Superior Labrum
The morphology of the labrum in this region is highly variable, with many anatomical variants having been described [6,20,22-23]. Cooper et al [20] likened the superior labrum to the meniscus of the knee, being attached at its periphery whilst having a central free edge overlying the glenoid.
Similar to other studies, we found the morphology of the superior labrum was found to be highly variable [Table 18]. [17-19] Though our results slightly differ from those of others, it is difficult to compare and contrast the findings because of the relative paucity of such documentation. Like other studies [17-18], no cases of a discoid type meniscal labrum were noted. We believe this variant is quite rare.
Our results are highlighted in grey: Different Types of Superior labrum % Prevalence Bumper labrum – “…characterised by a small excrescence of fibrous tissue”. [18] The superior labrum is “…firmly attached to the glenoid tubercle and [abuts] the articular face of the glenoid”. [18] 18% - Arthroscopic study [18] 43.2% - Arthroscopic Study Meniscoid labrum – the labrum extends onto the glenoid surface [6] ~ 50% - Anatomic study [17] 38% - Arthroscopic study [18] ~15% – Arthroscopic study [6] 2.3% - Arthroscopic Study Triangular labrum – the labrum is “…not draped over the glenoid face…” [18] 44% - Arthroscopic study [18] 31.8% - Arthroscopic study Rounded labrum ~ 50% - Anatomic study [17] Mobile superior labrum – articular cartilage is present on the apex of the supraglenoid tubercle underlying the labrum [18] Not specified – Anatomic study [17] 26% – Arthroscopic study [18] 22.7% - Arthroscopic Study Discoid type meniscal labrum – labrum nearly covering the entire surface of the glenoid [19] 1 case – Arthroscopic study [19]
