Osteochondritis dissecans (OCD): Clinical manifestations and diagnosis. [Updated 2019 Jun 4]. 2009 Jun;22(6):20-25. People with the highest risk of tearing their MCL are those who play contact sports or sports that are more likely to cause twisting of the knee by pivoting or stopping abruptly. Wait at least an hour before icing the knee again. If the immediate pain and swelling makes it too difficult to judge how severe the injury is, you may need to wear a light splint, apply ice and raise the knee. This can cause an injury to either the MCL or to the ligament stabilizing the outer side of the knee, called the lateral collateral ligament (LCL). How can doctors tell you have suffered a torn MCL, and tell the grade of injury, by examining your knee? J Orthop Surg Res. Pain is the most common symptom. Your MCL, which is short for medial collateral ligament, is one of the four major ligaments in your knee. MCL injuries can occur from being hit on the outside of your knee. If the pain is significant, a medical professional may suggest that you use crutches. If you’re thinking about having knee replacement surgery, you’re in good company. Multiple Ligament Knee Injury: Complications. Malignant Bone Tumors of the Knee: How to Identify and Treat. Petersen W, Rembitzki I, Liebau C. Patellofemoral pain in athletes. Open Access J Sports Med. She holds a master's degree in kinesiology from California State University, Fullerton. 8 Sleep Tips to Ease Back, Neck and Shoulder Pain. Ligament Injuries to the Knee. An MCL tear or rupture can be a debilitating injury, but it often responds well to conservative treatment options like physical therapy. 2011;35(3):355-8. doi:10.1007/s00264-010-1033-5, Beals C, Flanigan D. A Review of Treatments for Iliotibial Band Syndrome in the Athletic Population. All Rights Reserved. Swimmers can also tear their MCL as an overuse injury. Medical Reviewer: William C. Lloyd III, MD, FACS. 1. All grades of MCL injury can be treated without surgery. If you have suffered a knee injury that you think is a torn MCL, watch the video to learn how orthopedic surgeons can often figure out if you have an MCL injury and how severe it is without an MRI for an MCL tear. doi: 10.1302/2046-3758.32.2000241. Basic science of anterior cruciate ligament injury and repair. Bone Joint Res. 2017;3(1):e9-e16. Physical Examination of the Knee: Meniscus, Cartilage, and Patellofemoral Conditions. This important ligament allows you to rotate your knee. Apply ice to the MCL injury for about 20 minutes at a time several times a day. MCL injuries hurt. Reinking MF. Grade 2: Pain on the inside of the knee is more intense, and there might also be swelling. doi:10.7759/cureus.780. Other complications include fractures, loss of motion and stiffness, and damage to nerves and blood vessels. There are three grades of MCL injuries. Here's what you need to know to make your time a little easier. If the torn MCL occurred along with tears in one or more other knee ligaments, the joint may continue to be unstable even after treatment. The knee now loses stability and the athlete experiences pain, typically over the inside of the knee. 2017 May;25(5):365-374. Johns Hopkins Medicine. The medial collateral ligament (MCL) is the thick ligament on the side of the knee closest to the midline of your body. UpToDate. When the MCL tear occurs, the person may hear a popping sound in the knee. Collateral Ligament Injuries. Primary traumatic patellar dislocation. J Am Acad Orthop Surg. MCL healing times differ based on the extent of injury 3. 2017;8:143-154. doi:10.2147/OAJSM.S133406, Frush TJ, Noyes FR. She will then reach across and place her other hand on the inside of your ankle, pulling your ankle toward her. A fall in which you land with your leg splayed out can also can tear the MCL. 2016;11(6):854-866. One of the most common knee injuries in contact and collision sports is a medial collateral ligament (MCL) injury. This pushes the bones apart on the inside of the knee which overstretches the ligament tearing the MCL. Who Gets Medial Collateral Ligament Tears? A mild MCL sprain often heals within 3 to 6 weeks, while more serious injury can take 8 to 12 weeks. The thick membranous band is located on the inside of your knee joint, attaching at your femur and tibia. Int J Sports Phys Ther. The doctor will rest her hip against your knee, then place her closest hand on the inside of your knee to keep it steady against her hip. American Academy of Orthopaedic Surgeons. Rest is the starting point for nonsurgical