The present technique is designed to transect the medial patellar ligament indicated for treatment of upward fixation of patella in cattle and donkeys. A medial patellar desmotomy was performed first on cadavers and then on 21 live cattle or donkeys. In live animals under local anesthesia, a sterile silk strand (USP 1) mounted on a curved needle is inserted through skin at the medial aspect of the medial patellar ligament to the subcutaneous fascia and directed beneath the ligament to emerge at opposite side. The silk is then sawed to cut the ligament. In contrast to other procedures, the desmotomy is less invasive as skin at the surgical site is not incised, pericapsular fat and joint capsules not invaded, and the ligament is fully transected in a one-step procedure. Minimal tissue invasiveness limited infection of surgical site, minimized bleeding, and decreased related postoperative consequences.