Re: decalcification: an aside
|From:||Jeffrey S Crews <firstname.lastname@example.org>|
In case this might help some other small labs, this is how I cut bone
samples in the lab where I used to work. When we started getting in
orthopedic research samples (usually goat knees) I bought a scroll saw
(about $125) from the local hardware store. These have a flat table and
an oscillating arm to move the blade.
The thing that made it attractive to me was that very fine-toothed and
thin blades are available. Our machinist made us two polycarbonate blocks
of appropriate size and faced them with rubber. I used these to grip the
chunks while sawing when they became too thin to cut safely by hand.
Wooden blocks would work, too.
With this setup I was able to cut very accurately and safely, even very
thin slices. It might be something for other research labs to consider.
One other note: the hole in the table where the blade passes through
might be too large for sawing very small pieces. For that I glued a piece
of plastic TC tray over the table hole, with a much smaller hole cut in
Jeffrey Crews, HTL (ASCP)
On Fri, 29 Sep 2000 19:57:11 -0400 (EDT) RSRICHMOND@aol.com writes:
>Several people on the list have talked about decalcification
>clinical practice. Let me contribute experience of a small-laboratory
>surgical pathologist laboring in his last years of practice under
>Care. In these circumstances we cannot hope for new technology, but we
>sometimes salvage old technology. In many of the small laboratories I
>in, decalcification skills are being lost.
>As to turnaround time: I wish I knew what TAT large orthopedic
>(mostly hips and knees) require. If they need a surgical pathology
>billing purposes, they need it in a bit less than a week.
>If I receive a femoral head on Monday, I can slab it, fix the slabs
>overnight, and decalcify a piece of a slab over another night - that
>have slides Thursday morning. To take a day off of this, somebody has
>the specimen from fixative to decalcifying solution late at night.
>The elegant radiographic technique one of you described would be nice
>have, but I've seen an in-department radiographic unit (Faxitron) in
>one of perhaps forty surgical pathology labs I've worked in since
>If I had this technique, I'd use it, though I suspect its yield of
>useful information would be small. My normal special tools for
>bone are a dime-store hacksaw and a wad of paper towels - a Satterlee
>(from Lipshaw) is usually many managers away.
>For clinical purposes, gross diagnosis is often adequate for joint
>replacement specimens done for osteoarthritis. The description and
>diagnosis are simple once you know what to look for. The high school
>who decide whether or not surgeons get paid are programmed to
>following string: "eburnation and osteophyte formation consistent with
>stage osteoarthritis", and those exact words should appear in the
>Osteophytes are the mounds of cartilage and distorted bone that appear
>edges of articular surfaces. Eburnation is the baring of bone (the
>originally meant "turning into ivory") by the erosive process. The
>point of a
>knife will not enter an eburnated surface, as it will even the
>abraded articular cartilage. Eburnated surfaces are usually oval and
>I would describe such a specimen as "Received in formalin is 120 grams
>products of a total knee replacement, including an intact tibial
>fragments of femoral condyles, loose osteophytes, menisci, and fatty
>synovium. The condylar fragments show oval areas of grooved eburnated
>bone as much as 30 mm wide, and smaller eburnated foci are present on
>tibial surface also. Osteophytes up to 10 mm wide surround the
>surfaces. No sections are submitted." (Victoria Ryder, is this the
>you wanted an answer to?)
>If the laboratory's ritual requires decalcified sections, I painfully
>out sections of eburnated bone. Real men use an oscillating (Stryker)
>this purpose, but this technique is thoroughly unsafe, and would not
>permitted if people anybody gave a damn about were doing the gross
>Fractured femoral heads need microscopic examination, because
>cancer occasionally causes fractures ("pathologic fractures") and
>needs to be
>identified. (Remember that the pathologist is working without the
>history.) Usually the osteoporotic bone is easy to slab with a
>though some of them indeed are hand-hurters. If the service is well
>managed that the pathologist or assistant is working entirely without
>patient's history, the 10 mm wide hemorrhagic fracture zone in the
>dull yellow cancellous bone identifies a recent fracture.
>Obviously I'm describing clinical techniques, not research. I prefer
>to do my
>own decalcification, though many pathologists prefer to hand it to the
>technologist. The important thing is to decide who's going to do it,
>the decalcifying specimen doesn't go astray - and pathologists are
>for mislaying them.
>Arthroscopic specimens need microscopic examination, though many
>are required to gross-only these specimens. The diagnostic yield on
>arthroscopic specimens is quite high, even though in a well run
>is impossible for the pathologist to obtain clinical history or
>findings. It's usually acceptable to avoid gross bone fragments in
>arthroscopic tissue for microscopic examination.
>Gayle Callis mentions "For articular cartilage in osteoarthritic
>safranin O/Fast Green is commonly used, and toludine blue may also be
>useful." The safranin O trichrome variant - basically it's in Lillie's
>ed. - would be nice to have for arthroscopic material, but I have
>it. Gayle, are the complex techniques you describe designed for
>clinical use, or for research purposes?
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