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Medial Collateral Ligament Injury of the Knee


A medial collateral ligament (MCL) injury is a stretched partial or complete tear of the ligament on the inside of the knee. It is one of the most common knee injuries and is mainly caused by knee valgus forces [1] [2].

Clinically Relevant Anatomy 

The medial collateral ligament is a large ligament on the inside of the knee. For more clinically relevant knee anatomy, click here. The medial collateral ligament (MCL) is one of four ligaments critical to maintaining the mechanical stability of the knee joint. ligament The sleeve spans the entire inside of the knee from the inside of the extensor mechanism to the back of the knee [3]

Ligaments, made up of lots of collagen fibers and few elastic fibers, not only control excessive motion by limiting joint range of motion, but are also a source of proprioception. Its function is to resist forces applied from the outer surface of the knee, thereby preventing the inner part of the knee from The joint widens under stress [1]. Proprioceptors are located in ligaments, but also in muscles and joint capsules. These proprioceptors monitor the position of our limbs in space, our movements, and the effort we put into lifting objects. [4]

Epidemiology /Etiology

MCL injuries mainly occur after an impact to the knee, calf or outer thigh when the foot is in contact with the ground and cannot move. The MCL on the medial side of the knee will be stressed by impact, and the combined flexion/valgus/external rotation motion will cause Tears in the fibers. Athletes may experience immediate pain and feel or hear a pop or tear. [5] In most cases, the deep part of the ligament is damaged first, which may result in medial meniscal injury or ACL injury [3] [5]

Characteristics/Clinical Presentation

Like all ligament injuries, MCL injuries are graded I II or III (the grade depends on how much the tear persists). Grade I tears include less than 10% of the collagen fibers being torn, with some tenderness but no instability. Most patients experience pain when we apply Bend the outside of the knee slightly to exert force, but no other symptoms. [5]

Symptoms of grade II tears vary, so they are further subdivided into grade II (which is closer to grade I) and grade II which is closer to grade III, but both count as tender but not unstable. [5] Pain and swelling are more severe than grade I injuries. when the knee is Emphasize (for grade I) that the patient complains of pain and marked tenderness on the medial side of the knee joint, and moderate laxity of the joint is observed.

Obviously, this means that a Grade III tear is a complete rupture of the MCL, resulting in instability. The patient had significant pain and swelling over the MCL. Most of the time, they have difficulty bending their knees. As mentioned earlier, grade III tears can cause instability when the knee is under pressure (As above) There is laxity in the joints. Grade III MCL injuries have an additional scale to measure the degree of instability. These are more information described from the amount of joint separation in the 30° valgus test. [3][6]

Grade Symptoms Signs Test joint space I Mild medial pain Swelling and claudication Possibility of medial edema tenderness Medial edema tenderness Positive abduction stress test 0 to 5 mm II Moderate medial pain Swelling and claudication Unstable Medial edema tenderness Positive McMurray test (if meniscus is Involve) Abduction Stress Test 6 to 10 mm III Severe medial pain Swollen knee gives way to valgus Significant medial edema tenderness Rahman’s test for ACL stability should be done when Grade III MCL instability is present. > 10 mm

Grade I and II injuries have clear endpoints, in contrast to grade III tears, which have a soft endpoint on the valgus stress test. [7]

Grade I tears involve tearing less than 10% of the collagen fibers. Symptoms of grade II tears vary, so they are further subdivided into grade II (closer to grade I) and grade II (closer to grade III). Obviously this means that a Grade III tear is a complete rupture of the MCL. when Patient with knee compression (for grade I) complains of joint pain with moderate laxity and marked tenderness on the medial side of the knee. When we talk about grade III tears of the MCL. The patient had significant pain and swelling over the MCL. They are hard to bend most of the time knee. Another common finding in Grade III tears is instability. Joint laxity occurs when we put stress on our knees (as described above).

