Author

Dr Keran Sundaraj MBBS MSc (Trauma) FRACS FAOA

Medial collateral ligament (MCL) sprains or tears are common sporting injuries. They are particularly common in contact sports such as soccer, football and skiing.

Anatomy

The MCL is compromised of two components running on the inner side of the knee:

Superficial MCL; 

• Begins at the end of the femur (thighbone) on a bony prominence called the medial epicondyle.

• Inserts on the tibia (shin bone) below the pes anserinus (the end of the hamstring tendons)

Deep MLC;

• Lies underneath the superficial MCL.

• Begins just below the medial epicondyle.

• Attaches to the rim of the medial meniscus.

• Inserts on the tibia just below the joint line.

Cause

Injury to the MCL is usually caused by force pushing the knee into valgus (knock-kneed). MCL injuries are more commonly seen during contact injuries.

Imaging

X-ray

• They are used in acute episodes of a knee injury to ensure there are no fractures around the knee joint.

• A bony formation may be seen around the medial epicondyle (Pellegrini Stieda lesion) in chronic injuries. This is only an x-ray finding and will not cause any symptoms or affect function.

MRI

• An MRI is performed for all suspected MCL injuries. This will help to determine the location and type of MCL injury.

• This should be performed within days of the initial injury.

• MRI grading may be applied to help classify the nature of the injury. However, this is not the same as the 'clinical' grading system.

Grading

Clinical examination - involves assessing how tight the MCL is in a specific position (30 degrees of flexion). <3mm of movement is considered normal, and all measurements should be compared to the other (normal) knee:

• Grade 1 - 3-5mm

• Grade 2 - 6-10mm

• Grade 3 - >10mm

MRI examination

• Grade 1 - minor sprain with fluid under the ligament

• Grade 2 - partial tear with high signal inside the ligament

• Grade 3 - complete disruption of the ligament

Clinical examination, rather than the MRI grading, is the most critical determination for treatment.  

Treatment

Initial treatment is with a period of rest, ice, compression, and elevation (RICE).

Conservative Treatment

This is appropriate for nearly all MCL injuries at the initial presentation. Depending on the location of the injury, this has more than a 90% chance of healing successfully.

Brace 

• May be applied initially to prevent sideways movement that strains the MCL.

• The most appropriate brace is a range-of-motion extension blocking splint. This allows the knee to move from 30 to 90 degrees. It provides side-to-side stability for the MCL to heal in the most appropriate position.

• You can walk in the brace but may require crutches for support.

• The brace can be removed to shower, but the knee flexed position must be maintained to prevent re-tearing the ligament.

Ice

• Can be applied for 10 minutes before and after exercise to help with inflammation and swelling.

Physical therapy

• Can be directed by your physiotherapist.

• Generally, a stationary exercise bike program can be commenced in the days following injury whilst wearing the brace.

Surgical Treatment

This may be required in certain circumstances:

• Injuries that remain lax despite appropriate conservative (brace) treatment after six weeks.

• Injuries associated with other ligament injuries (e.g. ACL injuries)

• Injuries off the tibia (shin) bone as these heal poorly, with high rates of residual laxity.

Surgery is performed as a combined arthroscopy (key-hole) and mini-open procedure to tighten the MCL. In general, a brace is not required after the operation, and you are allowed to put full weight on the leg whilst using crutches.

What is involved for you as the patient if surgery is required?

• Healthy patients are admitted on the morning of their surgery and discharged in the afternoon.

• There must be no cuts, scratches, pimples or ulcers on your lower limb as this increases the risk of infection. You should not shave or wax your legs for one week before surgery.

• Patients should cease smoking and taking the oral contraceptive pill one week before surgery.

• Sedentary and office workers may return to work approximately 2-5 days following surgery.

• Driving an automatic car is possible as soon as pain allows after left knee surgery. Should the right knee be involved, driving is permitted when you can walk without crutches.

• Physiotherapy is commenced immediately. Your physiotherapist will supervise strengthening and walking. Crutches, but no brace, are required for 3 weeks to protect the MCL repair.

• Playing sport non-competitively or training is possible at 6 weeks. A return to competitive sport is permitted at 3 months following surgery, provided that there has been a complete rehabilitation.

Potential complications related to surgery  

• Pneumonia: Patients with a viral respiratory tract infection (common cold or flu) should inform the surgeon as soon as possible and may have their surgery postponed. Patients with asthma should bring their inhalers to the hospital.

• Deep vein thrombosis and pulmonary embolus: Although this complication is rare, a combination of a knee injury, prolonged transportation and immobilisation of the limb, smoking and the oral contraceptive pill or hormonal replacement therapy (HRT) all multiply to increase the risk. Any history of thrombosis should be brought to the attention of the surgeon. The oral contraceptive pill, HRT and smoking should be ceased one week before surgery.

• Excessive bleeding resulting in a haematoma is known to occur with patients taking aspirin or nonsteroidal anti-inflammatory drugs such as Voltaren, Naprosyn or Indocid and should be stopped at least one week before surgery.

Potential complications specifically related to your knee reconstruction surgery 

• Postoperative bleeding and marrow exuding from the bony tunnel may track down the shin causing red, inflamed and painful areas. When standing up, the blood rushes to the inflamed area causing throbbing. This should ease with elevation and ice packs. This is a normal postoperative reaction and only delays short term recovery.

• Due to the skin incision, you may notice a numb patch on the outer aspect of your leg past the skin incision. The numb patch tends to shrink with time and does not affect the result of the reconstructed ligament.

• Reinjury rates are specific to you based on anatomical and lifestyle factors. These will be discussed with you at the time of your consultation.

• Surgery is carried out under strict germ-free conditions in an operating theatre. Antibiotics are administered intravenously at the time of your surgery. Despite these measures, following MCL surgery, there is a < 1 in 400 chance of developing an infection within the joint.

As with all operations, if at any stage anything seems amiss, it is better to call for advice rather than wait and worry. A fever, redness or swelling around the line of the wound or an unexplained increase in pain should all be brought to the surgeon's attention. You can contact Dr Sundaraj by telephoning his staff during business hours or the Mater Hospital after hours. For any questions, please do not hesitate to contact our staff (02) 9437 5999 For after-hour assistance contact Mater Hospital (02) 9900 7300 Further information is available on our website.