Morphological matching of proximal interphalangeal (PIP) joint arthritis-related entheses

Abstract

The bony attachments of the PIP (proximal interphalangeal) joint's collateral ligaments of the finger, are known as the so-called entheses. Enthesitis as a key-mechanism in human arthritis was investigated by various authors (e.g., McGonagle et al., 2003). Therefore we carried out a meticulous morphological reappraisal, based on coronal HR-MRI slices of a normal anatomical specimen of an extended PIP joint (Lippens et al. , 1997). Additional coronal histological sections (Masson Trichrome & Weigert Orcein staining) of a PIP collateral ligament from a normal finger anatomical specimen, observed under low power magnification, reveal crisscrossing of collagen fiber bundles with virtually no elasticity. This contrasts with the simple parallelism of collagen fibers as sketched in the diagrams from literature.