New Techniques Lengthen Legs
Orthopedic advances focus on cases where limbs are of unequal length
THURSDAY, March 23, 2006 (HealthDay News) -- Differences in limb length or congenital limb deformities can lead to bigger health troubles throughout life, but experts say new techniques and technologies may prevent that from happening.
Recent advancements in limb lengthening and deformity correction techniques were on the agenda Wednesday at the annual meeting of the American Academy of Orthopaedic Surgeons, in Chicago.
"Although different types of bone fixation are used today, the underlying method of limb lengthening and realignment is virtually the same throughout the world," Dr. William G. Mackenzie, chairman of the department of orthopaedics at the Alfred I. duPont Hospital for Children in Delaware, explained in a prepared statement.
A person's legs can be different lengths due to previous injury, neurological conditions, bone infections or disease, or congenital conditions. Minor differences -- 1.5 centimeters or less -- in leg length are common. But adults and children with more than two centimeters of difference in leg length may be at increased risk for wear and tear on the back, hips and knees.
Bone fixation is one method of remedying the problem. After applying a device called an external fixator -- placed on the outside of the leg to hold the bone in position with pins and wires -- the bone is divided using a non-traumatic method to preserve the surrounding tissues. As the bone is gradually lengthened, new bony tissue fills the gap in the bone.
A newer method uses an external fixator and a metal rod inserted into the canal of the bone. This procedure reduces the risk of bending or breaking in the newly lengthened bone after the external fixator is removed. However, the experts said this method requires prolonged use of crutches or a walker, and carries a possible risk of severe bone infection.
Another method involves the use of a telescoping "nail" that's inserted into the bone to gradually lengthen it. The lengthening action of the nail is activated by leg movement. This approach does not require an external fixator.
Finally, an experimental technique under development uses a telescoping plate that's attached to the surface of the bone. The bone is gradually lengthened by frequent adjustments made using a small wrench inserted through a small incision in the skin.
The American Academy of Orthopaedic Surgeons has more about limb discrepancy.