My 19 Month Old Has A Bad UTI..was Just Hospitalized

My 19 month old has a bad UTI..was just hospitalized for two days..has not affected kidneys.. She had neck pain and stiffness.ruled out menegitis.. Now she has trouble walking..seems to come from top of legs..had spinal tap in hospital..could that cause that?..or antibiotics?.or not walking for two days?..what could cause this