In my April 29, 2019 post, Big Bone Business on eBay, I noted that the fossilized skeleton of a baby Tyrannosaurus rex was for sale on eBay for $2.95 million. The seller recently ended the auction–apparently no takers. Should they repost the offering please do humankind and science a favor: buy it and have it shipped directly to a natural history museum. On the eBay posting, the seller hyped the auction with some cock and bull about not wanting this treasure to fall into the hands of a museum, which “has limited opening hours and might be prohibitively expensive for some to visit”. Rather, the seller stated, “Once put ONLINE, the entire World can enjoy it 24/7/365.” OK, give it to a museum while stipulating that the museum posts the images online. Then everybody can enjoy the photos, and interested paleontologists can access the real deal for close study.
Only 20 relatively intact sets of T rex stone bones exist overall, and there is recent good news about several Tyrannosaurus specimens that are safely ensconced for scientific study and public awe.
Sue, the most intact specimen found to date, is about 90% complete and continues to terrify and delight museum goers at the Field Museum in Chicago. Since December she resides in the Museum’s new Griffin Halls of Evolving Planet and is now positioned in a less crouched and more aggressive position than before. Because her supporting armature allows temporary removal of any of her bones individually for intense study, a generation of paleontologists has learned much about T rex’s posture and movement and has even estimated her body weight.
Opening with much anticipation and fanfare on June 8, the David H. Koch Hall of Fossils at the National Museum of Natural History in Washington, DC, displays “The Nation’s T Rex“. It is posed to soon devour a hapless Triceratops. This T rex is on 50-year lease from the Army Corps of Engineers, which owns it since the fossils were discovered on federal land in Montana.
A few months earlier came a full scientific description of Scotty, a T rex originally discovered in 1991, the year after Sue surfaced. Full-scale excavation of Scotty began in 1994 and proceeded slowly because of the extremely dense rock encasing the specimen. This and other difficulties delayed the publication of a complete analysis until now. Investigators estimate that Scotty lived into his early 30’s (extremely long for a dinosaur) and, based on the length and girth of his bones, stretched 40 feet from snout to tail tip and might have slightly outweighed Sue. I doubt, however, that either one obsessed much over their weight. A full-scale replica of Scotty recently went on display at the Royal Saskatchewan Museum in Regina, near its discovery site.
In addition to nicknames such as Sue and Scotty, other T rex specimens sport monikers such as Stan, Bucky, Tristan, and Trix, although the sex of any dinosaur has yet to be determined. Supposing Sue was actually male, I wonder if his name predisposed him to bar fights a la Shel Silverstein and Johnny Cash? If so, what do you think the bar bullies had been drinking? Who do you think would have won?
In my quest to
learn everything about bone, over the past three years I have visited at least
100 museums on four continents as well as scoured additional museums’ on-line
collections and untold numbers of books and journal articles. Recently I spent
a day in Oxford, England, visiting two anthropology museums, a natural history
museum, and a history of science museum. In each, I found interesting bone
objects but really nothing I had not seen before. Therefore with low expectations,
I stopped by the Museum of Oxford.
The museum was undergoing renovation (“refreshments” in British parlance), but they had set up a temporary micro-museum in a large room at the Oxford Town Hall. It had no ticket counter or guard and just two or three other visitors. One case displayed several bone needles and an ice skate made from a horse or cow cannon bone, examples of which I had seen before.
Then I saw a surprise–a three-foot square slab laid flat on a waist-high display case. The shapes of the pieces creating this large mosaic immediately revealed their source—the ends of cannon bones from large animals. (For a description of it, see my previous post, The versatile cannon bone. What is it?)
The bones had been cut in half, placed vertically, and mortared in place to form a pavement of, well, cobblebones. Archaeologists had unearthed the surface at nearby Park End Street and dated it to the 1700’s. At that time the area was a shambles, now an obsolete word for an open-air slaughter house and meat market.
