Bozzo Isabella, Kooner Paul, Nelson Ralph, Marwan Yousef, Paruthikunnan Samir, Laverdière Carl, Boily Mathieu, Martineau Paul A
Faculty of Medicine, McGill University, Montréal, Québec, Canada.
Division of Orthopaedic Surgery, McGill University Health Centre, Montréal, Québec, Canada.
Orthop J Sports Med. 2023 May 18;11(5):23259671231168879. doi: 10.1177/23259671231168879. eCollection 2023 May.
Determining the magnitude of glenoid bone loss in patients with anterior shoulder instability is an important step in guiding management. Most calculations to estimate the bone loss do not include the bony Bankart fragment. However, if it can be reduced and adequately fixed, the estimation of bone loss may be decreased.
To derive a simple equation to calculate the surface area of the bony fragment in Bankart fractures.
Case series; Level of evidence, 4.
A total of 26 patients suspected of having clinically significant bone loss underwent computed tomography imaging preoperatively, and the percentage of glenoid bone loss (%BL) was approximated with imaging software using a freehand region of interest area measurement with and without the inclusion of the bony Bankart fragment. By assuming this bony fragment as a hemi-ellipse with height, H, and thickness, d, we represented the surface are of the bony piece (), and subtracted it from the overall %BL. They compared this value with the one found using imaging software.
Without the inclusion of the bony Bankart, the overall %BL by the standard true-fit circle measured using imaging software was 23.8% ± 9.7%. When including the bony Bankart, the glenoid %BL measured using imaging software was found to be 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 measured using the equation and the imaging software ( = .46).
Using a simple equation that approximates the bony Bankart fragment as a hemiellipse allowed for estimation of the glenoid bone loss, assuming that the fragment can be reduced and adequately fixed. This method may serve as a helpful tool in preoperative planning when there are considerations for incorporating the bony fragment in the repair.
确定前肩不稳患者肩胛盂骨丢失的程度是指导治疗的重要一步。大多数估算骨丢失的计算方法未将骨性Bankart骨折块纳入。然而，如果该骨折块能够复位并得到充分固定，骨丢失的估算值可能会降低。
推导一个简单的公式来计算Bankart骨折中骨块的表面积。
病例系列；证据等级，4级。
共有26例怀疑存在具有临床意义骨丢失的患者在术前接受了计算机断层扫描成像，使用成像软件通过徒手绘制感兴趣区域测量肩胛盂骨丢失百分比（%BL），测量时分别纳入和不纳入骨性Bankart骨折块。通过将该骨性骨折块假设为一个高为H、厚为d的半椭圆，我们表示出骨块的表面积（），并从总体%BL中减去该值。他们将此值与使用成像软件得出的值进行比较。
不纳入骨性Bankart骨折块时，使用成像软件通过标准真拟合圆测量的总体%BL为23.8%±9.7%。纳入骨性Bankart骨折块时，使用成像软件测得的肩胛盂%BL为12.1%±8.5%。我们的公式在纳入骨性Bankart骨折块时计算出的%BL为10%±11.1%。使用该公式计算得出的%BL值与成像软件测量得出的%BL值之间无统计学显著差异（P = 0.46）。
使用一个将骨性Bankart骨折块近似为半椭圆的简单公式，可以在假设骨折块能够复位并得到充分固定的情况下估算肩胛盂骨丢失。当考虑在修复中纳入骨块时，该方法可作为术前规划的有用工具。
