All of the following structures forms the border of Quadrangular space, EXCEPT:

Structures forming the borders of Quadrangular space are teres major and teres minor muscles, long head of the triceps brachii muscle, and the humerus. Contents of this space are: axillary nerve and the posterior circumflex humeral aery. Structures forming the border of triangular space are:Teres major and teres minor muscles and the long head of the triceps brachii muscle.Its contents is Circumflex scapular aery.Ref: Moon D.A., Foreman K.B., Albeine K.H. (2011). Chapter 30. Shoulder and Axilla.