It all fits. Butchers would have little use for cannon bones because they have virtually no meat outside and no marrow inside. So, possibly to get relief from the muddy street, some enterprising soul cut the otherwise useless, readily available, and extremely hard cannon bones in half and paved away.
No one seems to know what fraction of the entire pavement the museum’s section constitutes, so more cobblebone may be resting under adjacent modern buildings. Since returning home, I have discovered that archaeologists have recorded 16 similar examples from Britain in the 17th and 18th centuries, nearly all of them from the Oxford area and many from private dwellings, so it seems like cobblebone underfoot was a unique local tradition.
Imagine growing up in the 1950s in
the Soviet Union and not being able to hear Bill Haley and the Comets sing Rock Around the Clock or to dance to Boogie Woogie Bugle Boy. The authorities
feared that such subversive Western influences would turn youthful passion away
from love for the Motherland, and they therefore banned them along with
recordings of both tango and saxophone.
An ingenious workaround, variously
known as Bone Music, Jazz on Bones, and Ribs, came about. Bootleggers would play
a smuggled, commercially produced record next to a transcription lathe armed
with a sharp needle. This would scratch the music’s audible vibrations into a
long spiral groove on a spinning disc of discarded vinyl X-ray film. The vinyl
was soft enough to accept the groove and hard enough to preserve it.
The task was tedious because a
bootlegger had to cut the x-ray films one by one into crude circles, record each
one, and burn a center hole with a lit cigarette. The product, however, was
cheap and also easy to conceal and sell using the standard methods for
distributing urban contraband.
The audio quality of Ribs has been
variously described as “sounding like sand” or as if listening to Ella
Fitzgerald “from across the street while being pummeled by torrential rain.”
Furthermore, the grooves wore out quickly, sometimes after only five to ten
playings. The demand for Bone Music dried up after 1964, when tape recorders
became legal.
Curiously, the banned music itself
had nothing to do with bones or ribs. Why then, the names? At that time in the
Soviet Union, vinyl was scarce and tuberculosis was common. Strangely, there is
a connection. Bootleggers repurposed old vinyl X-ray films that hospitals
discarded in bulk. Many of these were chest X-rays that had been taken to
diagnose lung infections. Listen to a rendition of St. Louis Blues
recorded on a skull film, to Ella Fitzgerald singing Lullaby
of Birdland, and to Elvis crooning Heartbreak Hotel.
The latter two were both recorded on chest X-rays with easily identifiable
ribs.
Consider the irony if a bootlegger
had recorded one of Mr. Presley’s hits on a pelvic X-ray. Subversive indeed.
During life, a goat’s knucklebones allow for ankle motion, which the goat finds useful but probably not fascinating. In their afterlife, however, knucklebones from goats and sheep have fascinated humans for thousands of years, probably beginning in ancient Egypt or in what is now western Turkey. Roughly rectangular, each bone is about the size of a hard candy. Four or five fit easily in the palm, and it is almost impossible not to jiggle them momentarily and roll them out—a thrill of touch, sight, sound, and … anticipation.
Although the ends are too small and rounded for them to stand straight up, the knucklebones’ four long sides are uniquely shaped, so the odds vary for one coming to rest on any given side. Without concern for how they landed, children played jacks with them or tossed them up and tried to catch them on the backs of their hands. By attributing different values for each landing surface, adults used them for gambling, hence the expression, “Roll the bones.” Fortune tellers attributed meaning to the landing positions both of the individual bones and their relationships to one another.
Kuncklebones’ ageless popularity for gaming and forecasting is apparent from their frequent presence in archaeological discoveries, with the objects both in their original osseous forms as well as reproductions made from metal or clay. Through the ages, sculptors, potters, and painters have recorded people’s fascination with knucklebones.
Cubic dice evolved from knucklebones and standardized the odds of a gaming piece landing on a given side. Other shapes ensued, from four sides to twenty sides and nearly every sidedness in between.
