Thyroplasty is a specialised procedure performed on the larynx for patients with vocal cord paralysis, a serious condition that occurs when there is an injury to the recurrent laryngeal nerve, which supplies the majority of the muscles of the larynx. Nerve injury can be due to a number of causes, the most common of which is surgery, typically of the thyroid gland. It can also be caused by tumors, radiation injury, and neck trauma, among others.