3D CT scan-based study of glenoid morphology in Indian population: Clinical relevance in design of reverse total shoulder arthroplasty.

Background: The knowledge of normal anatomy of glenoid in a population has relevance in terms of comparison with other regional and national population. Furthermore, it could enable clinicians to judge whether the available sizes of reverse total shoulder arthroplasty (RTSA) prosthesis could provide optimal fit for the glenoid in Indian patients.

Methods: We evaluated consecutive 200 3-dimensional chest CT scans of 50 male and 50 female patients which included both shoulder joints and done for non-orthopaedic diseases at a tertiary care institute. The glenoid height, width, and version were measured using commercially available computer program.

Results: Mean age of the patents was 38.6 ± 13.8 years (range, 19-59 years). The mean glenoid height was 33.9 ± 3.1 mm and maximum glenoid width was 24.2 ± 2.1 mm. Mean glenoid version in the study population was a retroversion of 3.47 ± 4.7. The maximum glenoid width of 45% female and 15% male patients was less than 25 mm which is the diameter of smallest available glenoid baseplate among the commonly used RTSA systems.

Conclusions: The normal glenoid size of a large cohort of Indian population studied was smaller than that reported in cohorts from western countries. The glenoid width of substantial proportion of patients, especially female patients, was less than the diameter of smallest available glenoid baseplate. Clinical studies are needed in future in Indian patients undergoing RTSA to evaluate the glenoid bone-baseplate mismatch and ascertain the necessity of development of smaller size glenoid baseplate for optimal prosthesis fit in Indian patients.