Abstract：
Total joint replacement has become significantly more common as a treatment for advanced trapeziometacarpal joint osteoarthritis in recent years. The latest generation of prostheses with dual-mobility designs leads to very good functional results and low rates of loosening and dislocation in the short and medium term. Biomechanical studies showed that central placement and parallel alignment of the cup with respect to the proximal articular surface of the trapezium are crucial for both cup stability and prevention of dislocation. Despite correct positioning of the guidewire, incorrect placement or tilting of the inserted cup may occur, requiring immediate intraoperative revision.
The existing spherical and conical cup models in sizes 9 mm and 10 mm were transferred to a computer-aided design dataset. Depending on the intraoperative complication (tilting or incorrect placement), the revision options resulting from the various combinations of cup type and size were simulated and analyzed according to the resulting defect area and bony contact area.
In well centered cups, a size 9 conical cup could be replaced by a size 9 spherical cup and still be fixed by press-fit. Conversely, a size 9 spherical cup could not be replaced by a size 9 conical cup, but only by a size 10 cup, of whatever shape. When a size 9 conical cup was tilted up to 20°, the best revision option was to resect the sclerotic margin and insert a size 10 conical cup deeper into the cancellous bone, to achieve the largest contact area with the surrounding bone. When a size 9 cup of whatever shape was poorly centered (misplaced with respect to the dorsopalmar or radioulnar line of the trapezium), placement should be corrected using a size 10 cup, combined with autologous bone grafting of the defect. Again, the size 10 conical cup showed the largest bony contact area.
Our computer-based measurements suggested options for intraoperative cup revision depending on cup shape and size and on type of misalignment with resulting bone defects. These suggestions, however, need to be confirmed in anatomic specimens before introducing them into clinical practice.
The existing spherical and conical cup models in sizes 9 mm and 10 mm were transferred to a computer-aided design dataset. Depending on the intraoperative complication (tilting or incorrect placement), the revision options resulting from the various combinations of cup type and size were simulated and analyzed according to the resulting defect area and bony contact area.
In well centered cups, a size 9 conical cup could be replaced by a size 9 spherical cup and still be fixed by press-fit. Conversely, a size 9 spherical cup could not be replaced by a size 9 conical cup, but only by a size 10 cup, of whatever shape. When a size 9 conical cup was tilted up to 20°, the best revision option was to resect the sclerotic margin and insert a size 10 conical cup deeper into the cancellous bone, to achieve the largest contact area with the surrounding bone. When a size 9 cup of whatever shape was poorly centered (misplaced with respect to the dorsopalmar or radioulnar line of the trapezium), placement should be corrected using a size 10 cup, combined with autologous bone grafting of the defect. Again, the size 10 conical cup showed the largest bony contact area.
Our computer-based measurements suggested options for intraoperative cup revision depending on cup shape and size and on type of misalignment with resulting bone defects. These suggestions, however, need to be confirmed in anatomic specimens before introducing them into clinical practice.
摘要：
背景：近年来，全关节置换作为晚期梯形掌骨关节炎的治疗方法越来越普遍。具有双移动性设计的最新一代假体在短期和中期内具有非常好的功能效果以及较低的松动和脱位率。生物力学研究表明，杯子相对于梯形近端关节表面的中央放置和平行对齐对于杯子的稳定性和防止脱位至关重要。尽管导丝定位正确,插入的杯子可能会出现不正确的放置或倾斜，需要立即术中翻修。
方法：将尺寸为9mm和10mm的现有球形和锥形杯模型转移到计算机辅助设计数据集中。根据术中并发症（倾斜或错误放置），根据所产生的缺陷面积和骨接触面积，模拟和分析了由杯子类型和尺寸的各种组合产生的修订选项。
结果：在居中的杯子中，9号锥形杯可以用9号球形杯代替，并且仍然可以通过压配合固定。相反，9号球形杯不能用9号锥形杯代替，但只有10号杯子，无论什么形状。当9号锥形杯倾斜到20°时，最好的翻修选择是切除硬化边缘，并将10号锥形杯更深地插入松质骨，实现与周围骨骼的最大接触面积。当任何形状的9号杯子中心位置不好时(相对于梯形的背脉或尺弧线错位)，应使用10号杯子校正放置，结合自体骨移植修复缺损。再一次,10号锥形杯显示最大的骨接触面积。
结论：我们的基于计算机的测量结果根据杯子的形状和大小以及导致骨缺损的错位类型提出了术中杯子翻修的选择。这些建议,然而,在将其引入临床实践之前，需要在解剖标本中进行确认。
方法：将尺寸为9mm和10mm的现有球形和锥形杯模型转移到计算机辅助设计数据集中。根据术中并发症（倾斜或错误放置），根据所产生的缺陷面积和骨接触面积，模拟和分析了由杯子类型和尺寸的各种组合产生的修订选项。
结果：在居中的杯子中，9号锥形杯可以用9号球形杯代替，并且仍然可以通过压配合固定。相反，9号球形杯不能用9号锥形杯代替，但只有10号杯子，无论什么形状。当9号锥形杯倾斜到20°时，最好的翻修选择是切除硬化边缘，并将10号锥形杯更深地插入松质骨，实现与周围骨骼的最大接触面积。当任何形状的9号杯子中心位置不好时(相对于梯形的背脉或尺弧线错位)，应使用10号杯子校正放置，结合自体骨移植修复缺损。再一次,10号锥形杯显示最大的骨接触面积。
结论：我们的基于计算机的测量结果根据杯子的形状和大小以及导致骨缺损的错位类型提出了术中杯子翻修的选择。这些建议,然而,在将其引入临床实践之前，需要在解剖标本中进行确认。