Goats and sheep are not the sole original possessors of knucklebones. Any hoofed animal with cannon bones (the topic of a previous blog post) has knucklebones. This includes horses and cattle. These, however, would be too large to jiggle and roll more than one, which would have made a game of Monopoly tediously slow.
Bones are structural and aesthetic wonders. They epitomize the melding of form and function.Each one is beautiful. What then accounts for the current chatter on social media regarding the “beauty bone”? Is this one really more stunning than the others?
To look at the collar bone in isolation, it has a gentle S-shape with flattened ends, one connecting to the breast bone and the other to the shoulder blade. The collar bone is the only bony connection between our upper limb and the chest skeleton, which accounts for its proclivity to fracture when reaching out to stop a fall. It also provides attachment for a number of large and important shoulder muscles. Absence of the collar bones, a rare birth anomaly, allows the owner to draw the shoulders together in front such that they nearly touch–definitely not beautiful.
What then, in life, makes the collar bones, draped closely with skin, alluring? To some owners and observers, prominent collar bones signal “skinny” and “fit” even if the rest of the torso is loosely tented. The beauty bones become an easy and noncontroversial expression of sex appeal–perfection without apparent effort.
Ah, but the effort required to fulfill this obsession. Websites encourage wannabes to regularly perform pushups, abdominal crunches, shoulder shrugs, yoga exercises including bridge position, and local massage. How these help I am not certain. Weight loss through aerobic exercise and diet is paramount, and I suppose it is in the eyes of the beholder where allure stops and emaciation starts. For those less committed, makeup helps, and Youtube videos can show you the tips. To date, it seems that surgical enhancement has not been tried. Liposuction, anyone?
One can demonstrate the magnitude of the depression above the beauty bone by placing a stack of quarters in the hollow. (I’ve seen the photos.) It might also work with golf balls, but they would probably roll out during your backswing. For me, I noticed that the depression becomes more pronounced when I shrug my shoulders; so if you see me in a tank top walking with a Frankenstein posture, you will know that I am styling my beauty bones, but not obsessing over them, because the other bones are equally functional and aesthetic.
Fish, frogs, snakes, birds, and humans
all have spines, which consist of individual vertebral segments that protect
our spinal cord while allowing neck and trunk movements. The vertebral column distinguishes
“vertebrates” from spineless creatures such as squid, worms, snails, and
beetles. Not that we should feel particularly smug about possessing a spine,
because the spineless animals don’t have to concern themselves with lumbago,
pinched nerves, and chiropractic adjustments.
Excluding sharks, skates, and rays, whose spines are made of cartilage, all other vertebrates have bony spines. Most mammals, giraffes and humans included, have seven vertebrae in their necks, while birds may have more. For instance, owls have 14, which allows them to turn their heads 270 degrees; and those contortionist flamingos have 19. Lower in the spine, the number of vertebrae is even more variable from species to species; and depending on the need for stability over flexibility, multiple segments may be fused together. The human sacrum, for example, consists of five fused segments, and the coccyx has four. Conversely, in snakes, with as many as 500 vertebrae, none of them are fused together. In short, vertebrae are versatile.
The bony ones are also hard, dense, and have complex shapes. The first two features mean that these bones endure a long time after the original owner is finished with them. Their complex shapes fascinate various people, who have re-purposed them in many ways, hence versatile and venerable.
For function, the Inuits hollowed out the cylindrical portion of whale vertebrae to make flues for their rib bone/tundra/hide dwellings. Other cultures have use scooped out vertebral bodies of smaller animals to serve as drinking cups.
Perhaps functional but of questionable esthetic value, vertebra have also morphed into chairs.
Solely for beauty, vertebrae have found second lives in necklaces, bracelets, and brooches.
They have also been crafted into likenesses of John Wesley (1703-1791), a British religious leader and founder of Methodism. It is unclear whether the folk artists were devout Methodists or were detractors who placed the effigies in pubs and soused them in beer to protest Wesley’s call for temperance.
