valgus intertrochanteric osteotomy

Sarmiento Osteotomy for Intertrochanteric Frx

- involves creating an oblique osteotomy of the distal fragment (valgus osteotomy) to obtain stability in unstable intertroch frx;

- this osteotomy changes frx plane from verticle to near horizontal & creates contact between the medial and posterior cortex of proximal and distal fragments;

- goal is too obtain medial stability;

- advantage of this valgus osteotomy is that valgus realignment of proximal fragment makes up for less of length at ostetomy site so that limb lengths remain equal;

- a 45 deg oblique osteotomy of distal frag begins just below flare of greater trochanter and crosses distally and medially to exit about 1 cm distal to apex of fracture;

- if osteotmy is made too transverse it places head in exaggerated valgus position;

- this results in leg's being too long or hip's being unstable;

- excess valgus may incr joint reactive forces and incr DJD;

- to avoid this, the medial end of the osteotomy should exit 1 cm below frx surface medially to compensate for incr length caused by valgus osteotomy;

- guide wire & then implant are inserted at 90 deg to plane of frx of the proximal fragment;

- w/ more vertical alignment of frx, insert guide pin so that it ends up more inferiorly in the femoral head (otherwise, the osteotomy will be placed in varus;

- note, however, the guide pin must still enter center of femoral head;

- insert 135 sliding screw in usual manner;

- frx is reduced and impacted;

- medial cortical opposition and, hence, stability are restored;

- avoid creating an external rotation deformity which would place the shaft in slight internal rotation;

- w/ severe medial comminution, even a valgus osteotomy may not create enough bony contact to ensure stability