HEALTHNET

Knee Ligament Injuries

It's just after the exams, the twin brothers Kin and Keung are already devoting themselves to summer football training. They love playing football and always dream of becoming star players like their favorite idols from English Premier League and South American footballs. Both of them have had some kinds of foot injuries, though not serious. They are practicing particularly hard this summer. One day, their father came to cheer for them. The twin brothers played perfectly on the football pitch, Keung made a high speed pass and Kin turned agilely to catch. Immediately after a sudden "snap" sound was heard, Kin felt a tearing pain from his knee joint and fell down. Everyone ran to his aid nervously. "He might have torn his ligament!" said the coach. "He will need a surgery just like those football stars!" Keung thought. "Is it really that serious?" their father doubted.

 

• The four knee ligaments with different functions
• Different levels of tears could be concealed
• Muscular atrophy due to negligence of tears
• The surgery to reconstruct the ligament can only be conducted under steady condition.
• Recovery physiotherapy to train body motions
• Warm up and cool down before and after exercise

Source: Dr Kenric S. K. Lau, Specialist in Orthopaedic Surgery

The four knee ligaments with different functions

A knee joint is connected by anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament and lateral collateral ligament. The ligaments hold the joint in position, coordinate movement and smooth out knee bending motions. Each ligament has different functions:

• Medial collateral ligament: prevents the legs from bending outwards when stretching or folding the joint.
• Lateral collateral ligament: prevents the legs from bending inwards when stretching or folding the joint.
• Posterior cruciate ligament: prevents posterior displacement of the joint.
• Anterior cruciate ligament: prevents anterior displacement of the joint and stabilizes twisting motions.

 

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Different levels of tears could be concealed

There are two types of knee joint ligament tears, partial or complete tears, resulting from external forces. Ligaments are composed of several bundles of rope-like fibers. A tear starts with partial laceration and pulling of ligament until it slackens, no sharp cut-like wound will be observed. Such injury is partial tear, or called "sprain". With further stress, the ligament be torn apart completely. Not only complete tears but also partial tear with repetitive strain would affect knee motions.

Most people are unaware of their ligaments being pulled longer and longer after recurring knee joint injuries, as medication and a good rest could relieve the pain and swelling well, which wouldn't be obvious until serious injury occurs and be diagnosed by well-trained doctor.

Among the ligaments, the medial collateral ligament and anterior cruciate ligament are mostly injured. The most common causes of injury are:

• Collisions with players during ball games such as football and basketball.
• Sudden halt during high speed running when playing football, resulting to great pressure multiplied by the weight of the player. Also some rapid twisting motions of the upper torso can lead to severe twist of knee joint that pulls the anterior cruciate ligament.
• Landing hard after jumps can lead to rolling of legs that causes ligament injuries of basketball players.
• Water surfing, especially wakeboarding, places great pressure on both knees and causes injuries.
• Slip and fall during walking or exercise can cause sudden twisting of the knee and injure the ligament.

 

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Muscular atrophy due to negligence of tears

When the anterior cruciate ligament is torn, an obvious "snap" sound would be heard. The wound would then swell slowly, giving painful feeling, stiffness and immobility after an hour. The injured knee should be held in place and fixed firmly with support such as protection pads and compression bandages. The wound can also be treated with ice to reduce bleeding. Walking action should also be avoided lest pressure on legs should increase.

Some people consider sprained knee as minor injury and only apply simple treatments. The easing of bruises and swelling and lessening of pain are always mistaken for full recovery. The fact is that the ligament is already injured and the patient will find it difficult to apply force on legs. Due to the minor atrophy of quadriceps which ebb away strength, the patient will walk unsteady steps and have a feeling of walking with length-discrepant legs, gradually losing confidence in walking and exercising.

 

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The surgery to reconstruct the ligament can only be conducted under steady condition.

On the whole, regardless of partial or complete ligament tears, the condition can never be wholly recovered. Only the medial collateral ligament has a higher ability of healing among all bundles of ligaments. Surgery for the more common anterior cruciate ligament tear may be conducted depending on individual condition.

Certain motions would be affected for non-operated torn anterior cruciate ligament. Though most daily movements can still be done as usual, the patient might find difficulties in performing some actions such as ascending and descending stairs, making sudden halt and turn, and catching buses with hasty paces. If the patient gives up vigorous sport, serious problem can be avoided, only that early aging would be experienced. However if the patient continues with sport; or if physical labour is involved at work (e.g. policemen and fire fighters), the non-operated knee joint will encounter serious aging problem. The joint movements can be maintained at a higher level of agility for a longer period if surgery is conducted, even though aging would finally happen earlier than uninjured knee.

If it is confirmed that only the anterior cruciate ligament is torn after physical examinations and Magnetic Resonance Imaging scan, surgery is not immediately needed lest the joint should experience post-surgical inflammation and stiffness. Initial treatments include aspiration of knee joint if swollen and "RICE" (Rest, Ice treatment, Compression with bandage, Elevation). It's not too late for surgery to be conducted after three to four weeks when the knee joint restores its normal motion range. In the meantime, the patient can receive physiotherapy to strengthen muscles and to reduce the extent of muscle atrophy. The result would be undesirable if surgery is conducted one or two years after the injury, by which time the seriousness of muscle atrophy would make it difficult to train and strengthen muscles.

Taking the more common anterior cruciate ligament as an example, the surgery called the "anterior cruciate ligament reconstruction" first takes out the tendon from other parts of the body, mostly from the knee or inner thigh, then uses minimally invasive surgical skill to attach the tendon onto the bone to replace original ligament. The tendon will grow securely on the bone about three to six months after the surgery and the patient will fully recover with the help of proper physiotherapy.

 

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Recovery physiotherapy to train body motions

Post-surgical physiotherapy is an important step towards recovery, as it helps to:

• Strengthen and train the muscles for patients to walk steadily with confidence.
• Rebuild the died-down feeling of exercising due to knee joint injury.
• Grasp the motions in exercise.

The whole recovery therapy takes about six months for the patient to reclaim the motions in exercise. Then special training on individual exercise would be intensified. The most desirable period for the patient to return to original exercise habit is around nine to twelve months after surgery. As a result, professional football players suffered from anterior cruciate ligament injury need a whole season of rest before they can return to the pitch again.

Approximately 80% of function can be recovered if a patient follows through treatment procedures and guidance as well as receives physiotherapy consistently. Most patients are able to participate in pre-injury physical exercise.

 

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Warm up and cool down before and after exercise

Warm up exercise can reduce injury from strain of joints, ligaments and muscles, thereby avoiding ligament tears. Also stretching is needed after exercise to soothe muscle and reduce the lactic acid level, which help to enhance the flexibility of muscles.

Ligaments would not be deteriorated even for those who never exercise as daily body movements require motions of ligaments. Yet lacks of exercise would reduce strength as flexibility of joints, ligaments and muscles diminishes. Accidents or unexpected vigorous exercise will make it easier for muscle and ligament injury to those with weak muscle coordinating ability and blunt reaction.

 

Source: Dr Kenric S. K. Lau, Specialist in Orthopaedic Surgery

 

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