1. A method for designing a patient-specific orthopaedic surgical instrument to be used on a knee of a patient, the method comprising: coupling a knee sleeve to a leg of the patient, the knee sleeve including (i) a first sensor coupled to a superior half of the knee sleeve and generating first data indicative of the position of the first sensor and (ii) a second sensor coupled to an inferior half of the knee sleeve and generating second data indicative of the position of the second sensor; determining angulation data based on the first data indicative of the angulation of the knee of the patient based on the first data and the second data; generating a medical image of the knee of the patient; and determining a design of a patient-specific orthopaedic surgical instrument based on the medical image and the angulation data.