Differential Diagnosis

A differential diagnosis is necessary to rule out injuries that may cause the same symptoms as an MCL injury of the knee. These injuries are: [8] [9] [10]

  • Medial meniscal tear/injury
  • Anterior cruciate ligament (ACL) tear
  • Tibial plateau fracture
  • Femur injury or fracture
  • Patellar subluxation/dislocation
  • Medial knee contusion
  • Pediatric distal femoral fracture
  • Damage to posteromedial horn structures

A physical examination will help ensure a correct diagnosis. A medial meniscal tear may be mistaken for an MCL sprain because the tear can cause joint tenderness like a sprain. A medial meniscal tear can be distinguished from a grade II or III MCL sprain by examining valgus laxity. this An opening at the joint line indicates a tear in the medial meniscus. Grade I MCLs are more difficult to differentiate from medial meniscus tears. The distinction can be made by MRI or by observing the patient for several weeks. If an MCL sprain occurs, there is usually tenderness Resolved as the meniscal injury persisted. [1] [11] [12]

When there is tenderness but no abnormal valgus laxity, a medial knee contusion is likely. If the tenderness is near the adductor tubercle or medial retinaculum close to the patella, the cause is more likely to be a luxation or subluxation of the patella. Instability of the patella may be Differentiate from MCL sprains with the patellar fear test. A positive result means patellar instability is present. [1][11][12]

If the patient is a child, mild stress test radiographs can determine if they have a distal femoral fracture rather than an MCL sprain. [1][11][12]

Diagnostic Procedures

The patient’s medical history is important to know where the pain is. After identifying the pain site, the therapist must feel for tenderness or soft tissue swelling. For this, he needs to palpate the knee joint. Most often, the pain is on the inner side of the knee. Soft tissue swelling may also occur. As mentioned previously, there are three grades of MCL tears. The grade is based on the degree of pain or the extent of the opening of the joint space during the patient’s knee stress test. [13] [14]

  • MCL valgus stress test
  • Swain test
  • Anteromedial drawer test
Outcome Measures
  • International Knee Documentation Committee (IKDC)
  • Tegner function score 
  • Lysholm knee score [15][7]

An international committee of knee experts created the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF), a knee-specific rather than disease-specific measure of symptom function and physical activity. IKDC-SKF is a reliable and valid knee-specific measurement Symptomatic, functional and physical activity for patients with various knee problems. Outcomes are related to the severity of the injury and possible functional recovery. [16]

Clinicians use different instruments to identify pain dysfunction and changes in patient status during treatment. They used validated patient-reported outcome measures, general health questionnaires, and validated activity scales. [14][15]


Clinical assessment is important to determine whether the injury is localized to the MCL or whether other structures have been compromised. First of all, a lot of information can be obtained through the patient’s description of the injury. Second, the opposite knee should be checked so that both legs can Comparison of. When examining the knee, it is important to determine the presence and localization of swelling. Typically, solitary swelling occurs on the medial side of the knee joint [17]. It is important to palpate the MCL along the medial side of the knee and assess for tenderness Note the location of greatest tenderness (femoral and tibial sides) [18]. From this angle we are almost certain that MCL is injured. Third, attention to damage mechanisms is important to determine which structures are damaged. [19]

Also, it’s important to note that the best time to check your knee immediately is after an injury, before any muscle spasms occur. Unfortunately, this opportunity is only available if a doctor was present at the time of the injury. In those patients with severe muscular In patients with spasticity, it is usually sufficient to give them a fixed period of 24 hours to relax and examination under anesthesia is rarely required [3].

