Richly innervated soft tissues covering the superficial aspect of the extensor origin in patients with chronic painful tennis elbow - Implication for treatment?

Tennis elbow is difficult to treat. The

The results provide new information on the innervation patterns of the superficial tissues of the extensor origin and their potential as source of tennis elbow pain. Level of evidence: IV.

Nine tissue specimens from the fibrous/fatty tissue covering the extensor origin was taken from seven patients (mean age: 45 years) undergoing surgical treatment for chronic painful tennis elbow. The specimens were stained for morphology (haematoxylin and eosin, H and E) and immunohistochemically for general nerve marker protein gene product 9.5 (PGP 9.5) and markers for sympathetic (tyrosine hydroxylase, TH) and sensory nerve fibres (calcitonin gene-related peptide, CGRP).

All specimens contained multiple blood vessels and nerve structures indicated by morphology and immunoreactions. There was a frequent occurrence of TH reactions, especially peri-vascularly, but also in nerve fascicles. Immunoreactions for CGRP were seen in nerve fascicles and isolated nerve fibres.