TENSILE LOAD AND THE METABOLISM OF ANTERIOR CRUCIATE LIGAMENT CELLS

It generally is recognized that tensile load plays a major role in mai ntaining the homeostasis of the anterior cruciate ligament fibers, but its detailed mechanism remains a matter of controversy. The effects o f cyclic tensile load on the metabolism of the anterior cruciate ligam ent were investigated experimentally using cultured cells from the ant erior cruciate ligament of rabbits. Using culture plates with flexible rubber bases, a cyclic tensile load was applied to the cultured cells for 24 hours, and the changes in shape, alignment, and metabolism of the cells were analyzed, Under the cyclic tensile load, the shape of t he cells from the anterior cruciate ligament changed to spindle and al igned perpendicularly to the direction of the tensile load. The cyclic tensile load also caused an increase in collagen synthesis by the cel ls from the anterior cruciate ligament, which was predominant in Type I. The cells from the synovium showed similar changes in shape and ali gnment under the cyclic tensile load, but no significant change was ob served in cell metabolism. These observations suggest that the applica tion of cyclic tensile load on the anterior cruciate ligament cells is an important factor in the regulation of collagen synthesis in the an terior cruciate ligament.