The concept of valgus under reduction in fixation of displaced trochanteric femoral fractures with sliding hip screw.

Sixty-six patients (male 30, female 36) with displaced trochanteric fractures (according to AO classification = A1.2, A1.3 A2 and A3 groups) have been studied during the period November 2011 to September 2013. Displaced stable fractures also have been included because in grossly osteoporotic elderly patients, this may lead to gross uncontrolled collapse and act like unstable fracture and it has fixation failure rate of 1-9%. Mean age of the patients was 8.5 years. DHS was used for the patients with intact lateral cortex and used DCS for the fractures with comminuted lateral cortex extending up to vastus ridge and also in A3 types. The screw placement was inferior to central in AP view, and central to posterior in lateral view. In AP view under reduction was done with slight lateralisation and upward displacement of distal fragment and fixed with DHS/DCS with affected limb in abduction 30 to 40 degree to achieve valgus angle of about 160-170. In lateral view neck shaft angle was maintained to 160-180 degree, on higher side, avoiding retroversion. All the parameters of fixation failure like varus displacement, retroversion, external rotation, medialisation, cut out, collapse and shortening of limb, pullout side plate and implant failure have been studied. Only the patients treated with valgus under-reduction have been included in this study. We conclude that under-reduction in valgus position gives excellent posteromedical stability as it provides controlled collapse as the calcar fragment is abutting against the medial femoral shaft (as in Weyne County reduction) and also prevents shortering by valgus reduction (Parker).