All these classification systems are based on the 2-D appearance of the glenoid and should be considered cautiously. The glenoid is a complex 3-D structure that can be affected by any number of disease processes, trauma, and surgical intervention. Using more modern CT techniques and 3-D imaging, we now know that many deformities previously classified as unidirectional are, instead, complex and multidirectional.
Frankle and colleagues9 developed a classification based more 3-D CT models which has further classified severe glenoid vault deformities in relation to direction and degree of bone loss (Figures 2A-2E). Using this system, they were better able to determine degree and direction of deformity than in previous 2-D evaluations, and they were able to determine the amount of glenoid vault bone available for baseplate fixation. Scalise and colleagues10 further defined the influence of such 3-D planning in total shoulder arthroplasty.
With knowledge of these classification systems and use of contemporary imaging systems, shoulder arthroplasty in cases of severe glenoid deficiency can be more successful. Potentially, we can improve outcomes even more in the more severe cases of bone loss with use of patient-specific planning tools, including the guides and patient-specific implants that are now readily available with many implant systems.11
Preoperative planning tools, bone-grafting techniques, augmented and specialized glenoid and humeral implants, and patient-specific implants are discussed this month to give our readers a comprehensive review of the latest concepts in shoulder arthroplasty in cases of significant bone loss or deformity.
This month of The American Journal of Orthopedics presents the most current and cutting-edge solutions for humeral and glenoid bone deformities and deficiencies in contemporary shoulder arthroplasties.