How the MCL Heals Treatment for the three grades of isolated MCL injury is nonoperative because the MCL exhibits good healing response. Grade 3 injuries are more likely to be associated with other injuries that require surgery. The MCL cells are longer, allowing greater proximity to the ligament's collagen fibers. The fibers increase healing, and their presence is associated with healing. The first phase of healing occurs within 3 days after injury.
Inflammatory mediators give way to fibroblasts that produce type III collagen and proteoglycans.
Repair and regeneration. The second phase occurs about 6 weeks after injury as type 3 collagen decreases and type I collagen increases. Weight bearing is allowed as tolerated for grade 1 and 2 MCL tears. Pain abates after 3 to 5 days in grade 1 MCL injuries but may continue for up to 2 weeks in grade 2 MCL injuries. By 4 weeks the patient should be fully weight bearing.