MCL tear treatment. a tackle hitting the outer side of the knee. 2016;5:Doc01. Most commonly, a strong force against the outside of the knee causes the MCL injury as the knee bends inward toward the other knee. This usually causes some instability in your knee joint. Weak muscles are the leading cause of knee injuries, therefore the best thing you can do for your knees is strengthen the surrounding muscles. The MCL, along with three other knee ligaments, provides stability and strength for the joint. Endoscopic treatment of prepatellar bursitis. You can take steps to determine whether it’s likely you’ve torn your MCL, but an MRI is needed for a true diagnosis. Grade 1 and 2 MCL injuries usually heal within three weeks, but grade 3 tears might require six weeks or longer before the person can return to sports. Using Medical Intervention Download Article Take medications to control the pain caused by … 2013;2013:718423. doi:10.1155/2013/718423. doi:10.3205/iprs000080, Voskuil R, Evenski AJ, Montgomery C, Emory CL. 2013;106(7):259-68. doi:10.1177/0141076813482831. Twisting: Sudden twisting of the knee, such as changing direction quickly, particularly if you are wearing studs that fix the foot … Surg J (N Y). Basic science of anterior cruciate ligament injury and repair. Instability is usually associated with more severe MCL tears. Pain when bearing weight, such as when walking, sitting down, or rising from a chair. People who play contact sports or sports that involve quick turns and sudden stops have a higher risk of tearing their MCL. Medial Collateral Ligament (MCL) Knee Injuries. Bone Joint Res. North American Journal of Sports Physical Therapy: NAJSPT. 2013;2013:367169. doi:10.1155/2013/367169, Tsai CH, Hsu CJ, Hung CH, Hsu HC. Bachur RG, ed. It is swollen and painful but the knee is stable. A grade 2 tear is a partial tear and there may be some slight opening of the joint when stressed. Decrease pain and swelling to allow more accurate diagnosis testing. The MCL also can tear if the knee is hit forcefully from the side. MCL tears can occur from a sudden blow to the knee or from overuse of the ligament. Decrease swelling by applying ice, taking non-steroidal anti-inflammatory drugs (if approved by your doctor) and elevating your knee above your heart. How to perform a comprehensive examination of the knee. If you are experiencing serious medical symptoms, seek emergency treatment immediately. Your doctor may also order an MRI or an x-ray to get a firm diagnosis and rule out other problems. Anterior Cruciate Ligament (ACL) Knee Injuries. The acute swollen knee: diagnosis and management. Anterior Cruciate Ligament Injuries. Your range of motion will be tested. Grawe B, Schroeder AJ, Kakazu R, Messer MS. Lateral Collateral Ligament Injury About the Knee: Anatomy, Evaluation, and Management. It connects your thighbone to the bone of your lower leg. Without the MCL or LCL your knee will feel wobbly, especially if you do a side-to-side cutting motion. American Academy of Orthopedic Surgeons. doi:10.1055/s-0037-1598047, Vaishya R, Azizi AT, Agarwal AK, Vijay V. Apophysitis of the Tibial Tuberosity (Osgood-Schlatter Disease): A Review. A doctor may order one or more medical imaging tests to confirm the presence and determine the severity of an MCL injury. Joints. MCL reconstruction surgery comes with risks associated with any surgery, which include: Anesthesia reaction, such as an allergic reaction and problems with breathing. While you’re waiting to determine the extent of your injury, avoid additional stress by wearing a knee brace for support. EFORT Open Rev. An MCL injury is a sprain or tear to the medial collateral ligament. Cureus. Surgery is rarely needed to treat a torn MCL, but there are cases when it is needed. The incidents can put immense tension on your MCL ligament. 7,752,060 and 8,719,052. Rarely, the most severe grade 3 MCL tears might need surgical repair. The medial collateral ligament (MCL) is a sturdy band of tissue on the inner side of the knee that connects the thighbone (femur) to the shinbone (tibia). MCL tears generally heal well as long as you do not re-sprain the ligament and the medial meniscus (attached to the MCL) is not damaged. Unstable Kneecap. Appl Bionics Biomech. Also, landing incorrectly while jumping may twist the knee, thus causing an MCL tear. Marieswaran M, Jain I, Garg B, Sharma V, Kalyanasundaram D. A Review on Biomechanics of Anterior Cruciate Ligament and Materials for Reconstruction. Instability, or feeling like the knee … She’s had