Device for measuring leg length and off-set for a total hip replacement

摘要

A device for use in an orthopedic surgical procedure for replacement of a patient's hip that, prior to dislocation of the pathologic hip, is used by the surgeon to determine leg length and leg displacement, with these measurements then used as references for reproducing or adjusting leg length and positioning. The device includes an ilium pin that is to be driven into the patient's ilium to serve as a fixed reference. Preferably, the ilium pin includes a pair of pointed end portions, the one forking off from the other, with the ilium pin top end arranged to be driven into the ilium using a driver. A straight measuring bar that includes an ilium mounting end is arranged for fitting onto the ilium pin to extend at a right angle therefrom and a scale is formed around the opening through the ilium mounting end and a radial indicator is scribed into the top of the ilium pin, for use in determining femur medial or lateral displacement. The measuring bar includes a scale scribed therealong and is arranged to receive a femoral slide fitted to slid over the scale, whereby a femoral slide side is to serve as an indicator for comparison to the scale markings for determining femoral slide positioning from the ilium pin. The femoral slide further includes a hole formed therethrough that a straight femoral pin is fitted through, forming a right angle to the measuring bar, the femoral pin having, has a pointed end to contact a fixed location on the proximal femur. A scale is scribed along a femoral pin upper portion that is arranged to receive an indicator sleeve fitted to travel along the femoral pin to engage a top surface of the femoral slide for comparison with the scale markings to determine a distance the femoral pin end is extended from the femoral slide. The device includes set screw type locks for releasably locking the device components together allowing them to be maintained in position and then reinstalled to the ilium after installation of the hip prosthesis for use in duplicating or adjusting the leg positioning relative to the acetabulum, as the surgeon determines.