Knee Conditions

How are knees injured in sport?

Knees are commonly injured in sport from jumping, baulking, twisting, tackling and falling. Injuries can be minor and tolerable, or they can be career-ending. Frequently seen are ligament injuries such as the cruciates or collaterals, or damage to the cartilage lining or meniscus inside the joint. A clear description of the injury mechanism usually reveals the structure that has been damaged. Early diagnosis is imperative to plan the correct rehabilitation. While some structures heal satisfactorily with time and treatment, other tissue damage is irreparable such as cartilage, cruciate ligaments. Surgery is often needed along with an exercise programme to strengthen the knee for return to sport.

What knee conditions result from mal-alignment?

Knees can also be effected by more subtle forces such as those imposed by poor alignment of the lower limb. While these problems can strike at any age, they are common in growing and active children. Children with mal-aligned legs are susceptible to patellofemoral joint pain (knee cap problems) or growth plate problems such as Osgood Schlatter Disorder. These needn’t prevent participation in sport, but they often require some modification of sport while the symptoms are acute. Mal-alignment problems should be assessed and treated by physiotherapy + podiatry to address alignment issues while the child is young. The same postural problems in the adult manifest as runners’ knee, knee cap mal-alignment or dislocation, jumpers’ knee (patella tendon), amongst others. Chronic mal-alignment will lead to specific patterns of joint wear and tear (arthritis), which may eventually require surgery to replace the joint and re-align the lower limb.

What knee conditions result from degeneration?

Knees are the same as car tyres; whether you tolerate a subtle wheel alignment problem, or impose a sudden force upon then, they will become damaged and wear out. When the knee wears out, it is the cartilage lining that fails, allowing forces to be imposed on the bones, resulting in degeneration.

How do we examine knee joints?

Unlike other body regions as shoulder and spine, the knee can be a rewarding joint to examine because pathologies seem to be well defined (not all), particularly where there is trauma. For the acute sporting injury, a clear explanation of the injuring force, plus the knee’s immediate response, usually gives a clue to the structure damaged, eg. a landing/twisting injury where the knee buckled and a click was heard, especially if followed by an instant effusion (swelling) is damning of an anterior cruciate until proven otherwise. A force that bends the knee sideways/inward will damage the medial collateral ligament, where as a force onto the top of the shin bone as would occur with a fall into the kneeling position, will damage the posterior cruciate. Meniscal and joint lining cartilage damage commonly accompanies ligament trauma. There is a well established series of clinical observations and tests that can be performed to tests the structures of the knee joint. Radiological investigation, particularly MRI, is now common-place for confirmation of clinical suspicion. For the atraumatic knee, there must be a biomechanical problem that has made the knee and associated structures vulnerable to failure under load of sport or work demands. The key to managing these problems is to accurately identify the underlying postural problem that are imposing adverse forces on the knee, and this involves examination not just of the knee itself, but above and below the biomechanical chain to ankle and hip/pelvis. Most mal-alignment problems are related to hip and spine dysfunction. An arthritic knee is obvious clinically as it is often associated with restriction of movement, swelling, tell-tale deformity and crepitus. Plain x-rays are essential for this pathology.

How do we treat knee joints?

If the knee has been damaged by trauma and a ligament injury is diagnosed, there is usually a recommended method of managing the injury dependant on the ligaments potential to heal and protection form select movements/forces, eg. a partial or complete anterior cruciate injury (ACL) will not heal, so reconstruction may need to be considered if the athlete is returning to a sport that requires dodging/baulking/jumping; a damaged medial collateral ligament (MCL) will heal without surgery, but may need to be protected in a brace etc. Meniscal tissue is avascular (doesn’t have a blood supply) therefore it doesn’t have potential to heal. The very perimeter of the meniscus where it connects onto the capsule is the exception. Arthroscopy will be required to address a torn meniscus; the principle here is to trim as little as possible. Peripheral tears may be able to be repaired. Articular cartilage does not have a blood supply; it receives its nutrition through the joint fluid. If damaged, it won’t recover, and arthroscopy may be required to ‘tidy-up’ the articular surface. Cartilage damage accelerates arthritis. Biomechanical and alignment problems are treated according to the examination findings. Invariably this requires some realignment work at the hips and pelvis, muscle stretching and strengthening, perhaps taping and strapping, perhaps orthotics. Assessment of sporting technique, running style, jumping and landing techniques may be required to more comprehensively rehabilitate. While surgery is now common place to clean out arthritic joints arthroscopically, or more major surgical intervention to replace joints, there are steps that can be taken that are less invasive, or compliment the surgical procedure, eg. glucosamine, and respectful exercise to strengthen and lubricate the joint to maintain your function and leisure and sporting liberties.