2023 ISAKOS Biennial Congress ePoster
Contribution Of The Bony Bankart In Calculating Glenoid Bone Loss
Isabella Bozzo, MDCM (c), M. Eng., Montreal, QC CANADA
Paul Kooner, MDCM, Montreal, QC CANADA
Ralph Nelson, MDCM, Montreal, QC CANADA
Yousef Marwan, FRCSC, MDCM, Montreal, QC CANADA
Carl Laverdière, MDCM, B. Eng., Montreal, QC CANADA
Samir Mustaffa Paruthikunnan, MBBS, MD, FRCR, M.Med (Diag. Radiology), York, North Yorkshire UNITED KINGDOM
Mathieu Boily, MD, FRCP(C), Montreal, QC CANADA
Paul André Martineau, MD, Montreal, QC CANADA
McGill University Health Centre, Montreal, QC, CANADA
FDA Status Not Applicable
Summary
Accurately calculating the glenoid bone loss with the inclusion of the bony Bankart surface area, using our derived equation, can significantly reduce the total glenoid bone loss, favoring arthroscopic repair over open bony procedures.
ePosters will be available shortly before Congress
Abstract
Determining the magnitude of glenoid bone loss (BL) in patients with anterior shoulder instability is an important step in guiding management for shoulder surgeons. A large deficit of the glenoid width has been associated with poor outcomes after arthroscopic repair and is often an indication for a more extensive bony reconstruction. Therefore, a simple and accurate calculation of the degree of glenoid bone loss is crucial for determining the most successful treatment option.
The aim of this study was to derive a new equation to calculate glenoid bone loss with and without the bony Bankart fragment fixation. By assuming this bony fragment as a hemi-ellipse, we can consistently represent the surface area of the bony piece in the reduction and subtract it from the overall glenoid bone loss. 26 patients suspected to have clinically significant bone loss underwent CT imaging pre-operatively, selecting for severe cases of bone loss. Using PACS InteleViewer, the CT imaging was reviewed to measure the "true fit" circle glenoid area, the area of glenoid bone loss, the area of the bony Bankart, and the dimensions required for our equation.
Without the inclusion of the bony Bankart, the glenoid %BL by the standard “true fit” circle measured with imaging software found the glenoid %BL for all patients was 23.8% ± 9.7%. When including the bony Bankart, the glenoid %BL calculated with the software was found to be a mean of 12.1% ± 8.5%. The %BL calculated by our equation with the bony Bankart included was 10% ± 11.1%. There was no statistically significant difference between the %BL values with our equation and the imaging software (p=0.46 > 0.05).
By assuming a cut-off glenoid %BL less than 13.5% for arthroscopic soft tissue repair instead of open repair, then 13 of the 26 patients, i.e. 50% of the patients in this study, would have been treated arthroscopically instead of with bony procedures. By assuming a cut-off of 25% as the threshold for bony procedure, 9 of the 26 patients would have been selected for arthroscopic repair by including the bony Bankart. While much debate exists over deciding on the most optimal treatment, the result of this study gives more reason for consideration of inclusion of the osseous bone fragment, if present.