Abstract：
BACKGROUND: Maintaining anteromedial cortical support is essential for controlling sliding and decreasing postoperative implant-related complications. However, adequate fracture reduction with cortical support in immediate postoperative fluoroscopy is not invariable in postoperative follow-ups. This study was conducted to investigate the risk factors leading to anteromedial cortical support failure in follow up for pertrochanteric femur fractures treated with cephalomedullary nails.
METHODS: This retrospective study enrolled 159 patients with pertrochanteric fractures (AO/OTA- 31A1 and 31A2) that fixed with cephalomedullary nails. All patients were evaluated as adequate fracture reduction in immediate postoperative fluoroscopy before leaving the operation theater. The patients were separated into two groups based on the condition of the anteromedial cortex in the postoperative 3D CT with full-range observation: those with calcar support maintained in Group 1 and those with calcar support lost in Group 2. Demographic information, fracture classification, TAD (tip-apex distance), Cal-TAD, Parker ratio, NSA (neck-shaft angle), reduction quality score, and calcar fracture gapping were collected and compared. Logistic regression analysis was conducted to explore the risk factors leading to anteromedial cortex change.
RESULTS: Anteromedial cortical support failure was noted in 46 cases (29%). There was no significant difference between the two groups concerning age, sex, side injury, TAD, Cal-TAD, Parker ratio, or NSA. There was a significant difference in the AO/OTA fracture classification in univariate analysis but no difference in the multivariable analysis. The reduction quality score, calcar fracture gapping in the AP (anteroposterior), and lateral views were significantly associated with anteromedial cortical support failure in follow-up after cephalomedullary nailing in the multivariable analysis. The threshold value of calcar fracture gapping for the risk of loss was 4.2 mm in the AP and 3.8 mm in the lateral fluoroscopies. Mechanical complications (lateral sliding and varus) were frequently observed in the negative anteromedial cortical support group.
CONCLUSIONS: Good reduction quality was a protective factor, and larger calcar fracture gapping in the AP and lateral views were risk factors leading to the postoperative loss of anteromedial cortical support. Therefore, we should pay close attention to fracture reduction and minimize the calcar fracture gap during surgery.
METHODS: This retrospective study enrolled 159 patients with pertrochanteric fractures (AO/OTA- 31A1 and 31A2) that fixed with cephalomedullary nails. All patients were evaluated as adequate fracture reduction in immediate postoperative fluoroscopy before leaving the operation theater. The patients were separated into two groups based on the condition of the anteromedial cortex in the postoperative 3D CT with full-range observation: those with calcar support maintained in Group 1 and those with calcar support lost in Group 2. Demographic information, fracture classification, TAD (tip-apex distance), Cal-TAD, Parker ratio, NSA (neck-shaft angle), reduction quality score, and calcar fracture gapping were collected and compared. Logistic regression analysis was conducted to explore the risk factors leading to anteromedial cortex change.
RESULTS: Anteromedial cortical support failure was noted in 46 cases (29%). There was no significant difference between the two groups concerning age, sex, side injury, TAD, Cal-TAD, Parker ratio, or NSA. There was a significant difference in the AO/OTA fracture classification in univariate analysis but no difference in the multivariable analysis. The reduction quality score, calcar fracture gapping in the AP (anteroposterior), and lateral views were significantly associated with anteromedial cortical support failure in follow-up after cephalomedullary nailing in the multivariable analysis. The threshold value of calcar fracture gapping for the risk of loss was 4.2 mm in the AP and 3.8 mm in the lateral fluoroscopies. Mechanical complications (lateral sliding and varus) were frequently observed in the negative anteromedial cortical support group.
CONCLUSIONS: Good reduction quality was a protective factor, and larger calcar fracture gapping in the AP and lateral views were risk factors leading to the postoperative loss of anteromedial cortical support. Therefore, we should pay close attention to fracture reduction and minimize the calcar fracture gap during surgery.
摘要：
背景：保持前内侧皮质支持对于控制滑动和减少术后植入物相关并发症至关重要。然而,在术后随访中,在术后即刻透视中使用皮质支持充分的骨折复位并非一成不变.本研究旨在探讨在采用头髓内钉治疗股骨转子骨折的随访中导致前内侧皮质支持失败的危险因素。
方法：这项回顾性研究纳入了159例股骨粗隆间骨折（AO/OTA-31A1和31A2）患者，这些患者采用头髓内钉固定。在离开手术室之前，在术后立即进行透视检查时，所有患者均被评估为足够的骨折复位。根据术后3DCT中前内侧皮质的情况将患者分为两组，并进行全方位观察：第1组保持calcar支持的患者和第2组失去calcar支持的患者。人口统计信息,断裂分类,TAD(尖端-顶点距离),Cal-TAD,派克比率,NSA（颈轴角度），还原质量分数，收集并比较了calcar骨折间隙。采用Logistic回归分析探讨导致前内侧皮质改变的危险因素。
结果：发现前内侧皮质支持失败46例（29％）。两组的年龄差异无统计学意义,性别,侧面受伤,TAD,Cal-TAD,派克比率,或者国安局.在单变量分析中，AO/OTA骨折分类存在显着差异，而在多变量分析中没有差异。还原质量分数，AP（前后）的cal骨骨折间隙，在多变量分析中，在头端髓内钉固定后的随访中，侧视与前内侧皮质支持失败显著相关。在AP中，calcar骨骨折间隙对丢失风险的阈值为4.2mm，在侧视荧光镜检查中为3.8mm。在阴性的前内侧皮质支持组中经常观察到机械并发症（外侧滑动和内翻）。
结论：良好的还原质量是一个保护因素，AP和侧位视图中较大的calcar骨折间隙是导致术后前内侧皮质支持丢失的危险因素。因此,术中应注意骨折复位，尽量减小骨折间隙。
方法：这项回顾性研究纳入了159例股骨粗隆间骨折（AO/OTA-31A1和31A2）患者，这些患者采用头髓内钉固定。在离开手术室之前，在术后立即进行透视检查时，所有患者均被评估为足够的骨折复位。根据术后3DCT中前内侧皮质的情况将患者分为两组，并进行全方位观察：第1组保持calcar支持的患者和第2组失去calcar支持的患者。人口统计信息,断裂分类,TAD(尖端-顶点距离),Cal-TAD,派克比率,NSA（颈轴角度），还原质量分数，收集并比较了calcar骨折间隙。采用Logistic回归分析探讨导致前内侧皮质改变的危险因素。
结果：发现前内侧皮质支持失败46例（29％）。两组的年龄差异无统计学意义,性别,侧面受伤,TAD,Cal-TAD,派克比率,或者国安局.在单变量分析中，AO/OTA骨折分类存在显着差异，而在多变量分析中没有差异。还原质量分数，AP（前后）的cal骨骨折间隙，在多变量分析中，在头端髓内钉固定后的随访中，侧视与前内侧皮质支持失败显著相关。在AP中，calcar骨骨折间隙对丢失风险的阈值为4.2mm，在侧视荧光镜检查中为3.8mm。在阴性的前内侧皮质支持组中经常观察到机械并发症（外侧滑动和内翻）。
结论：良好的还原质量是一个保护因素，AP和侧位视图中较大的calcar骨折间隙是导致术后前内侧皮质支持丢失的危险因素。因此,术中应注意骨折复位，尽量减小骨折间隙。
