title: [Significance of the glenoid labrum for stability of the glenohumeral joint. An experimental study].
abstract: In human cadavers we were able to show that the glenohumeral joint is comparable to the model of a physical piston. The labrum glenoidale functions like a valve against atmospheric pressure. It is possible to characterize the behavior of intraarticular negative pressure by the equation (formula; see text). The calculations of the force F of atmospheric pressure tending to resist distraction of the joint surfaces leads to a 95% confidence interval from 6.9 to 22.9 kp. Under a general anesthetic, distraction of the healthy glenohumeral joint also produces negative intraarticular pressure in the area of the fossa glenoidalis in vivo. Joints with a labral tear (Bankart defect) and a chronic instability are not characterized by this phenomenon. A change in intraarticular pressure might stimulate intraarticular pressure receptors. This could be important in functioning as a neuromuscular protection reflex for the joint.
authors.affiliation: Chirurgische Klinik Innenstadt und Chirurgische Poliklinik, Ludwig-Maximilians-Universität München.
authors.forename: P
authors.initials: P
authors.lastname: Habermeyer
authors.forename: U
authors.initials: U
authors.lastname: Schuller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002908:Chronic Disease; D006801:Humans; D006874:Hydrostatic Pressure; D008875:Middle Aged; D012783:Shoulder Dislocation / Q000503:physiopathology*; D012785:Shoulder Joint / Q000503:physiopathology*
vernacular_title: Die Bedeutung des Labrum glenoidale für die Stabilität des Glenohumeralgelenkes. Eine experimentelle Studie.