Sportsperson?s Knee

Plymouth Orthopaedic and Sports Injury Clinic

Running, landing, twisting and contact sports render the knee vulnerable to injury. Whilst fractures can occur (at any age) they are relatively rare in sports injuries.

Meniscal Tears (“Torn Cartilage”)

It may be that some people are pre-disposed to this injury. In the normal young adult knee the meniscus is enormously strong, some estimates suggesting that it withstand forces of ten tons! When the knee is flexed and loaded, a sudden twist may trap the meniscus, typically medial (inner side of knee) and cause it to tear. This is unlikely to heal and can cause persistent pain, often provoked by twisting, swelling, a feeling of instability and occasionally locking of the knee. Clinical diagnosis can be very accurate in this condition; MRI scan will invariably confirm or refute. A symptomatic torn meniscus can be treated with arthroscopic (key-hole) surgery and the vast majority of patients will make a quick recovery.

Ligament Injuries

The ACL (Anterior Cruciate Ligament) is the most commonly injured ligament, it is often non contact. The collateral ligaments are more frequently damaged in a contact injury. The PCL (Posterior Cruciate Ligament)is much stronger than the ACL, but is susceptible to rupture caused by impact to the front of the lower leg (falling onto flexed knee). Multi-ligament injuries are fortunately rare, but may be caused by high energy impact injuries, perhaps combined with a twisting injury. Ligament injuries can be a cause of significant disability. It is often said that an ACL rupture is the worst, but in fact we have a very reliable operation for reconstructing the ACL. Sometimes it is the undiagnosed collateral ligament, or multi ligament injury that is the most difficult to manage. This means that it is important following a knee injury that the patient is examined by someone with an experience in this area as soon as possible and preferably within the first week, because occasionally urgent surgery is appropriate and often this is best done within the first ten days.

Chondral Injuries

This implies an injury to the lining articular cartilage. It may result from direct impaction or from shearing during a twist. Instability, following a ligament injury may make this more likely. A large meniscal tear can be another cause. Once damaged the articular cartilage cannot repair itself. A considerable research effort is going into finding ways to treat this problem and there are some promising emerging treatments although at this time most remain experimental. A technique called Microfracture is the most common treatment if this condition requires surgery. It stimulates healing with a second best tissue called fibrocartilage. This surgery is done arthroscopically, but recovery is relatively slow with considerable rehab effort required for best results.

Post traumatic arthritis

The effect of this is no different to osteoarthritis, but of course it results from an injury (as above) rather than ageing, and wear and tear. This can be a difficult issue to manage in the younger patient, not least because joint replacement is not to be routinely recommended in patients under 60.
Sometimes it is appropriate to realign the knee to try to redistribute load from a damaged area of the knee to a healthier area. This is called an osteotomy.

Catastrophic Knee Injury

This is a useful concept. It is usually applied to sporting injury but not exclusively. Following injury the knee collapses. It is immediately painful and there may be an audible crack or pop. The patient is unable to mobilise due to pain or further giving way. Usually the knee becomes rapidly (within 30 minutes) and tensely swollen. The knee may have obviously dislocated, even if it has spontaneously relocated.

The sudden swelling means that something has bled into the knee joint. Almost invariably that means either a ligament has ruptured or there is a fracture.

It is important in a catastrophic injury to make an accurate diagnosis as soon as possible, and all patients in this situation should ideally be seen by an experienced specialist within a few days of injury at the latest.