Immunohistochemical analysis of mechanoreceptors in the human posterior cruciate ligament: association with aging male.

Introduction: The aim of this study was to evaluate the association between frequency of the posterior cruciate ligament (PCL) mechanoreceptors and age in men.

Methods: Nineteen normal right knees harvested from human male cadavers were evaluated. Age ranged from 17 to 64 years with a mean of 35 years old. PCL was separated for sampling in femoral and tibial portions. Topographic distribution and frequency within the ligament texture were determined employing the Pro-Image digital analysis system. Mechanoreceptors were counted and classified according to the criteria proposed by Freeman & Wyke.

Results: A total of 1820 mechanoreceptors were found, type II being the most frequent one. Analysis of the femoral portion of the ligament showed an equivalent predominance of Types II and IV mechanoreceptors. Tibial portion had a predominance of type II mechanoreceptors, followed by type IV. At this portion, receptors Types I and III were less commonly identified.

Conclusion: In the tibial portion of the PCL, there is predominance of Type II mechanoreceptors followed by types IV, I and III mechanoreceptors, respectively. No relationship was found between the total number of mechanoreceptors and age in the femoral and tibial portions of the PCL.