Tenosynovitis and synovitis of the first extensor compartment of the wrist: what sonographers should know*

To the best of the author’s knowledge, there is no scientific evidence indicating that the condition is caused by occupational or recreational overuse. Conversely, the analysis of historical series documents its higher prevalence among women over the centuries, even at times when only men effectively participated in the manual, repetitive work. Therefore, even though overuse may exacerbate symptoms, the cause of tenosynovitis is widely unknown, with a probable predominant role of sex-related genetic factors. An illustrative comparison can be made with patients suffering from ischemic heart disease, in whom excessive physical activity exacerbates symptoms, but does not cause the disease. The legal implications of the semantic difference between the verbs cause and exacerbate are considerable and must be emphasized. Genetic factors may equally predispose individuals to anatomical variations in the first compartment such as vertical septum and accessory tendons of the abductor pollicis longus, both considered as risk factors for development of tenosynovitis. Besuch eponym is controversial, since the original article simultaneously describes the cases of three physicians, Quervain, Sandos and Kocher, the latter having formerly been boss of Quervain and a Nobel prize winner in 1909 for his studies on the thyroid gland. The pioneerism in these reports is also questionable, since a very similar clinical entity had been described about 20 years before by Henry Gray on his classical anatomy book, where the term washerwoman’s sprain was coined. The term tenosynovitis is also somewhat inappropriate, since the main histological marker for the condition is the mucopolysaccharide deposition in the tendon sheath, indicating degenerative process. More precisely, the external reticular layer of the sheath is histologically normal, while the internal layer demonstrates myxoid or mucinous degeneration, and the central layer demonstrates vascular proliferation, and macrophage infiltration. Despite this remark, the authors routinely use the term tenosynovitis to describe the tendon sheath thickening in order to facilitate the communication with the referring physician. Fluid distension of the tendon sheath, without associated parietal thickening or tendon abnormalities, is described as synovitis. In the present paper, the term tenosynovitis is liberally utilized to describe the INTRODUCTION