multiple short screenplays produced and her feature scripts have placed at the Austin Film Festival. The medial collateral ligament (MCL) runs along the inside of the knee and connects the shinbone, or tibia, to the femur, or thighbone. By wearing a brace on your knee, you can prevent another sideways movement that could make the injury worse. Bhatia D, Bejarano T, Novo M. Current interventions in the management of knee osteoarthritis. J Sports Med (Hindawi Publ Corp). Learn More. Your doctor might also recommend using crutches for a few days to reduce stress on your knee. These are symptoms of a complete MCL tear. Other nonsurgical treatments include: Nonsteroidal anti-inflammatory drugs will reduce pain and swelling in the knee. MCL tears happen most often during sports involving turning, cutting, and pivoting like skiing, soccer, football, basketball, and tennis. Zanon G, Di vico G, Marullo M. Osteochondritis dissecans of the knee. Visit a medical professional to receive a true diagnosis. ; A direct blow to the knee or a noncontact injury due to cutting or sudden deceleration or stopping may damage the MCL. JAAPA. Privacy Policy | Advertising Policy | Cookie Policy | Privacy Preferences Center | Do Not Sell My Personal Information. 2014;3(2):20-31. doi:10.1302/2046-3758.32.2000241, Doral MN, Bilge O, Huri G, Turhan E, Verdonk R. Modern treatment of meniscal tears. 2010;40(11):705–721. It’s important to always wear appropriate safety equipment and use proper technique when participating in any type of sport or exercise. person to person. Manske RC, Hosseinzadeh P, Giangarra CE. Ann R Coll Surg Engl. You might hear a pop when the damage to the … Recovering from a broken leg can vary from 2018; 2018: 4657824. doi: 10.1155/2018/4657824. // Leaf Group Lifestyle, MedlinePlus: Torn Medial Collateral Ligament, SportsInjuryClinic.net: Medial Ligament Sprain, OrthopaedicsOne: Valgus Stress Test of the Knee, Kazemi M, Dabiri Y, Li LP. Eitzen I, Moksnes H, Snyder-Mackler L, Risberg MA. Crushed ice on the knee works best. CURRENT CONCEPTS IN THE TREATMENT OF PATELLAR TENDINOPATHY. Help Millions of people find the right doctor and care they need, Get immediate care and visit with providers from the comfort of your home, or anywhere, Urgent care centers can be faster and cheaper for situations that are not life threatening, Doctors and patients discuss the latest medical treatments and health tips, Search prescription drugs for why they’re used, side effects and more, Back and Neck Surgery (Except Spinal Fusion), https://www.ucsfhealth.org/conditions/mcl_tear/, https://emedicine.medscape.com/article/89890-overview, https://orthoinfo.aaos.org/en/diseases--conditions/collateral-ligament-injuries, https://health.ucsd.edu/specialties/surgery/ortho/areas-expertise/sports-medicine/conditions/knee/pages/mcl-sprains.aspx, https://www.hopkinsmedicine.org/healthlibrary/conditions/orthopaedic_disorders/ligament_injuries_to_the_knee_85,P00926, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953344/. A grade 3 MCL tear often occurs along with a tear of the anterior cruciate ligament. University of California San Francisco Medical Center. After the injury, symptoms of a torn MCL can be mild or severe, depending on how badly the knee was hurt. The MCL prevents forces that cause your knee to collapse inward. Since MCL injury symptoms can be confused with symptoms of other medical conditions, your doctor may want to confirm an MCL tear with an X-ray, MRI or other test. You will sit on a table with both legs extended, the leg of your injured knee slightly hanging off one side. Most people feel pain along the inside edge of the knee, and they also have swelling. 2019;32(4):305-314. doi:10.1055/s-0038-1675828, Gupte C, St mart JP. Different breaks involve varying lengths of treatment and recovery. [Updated 2019 Mar 8]. Waltham, MA: UpToDate Inc. Dr. Howard Marans would be happy to meet with you about whether or not MCL surgery is right for you. If you’re willing to try a few new things, though, you might find some relief. In: StatPearls [Internet]. J Am Acad Orthop Surg. GMS Interdiscip Plast Reconstr Surg DGPW. Hindle P, Davidson E, Biant LC. The MCL connects the femur (thighbone) to the tibia (shinbone) and helps stabilize and control the sideways movement of the knee. X-rays use low levels of radiation and give doctors a view of a person’s bones. Third Party materials included herein protected under copyright law. Some of these sports include: Swimming (due to leg kicks for the breaststroke or whip-kick