3-year-old gets prosthetic arm bone

In what they called a medical first in a toddler, surgeons at Stanford University’s Lucile Packard Children’s Hospital have implanted a telescoping artificial prosthesis in the arm of a 3-year-old to replace a humerus that was removed because of cancer. Nearly a year later, Mark Blinder is thriving and cancer-free.

Mark, now 4, developed pain in his right arm in April of last year. By July, oncologists had diagnosed Ewing’s sarcoma, a rare bone tumor. Chemotherapy reduced the pain but did not eradicate the tumor. Radiation would have destroyed the growth plates in the bone, producing a physical impairment as the boy grew. The other common alternative is amputation.

Orthopedic surgeon Dr. Lawrence Rinsky of Stanford convinced parents Alla Ostrovskaya and Gene Blinder to consider a third option, an artificial bone produced by Biomet Inc. of Warsaw, Ind. Biomet produces artificial joints, which are quite common, and artificial bones, which are less so. The titanium/cobalt chrome expandable bone designed specifically for Mark was rare, spokesman Bill Kolter said.

The prosthetic bone had to be small enough to fit in a 3-year-old’s arm, durable enough to last a lifetime and expandable to allow for Mark’s growth.

Most artificial bones are used to replace only part of a bone, so they are glued securely to remaining bone. In Mark’s case, the entire humerus was being removed, so the prosthetic had to be attached to soft tissue.

On Dec. 4, Mark was wheeled into the operating room and greeted by Rinsky’s team, all dressed in space-suit-like outfits to reduce the risk of infection. Because of fears that touching the diseased bone might dislodge cancer cells that would spread to the rest of the body, the team carved out a little bit of flesh all around it.

“It was like carving out a peach pit without ever touching the pit, staying in the pulp,” Rinsky said.

Once the bone was removed, Rinsky implanted the prosthetic, sewing an attached piece of Dacron fabric to soft tissue in Mark’s shoulder. At the elbow, Rinsky saved the ligaments and placed them around the prosthetic.

Subsequent studies showed that the tumor had been entirely removed. Mark spent a month recuperating from surgery, then received more chemotherapy as a precaution.

He will have three to four minor surgeries over the next few years in which Rinsky will make a minor incision in the shoulder and lengthen the implant with a few turns of a screwdriver.

Mark is gradually relearning how to use his arm. He’s moving his wrist and fingers, can pick up small objects, and is receiving physiotherapy to rebuild strength and flexibility in the elbow and shoulder. He won’t ever regain full function in those joints, but he is using the arm more each day, his mother said.

Mark often tells his family, “I have a special arm.”

thomas.maugh@latimes.com