Anatomical Evaluation of the APL Tendons in Thumb CMC Joint and Osteoarthritis

Anatomical Evaluation of the APL and FCR Tendons in Thumb CMC Joint in Relation to Osteophytes Formation of the Trapezium and Osteoarthritis.

Certain ligaments in the human body are designed to be a static stabilizer and others to have a sensory function thus remains an unresolved issue.

The presence of mechanoreceptors (sensory corpuscles and free nerve endins) in the human knee and ankle ligaments has implies a sensory role of ligaments in providing afferent information, which in turn regulates intrinsic stiffness in the muscles surrounding the joint, contribuiting to dynamic joint stability.

The aim of this study is to use immunohistochemical methods to analyze the general innervation and possible existence of sensory corpuscles in the thumb carpometacarpal (CMC) joint. This study can help to know the contribution of the tendon insertions and ligaments in the dynamic thumb CMC joint stability.

The accessory APL tendons insertions, number of accessory tendons and insertion in trapezium can be a mechanical factor that develop osteophytes and thumb CMC joint osteoarthritis.

Antibodies against the general nerve marker protein gene product 9.5 (PGP 9.5) and the glial marker S-100 will be use to depict innervation and corpuscular structures. Innervation pattern and sensory corpuscules were investigated by other authors in the wrist. S-100 immunoreactivity is in the Schwann cells in the central regions of the corpuscle, and PGP 9.5 immunoreactivity marked the axonal structures in the corpuscles. The presence of nerve fascicles and particularly sensory corpuscles in the structures, for exemple capsule and APL insertion near the thumb carpometacarpal joint suggest that these structures in the CMC joint have a propioceptive role in the stability of the joint.

Inclusion Criteria:

• Specimens: Adults from 50 to 90 years.

Exclusion Criteria:

• Specimens: younger than 50 or older than 90 years.