malalignment

Definition

Deformity causing alteration of mechanical axis from knee centre

Aims

1.  Normal leg alignment

2.  Equal leg lengths

Principle

Correct alignment and soft tissue balancing

- two of the most important aspects of successful TKR

Technical Goals

1.  Restoration of mechanical alignment

- forces of the leg pass through the centre of the hip, knee and ankle

Displaced Tibial Shaft Fractures

Acceptable reduction

- varus / valgus < 5^o

- anterior / posterior < 5^o

- rotation 5^o

- shortening 10 mm

Poor remodelling potential

- valgus 

- apex posterior angulation  / recurvatum

- rotational alignment does not remodel

- shortening / in 2-10 year old average overgrowth is only 5mm