UAB Regrows Bones Using Living Membrane

Feb 11, 2015 at 04:50 pm by steve


A motorcycle accident in December left the soldier on leave from Afghanistan with a broken shin. The bone had punctured through the skin. A month later, the bone became infected despite treatment, and the soldier arrived at the UAB Division of Orthopaedic Surgery. “It had been so severely injured in the crash that over five inches of the bone was dead,” says Jason Lowe, MD, a fellowship-trained orthopedic trauma surgeon at UAB. He is one of only three in the Birmingham area.

Lowe used the Masquelet procedure on the soldier’s leg. It requires no external or internal apparatus, braces or screws. Within two months, the soldier had grown back enough new bone to bear full weight. By October, Lowe announced the soldier fully healed. He had been back on active duty since June.

“With the Masquelet technique, they’re usually weight-bearing within two months after grafting, and the bone is fully incorporated in three to four months,” Lowe says. The soldier took longer to grow the missing section of bone, because at 14 centimeters, it had been twice the average length for bone regeneration procedures.

“There are a couple of options to salvage these limbs, but about 40 percent often end in amputation,” Lowe says. Using the Masquelet technique, he and the other two orthopedic trauma surgeons at UAB — Emily Keener, DO, and Candice Dubose, MD — have a high rate of success.

“Essentially where there is no bone, we create an environment which tricks the body into regenerating bone,” Lowe says. The procedure starts by cutting away the dead bone, like in any bone-regenerating technique. A stabilizing rod is inserted between the two healthy bone sections to span the empty space. Then the surgeon packs a layer of polymethylmethacrylate (PMMA) — commonly called cement spacer — around the rod and over the native bone for 1.5 centimeters.

“In about four to six weeks, we come back and the body has formed a membrane around the cement, and that membrane is very biologically active,” Lowe says. “Under a microscope, it looks like the periosteum — the normal outer surface of bone.”

Because of the overlay of the PMMA onto the normal bone, the membrane is firmly attached at both ends, forming a living sheath. “We chisel or scoop out the cement spacer, and what’s left is a sleeve of tissue, like on a hotdog,” Lowe says. “We cut that membrane open, put in the graft, and close it up.”

The bone graft, ground from the pelvis or other large bones, resembles coarse sand. When the patient puts weight on it, the stress signals the body to make the graft pieces into a solid mass and incorporate it into normal bone.

The membrane was first discovered about 15 years ago while utilizing PMMA’s other notable benefit of being able to release large doses of antibiotics over time. “So they put these antibiotics beads into wounds, and they found that if you left it for weeks, then this fibrous membrane formed around the beads,” Lowe says. “That membrane is a living thing. In grafting procedures, it helps support new bone growth.”

The largest section Lowe has replaced using the Masquelet technique ran along the tibia for 17 centimeters, about eight inches. The most complex was in the arm. “They’re a little more cumbersome and tricky then legs, especially in the forearm because it rotates,” he says.

A few years ago, he replaced eight centimeters in both bones of a woman’s forearm. “We grew back all 16 centimeters of her bone,” he says. It was one of the first reported case for successfully using the Masquelet method on both the radius and ulna simultaneously.

Like the woman’s forearm, most of the Masquelet cases at UAB derive from vehicular accidents. “Most of the force in a crash comes up through the floorboard, so we see a preponderance of lower limb trauma,” Lowe says. Arms generally get severely injured only during rollovers or if someone has their arm out the window.

Other primary reasons Lowe and his colleagues have used the Masquelet technique over the last five years include gunshots and infection. “We’re the acute Level 1 trauma center for the state, so our practice is called to treat those fractures that don’t heal, healed badly or are infected,” he says. “People send us their problems, and we pride ourselves on being available to the community.”

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