through an arthroscope, the variable sized glenoid can normally be seen throughout its entirety, where it “…is described as a kidney bean or an inverted comma”. [1,4,13] the glenoid is a pear shaped structure, the inferior half being wider than the superior half. 
the anterior margin of the glenoid bears a notch that varies in appearance from being very prominent to absent [figure 3]. [6,14] at the glenoid notch, normal synovial outgrowths often occur, and may resemble “…fraying of the synovium and a small synovial fringe…” [6,10]
figure 3 – arthroscopic image of the glenoid notch (arrow). this normal anatomical feature is an indentation along the anterior margin of the glenoid.  it has a variable appearance, ranging from very prominent to being absent. 
in an anatomical study, prescher & klümpen  reported the glenoid notch to be present in 55% of scapulae, with such glenoids adopting a pear-shaped or an inverted comma-shaped configuration. the remaining 45% of the scapulae without a glenoid notch were round or oval in shape.  no gender difference was noted regarding the incidence of the notch. 
in a cadaveric study, lehtinen et al  reported variation in the anatomy of the glenoid rim angle, with it being slightly higher at the 3-o’clock position on the anterior rim than the 9-o’clock position on the posterior rim. the posterior glenoid was shown to be concave, whilst the anterior glenoid extends almost straight medially. 
in our study, the glenoid notch was found to be present in 46.2%, absent in 52.3% and not visualised in 1.5% of cases. no other arthroscopic study has noted the prevalence of the glenoid notch. the results obtained show a slightly lower prevalence of the notch than those previously reported in an anatomical study,  who reported it to be present in 55% and absent in 45% of scapulae. the differences obtained may be attributed to the often poorly visualised anterior margin of the glenoid at arthroscopy.
both the anatomical study  and the one conducted by ourselves differ slightly with regards to the sex prevalence of the glenoid notch. no gender difference was found in the anatomical study  whereas we found it to be marginally more common in women.
a shallow notch was more frequently observed than a prominent one. no other study has commented on the prevalence of the shape of the glenoid notch.
at the top; towards the head
at the back; behind
towards the centre of the body; inwards
at the botom; towards the feet
'key-hole' surgery. Surgery performed via small incisions, using special instruments and a viewing scope..
at the front; in front
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