HISTOMORPHOMETRIC ANALYSIS OF INNERVATION OF THE ANTERIOR CRUCIATE LIGAMENT IN OSTEOARTHRITIS

The aim of this study was to determine whether there are quantitative changes in the innervation of the anterior cruciate ligament in osteoa rthritis. Eleven whole anterior cruciate ligaments were obtained at au topsy from cadavera of individuals with advanced osteoarthritis; five healthy ligaments were used as controls. The ligaments were transected and stained with hematoxylin and eosin, oil red O for fat, and a modi fication of Gairn's gold chloride method. The latter stain permits vis ualization of axons, mechanoreceptoss, and free nerve endings that are not apparent on routine stains. The ratio of nerve tissue to periliga mentous synovial tissue was determined histomorphometrically by the po int-counting method. The nerve tissue was located almost exclusively i n the periligamentous synovial tissue. There was a statistically signi ficantly greater area of nerve tissue (as a percentage of the total ar ea) around the anterior cruciate ligaments in the osteoarthritic group than around the ligaments in the control group (p < 0.02). The nerve tissue was distributed evenly throughout the periligamentous synovial tissue in the specimens in both groups. A neurological role has been p roposed for the anterior cruciate ligament in osteoarthritis. This stu dy provides morphological evidence for neural pathology of the anterio r cruciate ligament in subjects with osteoarthritis.