To examine the medial collateral ligament itself, a two-part valgus stress test can be used. First, a valgus stress is applied to the knee with the knee fully extended. The same test is then performed, but with the knee bent at 30 degrees [17]. Purpose of testing MCL Knee flexion of 0° and 30° is necessary to assess the medial joint space widening and sensory firm endpoints. It is important that the foot remains externally rotated during the test so that the examiner does not overestimate slack The result of knee rotation from internal to external rotation [18]. Any asymmetry is considered a positive result of the test [17] Laxity of valgus stress with the knee at 0° indicates the possibility of a compound injury. This can cause cruciate ligament or posteromedial injury Cystic structure [18]. For more information on this test and its interpretation, you can consult Knee Exam.

A second test may be done to check the medial collateral ligament, the Swain test. This test checks for chronic damage and rotational instability of the knee joint [17]. This test is performed by bending the knee to 90 degrees and rotating the tibia outward. knee position This leads to laxity of the cruciate ligaments while tightening of the collateral ligaments [17]. When pain is felt on the medial side of the knee, it is likely that the MCL complex has been injured [17].

Another test that can also be performed to assess the amount of rotational stability present and whether the injury involves only the superficial and deep MCL is the anteromedial drawer test. For more information on this test, see the page: Knee MRI Anterior Drawer Test Imaging (MRI) is also an important tool in the detection of medial collateral ligament injuries. It is currently the only instrument that can visualize morphological and functional joint damage [20]. For more information on ACL and PCL checking, see these pages harm:

Medical Management

The first three grades are the same for every ligament injury. Grade I sprain Grade II is a partial tear Grade III is a complete tear of the ligament. Some surgeons describe grade 4 injuries of the MCL, also known as medial column injuries. When harm affects more than just Medial collateral ligament (MCL), which may require surgery. Common injuries in combination with medial collateral ligament injuries are anterior cruciate ligament (ACL) injuries, bony contusions, lateral collateral ligament injuries (LCL), lateral and medial meniscus tears, and posterior Cruciate ligament injury (PCL). ACL disruption is most often associated with advanced MCL tears.

Regardless of severity, most isolated MCL injuries are well managed with nonsurgical management. The treatment of grade I and II MCL injuries must be differentiated from that of grade III MCL injuries. [3][21] We can also differentiate grades according to laxity and pain:

  • Grade I injuries produce pain without relaxation (
  • 5-10 mm of laxity usually makes grade II injuries more painful;
  • Grade III injuries may be less painful due to complete rupture of the ligament, which allows for significant laxity (>10 mm) at the time of testing [18]

Most treatments for isolated grade I and II MCL injuries are nonoperative and require physical therapy approaches [3] In the case of grade III injuries, results of nonoperative management are less clear. Treatment depends on whether the lesions are isolated to the MCL, or whether they Combining other ligaments damages their location (more tibial or femoral side of the ligament) and involvement of posterior structures. With MRI imaging, the exact location of the injury can be localized, which helps in deciding on treatment decisions [3] [21]. so Injuries involving multiple ligaments (Grade 4) may require reconstruction or augmentation on an acute basis. Augmentation can be done by different techniques. [3] When performing strengthening tendons from muscles, such as hamstrings are used to “replace” the ACL. [twenty two]

Failure to recognize compound injuries or incomplete healing of the medial knee joint may result in persistent chronic valgus and rotational instability and functional limitations. Especially when the posterior oblique ligament complex (POL) is involved. must have special Care should be taken to identify involvement of the posterior oblique ligament and joint capsule [21]. Some investigators have reported good outcomes after nonoperative management of grade III MCL injuries, but the results were not as consistent as grade I and II tears.

Most isolated grade III injuries are in the femur and do not require surgery. An important test to determine if surgery is necessary is to look for damage to the posterior oblique ligament (POL) and posterior capsule. Surgery should also be considered in the case of goosefoot tendon be damaged. The case of an entire superficial injury is a complete injury of the superficial and deep MCL of the tibia, is a typical injury, and is best managed surgically. Grade III injuries with 0° extensional instability are also classified as Categories of recommended actions [3][21]. In addition, we should note that surgical reconstruction is recommended for isolated symptomatic chronic medial knee injuries [3].

