Joint Replacement: Baked-In Strength
Artificial hips and knees must endure great stress, so researchers at MGH’s Harris Orthopaedic Laboratory created a more durable version.
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600
Pounds of force exerted per step on a 200-pound person’s hip
3 million
Steps an average active 50-year-old takes in one year
31,536,000
Steps taken in one year by one hip simulator at MGH’s Harris Orthopaedic Laboratory, used to predict how artificial joints will respond to extended use
1970s
First recognition by MGH orthopedic surgeon William Harris of the phenomenon of smooth polyethylene joints shedding small particles, causing bone deterioration
1998
First implant of a joint made of highly cross-linked polyethylene, which proved more durable than smooth polyethylene
30
Atoms in a molecule of candle wax, a compound structurally similar to ultrahigh-molecular-weight highly cross-linked polyethylene
1,071,428
Atoms in a molecule of ultrahigh-molecular-weight polyethylene before it is cross-linked, resulting in its exceptional durability
248
Degrees Fahrenheit at which vitamin E, which counters the free radicals that can break down a joint, diffuses into the polyethylene
5,000
People implanted with MGH-developed highly cross-linked polyethylene hip joints every day