The highest artistic achievement inspired by vertebrae belongs to British sculptor Henry Moore (1889-1986). He is well known for his semi-abstract bronze forms of reclining women, which grace sculpture parks worldwide. These monumental sculptures often have hollow spaces and openings, which some viewers compare to the undulating landscape of Moore’s native Yorkshire; but those observers should look more closely at bone. In 1940 Moore was bombed out of his London home and moved to a farmhouse appropriately named Hoglands because it was situated on a former pig farm. On walks, Moore would pick up scattered bones and take them into his studio. He commented that his primary interest was the human figure but that he paid great attention to natural forms, including bones, pebbles, and shells. It is apparent that he studied vertebrae closely and was taken by their rounded openings and curved, merging surfaces. They inspired him to create his shapes, iconic in their own right, and referencing beautiful, timeless bone.
Probably primitive man’s curiosity markedly increased soon after he stood up and started walking on just his feet. He could both peek into caves and drop back onto all fours to peer down badger holes. Looking into his family’s mouths and ears soon followed. Many generations later his progeny developed metal tubes and glimpsed human interiors through all of our natural orifices. Lighting, however, was always an issue, and the torch that satisfactorily illuminated the cave was poorly accepted by early patients in the proctology clinic.
This changed in 1879 with Edison’s invention of the incandescent light bulb. Just seven years later, two German doctors were lighting up bladders with a tiny bulb on the end of a steel tube through which they squinted. Heat from the bulb and risk of breakage, however, posed problems. Nonetheless, enterprising doctors began poking holes in the skin and exploring the bladder, abdomen, and chest with lighted tubes. In 1912, Severin Nordentoft, a Danish doctor, extended this concept to the knee and coined the word “arthroscopy” (joint-view). Multiple investigators from the world around then refined and continue to refine the technique.
Prior to antibiotics, tuberculosis, especially in the knee, occupied much of orthopedists’ time. This was particularly so in Japan, where squatting and kneeling have long been cultural imperatives. In 1918 Doctor Kenji Takagi began using a bladder scope to examine tuberculous knees. His idea was to develop early treatment that would preclude the awkward outcome of an entirely stiff knee. Over the next 20 years he designed and tested 12 versions of arthroscopes that were progressively smaller in diameter and that incorporated better optical systems. None of them, however, were entirely practical.
In my April 29, 2019 post, Big Bone Business on
eBay, I noted that the fossilized skeleton of a baby Tyrannosaurus rex were for sale on eBay for $2.95 million.
It is still up for auction; and remember, the seller accepts credit cards and
includes shipping. Do humankind and science a favor. Buy it now and give it to
a natural history museum. On the eBay posting, the seller counters with some
cock and bull about not letting this treasure fall into the hands of a museum,
which has limited opening hours and might be prohibitively expensive for some
to visit. Rather, the seller states, “Once put ONLINE, the entire World
can enjoy it 24/7/365.” OK, give it to a museum while stipulating that the
museum posts the images online. Then everybody can enjoy the photos, and
interested paleontologists can access the real deal for close study.
Only 20 relatively intact T rex specimens exist overall, and there is recent good news about
several sets of T rex‘s stone bones that are safely ensconced for scientific study
and public awe. Sue, the most intact specimen found to date, is
about 90% complete and continues to terrify and delight museum goers at the
Field Museum in Chicago. Since December she resides in the museum’s new Griffin Halls of Evolving Planet and is now positioned in a more crouched and threatening
position than before. Because her supporting armature allows temporary removal
of any of her bones individually for intense study, a generation of
paleontologists has learned much about T rex’s posture and movement and has even estimated her body weight.
Opening with much anticipation and fanfare on June 8, the
David H. Koch Hall of Fossils at the National Museum of Natural History in
Washington, DC, displays “The Nation’s T Rex“, which is posed to devour a hapless Triceratops. The T rex is on 50-year
lease from the Army Corps of Engineers, which owns it since it was discovered
on federal land in Montana.
