To introduce an unreported intraoperative complication in intramedullary nailing (IN) of an anatomically reduced trochanteric fracture variant characterized by a basicervical fracture line and coronally disrupted greater trochanter (GT). A total of 414 trochanteric fractures (TF) treated with intramedullary nails from 2013 to 2017 were included in this study. After analysis of intraoperative fluoroscopy data, 33 cases, including 21 females and 12 males, with a mean age of 72.5 years (33 to 96 years) were identified for internal rotation of the cephalocervical fragment and inferior opening at the basicervical fracture line caused by nailing a satisfactorily reduced TF. The morphological features of this group of patients were analyzed on computed tomography (CT) scan. On radiograph, the magnitude of the displacement and final femoral neck-shaft angle (NSA) were measured. CT analysis demonstrated that the basicervical fracture line and the posterolateral fragment (PLF) detached from the GT were the two dominant features of this cohort. They were classified according to the number of main fragments: a 3-fragmentary subgroup containing three consistent fragments (cephalocervical fragment, PLF and distal femoral shaft) and a 4-fragmentary subgroup embracing one additional fragment (lesser trochanter). The four subtypes were as follows: the 3-fragmentary S indicating a small PLF (6 cases), the 3-fragmentary M presenting a moderate PLF (3 cases), the 3-fragmentary L standing for the PLF involving whole lesser trochanter (LT) (4 cases) and the 4-fragmentary GL incorporating separated PLF and LT fragments (20 cases). Geological analysis demonstrated that the majority of the basicervical fracture lines (81.8%) just crossed the center of the piriformis fossa, while the others marginally involved the medial wall of the GT. Postoperatively, the mean width of the inferior opening at the basicervical region was 9.2 ± 4.6 mm. The mean NSA was 135.2 ± 7.8 degrees. The comparison between the 3- and 4-fragmentary subgroups revealed no significant differences in magnitude of displacement and NSA. This unreported intraoperative complication predominantly occurred in the intramedullary nailed basicervical trochanteric fracture variant combined with a PLF from the GT. The magnitude of the secondary displacement was substantial and resulted in a relative valgus reduction. This secondary displacement was caused by an impingement of the reamer with the superolateral cortex of the cephalocervical fragment and should be addressed during the operation. Therapy IV.

中文翻译：

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髓内钉固定基本神经转子转子骨折变体并机械损伤较大转子时产生的反向楔效应

要在髓内钉（IN）中引入未报告的术中并发症，其特点是解剖减少的转子转子骨折变种，其特征为基本神经骨折线和冠状动脉大转子（GT）破裂。该研究共纳入了2013年至2017年用髓内钉治疗的414例股骨转子转子骨折（TF）。在分析术中透视数据后，发现33例平均年龄为72.5岁（33至96岁）的女性21例，男性12例，其原因是由于钉子引起的头颈碎裂的内部旋转和下颌基本开放令人满意地降低了TF。在计算机断层扫描（CT）扫描上分析了这组患者的形态特征。在射线照相上 测量位移的大小和最终的股骨颈轴角（NSA）。CT分析表明，该组的两个主要特征是基本神经断裂线和从GT脱离的后外侧骨折（PLF）。根据主要片段的数量将它们分类：一个包含三个一致片段（头颈片段，PLF和股骨远端）的3片段亚组和一个包含一个附加片段（小转子）的4片段亚组。四个亚型如下：3片段S表示小PLF（6例），3片段M表示中度PLF（3例），3片段L代表PLF，涉及整个小转子（LT） ）（4例）和合并了分离的PLF和LT片段的4片段GL（20例）。地质分析表明，大部分基本神经断裂线（81.8％）刚刚越过梨状窝的中心，而其他则略微涉及到了GT的内壁。术后，基本神经区域下开口的平均宽度为9.2±4.6 mm。平均NSA为135.2±7.8度。3和4片段亚组之间的比较显示，位移和NSA的大小没有显着差异。这种未报告的术中并发症主要发生在髓内钉基本神经系统的转子粗隆骨折变体与GT的PLF结合中。二次移位的幅度很大，导致相对的外翻减少。该二次移位是由于铰刀撞击头颈碎片的上外侧皮质引起的，应在手术中解决。治疗IV。