Quantification of mechanoreceptors in the canine anterior cruciate ligament

Ten canine anterior cruciate ligaments (ACLs) were harvested while preserving their bony attachments. Specimens were stained using a modified gold chloride technique, divided into thirds, and serially sliced at 0.5 microns. The slides were viewed to count the mechanoreceptors present. The average numbers of receptors found were: proximal 67, middle 43, and distal 18 (ANOVA: P < 0.001). The statistical test (Sheffé) revealed that the proximal third contained a greater mean number of receptors (S = 3.8). No significant difference was found between the number of receptors in the middle and distal thirds (S = 0.85).