Knee

When a player injures his knee it is important to make a decision as to whether the injury is severe or minor.

Severe injuries, which require the removal of the player from the field, can be diagnosed by :

1. The player feels or hears a tear or pop in the knee.
2. The player feels the knee went out of place or felt unstable.
3. The player is unable to take full weight pain free on the knee.

These injuries include ligament sprains or tears, dislocations of the kneecap and cartilage (meniscus) injuries.

Minor injuries are usually bumps or kicks on the knee and in most cases, after a short period of recovery from the initial pain (with possibly local application of ice packs) the player can run freely, feel stable and functions normally.

Ligaments

There are two main ligaments within the centre of the knee. These cross one another from front to back and back to front and are appropriately called the cruciate (or cross) ligaments. These are the major stabilisers of the joint, especially for rotational movements.

The anterior (or front) cruciate ligament called the ACL is the more frequently injured. It can be torn either by contact, i.e. a tackle that causes the knee to rotate or twist, or even more commonly it is injured without contact. The player changes direction but his boot sticks in the grass and the knee is twisted, tearing the ACL.

The danger of continuing to play with this injury is that because of the potential instability of the knee, the cartilages (menisci) can be torn as they get pulled between the upper and lower bones (femur and tibia) as the knee twists out of place.

The posterior cruciate ligament (PCL) is usually injured by a direct blow (or fall) on to the front of the upper part of the tibia. It may get injured in a tackle with severe twisting. Usually other structures are injured in this latter mechanism.

The collateral (or side) ligaments are outside the actual joint. One is on the inner aspect of the knee (medial collateral ligament or M.C.L.) and one is on the outer aspect of the knee (the lateral collateral ligament or L.C.L). These ligaments are usually hurt when a force is applied to the opposite side of the knee bending the knee “open” on the side of injury, thus stretching the ligament. The M.C.L. can also be injured in a twisting movement. The M.C.L. is a very commonly injured ligament in rugby.

The cartilages usually get injured with a twisting motion often with the knee bent.

Swelling in the knee

It is important to note when swelling occurs in relation to injury –

Swelling that develops in the first 12 – 24 hours (and often sooner) usually indicates bleeding into the joint. This usually denotes a severe injury. Causes for this haemarthrosis (blood in the joint) are in order of frequency:

1. torn ACL
2. dislocated patella (knee cap)
3. tearing of the lining of the joint (called the synovium)
4. breaking off of a piece of joint surface (osteochondral fracture)
5. a tearing of one of the cartilages (menisci) where it attaches to the side ligaments
6. a fracture of the bones into the knee joint.

Swelling that develops 24 hours or later usually is clear fluid (water on the knee) and can be caused by:

1. a torn meniscus (cartilage) in its substance
2. an M.C.L. injury in which although outside the joint there is a reaction within the joint with a small amount of fluid and swelling
3. certain injuries to the fat pad and lining of the joint can also give rise to clear fluid swelling.

What Should Be Done About An Injury

1. Immediate first aid – R.I.C.E.
2. Crutches to take weight off the injured knee.
3. If there is a possibility of blood in the joint (early swelling) a specialist in knee injuries should be consulted. The blood should be drained under sterile conditions. This not only relieves pain, but also allows the doctor to check for fat in the blood, which may mean a severe injury. It also helps the player to get his quadriceps to work better which is important in order to maintain muscle tone.
4. X-rays need to be taken to check for any bone fragments or fractures.
5. Urgent surgery is NOT usually required unless there is a displaced piece of bone.
6. Treatment is based on accurate diagnosis and hence the need for consultation with a knee specialist is recommended.

Treatment

1. Torn A.C.L.

Reconstructive surgery when the inflammation in the knee is settled. This usually takes 3 – 5 weeks or even longer after the injury. It is not recommended to do surgery in the acute phase because of a stiffness problem after the operation.

2. Torn M.C.L.

Conservative treatment is usually sufficient to get a good result. The results from surgery and from conservative management are exactly the same. Bracing to protect the healing ligament from stress and crutches in the early phases is important. Physiotherapy and quadriceps rehabilitation is the cornerstone of management.

3. Torn P.C.L.

This may or may not require surgery depending on the degree of injury and if there are any other ligaments involved.

4. Torn L.C.L.

This often requires surgery because it usually gets damaged with other ligaments. Occasionally a simple sprain of this ligament occurs and can be treated conservatively.

5. Dislocated patella (knee cap)

This may need surgery depending on the extent of the damage. If treated conservatively bracing and rehabilitation can be used in those cases.

6. Torn cartilage

This is treated with arthroscopic surgery. Only the damaged piece of cartilage is removed or if the tear is near the edge where the blood supply is, the cartilage can often be repaired.

MRI Scans

These are only needed in a small number of cases in which the specialist may need more information to accurately diagnose and manage the problem. They are not needed in the routine case and almost all ligament injuries can be diagnosed clinically.

Prevention

Muscle strength and agility training and avoidance of fatigue and overload are the cornerstones of preventing major knee injuries.

Summary

Knee injuries are common and often career threatening in rugby. Awareness of the possibilities, correct diagnoses and management are essential to restore the joint to the best functional state. Re-injury is common in knees that have not been adequately rehabilitated and the deficiencies corrected.

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