The sublabral foramen. Congenital or an acquired variance?

Abstract

The sublabral foramen is considered to be a clinically asymptomatic, isolated variant of the anterior-superior capsulo-labral-complex. It may be observed during shoulder arthroscopy and may implicate problems in differential diagnosis of traumatic lesions. In an anatomic study on 89 macroscopically healthy shoulder specimens the age distribution and the incidence in relation to the varying shape of the glenoid as feasible factors of influence for a sublabral foramen (SF) were analyzed in order to elucidate the unknown pathogenesis of SF. In addition histologic sections of three SF samples were obtained. Mean age of the specimens with a sublabral foramen [n=20; 69 (37-84) years] was significantly higher (p=0.04) compared to samples without a sublabral foramen [n=69; 59 (18-94) years]. An increased incidence of a sublabral foramen in relation to a distinct shape of the glenoid could not be established although a prevalence of a glenoid with anterior notch was observed. The results indicate an age-related development of the sublabral foramen,thus in younger patients with an anterior-superior capsulolabral displacement local signs of trauma and involvement of the biceps anchor should be controlled before definitive diagnosis.