Cadaveric and three-dimensional computed tomography study of the morphology of the scapula with reference to reversed shoulder prosthesis.
OBJECTIVE
The purpose of this study is to analyze the morphology of the scapula with reference to the glenoid component implantation in reversed shoulder prosthesis, in order to improve primary fixation of the component.


METHODS
Seventy-three 3-dimensional computed tomography of the scapula and 108 scapular dry specimens were analyzed to determine the anterior and posterior length of the glenoid neck, the angle between the glenoid surface and the upper posterior column of the scapula and the angle between the major craneo-caudal glenoid axis and the base of the coracoid process and the upper posterior column.


RESULTS
The anterior and posterior length of glenoid neck was classified into two groups named "short-neck" and "long-neck" with significant differences between them. The angle between the glenoid surface and the upper posterior column of the scapula was also classified into two different types: type I (mean 50 degrees-52 degrees ) and type II (mean 62.50 degrees-64 degrees ), with significant differences between them (p < 0.001). The angle between the major craneo-caudal glenoid axis and the base of the coracoid process averaged 18,25 degrees while the angle with the upper posterior column of the scapula averaged 8 degrees .


CONCLUSIONS
Scapular morphological variability advices for individual adjustments of glenoid component implantation in reversed total shoulder prosthesis. Three-dimensional computed tomography of the scapula constitutes an important tool when planning reversed prostheses implantation.
Torrens
Carlos
C
Orthopaedic Department, Hospital del Mar de Barcelona, Passeig Marítim 25-29, 08003 Barcelona, Spain. 86925@imas.imim.es
Corrales
Monica
M
Gonzalez
Gemma
G
Solano
Alberto
A
Cáceres
Enrique
E