Magnetics Business & Technology - Summer 2016 - (Page 17)

RESEARCH & DEVELOPMENT Magnet-Powered Bone Lengthening Device Saves Kids Pain, Infection Risk Orthopedic surgeons have developed a new device that reduces the pain, scarring and infection risk associated with lengthening a leg bone. It replaces an awkward external brace, which must be attached outside the leg using pins through the skin, with a sleek, magnet-powered telescoping rod that is bolted entirely inside the bone. "This device is a big step forward for kids with discrepant leg lengths," said Stanford Children's Health orthopedic surgeon Scott Hoffinger, MD, who has used it in seven patients, including the firstever child in Northern California to receive the new implant. To lengthen a bone using either the old or the new device, a surgeon saws crosswise through the bone and braces the sawed ends one millimeter apart. The body grows new bone into the gap. The patient adjusts the brace to move the bone ends half a millimeter further apart, twice a day, until the bone reaches the desired length. Bracing continues until the bone has hardened. Now, instead of pinning a patient's leg into a bulky external brace, surgeons can accomplish the same thing by placing a small telescoping rod inside the bone's shaft to brace and extend it. The implant contains a magnet-powered motor. The patient holds a compatible magnetic motor against the leg for twice-daily, six-minute lengthening sessions. "The biggest advantage is that we can lengthen a child's bone without having to pierce his or her skin and muscles for months with an external fixator," said Hoffinger, a clinical associate professor of orthopedic surgery at the Stanford University School of Medicine andLucile Packard Children's Hospital Stanford. "It's more comfortable for the patient both physically and psychologically to 18-year-old Andrew Hirsch of Walnut Creek, Calif., is pictured with orthopedic surgeon Scott Hoffinger, MD, of Stanford Children's Health and Lucile Packard Children's Hospital Stanford. avoid having a big frame outside their leg with pins going through to the bone." The external frame is still required in cases where a leg bone needs straightening, such as when a child's foot is aligned at the wrong angle. However, the new, magnet-powered internal device will work for most children with different-length legs. Leg-length Magnetic field measurement Go anywhere, measure anything! www.agence-arca.com - Photo: Scott Maxwell, Jeremyculpdesign THM1176: The world's most compact 3-axis magnetometers. A selection of five probes measure from nanoteslas to 14 T, and get into the smallest of gaps: * THM1176-MF: general-purpose up to 3 T. * THM1176-LF: millitesla fringe ﬁelds. * THM1176-HF: superconducting magnets to 14 T. * THM1176-HFC: sub-millimeter gaps. * TFM1186: nanotesla-range perturbations. Powered by USB, with your own computer or an optional handheld, and with sophisticated analysis software, including spectral analysis. Flexibility simplicity that are out of this world! Pantone and 286 Pantone 032 Magnetic precision has a name annonce187x121.indd 2 www.MagneticsMagazine.com www.metrolab.com 08/11/12 09:49 Summer 2016 * Magnetics Business & Technology 17 http://www.agence-arca.com http://www.metrolab.com http://www.MagneticsMagazine.com

Table of Contents for the Digital Edition of Magnetics Business & Technology - Summer 2016

Editor's Choice
Extending the Limits of the Sm2Co17 System
Advances in Manufacture of Low or No Heavy Rare Earths NdFeB magnets
Research & Development
New Measurement Technique Characterizes Permanent Magnets
Electromagnetics
Industry News
The Ambition to Get Highest Flux Densities,Is It Always Reasonable
Marketplace / Advertising Index
Spontaneous Thoughts: Permanent Magnet Mistakes, Part 2

Magnetics Business & Technology - Summer 2016