Continuous Passive Motion Causes Chondrocyte Production of Joint Lubricant
NEW YORK (Reuters Health) Dec 04 - Continuous passive motion (CPM), a rehabilitation technique used after various orthopedic operations, stimulates chondrocyte production of proteoglycan 4 (PRG4), a molecule found in synovial fluid with putative lubricating and chondroprotective properties.
The findings come from in vitro experiments using bovine joints in a culture medium. The researchers believe the findings could have important implications for growing joint tissue for transplantation.
CPM is known to promote joint healing, but the cartilaginous effects of the technique were unknown. Recent evidence from in vivo and in vitro studies suggests that CPM may affect PRG4 metabolism, according to the report in the November issue of Osteoarthritis and Cartilage.
Using bovine knee joints encased in a sealed bioreactor, Dr. Robert L. Sah, from the University of California at San Diego, and colleagues measured the amount of PRG4 biosynthesis with 24 hours of CPM.
The researchers found that CPM did, in fact, increase chondrocyte production of PRG4. Moreover, in joint regions continuously or intermittently exposed to sliding motion, chondrocyte biosynthesis of PRG4 was greater with CPM than without it.
"We have shown that shear forces on cartilage prompt chondrocyte cells in it to produce proteoglycan 4," Dr. Sah said in a statement. "This is an important step toward our goal of eventually growing joint tissue for transplantation."
Osteoarthritis Cartilage 2006.
Reuters Health Information 2006. © 2006 Reuters Ltd.
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