Kristine Italia, Nicholas Green, Katrien Plessers, Jashint Maharaj, Peter Pivonka, Kenneth Cutbush, Ashish Gupta
The primary aim of this study was to measure joint line lateralisation amongst patients who underwent reverse shoulder arthroplasty (RSA) with structural bone grafting (BIO-RSA) using a statistical shape model (SSM). Secondly, it was aimed to characterise differences between the individual pre- and post-operative glenoid to the SSM reconstructions...
Restoring the native glenohumeral joint line in RSA and identification of its original anatomy can be challenging. It is strongly believed that knowing the premorbid joint line will provide better morphologic understanding and might improve clinical results. Currently, the use of contralateral computed tomography (CT) scans for accurate three-dimensional (3D) reconstruction from the contralateral shoulder are conducted for measuring preoperative glenoid bone loss and joint medialisation. Since...
Between July 2016 and July 2018 21 patients who underwent RSA (primary n=20, revision n=1) with glenoid bone grafting (autograft n=15, allograft n=6) were enrolled prospectively. A Grammont design humeral stem with a 25mm long baseplate post was used. CT scans were conducted at 3 and 12 months with 3D modelling using the medical imaging software (Mimics 22.0, Materialise, Belgium). A previously validated scapula SSM was used to reconstruct the native glenoid shape of each preoperative bone...
The average postoperative lateralisation referenced from the predicted native glenoid joint line using SSM was 6.54 mm ± 3.3mm. On average measuring from the base of the coracoid, the glenoid base plate centroid was 20.7mm ± 4.57mm and the SSM centroid was 11.98 mm ± 4.33mm, with a mean difference of 8.72mm. The pre-operative glenoid defects had an average erosion depth of 6.81mm ± 4.65mm, defect area of 35.1% ± 33.5% and subluxation distance of 8.62mm ± 7.57mm and 20.1% ± 18.4% total vault...
Restoring and understanding pathologic glenoid morphologic anatomy is paramount in RSA. SSM increases accuracy in measuring the real bony defects and predicts the original joint line without the use of contralateral comparative imaging. Measuring the amount of bone loss preoperatively using SSM can dictate the required bone graft dimension to reconstruct the native vault...