technique). Recent advances in computational mechanics of the human knee joint. Comput Math Methods Med. How Is a Medial Collateral Ligament Tear Diagnosed? However, the symptoms can worsen within a few hours. The torn MCL might require reconstructive surgery if it is a grade 3 MCL tear that involves other knee ligament injuries, or if the knee joint continues to be unstable despite several weeks of nonsurgical treatment. Medscape. The medial collateral ligament is one of four ligaments that help stabilize the knee. 2. THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. You can suffer an MCL injury when someone hits you on the outside of your knee. Posterior Cruciate Ligament: Current Concepts Review. Arch Bone Jt Surg. A torn MCL is a fairly common sports injury. Due to the more complex anatomy of the outside of the knee, if you injure your LCL, you usually injure other structures in the joint, as well. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Knee Pain in Adults and Adolescents: The Initial Evaluation. and what type of treatment you need. Although MCL injuries do not show up on standard X-ray exams, they are a relatively inexpensive, fast way to rule out other possible injuries that might … Pain (ranging from mild to severe depending on injury grade) on the inside of the knee. Posterior Cruciate Ligament Injuries. Someone who has torn their MCL will notice pain and swelling in the knee after the injury. 7 Signs You're Ready for Knee Replacement. In the immediate aftermath of an impact to the knee, most people feel pain mixed with shock. Tear muscle hit dash: Mcl tear happens when your knee is hit directly on its outer side with a force, or by repeated stress.It will be really hard to tear mcl by hitting th … Ashley Festa is a Greenville, S.C.-based freelance writer and editor who has been writing professionally for nearly two decades. Treatment is usually with ice, a knee brace, and physical therapy. J Knee Surg. UC San Diego Health. Swelling of the knee can also occur in more severe injuries to the MCL, or if you injured the ACL at the same time. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK431095/, Evans J, Nielson Jl. Your recovery from an MCL injury can vary from weeks to months depending on the severity of the tear. A torn MCL usually happens from a blow to the outside of the knee. The twisting or bending of the lower leg too far can also result in the injury. Overuse of the MCL from repeated stress can stretch out the ligament and cause injury. These symptoms indicate a partially torn MCL. The most serious injury to the medial collateral ligament is classified as a grade 3 tear and involves a total rupture of the ligament. A torn MCL is the most common knee ligament injury and can be either a partial or complete tear. In: StatPearls [Internet]. Treatment for a sprained or torn … doi:10.2519/jospt.2010.3345, Lespasio MJ, Piuzzi NS, Husni ME, Muschler GF, Guarino A, Mont MA. The feeling of an MCL tear differs from person to person and based on severity. 2017;8(5):495-511. doi:10.1016/j.jare.2017.04.008, Lee PYF, Nixion A, Chandratreya A, Murray JM. The content on Healthgrades does not provide medical advice. 2012;94(5):351-5. doi:10.1308/003588412X13171221591015, Gwinner C, Märdian S, Schwabe P, Schaser KD, Krapohl BD, Jung TM. And while ACL tears and MCL tears can differ in severity and treatment, most tears will not heal on their own. Perm J. Crutches are a pain. Hergenroeder AC, Harvey BS. It seems unfair that a good night’s sleep, which would make you feel so much better, is so hard to attain when you’re suffering from back, neck or shoulder pain. Regular physical exercise to strengthen muscles and bones may help prevent MCL injuries. In severe cases, multiple ligament injuries may lead to amputation. Surgery is rarely needed to treat a torn MCL. Wearing a brace and applying ice to the injury, along with doing physical therapy exercises, will usually allow the ligament to heal completely. What happens when your immune system attacks your joints? It may take 6 months or longer until you regain full use of the knee and are able to do high-impact activities. However, because these injuries are somewhat less common than other knee injuries like ACL tears, you may be unfamiliar with the symptoms and available treatment options. 