William, 33, lived a high-octane life working in the advertising industry. In his leisure time, he got his thrills from sports such as wakeboarding, adventure racing, hockey and scuba diving.
In 2006, William (whose full name has been withheld for reasons of patient confidentiality) twisted his knee while wakeboarding, which caused a large tear in the meniscus of his left knee.
A human knee has two menisci, which are crescent-shaped pads made of fibro-gelatinous materials located between the thigh bone (femur) and shin bone (tibia). They are the shock absorbers of the knee joint and help keep it stable.
Meniscal tears are commonly known as torn cartilage in the knee. Moderate to severe tears might result in a "pop" sound when the injury occurs. Meniscal tears might cause pain, swelling and stiffness in the knee, which can also suffer limited range of motion or might even give way.
The tear on the inside of his left knee was severe enough that doctors had to trim the damaged portion, leaving him with only about half of the meniscus. Each meniscus is divided into a "red" zone and a "white" zone. The red zone is the portion closest to the outside of the knee and enjoys an abundant blood supply. Minor injuries to this part of the meniscus may not need treatment and will heal on their own with rest. Larger tears can be surgically sutured and repaired.
The white zone is the part of the meniscus closest to the centre of the knee joint and has no direct blood supply. Without a blood supply, the meniscus is unable to heal. Severe injuries to this part of the disc, such as the type of tear in William's case, typically require surgery - a partial menisectomy - to remove the damaged portions.