A few months earlier came a full scientific description of
Scotty, a T rex originally discovered in 1991, the year after Sue surfaced.
Full-scale excavation of Scotty began in 1994 and proceeded slowly because of
the dense stone encasing the specimen. This and other difficulties delayed the
publication of a complete analysis until now. Investigators estimate that
Scotty lived into his early 30’s (extremely long for a dinosaur) and, based on
the length and girth of his bones, stretched 40 feet from snout to tail tip.
They estimate that he weighted about 10 tons, slightly more than Sue. A
full-scale replica of Scotty recently went on display at the Royal Saskatchewan
Museum in Regina, near his discovery site.
In addition to nicknames such as Sue and Scotty, other T rex specimens sport
monikers such as Stan, Bucky, Tristan, and Trix, although the sex of any dinosaur has yet to
be determined. Supposing Sue was actually male, I wonder if his name
predisposed him to bar fights? If so, what do you think his assailants had been
drinking? Who do you think would win?
After World War II, Takagi’s student, Masaki Watanabe, took up the banner and continued to make design improvements. In 1957, Watanabe presented a color movie describing his work, first to an international orthopedic meeting in Spain and then to major European and North American orthopedic groups on his way home to Japan. The response was tepid at best.
Undaunted, Watanabe pressed on. The twenty-first version finally provided an adequate view and good focus even though it necessitated grinding each lens by hand. By 1958 this version became the world’s first production arthroscope, but breakage of the incandescent bulb on the end of the tube continued to be problematic. Watanabe began to receive international visitors interested in learning his technique, but when they returned home, began using it, and reported their results, collegial criticism, even ridicule, prevailed.
In 1967 the twenty-second version, for the first time, incorporated a novel fiber optic cable. Now the hot, fragile light bulb could be 6 – 10 feet away from the operative field and transmit “cold light” into the knee joint via thousands of bundled glass threads.
Watanabe developed at least three more versions to further address the conflicting goals of better illumination and visualization vs. smaller diameter scopes that could probe the deepest recesses of small joints. His final version was less than 1/12th of an inch in diameter—about the diameter of a coat hanger wire. Later came miniaturized television cameras that could be attached to the arthroscope. A video monitor in the operating room displayed the images. Now residents, nurses, and students no longer had to stare at the back of the surgeon’s head as he squinted into an eyepiece attached to a narrow tube. Patients, when awake, could watch too, and a video recording of the event later allowed their families untold hours of viewing pleasure. Well, maybe minutes.
Along with further advances in arthroscopic instrument and in scope design, international interest began to grow. At first, every procedure was merely diagnostic and was followed immediately by a large incision and exploration of the joint under direct vision to treat whatever pathology the arthroscope had revealed.
Tiny nippers and shavers, first manual and then also powered, began to allow for arthroscopic treatment as well as diagnosis. Current techniques and instruments even allow the surgeon to place and tie sutures inside a joint. Such minimally invasive surgery allows for faster and more complete rehabilitation. Because the knee joint is large, the innovations started there, but now orthopedists also routinely apply these techniques to the shoulder, elbow, wrist, hip, and ankle joints. Undoubtedly our caveman ancestors, torches and clubs in hand, would be pleased to know where their curiosity for peering into holes has led.
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In my never-ending search for objects made of bone in
museums and on the web, I have found some finely crafted items with similar
decorations. These are small circles that surround central dots. The objects
come from far-flung regions of the world and span thousands of years. Is there
an overarching meaning? Was the motif designed anew in various cultures or did it
originate in one place and then go viral? Why this motif and not stars or
hearts?
To find an answer, I queried several art historians, decorative art historians, as well as curators and collection managers at the museums where I found these objects. I received a number of thoughtful replies. These included leads to several books and journal articles on primitive art. Here is a synopsis of what I have learned.