2014;2(1):29-36. Thankfully, neither the MCL nor the LCL are removed during a total knee replacement surgery. To schedule your consultation today, please click below and enter your information or call OC Orthopedic at (714) 979-8981. © Copyright 2020 Healthgrades Operating Company, Inc. Patent US Nos. Prevention. Use of this website and any information contained herein is governed by the Healthgrades User Agreement. An ACL tear will have a more distinctive and loud popping sound than an MCL tear. Knee Osteoarthritis: A Primer. The MCL keeps the knee from bending inward. 2014 Feb; 3(2): 20–31. MCL Sprains and Tears. It can occur when someone quickly changes direction or twists the knee while running. An individual with an MCL tear may notice the following: A popping sound when the injury is sustained. You are most likely to hurt your MCL while engaging in activities that involve twisting, bending or quick change in direction. According to Virtual Sports Injury Clinic, surgery is not typically needed for an MCL tear, but MCL tears are frequently associated with simultaneous damage to your anterior cruciate ligament, or ACL, and it’s important you receive the treatment needed for full recovery 3. A tear to the medial collateral ligament in the knee can cause pain, swelling, and a lack of stability in the knee. Most MCL tears are caused by a blow to the outside of your knee, which causes your knee joint to collapse toward the center of your body, placing stress on your MCL that causes it to rupture. 10 Things to Know About Psoriatic Arthritis. 2018;26(6):e120-e127. Grade 3: The person will have severe pain and tenderness on the inside of the knee, and there will be swelling at the site of the injury. Pache S, Aman ZS, Kennedy M, et al. A grade 2 MCL injury means that your ligament has been partially torn. Int Orthop. When a force overpowers the MCL’s strength, a tear occurs. Johns Hopkins Medicine. Synovial Plica Syndrome of the Knee: A Commonly Overlooked Cause of Anterior Knee Pain. This kind of blood clot can travel to your lungs and cause a pulmonary embolism. According to Virtual Sports Injury Clinic, a torn MCL is usually associated with significant knee swelling, a locking or catching as you extend and flex your knee joint, pain or tenderness to the touch at the inside of your knee — and your knee may give way when you’re walking 13. Browne K, Kurtz CA. It is possible to injure two or more ligaments at the same time. 2012;7:21. doi:10.1186/1749-799X-7-21, Ragab G, Elshahaly M, Bardin T. Gout: An old disease in new perspective - A review. Copyright © 2021 Leaf Group Ltd., all rights reserved. Additionally, the location of your pain and swelling could indicate either an ACL or MCL tear. The most common symptom of an MCL tear is feeling a snap or a pop on the inner side of your knee after you were struck. MCL injury is often the result of a direct blow to the outside of the knee, for example, when the trauma pushes the bones of the knee with enough force to tear or stretch the MCL ligament on the inside of the knee. If you think you may have a medical emergency, immediately call your doctor or dial 911. Or you can cut to change directions and injure it. Specific physical therapy exercises can strengthen your leg muscles and help restore your knee’s range of motion. Current concepts review: Fractures of the patella. 2008;3(4):226-233. 2016;8(9):e780. Football and basketball players are susceptible to MCL tears. J R Soc Med. 2017;21:16-183. doi:10.7812/TPP/16-183, Kiapour AM, Murray MM. Lateral Collateral Ligament The lateral collateral ligament runs along the outside of your knee and prevents it from moving too far out. Keeping the knee elevated decreases blood flow to the injured area and reduces swelling. (Reviewed March 2014). Blunt CW, Jonas CE. Find out about psoriatic arthritis. Kim Nunley has been screenwriting and working as an online health and fitness writer since 2005. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499848/, Kiapour AM, Murray MM. (n.d.). (Review February 2009). A grade 3 MCL injury is the most severe type of ligament injury. The MCL is commonly sprained or torn during athletic activities, when there is a valgus stress, or a blow from the outside of your knee 4. The MCL is one of the strongest and largest ligaments in the knee. You will likely feel pain in the center of your knee during an ACL tear. This can cause an injury to either the MCL or to the ligament stabilizing the outer side of the knee, called the lateral collateral ligament (LCL). Journal of Pharmacy & Bioallied Sciences 2013 Jan-Mar;5(1):30-38. doi:%2010.4103/0975-7406.106561. American Academy of Orthopedic Surgeons. Hence, it results in an unnatural bend towards your other knee. ; Medical professionals refer to knee injuries that involve the MCL injuries as sprains or tears. 