(Ivanhoe Newswire) -- A husband and wife research team has found a way to
use the periosteum, the sleeve-like cover on bone, to heal serious bone
injuries. Moreover, they have developed an artificial sleeve that spurs fast
healing when a car wreck, bomb blast or disease destroys the bone covering.
Melissa Knothe Tate, a joint professor of biomedical engineering and mechanical
& aerospace engineering at Case Western Reserve University, and Dr. Ulf Knothe,
an orthopedic surgeon at the Cleveland Clinic, used a new technique on a
wheelchair-bound patient who suffered from cerebral palsy, hip dysplasia and a
curved spine exacerbated by legs of differing length.
To lengthen her shorter leg while correcting her hip dysplasia, Knothe replaced
the hip joint with a long-stemmed prosthesis, in the process cutting and
spreading the femur to match the length of its mate. Around the newly-created
gap in the femur, he left a section of the periosteum, the bone's sleeve-like
cover, intact to envelop and heal the gap.
Inside the sleeve, bone grew and matured around the prosthesis stem. The patient
has since learned to walk again.
"The sock-like sheath on the outside of the bone is a habitat for stem cells,"
Knothe Tate was quoted as saying.
In
testing involving sheep in Switzerland, animals that had the periosteum
operation to bridge a one-inch gap in their legs stood within 24 hours and had
substantial bone filling the gap within two weeks. In the lab, Knothe Tate and
fellow researchers found that direct and angular pressure on stem cells from
periosteum stimulated the cells to develop into bone. They say they believe the
pressure of standing and shifting weight drove the bone growth in the sheep.
"Just like in the embryo, given the right trigger, the cells build bone like
crazy," said Knothe Tate.
She tested the periosteum process against the standard bone graft technique of
packing the gap with spongy bone taken from the pelvis and included a third
model in which the gap was packed with spongy bone and covered with periosteum.
The results showed the periosteum alone healed fastest and with the greatest
density. "Surprisingly,” she said, “including the bone graft slowed the healing
process."
In addition to yielding better results, the surgical procedure is simpler for
the doctor and patient -- no small matter. Of the nearly 8 million bone
fractures that occur in the U.S. annually, about 1.5 million result in bone
grafting operations.
Compared to the process called distraction osteogenesis, which uses pins
inserted through the skin and into two lengths of bone to pull them together and
bridge a large gap, the perisoteum procedure is far less invasive and less
likely to result in infection and other complications.
Knothe, who has worked with patients suffering bone cancer or bone loss from
traumatic injuries, knows that sometimes there is not enough periosteum to make
a sleeve.
With support from the Case-Coulter Translational Research Program, the couple
designed an artificial periosteum, and Knothe Tate produced the novel implant, a
sleeve made of materials approved by the Food & Drug Administration for other
treatments. In sheep testing, collagen and cells scraped from periosteum, and
pieces of periosteum were tucked into the artificial sleeves. Sheep treated with
pieces of periosteum healed fastest, followed by those with collagen and cells.
"The next step is to bring the technology to the clinic, to broaden its access
to the general public beyond the top clinics, for example, for patients relying
on hospitals in rural areas, as well as for soldiers injured on the
battlefield," said Knothe. "You can sterilize the membrane in an autoclave,
along with the surgical tools. Its modular design makes it easily adaptable to a
variety of clinical situations."
SOURCE: Presented at the annual meeting of the Orthopedic Research Society,
New Orleans, LA, March 5, 2010