ANATOMICAL AND BIOMECHANICAL CONSIDERATIONS IN AXIAL DEVIATIONS OF LOWER LIMB

Planning for surgical correction of lower-limb deformity requires assessment of character and extent of the deformity. Angular deformities of tibia or femur in frontal plane lead to mechanical axis deviation of the lower limb and malorientation of the joints above and below the level of deformity. Accurate correction of the malalignment and of the joint orientation is important for function and to prevent joint degeneration. An awareness of the three dimensional nature of deformity is essential if correction is to be achieved. This applies to all aspects of orthopaedics, from total joint arthroplasty (the knee in particular) to fracture management. Mechanical axis deviations in the lower extremity are commonly seen in both paediatric and adult orthopaedic practice. This paper describes, for the trainee, the consequences of such deformity and the methods by which they are quantified.