A 37-year-old female patient presented with a 1-month history of pain and repeated effusion in her right knee. Her preoperative Lysholm score was 24 points and International Knee Documentation Committee (IKDC) subjective score was 5.7%. Her Tegner activity level was 4 before injury and 0 before surgery. (A) Arthroscopy revealed a frayed lateral meniscus with degenerative changes. (B) There was an extensive horizontal cleavage tear at the posterior third of the meniscus, which reached the peripheral margins after the fibrillation had been abraded. (C) FAST-FIX was used to place vertical sutures to close the cleft of the tear. (D, E) Fibrin clots were inserted into the cleft before tightening the sutures and completed the repair in a sandwich fashion. (F) Follow-up arthroscopy at 6 months postoperatively. The cleft of the horizontal cleavage tear had closed and healed, and there was regenerated tissue on the lateral meniscus. (G) Probing confirmed that the suture knots had migrated into the regenerated scar tissue and that the repaired horizontal cleavage tear was well healed. The Lysholm score was 100 points, IKDC subjective score was 94.5%, and Tegner activity level was 4 at the time of follow-up arthroscopy. These improved scores were maintained at the final follow-up at 42 months postoperatively. This case was part of the complete healing group.