What is Cartilage and How is it Damaged?
Cartilage (hyaline cartilage or articular cartilage) is a 3-5 mm thin tissue that covers the bony surfaces inside our joints. It provides a very low friction articulation that ideally lasts a life-time.
Cartilage can be damaged acutely through accidents, such as during an ACL tear or patellar (knee-cap) dislocation. Cartilage can also break down slowly over time, eventually leading to osteoarthritis (wear-and-tear, rather than inflammatory arthritis).
Often, cartilage damage starts as a small "pothole," which then enlarges over time. Eventually, most or all cartilage is worn away, resulting in “bone-on-bone” arthritis. Ideally, cartilage damage is discovered in the early stages, when it can be treated with cartilage repair for younger and more active patients. More advanced damage, especially that in older and more sedentary patients, is generally treated with joint replacement.
What is Cartilage Repair?
Cartilage repair is a general term encompassing a number of different surgical procedures designed to heal cartilage damage by filling the cartilage defect with repair tissue or new cartilage. This includes techniques such as microfracture, osteochondral autograft transfer (also known as OATS or Mosaicplasty), osteochondral allograft transplantation and autologous chondrocyte implantation (ACI / Carticel). The choice of procedure depends on the size and location of the defect.
Who is a Candidate for Cartilage Repair?
The ideal candidate will have focal cartilage damage, i.e. the “pothole” stage. Once widespread or bone-on-bone arthritis has developed, cartilage repair is not an option anymore. Also, because cartilage repair surgery typically has a long recovery time before the patient can return to unrestricted activities, such as running or basketball, it is mainly performed in younger, active patients where joint replacement is not an option. Although there are no strict rules regarding patient age, the average patient treated with cartilage repair surgery is between 16 and 45 years of age.
What is the Typical Recovery After Cartilage Repair Surgery?
Every cartilage surgery is different. Some surgeries may be performed as outpatient (same day) surgery, while others may require 1-3 days in the hospital. Crutches may be required for up to 2 months after surgery. Typically, patients can begin riding a stationary bike at 4-6 weeks, swimming and elliptical trainer at 8-12 weeks, and light jogging at 1 year. Unrestricted activities such as basketball, squash or longer-distance running is permitted after 18 months.
Why Does Recovery Take so Long?
Simply, cartilage heals very slowly. Early activity can harm or destroy the repaired tissue.