His acetabular labrum, a shock absorbing ring of cartilage that surrounds the socket of the hip joint, was shot.
Luckily for Brick, he knew exactly what was needed to fix it. Unfortunately, he had to travel to the US to have it done.
"I'm the only surgeon in New Zealand who does the operation, and I couldn't do it on myself."
Not a common operation, the labral restoration was carried out using a graft from his leg.
What is becoming more common is keyhole surgery to correct the problems that cause the damage in the first place.
"Most hip arthritis in younger people is caused by it. It's caused when the hip socket is too deep or the sphere is actually slightly egg shaped. Or both. That's what causes the damage, but it can be rectified if it is identified early enough - if not, the hip joint destroys itself."
Brick has helped pioneer the keyhole surgery to correct the hip joint, and many of his patients are sportsmen and women.
"In a large number of athletes, groin pain is actually caused by the hip."
As a sportsman and a surgeon, Brick feels he has the trust of athletes.
"I'm lucky because athletes generally listen to me because they think 'Matt has been there and knows what he is talking about'.
"And it's easier for me to understand the disappointment and grief of someone who is injured out of sport, or who loses a season or two seasons because of injury."
Although he hasn't competed for many years, he still attends events with his sons and says it is rare for him not to meet some of his patients.
"I love running and I also love seeing younger ones coming through. My life now revolves around my daughter who is in Melbourne, and my three sons who are still at home - we train together on the surf, ski, paddling, biking, running - I do it now because I know in five or six years time they will be off to university."
Now 52, he still enjoys being physically active.
Brick was the world duathlon champion in 1991 and 1992. On Sunday, he completed the course in 1h 10m 10s, 10 minutes behind the winner Aiden Dunster.