Malalignment in plate osteosynthesis.

The aim for this review is to present general considerations in relation to malalignment after osteosynthesis with plate fixation and its consequences after fractures in adults in each of the following anatomical locations: humerus, forearm, femur, tibia. Recommendations for accepted malalignment in humerus diaphyseal fracture is varus <20 degrees, valgus <15 degrees, sagittal deformity <5 degrees and rotation <30 degrees. Recommendations when treating fractures of the forearm is anatomical reduction. Varus of ulna leads to loss of pronation. Valgus of ulna leads to loss of both pronation and supination. Recommendations for acceptable malalignment in femoral fractures is rotational deformity <15 degrees, increasing varus deformity in intertrochanteric fractures increases load on implant. Cortical-step-sign, profile of lesser trochanter, evaluation of ipsilateral neck anteversion are intraoperative methods to avoid rotational malalignment. Recommendations for accepted malalignment in the tibia is shortening <10mm, varus/valgus <5 degrees, sagittal deformity <10 degrees. Fixation of fibula leads to less rotational and valgus malalignment, but not enough to affect union rate of tibia, complications rate or functional score at 12 months. To avoid malalignment in plating, pre-contoured anatomical plates are available from most manufactures. Being aware that most such plates fit a 50-percentile Caucasian population is important in pre-surgical planning. Evaluation of the contralateral bone and the characteristics of the plate may help in planning additional bending of pre-shaped plates and bending tools should always be available when applying a plate, even a so-called anatomical one.