FDA clears externally controllable internal limb lengthening system

A pioneering new system codeveloped by Sinai Hospital orthopedic surgeons Shawn Standard, M.D., head of Pediatric Orthopedics at the International Center for Limb Lengthening (ICLL), and John Herzenberg, M.D., director of the ICLL, offers a major advancement in limb lengthening surgery. The PRECICE™ Limb Lengthening System can be used to lengthen limbs that are short as a result of birth defects or trauma. It is the first externally controllable internal limb lengthening system to receive FDA clearance.

Standard and Herzenberg served on the core development team along with Stuart Green, M.D., clinical professor of orthopedic surgery, University of California, Irvine. This revolutionary magnetic-powered device was invented by engineers at Ellipse Technologies of Irvine, California. The PRECICE™ Limb Lengthening System consists of a telescopic titanium rod that is surgically implanted into either the femur (thigh bone) or tibia (shin bone). Inside the rod, a miniature magnetic motor and gear box create the force needed to lengthen the rod. The power to drive the internal motor is supplied by a magnetic field generator that is held on the skin next to the leg several times a day for a few minutes.

Herzenberg and Standard recently performed the first tibial implantation in North America of a PRECICE™ device in a patient at Sinai Hospital's Rubin Institute for Advanced Orthopedics (RIAO). The limb lengthening specialists at the RIAO (Herzenberg, Standard and trauma specialist Janet Conway, M.D.) have implanted six PRECICE™ devices and are following their progress closely.

"The PRECICE™ system is state-of-the-art technology applied to limb lengthening," said Standard. "It offers a remarkable improvement over other previous lengthening devices because it is both completely internal and also fully controllable with the external magnetic field generator. We are grateful to the amazing engineering team at Ellipse who developed the miniaturized magnetic motor and gearing that makes this possible. It has been a fascinating journey helping them bring this product to its current state as a device that can make the bone lengthening process more comfortable and predictable for our patients."

Limb lengthening is used to treat upper and lower limb length deformities. Through this process, new bone and soft tissues are gradually grown through a combination of surgery and either an internal or external fixator. This new growth is called tissue regeneration. Bone and soft tissue regenerate when they are slowly pulled apart at a rate of approximately 1 mm per day.

The ICLL at the RIAO at Sinai Hospital is one of the world's leading centers for the treatment of children and adults with upper and lower limb length deformities. Children and adults from all 50 states and more than 50 countries have traveled to the ICLL to receive comprehensive orthopedic treatment.