Auto Text: “Insert Knee” or “Insert Joint”

Arthroplasty specimens are often performed for osteoarthritis involving the hip (femoral head), shoulder (humeral head), or knee (tibial plateau and femoral condyles). While these specimens are not routinely sent for pathologic examination, they may occasionally cross your bench.

They can also be performed for fracture, avascular necrosis (AVN), or metastasis.

For Osteoarthritis

1. Can be cut fresh or after fixation. If cut fresh, don’t forget to fix prior to decalcification.
2. If bones and soft tissues are received in a small container, transfer labels and specimen to a larger container for adequate fixation.
3. Measure specimen (single piece or aggregate pieces) in three dimensions.
4. Describe the integrity of the specimen and the articular surfaces (granularity, eburnation, osteophytes).
5. Transect the bone longitudinally: Make a full-thickness cut through bone, perpendicular to the articular surface. Do NOT simply “wedge out” a piece of the articular surface and underlying bone.
6. Describe the cut surface (subchondral cysts, necrosis, infarcts, or masses). Always check for these marrow lesions even if not stated on the requisition.
7. 
8. Note the presence of crystals or chalky debris in the periarticular tissues (including synovium, labrum or meniscus, tendon).
9. Note the presence of any wedge-shaped subchondral whitening – this may represent avascular necrosis.
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11. Submit representative section(s) of bone (one cassette) making sure to include the severest diseased areas, following fixation and and decalcification.
12. Be sure to state “after EDTA decalcification” or “after HCl decalcification” in your cassette summary and add a Decal stain (appears as “Decalcification process” NOT “H&E Decalcification”) in Beaker. One “stain” per container will suffice, as the only result of ordering the “stain” is to drop a billing charge.
13. Serially section and submit representative section(s) of soft tissues (one cassette), if present.

For Fracture, AVN, Metastasis

1. Can be cut fresh or after fixation. If cut fresh, don’t forget to fix prior to decalcification.
2. If bones and soft tissues are received in a small container, transfer labels and specimen to a larger container for adequate fixation.
3. Measure specimen in three dimensions.
4. Describe the integrity of the specimen and articular surface.
5. Describe the resection margin, including if hemorrhage, necrosis, or tumor is present.
6. Use a bone saw to section the specimen longitudinally (perpendicular to the articular surface), and look for lesions:
   • Fracture: friable bone with associated hemorrhage (may be red or brown depending on fixation).
   • Avascular necrosis: usually a wedge-shaped subchondral infarct (opaque yellow-white).
   • Metastatic tumor: measure distance to margins (marrow and peripheral). Be sure to ink peripheral soft tissue margins.
7. Take three sections of bone through the lesion and submit, following fixation and decalcification.
8. If for metastatic tumor, take marrow and peripheral margins. Also try to submit a cassette of UNDECALCIFIED tumor or EDTA-decalcified tumor to allow for molecular studies if those become indicated. State in cassette summary which block is not decalcified / EDTA-decalcified.
9. If soft tissue is present, serially section and submit a representative section.
10. Be sure to state “after EDTA decalcification” or “after HCl decalcification” in your cassette summary and add a Decal stain (appears as “Decalcification process” NOT “H&E Decalcification”) in Beaker. One “stain” per container will suffice, as the only result of ordering the “stain” is to drop a billing charge.