to the development of angulation deformities is discussed.