Physical Therapy Management

Treatment of medial collateral ligament injuries rarely requires surgical intervention. The extracapsular medial collateral ligament appears to have a fairly robust healing potential [8]. In case of instability or persistent instability after nonsurgical treatment After ACL and/or PCL reconstruction, MCL tears can be resolved with surgical repair or reconstruction [23]. Most isolated MCL injuries can be treated non-operatively with braces or immobilization. A few simple treatment steps along with rehabilitation will enable patients to return to their previous activity level. Most treatment options focus on early range of motion, reducing swelling to protect weight bearing progression, and strengthening and stabilizing exercises. The overall goal is to return the athlete or patient to full activity [21].

The overall rehabilitation principles are [24]:

  • To control edema
  • M. quadriceps activation is initiated within the first hours to days after injury.
  • Working to restore knee range of motion as early as possible

We can divide the medial knee joint injury into three grades. [19]

Grade 1

The treatment of isolated grade I injuries is mainly non-surgical. During the first 48 hours, ice compression and elevation should be used whenever possible. Typically, incomplete tears of the MCL are treated with temporary immobilization and the use of crutches to control pain. isometric Begin isotonic and eventually isokinetic progressive resistance training within a few days after pain and swelling subside. Weight bearing is encouraged and the speed is determined by the degree of pain. [8] .

Grade II / III

For the treatment of grade II/III injuries, it is important to protect and allow the ligament ends to heal without sustained damage. Undue stress on the healing structures should be avoided for three to four weeks after the injury to ensure the wound can heal Appropriately. Treatment of grade III injuries depends on whether the injury is isolated or associated with other ligamentous injuries [21]. For grade III medial knee injuries combined with another injury, such as an ACL tear, the general protocol is rehabilitation of the medial knee injury First, it can heal according to guidelines for isolated medial knee injuries. ACL reconstruction can be initiated if there is good clinical and/or objective evidence that the medial knee injury typically heals within 5 to 7 weeks of the injury. [twenty one] .


Rehabilitation with non-surgical treatment can be divided into four phases:

  • The first phase is one to two weeks. The first phase involves controlling knee swelling by applying ice for 15 minutes every two hours (for the first two days). The rest of the week the frequency can be reduced to three times a day. Use ice as tolerated and needed based on symptoms. at first The patient needs to use crutches. Early weight bearing is encouraged, as patients with increased weight bearing can gradually reduce their dependence on crutches. A cane was then developed, and the patient was only taken off the cane when normal gait was possible. Another goal of this phase is to try to maintain the ability to straighten and flex the knee joint from 0° to 90° of flexion. To achieve the knee’s range of motion, it is important to emphasize full extension and, where tolerated, flexion. Hamstring Quadriceps Painless Stretch Recommended for working the groin and calf muscles (especially). Finally there are therapeutic exercises. Patients can begin with static strengthening exercises (as long as pain permits). They include, for example, quadriceps sets, straight leg raises, range of motion exercises, seated hip flexions Sideways hip abduction stance hip extension stance and hamstring curl. Once patients are tolerable, they are encouraged to ride a stationary bike to improve the knee’s range of motion. This will ensure faster healing. Time and effort spent on a stationary bike Increased if tolerated. Obviously every patient is different and these are not standard exercises that have to be given to the patient. There is no limit to upper body exercises that do not affect the injured knee [21]. It is important for the patient to rest from all painful activities (crutches if necessary) and the MCL is well protected (by wearing a stabilizing knee brace).
  • From the third week, the second phase begins. The goals for range of motion are the same as for Phase 1. 20 minutes by bike. Also increases the resistance tolerated by the patient. Cycling will ensure healing rebuilds strength and maintains aerobic conditioning. this A physical therapist can perform other exercises such as hamstring curls, leg presses (for both legs) and steps. As a precautionary measure, the patient has the opportunity to be checked by a doctor every three weeks to verify the healing of the ligament [21].
  • The third stage starts from the fifth week. The main goal of this phase: Full weight bearing on the injured knee. Stop using the brace when you can walk with full weight bearing and no gait deviation. full range of motion must be achieved and must be used with No knee injury. The therapeutic exercises are the same as in the second stage. They may be good for progress. We continue with cold therapy and compression to remove swelling. At this stage, you can begin to work on balance and proprioceptive activities. To maintain aerobic fitness, patients can use Stepper or (if possible) maybe start swimming. As a precaution, patients have the opportunity to be checked by a doctor every five to six weeks. When needed, you may be allowed to have stress radiography as a precaution. [twenty one]
  • Six weeks after the knee injury, the fourth phase can begin. Stop wearing the brace during gait. Athletes may wear a competition brace for at least three months during the competition season. Cold therapy is still needed. The purpose of therapeutic exercises is to focus more on Specific sports or daily sports. The intensity of strengthening exercises should be increased, and double-leg exercises should be changed to single-leg exercises. Patient can start running again at a comfortable pace (make sure patient does not change running pace suddenly) direction). As a precaution, it is best to return to play after full motor and strength recovery and the patient has passed motor function testing [21].

