We're born with about 300 to 350 bones in our bodies. By the time we reach adulthood and bones fuse together, we're down to 206. And when an infection strikes, our bones can be in trouble.

Now one doctor is finding ways to heal bones that won't heal.

Getting home from work is no easy trek for Rick Trecartin, although the view can't be beat. He still has to walk several blocks from his office and catch a ferry each and every day. Even though he's done it for decades, this routine almost became unbearable.

Rick Trecartin, Arthritis Sufferer, explains how he knows he has a problem, "I knew I had a problem."

After suffering from arthritis for years, Rick went in for a knee procedure. He came out with MRSA, an antibiotic resistant infection.

Trecartin explains the symptoms he had, "All of a sudden, I started getting this puss out of the lesion of the leg where they had cut my skin."

The infection was in Rick's bone, just two-centimeters from his knee joint. If it got inside the knee, doctors might have amputated his leg. But orthopedic surgeon Amir Matityahu had a different plan.

Amir Matityahu, MD, Assistant Professor of Orthopedic Surgery, Director of Pelvis and Acetabular Trauma and Reconstruction, Orthopedic Trauma Institute, SFGH and UCSF, explains how the best treatment is, "You need to stop it as soon as possible to take care of the infection."

First he cleaned out Rick's bone and placed hardware inside to keep it stable. Then, he implanted a wafer filled with antibiotics near the knee. The high dose of antibiotics spread to the surrounding area, killing the bacteria.

Matityahu, MD, explains the results, "Bone basically heals without scar."

After six weeks of antibiotics, bone from Rick's hip was transferred to his leg to replace what had deteriorated. Now, Rick's bone has completely healed.

Trecartin explains what tests are showing if the infection is still there, "I just had a blood test to see if I had any indications of infection, and I don't."

Amir Matityahu, MD, explains what could have happened, "If that infection got worse, he could have lost his leg."

The next step for Rick is a knee replacement. He feels lucky to have that option.

Trecartin explains how the doctor saved his leg, "Amir saved my leg, and in the process saved my life."

A grateful patient, who's looking forward to getting out of the doctor's office and on with his life.

The doctor says smokers and people with diabetes have a difficult time with bone healing. Sometimes, their bones never heal.

In the best cases, these patients can get their knees fused. In the worst cases, they will need their leg amputated.