and surrounding tissues. Experimenting on twenty-four dogs, a dizzying
array of metal screws were placed close to each in the forearm bones of
dogs—realizing that each metal has its own “electromotive force,” or
EMF, a mathematical expression that describes its electric potential in
relation to other metals. Screws comprised of metals with widely
divergent EMF’s placed close to each other create an electric potential,
which creates galvanic action between the two screws. Of all the metals
and alloys tested, there was one that was best tolerated by the bone and
adjacent tissues: Vitallium.^9 Unlike other stainless steel alloys, Vitallium
had no iron, and was exclusively comprised of cobalt (65 percent),
chromium (30 percent), molybdenum (5 percent), with trace manganese
and silicon. Vitallium demonstrated the least electrolytic reaction and
greatest healing.
In their concluding paragraph, Venable and his coauthors stated, “... we
suggest an alloy for bone work that is similar to Vitallium ...” (provided
that its chromium did not end up being toxic in the human body). The die,
so to speak, was cast. Austenal Laboratories had been advocating the use
of Vitallium to dentists for some years, but Venable’s publication was the
first in a surgical journal to mention the alloy. Dr. Smith-Petersen (with
personal assurance of Dr. Venable, who told him that it was “entirely
suitable”), immediately set about making Vitallium molds, and after some
trial and error, was able to implant the first mold in June 1938. Just ten
months later, his most significant paper was published^10 —he already
knew the principle of mold arthroplasty was a major innovation—but the
breakthrough touch was the Vitallium material. Now that there was a
resilient and durable implant, he would ponder an intriguing eventuality in
the main body of his paper: “The question now arises whether the original
mold [sic] principle may not have to be sacrificed; if Vitallium proves to
be inert, even when interposed between two moving surfaces, there may be
no reason for the second stage, that is, the removal of the mold [sic].”^11
Smith-Petersen was guessing that the new “resurfacing” operation might
be enough, but only time would tell. As science fiction writer Jules Verne
said, “Science, my lad, is made up of mistakes, but they are mistakes
which it is useful to make, because they lead little by little to the truth.”
The conceptual leap from a mobile cap covering the femoral head to a
substituting metal head, in retrospect, is not surprising. Surgeons were
used to dealing with fractured and crumbling femoral heads; the