If there is no pain trying to lift the straight leg, it may just be muscle inhibition from the initial injury; try lifting the straight leg first from a standing position then gradually recline to add more gravity resistance, or have someone assist your lift while lying down until you can accomplish it on your own; if the quad was torn to the point of needing surgery then it's best not to wait, but if the only evidence for doing exploratory surgery is not being able to lift your leg up, then i'd work like the dickens to make it happen!