RL Anderson writes in his book, Art in Primitive Societies: Are there universal symbols? Freudian iconography? [Carl] Yung felt that all human beings, no matter what their cultural background, held in their minds a share of the “collective unconsciousness”. … Circle: a symbol of Self. It expresses the totality of the psyche in all its aspects, including the relationship between man and the whole of nature.
Another reference noted that the circle is a universal symbol with extensive meanings. These include the concepts of totality, wholeness, original perfection, self, infinity, eternity, timelessness, all cyclic movement, God.
Those explanations are rather encompassing, but neither says anything about the dot. Other sources have addressed both:
Shamans have the ability to see into other
worlds. Thus the circle and dot, both an eye and a hole, equate physical and
spiritual movement between worlds.
Images and hunting fetishes marked with the
circle and dot were supposed to watch for game, and by clairvoyant powers,
sight it at a great distance.
For succinctness and mastery of English, I particularly
like the British Museum’s Marcel Marée’s observation: The circle and dot motif is so common because
it is so easy to create, to great ornamental effect, simply by applying a
drill.
How was the circle and dot motif inscribed? Anthropologists think that a thin strip of flint, filed to a V shape at its tip with one point slightly longer than the other, would suffice when spun by rubbing it between the artisan’s palms. Metal drills would be more efficient, and the Shuswap tribe in British Columbia made such drills from handles of kettles procured from the Hudson Bay Company. (The author does not explain what they did with the handleless containers.)
So the conclusions run the gamut from mystical “collective unconsciousness” to simple aesthetic practicality. Maybe there is a middle ground, at least for the Inuit, where the motif appears on many hunting charms and everyday objects. In one Inuit language the circle-dot motif is designated as “the eye of awareness” and marks joints on the skeleton. William Thalbitzer in 1908 wrote, “According to Eskimo notions, in every part of the human body (particularly every joint, as for instance in every finger joint) there resides a little soul. How nice. Certainly, across time and space, the soul of each person crafting the circle and dot motif reaches out to us.
In the previous post, I began drawing an analogy between borrowing money and borrowing bone to repair/replace a skeletal defect produced by trauma or tumor removal. As with borrowing money, choosing the source of the bone loan depends on its proposed use, how much is needed, and the terms of repayment. I also noted that small bone loans have minimal obligations and are available from several local sources (pelvis, wrist, fibula). Small grafts, however, may not fund a major project quickly enough for the loan to achieve its ultimate purpose. What else is possible?
Orthopedists have several ways to coax the fibula into early service. If the bone gap to be bridged is less than half the fibula’s length, the fibular strut can be cut in half and doubled. It will still take many months for the grafts to thicken enough to provide adequate support, but it will take less time than using a single segment. In other words, it doubles the loan’s productivity without increasing the debt.
Whatever its size, getting a loaner part into service quickly also improves its effectiveness. An orthopedic surgeon can kickstart a fibula graft into service by meticulously harvesting the bone along with the blood vessels that supply it. After the bone graft is secured in the gap, the surgeon connects the fibula’s artery and vein to nearby vessels. Blood then flows through the fibula just the same as it did in the bone’s original location. With the immediate restoration of circulation, the grafted fibula can heal and enlarge far more quickly to make the loan pay off.
The bone loans described so far all come from the patient’s own body, so the patient’s immune system raises no concern, and there is no risk of rejection. At times, however, huge segments of bone are required and constitute loans too large for patients to make. Consequently, the surgeon may turn to a gift from an organ donor. These bones are taken from the donor immediately after removal of the recently deceased’s heart, liver, and kidneys, which require placement on ice, immediate transplantation into a grateful recipient, and life-long protection against immune rejection with powerful, rather risky anti-rejection drugs. By contrast, the bones undergo a leisurely cleaning to remove all the blood and protein they contain. Then they are dried, sealed in plastic bags, sterilized, cataloged, and shelved until needed. Absent their proteins, bones generate no immune response when implanted into a different person, so they can provide grafts of the needed size and shape without any risk of rejection. This is a wonderful gift, but it comes with some strings attached. Since the grafted cadaver bone has no blood supply and no cells, the recipient site has to supply these, which it does, but ever so slowly. In the meantime, the cadaver bone graft can crack, crumble, or dissolve. For that reason, grafting cadaver bone is not undertaken lightly.
