Cattails

New leg prosthesis is changing lives

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Some people wouldn't get too excited about wearing work boots or walking through tall grass. Unless they were someone like Dennis Telschow, Edgar, whose leg was amputated 14 years ago as a treatment for sarcoma, a bone cancer. He has had an artificial leg since then, and a new device is creating possibilities in his world.

"It's a phenomenal prosthesis," Telschow said about the TEC Harmony VASS leg device available at Marshfield Clinic. With prior devices, work boots would have been too heavy and uncomfortable for him. The artificial leg, known as a prosthesis, pulled off in the tall grass.

The VASS — Vacuum Assisted Suction Suspension — system uses vacuum, or negative pressure, to comfortably hold the prosthesis, said Dan Hill, certified orthotist-prosthetist at Marshfield Clinic Marshfield Center. Typically, artificial limbs are held in place by a series of straps or some type of suspension system. Some are suspended with a silicone sleeve that has a pin that locks in place. The VASS system creates vacuum to hold the seemingly weightless prosthesis.

A vacuum system improves the fit and comfort between the device and residual limb. A vacuum pump forces out air through a one-way valve, creating negative pressure, with every step the patient takes. A tiny tube connects the pump to a weight-bearing socket, which is enveloped in a urethane liner. By improving suspension, the prosthesis offers better control and less pressure on the limb and liner. The pump is powered by the wearer's body weight. Taking a step compresses the device, which creates the vacuum between the liner and socket.

"The device may seem heavy if you're holding it. But once the device is functioning, you don't feel the weight," said Lonny Damewood, registered prosthetic technician, who custom fabricates the devices at Marshfield Clinic.

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