Re: decalcification: an aside

From:Jeffrey S Crews <>

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) writes:
>Several people on the list have talked about decalcification 
>techniques in 
>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 
>report for 
>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 
>means I 
>have slides Thursday morning. To take a day off of this, somebody has 
>to move 
>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 
>slabbing heavy 
>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 
>recognize the 
>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 
>at the 
>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 
>thinnest of 
>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) 
>saw for 
>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, 
>so that 
>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 
>hospital it 
>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 
>never seen 
>it. Gayle, are the complex techniques you describe designed for 
>clinical use, or for research purposes?
>Bob Richmond
>Samurai Pathologist
>Knoxville TN

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