2018;3(5):260-268. doi:10.1302/2058-5241.3.170067. 7  The knee can be immobilized for a few days initially, but early range-of-motion will help in the recovery process. Bronstein RD, Schaffer JC. If you or someone you love is experiencing knee joint pain after a sports injury, you may be wondering if it could be a tear of the medial collateral ligament (MCL). 2015;7(4):359-65. doi:10.1177/1941738113520130, Huang YC, Yeh WL. Medial Collateral Knee Ligament Injury Treatment & Management. Never ignore professional medical advice in seeking treatment because of something you have read on the site. Diagnostic Imaging . Knee Ligament Repair. MCL tear also known as medial collateral ligament tear can happen when your knee gets struck. If your knee is too swollen, you will be unable to determine whether your MCL is injured. Your mechanism of knee injury can give a clue to whether or not you injured your MCL. Septic arthritis of the knee: the use and effect of antibiotics prior to diagnostic aspiration. Blood clot, particularly a deep vein thrombosis (DVT) that develops in the leg or pelvis. Your doctor will likely perform an MCL tear test called the valgus stress test. (2017). According to Virtual Sports Injury Clinic, a torn MCL is usually associated with significant knee swelling, a locking or catching as you extend and flex your knee joint, pain or tenderness to the touch at the inside of your knee — and your knee may give way when you’re walking 1 3. A progressive 5-week exercise therapy program leads to significant improvement in knee function early after anterior cruciate ligament injury. J Orthop Sports Phys Ther. There are 3 grades: A grade 1 tear is a sprain where the MCL is stretched but is not torn. (Review March 2014) Collateral Ligament Injuries. Contact: An MCL injury usually occurs when there is a force through the outer side of a bent knee, e.g. The doctor will rest her hip against your knee, then place her closest hand on the inside of your knee to keep it steady against her hip. He or she will ask how you hurt your knee and your symptoms right after the injury. Always consult a medical provider for diagnosis and treatment. You may need to adjust your daily routine to avoid certain movements, such as squatting or kneeling, that could worsen the MCL tear. In addition to Healthgrades, she also has written for Johns Hopkins School of Nursing, the University of Texas at Arlington School of Nursing and Health Innovation, and Fit Pregnancy magazine. Am Fam Physician. 2018 Nov 1;98(9):576-585. Baker's Cyst: Diagnostic and Surgical Considerations. When the knee is moved by hand, the joint will be loose. 2018;6(1):8–18. Physical contact may also be to blame. Some braces will allow your knee to move forward and backward, and others will completely immobilize the knee. When a grade III MCL tear occurs, patients should brace their knee and use crutches until the pain has subsided. Once the swelling and pain have lessened, your doctor will make the diagnosis. To diagnose an MCL tear, your doctor will ask you questions about your health and your level of activity. The MCL is a band of tissue on the inside of your knee. Naqvi U, Sherman Al. Sports Health. Hyperextension of the Calf. A torn MCL usually happens from a blow to the outside of the knee. The MCL is injured more often than the LCL. Grade 1: Mild pain and tenderness in the knee indicates an MCL sprain. As we saw with Steph Curry, an MCL injury can also occur if our leg slides to the side and our knee caves inward. MCL Tear. American Association of Orthopedic Surgeons. A doctor will likely order an MRI to confirm your ligament tear. Together, the ACL and MCL (along with the PCL and the LCL) are vital to knee stability and functionality. Prior to writing full-time, she worked as a strength coach, athletic coach and college instructor. The main symptoms of an MCL tear include pain, instability, and swelling. Your doctor will likely perform an MCL tear test called the valgus stress test of your knee 4. If your knee joint feels flimsy and has excessive laxity or is allowed to open further than normal, the MCL is torn or if you have an MCL sprain. Learn what to expect depending on what part of your leg you break A torn MCL is the most common knee ligament injury and can be either a partial or complete tear. American Academy of Orthopedic Surgeons. J Adv Res. The joint will be noticeably unstable when manipulated by hand and could buckle under pressure.