Obviously each patient is different, so application of these principles should be guided by principles of holistic rehabilitation [21]

Applying cold therapy can reduce swelling immediately after an injury, but it won’t help the ligament’s healing process. [25]


In many cases, an adequate warm-up can help prevent MCL injuries. In particular, a neuromuscular warm-up program appears to be effective in reducing multiple injuries to the knee. Program includes exercises targeting the legs and core muscles Balanced landing technique and proper joint alignment prevent lateral trunk displacement and excessive knee valgus. As mentioned previously, these are two risk factors for such injuries [26]. A warm-up can include exercises like side cuts and single-leg landings. these are high risk sports. By controlling them during the warm-up, it will ensure that the knee can respond appropriately to these movements [27].

Clinical Botom Line

A medial collateral ligament (MCL) injury is a stretched partial or complete tear of the ligament on the inside of the knee. Valgus trauma, or external rotation of the tibia, is responsible for this injury. There are 3 classes of this damage: I II and III. Category depends on pain level or degeneration of the knee joint. A therapist can use an valgus stress test to see if the diagnosis is correct. There are several rehabilitation methods for MCL injuries, but rest is the most important. When resting, the MCL has time to recover. There are other rehabilitation techniques such as And patellar/soft tissue mobilization and friction massage gait training cold therapy etc. In rare cases, surgical intervention is necessary.

Key Research
  1. Irrgang JJ Fitzgerald GK ( 2000 ) Rehabilitation of the knee joint with multiple ligament injuries
  2. Yastrebov O. Lobenhoffer P. (2009) Treatment of isolated and multiple ligamentous injuries of the knee: anatomical biomechanical diagnostic indications for revision surgery
  3. Swenson TM (2000) Physical diagnosis of the knee with multiple ligament injuries
  4. Scheidt DK (2003) Treatment of multiple ligament injuries and dislocations of the knee: a trauma perspective
  1. Bahr r Maehlum S Bolic T. (2002) Sports Injuries Clinical Guidelines: An Illustrated Guide to Sports Activity Injury Management p. 321-324 pages 328-329
  2. Carnarvon PK. (1998) Sports Medicine Rehabilitation: A Comprehensive Guide p. 293-295 pages 301-304
  3. Patrick J Macmahon MD (2007) Diagnosis and treatment in current sports medicine p. 77-82
  4. Bergner FA. (2006) Magnetic resonance imaging differential diagnosis p.396
  5. Brand Newman Road. (2004) Orthopedic Secrets p. 328-332
  7. http://www.jospt.org/doi/abs/10.2519/jospt.2017.0303 Clinical Practice Guidelines: 2017 Revision for Knee Ligament Sprains

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