Northwick Park Hospital 1 article published in JoVE Bioengineering A Novel Tenorrhaphy Suture Technique with Tissue Engineered Collagen Graft to Repair Large Tendon Defects Prasad Sawadkar1,3, Jason Wong2, Vivek Mudera1 1Division of Surgery and Interventional Science, University College London, 2Blond McIndoe Laboratories, Division of Cell Matrix and Regenerative Medicine, MAHSC, University of Manchester, 3Department of Surgical Research, Northwick Park Institute for Medical Research, Northwick Park Hospital In this paper, we present an in vitro and in situ protocol to repair a tendon gap of up to 1.5 cm by filling it with engineered collagen graft. This was performed by developing a modified suture technique to take the mechanical load until the graft matures into the host tissue.