In the article "Excessive Retroversion of the Glenoid Cavity. A Cause of Non-Traumatic Posterior Instability of the Shoulder" by B. J. Brewer, R. C. Wubben, and G. F. Carrera, published in the June issue of The Journal (68-A: 724-731, June 1986), there is an error in the text. On page 728, the sentence that begins on line 5 should read: "An arthrotomy is made transversely through the tendons of the rotator cuff and the capsule at the margin of the glenoid."