If
you happen to have an identical twin, you could borrow living bone filled with
cells and do so without risk of rejection, since you both have the same immune
system. Careful though, your twin might need one of your kidneys sometime—payback
for the bone loan.
Just as you weigh the options before borrowing money, orthopedists weigh with patients the pros and cons of one type of bone graft over another and discuss the relative merits of each. For instance, spongy bone is readily available without causing any permanent skeletal defect, and it heals faster than compact bone; but compact bone is immediately stronger than spongy bone. The surgery is much longer and more difficult when moving bone around with its blood supply intact, but healing time can be markedly shorter. Cadaver bone comes in any desired size and shape but is slow to heal. Sometimes the trade-offs are reduced by using two types of bone graft for the same debt—taking out a home loan and accepting a unique gift.
What happens when a segment of bone is missing after a severe fracture or removal of a tumor? The bone ends try to grow into one another as they do after routine fractures, but the gap and lack of immobilization are usually insurmountable despite how hard the world’s best building material tries to repair itself. The gap instead fills with fibrous scar tissue; this gristle-like material does not restore stability, and a false joint forms. Orthopedists can overcome this situation by bringing in new bone from afar. To help you understand bone grafts, consider the analogy of borrowing money.
If you find yourself just a couple of dollars short, searching under the sofa cushions and raiding the piggy bank may produce the necessary cash. Nobody misses the money, and there is no pressing need to pay off the loan. If you need a substantial amount of money, perhaps you can borrow from your retirement account or from your kid’s educational fund. Doing so solves the immediate gap in your finances but leaves a deficit elsewhere, which may or may not recover over time. Finally, if you cannot fund it yourself, you could go to the bank, and as strange as it might seem, ask for a gift.
The concepts are the same for bone grafting. If surgeons only need some hearty bone cells to stimulate new bone formation, maybe to supplement local bone for spinal fusion, then they can temporarily open the hard outer surface of the pelvis and scrape spongy bone from the pelvis’s interior. Several tablespoons of bone can be obtained in this manner without changing the outer contour of the pelvis. The crumbly graft offers no mechanical stability, but it is full of bone-forming osteoblasts that quickly overcome the small debit in the recipient bone. At the same time, the donor site fills with new bone and could be re-excavated later if necessary.
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Sometimes a surgeon needs a short section of structurally sound bone to fill a gap at the site of a nonhealing fracture or to span a gap after removal of a bone tumor. In these instances, a chunk of full-thickness bone from the patient’s own pelvis works well.
It comes from the rim of the pelvis, near where your thumb rests when you put your hands on your hips. Unless the owner is quite thin or the chunk is bigger than an inch square, the withdrawal is harmless and invisible. Otherwise there is permanent, but manageable evidence of the loan.
If a long, straight bone graft is needed, attention often turns to the leg. Of the two bones between the knee and the ankle, the sturdy one that transmits weight is the robust shinbone, aka tibia. Just to its outside is the half-inch-in-diameter fibula. Except for a short portion near the ankle, the fibula is expendable because it is mainly an attachment site for ankle and toe muscles, which are fully functional even if the fibula had been borrowed. Hence the fibula is a mainstay in the orthopedist’s “long-bone lumberyard.” Depending on the patient’s height, a six-to-ten-inch strut is available to span a large gap in a critical bone.
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The fibula strut is far more slender than most of the bones it replaces, so it will need support from a sturdy internal plate and an external brace for at least a year. This bridging graft is “seed money” and will grow stronger over time allowing it to resist the limb’s normal bending, twisting, and compression forces. The complete conversion of a grafted fibula from scrawny to robust and from muscle anchor to body-weight resister usually takes several years.
In the next post I will describe jumbo loans.
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