Current trends in the medial side of the knee: not only medial collateral ligament (MCL)

The medial collateral ligament (MCL) is by far the most commonly injured ligament of the knee. The medial ligament complex covers a broad bony surface on the extraarticular portion of the femur and is highly vascularized, which allows for a high healing potential. For this reason, most MCL complex lesions were treated conservatively in the past. However, recent advancements regarding the MCL anatomy and kinematics highlighted the complex biomechanical behavior of the isolated and combined MCL lesion, and it is now fully appreciated that some MCL lesions warrant surgical treatment. The present review aims to provide the reader with an overview of the new evidence and advancement on the complex anatomy, biomechanics, and treatment of the MCL.