Cain Megan E, Doornberg Job N, Duit Robin, Clarnette Jock, Jaarsma Ruurd, Jadav Bhavin
Department of Orthopaedic and Trauma Surgery, Flinders Medical Centre, Adelaide, South Australia, Australia, Flinders University and University of Amsterdam (PhD Candidate) Adelaide, South Australia and Amsterdam, The Netherlands, University of Adelaide (Masters Candidate), Adelaide, South Australia.
University of Amsterdam, Department of Orthopaedic Surgery, Academisch Medisch Centrum, Amsterdam, The Netherlands, Department of Orthopaedics and Trauma Surgery, Flinders Medical Centre, Adelaide, South Australia, Australia.
Injury. 2018 Apr;49(4):871-876. doi: 10.1016/j.injury.2018.02.024. Epub 2018 Mar 2.
Intramedullary-nails (IMN) are the treatment of choice for most tibial shaft fractures due to their minimally-invasive nature and non-demanding surgical technique. However, a potential iatrogenic pitfall is intra-articular interlocking screw positioning within the proximal (PTFJ) and distal (DTFJ) tibiofibular joints that may go unrecognized.
To evaluate the incidence of intra-articular screw penetration of the PTFJ and DTFJs after interlocking of IMN for tibial fractures.
Reamed IMN using modern techniques, including proximal interlocking via standard aiming jig and distal interlocking either freehand or using SureShot.
Prospective series of 165 consecutive patients with a tibial shaft fracture managed with an IMN. Diagnosis and incidence of penetration of the PTFJ and DTFJ was assessed on protocolled low-dose postoperative CT-scans (standardized clinical practice for assessing rotational alignment). The degree of penetration of the TFJ's was graded as: Grade 1-slight breach of the tibial cortex; Grade 2-clear penetration of the tibial cortex with intra-articular screw tip; and Grade 3-penetration of both tibial- and fibular cortices with screw tip in fibula.
Of the 165 tibial shaft fractures, using the AO/OTA classification, 69% were simple, 16% wedge and 15% complex fractures. Following IMN 42% of patients had intra-articular screw penetration of their PTFJ whilst 39% had penetration of their DTFJ. 66% of patients had penetration of either one- or both of their TFJs. The grading of PTFJ violation was distributed as follows: Grade 1 in 24 patients; Grade 2 in 26 patients and Grade 3 in 19 patients. DTFJ violation was graded as: Grade 1 in 21 patients; 40 patients had Grade 2 violation; and four patients had a Grade 3 penetration.
This diagnostic imaging study reports a high rate of intra-articular screw penetration of the PTFJ and DTFJ after interlocking of IMN for tibia shaft fractures. A prospective cohort study is underway to evaluate its clinical significance. Changes to enable alteration in forced angle of interlocking screw trajectory and avoidance of the anteromedial to posterolateral locking screw may reduce the incidence of TJF violation.
Level II - Diagnostic Imaging Study.
由于髓内钉（IMN）具有微创性且手术技术要求不高，因此是大多数胫骨干骨折的首选治疗方法。然而，一个潜在的医源性陷阱是近端（PTFJ）和远端（DTFJ）胫腓关节内的交锁螺钉定位可能未被识别。
评估胫骨干骨折行IMN交锁后PTFJ和DTFJ关节内螺钉穿透的发生率。
采用现代技术扩髓IMN，包括通过标准瞄准器进行近端交锁，以及徒手或使用SureShot进行远端交锁。
对165例连续的胫骨干骨折患者采用IMN治疗进行前瞻性研究。通过术后按方案进行的低剂量CT扫描（评估旋转对线的标准化临床实践）评估PTFJ和DTFJ的穿透诊断及发生率。TFJ的穿透程度分级如下：1级——轻微穿透胫骨皮质；2级——胫骨皮质明显穿透且螺钉尖端进入关节内；3级——螺钉尖端穿透胫骨和腓骨皮质且进入腓骨。
在165例胫骨干骨折中，根据AO/OTA分类，69%为简单骨折，16%为楔形骨折，15%为复杂骨折。IMN治疗后，42%的患者PTFJ关节内有螺钉穿透，39%的患者DTFJ关节内有螺钉穿透。66%的患者一个或两个TFJ关节内有螺钉穿透。PTFJ侵犯的分级分布如下：24例为1级；26例为2级；19例为3级。DTFJ侵犯分级为：21例为1级；40例为2级；4例为3级穿透。
这项诊断性影像学研究报告了胫骨干骨折行IMN交锁后PTFJ和DTFJ关节内螺钉穿透的发生率较高。一项前瞻性队列研究正在进行以评估其临床意义。改变交锁螺钉轨迹的强制角度并避免从前内侧到后外侧的锁定螺钉，可能会降低TFJ侵犯的发生率。
二级——诊断性影像学研究。
