Mechanoreceptor profile of the lateral collateral ligament complex in the human elbow

Active restraint for the elbow joint is provided by the soft tissue component, which consists of a musculoligamentous complex. A lesion of the lateral collateral ligament complex (LCLC) is thought to be the primary cause of posterolateral rotatory instability in the elbow. Its role as a protective reflexogenic structure is supported by the existence of ultrastructural mechanoreceptors. The aim of this study was to describe the existence and distribution of LCLC mechanoreceptors in the human elbow joint and to determine their role in providing joint stability.

Eight LCLCs were harvested from fresh frozen cadaver elbows. Specimens were carefully separated from the lateral epicondyle and ulna. The ligament complex was divided into 7 regions of interest and stained with modified gold chloride. Microscopic evaluation was performed for Golgi, Ruffini, and Pacinian corpuscles. The number, distribution, and density of each structure were recorded.

Golgi, Ruffini, and Pacinian corpuscles were observed in LCLCs, with variable distribution in each region of interest. Ruffini corpuscles showed the highest total mechanoreceptor density. Mechanoreceptor density was higher at bony attachment sites.

The existence and role of each mechanoreceptor defined the purpose of each region of interest. Mechanoreceptors are beneficial for its proprioceptive feature towards a successful elbow ligament reconstruction.