Determination of Dimensions of Glenoid Cavity from other Scapular Parameters in North Indian Population

ABSTRACT

Background: The Glenoid cavity dimensions can help to predict the incidence of glenohumeral dislocations in a population. Purpose of study The present study involved the measurements of the body of the scapula and the glenoid cavity and to draw the relationship of them to predict the chances of glenohumeral dislocations in North Indian Population. Methods: A total number of 130 adult scapulae of unknown sex showing complete ossification and without any damage were included in the study. The various shapes of glenoid cavities both on right and left sides were noted and analysed. A digital Vernier calliper was used to measure all the dimensions of scapula as well as glenoid cavity. The data was analysed and regression formulae to estimate the glenoid cavity dimensions were drawn. Results: Most common shape of the glenoid cavity in the present study was pear shaped (52.30%) followed by inverted comma shaped (33.07%) and least common was oval shaped (14.63%). Mean maximum height of scapula (MSH) was 142.45± 2.32 mm, mean maximum width of scapula (MSW) was 102.65± 0.21mm. Mean maximum glenoid height (MGH) was 38.77± 3.15mm, mean maximum glenoid width I (MGW I) was 23.82± 2.11 mm, mean maximum glenoid width II ( MGW II) was 14.78± 9.11mm. Mean scapular index (SI) was 71.32± 0.61(60-<73) % and mean glenoid index (GI) was 60.43± 5.43%( 60-69%). Bilateral differences in these parameters were statistically insignificant. Mean maximum scapular height was significantly correlated with both mean maximum glenoid height and mean maximum glenoid width. There was also found highly significant interglenoid dimension correlation. Conclusion: Glenohumeral dislocations are expected if indices are <50% or > 89%. A deviation from the normal relation between maximum glenoid width and maximum glenoid length also indicates glenohumeral instability.