I have broken my pelvis in 3 places and my saccrum. What would cause my left thigh to be numb to my knee?

Broken pelvis can be a cause of femoral nerve damage.

Also if you consider the mechanism of trauma causing pelvic fracture, i wonder if there is associated l2-3-4 spine injury. You see your doctor.

Nerves around and in the pelvis can be injured pressed by blood collection some sacral frx are right though the holes for th sacral nerve roots the sacral plexus is plastered on the front side the sacrum repeat the ct scan if getting worse.

Get a wheel chair for 3 months.