Biomedical Engineering Reference
In-Depth Information
in Manchester, he grew up in a stimulating environment and entered in 1929, after
his grammar school at Bury, the medical school of Victoria Hospital of Manch-
ester. After brilliant studies he graduated in 1935. After World War II, he returned
to Manchester in 1946 and specialized in orthopedics. After his marriage to Jill
Heaver (1957), he decided in 1958 to focus his efforts on the development of hip
replacement research and surgery and moved in his clinical practice in Wright-
ington. He died in 1982. His work is perpetuated by the John Charnley Research
Institute, Wrightington Hospital (Appley Bridge, Lancashire WN6 9EP, UK) [82].
Orthopedic surgeons as well as biomaterials scientists are all tributary to this
giant and a reference to his work should not be absent in this topic, the paper in The
Lancet is just one of his unsurpassed Å“uvre.
Epitome
: Half a century of intense and increasingly integrated research changed
the world of biomaterials. The discussion of the fracture of a hip stem was seized to
demonstrate the multifactorial character of the interaction between body and implant
as well as the intricately multidisciplinary character of the scientific approach. The
fracture of a metal is at first glance a mechanic problem and, indeed, it is one but
not exclusively a mechanical one. The biomedical community became aware that
a successful implant has to meet simultaneously a whole set of requirements to
increase the life span of the implants and the patients' comfort. The manufacturers
switched progressively from stainless steel over cobalt-chrome to titanium alloys
andinthenearfuturemaybetoˇ-titanium alloys, all with the aim to increase the
overall quality of the implant and to compromise as less as possible the body.
Multi-
factorial
means that the manufacturers have to reconcile simultaneously properties
as tensile or bending strength, fatigue strength, E-modulus close to bone, benign
reaction to bone meaning biotolerant, osteoconductive and/or osteoinductive.
A description of the structure of bone was added to show the complexity of the
tissue an implant has to substitute and the consequence for the design.
Survival rate of an implant is a great help in evaluating the quality. A decent
evaluation, however, requires the follow-up of a great number of cases, exactly
because of the very multifactorial character of implant success or failure. There-
fore, we included a section on the unique Swedish Total Hip Replacement Register,
which meets this requirement.
