The lateral collateral ligament (LCL, long external lateral ligament or fibular collateral ligament) is an extrinsic ligament of the knee located on the lateral side of the knee.
Ulnar collateral ligament reconstruction, colloquially known as Tommy John surgery, is a surgical graft procedure where the ulnar collateral ligament in the medial elbow is replaced with either a tendon from elsewhere in the patient's body, or with one from a deceased donor.