Agreement between Sanders classification of intraarticular calcaneal fractures and assessment during the surgery

BackgroundSanders classification, based on the number of displaced fractured fragments of posterior facet, can predict the prognosis of calcaneal intraarticular fractures. The aim of the study was assessing not only intraobserver reproducibility and interobserver reliability of Sanders classification but also the agreement between preoperative reported types based on computed tomography (CT) scan and direct observation during the surgery.MethodsIn this cross-sectional study, preoperative CT scans of 100 patients with intra-articular calcaneal fracture operated by a single surgeon were studied by two orthopedic and trauma surgeons (A & B), twice with an interval of three weeks. Their result were compared with each other and with the number of displaced fractured fragments recorded in the operation notes. Quadratic weighted kappa test was used to check the agreement between two observers and between the observers and the surgeon.ResultsIntraobserver reproducibility for Sanders classification of intraarticular calcaneal fractures was found to be good to excellent (A1–A2: 0.91 and B1–B2: 0.75). There was a moderate agreement between the two observers (A1–B1: 0.56, A1–B2:0.58, A2–B1:0.48, and A2–B2:0.51). The agreement between reported types of Sanders classification and the number of displaced fractured fragments seen during the surgery was fair (A1-surgeon: 0.27, A2-surgeon: 0.29, B1-surgeon: 0.38, and B2-surgeon: 0.50).ConclusionsAgreement between Sanders classification and what is real during surgery is fair. Hence, Sanders classification as determined in the widest cut of coronal CT scan extended posteriorly should be cautiously interpreted for surgery.     

Different types and epidemiological patterns of calcaneal fractures based on reviewing CT images of 957 fractures

IntroductionCalcaneal fractures may have lifelong debilitating sequences, if not treated properly. Identifying different types of calcaneal fractures based on the computed tomography (CT) scans can increase our conception about these fractures.MethodsIn a cross-sectional study, the available CT images of all consecutive patients with the diagnosis of calcaneal fracture, from January 2015 to December 2018, were reviewed to determine different patterns and types of these fractures.ResultsCT images of 886 patients (mean age, 41.29 ± 14.9; range, 3–89 years; male/female, 4.86; pediatric: 3.7%) with 957 calcaneal fractures were evaluated. The peak incidence of calcaneal fractures was seen in patients between 30 to 39 years of age (29%). The rate of open fractures and bilateral involvements were 2.4% and 8.0%, respectively. Among 680 (71.0%) intra-articular calcaneal fractures, subtalar calcaneal fractures were the most common type (94.3%). The majority of intra-articular subtalar calcaneal fractures were displaced (95.0%) with calcaneocuboid joint (CCJ) involvement (59.9%). Fracture lines were extended to the CCJ in about 86.9% of Sanders type IV, 66.3% of type III, and 60.2% of type II. Among 261 extra-articular fractures (27.3%), calcaneal body fracture (55.6%) was the most frequent type, followed by medial tubercle fracture (24.1%), calcaneal tuberosity fracture (10.4%), Degan type I anterior process fractures (5.4%), Degan type II anterior process fracture (3.4%), and isolated lateral tubercle fracture (1.1%). Most of bilateral calcaneal fractures were intra-articular subtalar fractures with involvement of CCJ. Although majority of intra-articular calcaneal fractures were displaced; less than half of the extra-articular fractures were displaced.ConclusionDisplaced intra-articular subtalar calcaneal fractures with CCJ involvement are the most frequent type of unilateral and bilateral calcaneal fractures. It appears that there is a correlation between Sanders type and the probability of CCJ involvement. Unlike intra-articular subtalar calcaneal fractures, the CCJ in the majority of extra-articular calcaneal body fractures was intact.Level of evidenceLevel IV.     

A measuremental approach to calcaneal fractures

Objective

The calcaneus is the most frequently broken tarsal bone in the setting of trauma. The diagnosis, treatment and prognosis of calcaneal fractures depend on the location and type determined by the Sanders classification. With the help of measurements on lateral view radiographs like the Böhler’s angle, the angle of Gissane, the calcaneal inclination angle and the calcaneal facet height, we can predict the severity of the trauma and prognosis by assessing the collapse of the calcaneus. On computed tomography (CT), calcaneal fractures which reach into the joint space can be classified by the Sanders classification system according to the number of fragments. In this study, we tried to determine whether calcaneal fracture severity determined by angle and facet height measurements on lateral X-ray radiographs correlate with the Sanders classification.

Materials and methods

Among 69 patients diagnosed with calcaneal fractures, we performed a retrospective study by analysing the Böhler’s angle, the angle of Gissane, the calcaneal inclination angle and the calcaneal facet height on digital lateral X-rays and by classifying the fractures according to the Sanders classification by CT. We compared the results of the two different imaging modalities.

Results

We found that, as the Sanders classification type became more severe from type 1 to type 4, a general decrease was observed in the Böhler’s angle, the inclination angle and the facet length, whereas a general increase was observed for the mean values of the angle of Gissane.

Conclusion

These findings suggest that measurements obtained from lateral X-rays coincide with the Sanders classification and, therefore, might indicate the prognosis.     

CT morphometry for calcaneal fractures and comparison of the Zwipp and Sanders classifications

AIM: The aim of the study is to correlate the CT-morphological changes of fractured calcaneus and the classifications of Zwipp and Sanders with the clinical outcome. METHOD: In a retrospective clinical study, the preoperative CT scans of 75 calcaneal fractures were analysed. The morphometry of the fractures was determined by measuring height, length diameter and calcaneo-cuboidal angle in comparison to the intact contralateral side. At a mean of 38 months after trauma 44 patients were clinically followed-up. The data of CT image morphometry were correlated with the severity of fracture classified by Zwipp or Sanders as well as with the functional outcome. RESULTS: There was a good correlation between the fracture classifications and the morphometric data. Both fracture classifying systems have a predictive impact for functional outcome. The more exacting and accurate Zwipp classification considers the most important cofactors like involvement of the calcaneo-cuboidal joint, soft tissue damage, additional fractures etc. The Sanders classification is easier to use during clinical routine. CONCLUSION: The Zwipp classification includes more relevant cofactors (fracture of the calcaneo-cuboidal-joint, soft tissue swelling, etc.) and presents a higher correlation to the choice of therapy. Both classification systems present a prognostic impact concerning the clinical outcome.     

Interobserver and intraobserver reliability of two classification systems for intra-articular calcaneal fractures

BACKGROUND: For a fracture classification to be useful it must provide prognostic significance, interobserver reliability, and intraobserver reproducibility. Most studies have found reliability and reproducibility to be poor for fracture classification schemes. The purpose of this study was to evaluate the interobserver and intraobserver reliability of the Sanders and Crosby-Fitzgibbons classification systems, two commonly used methods for classifying intra-articular calcaneal fractures. METHODS: Twenty-five CT scans of intra-articular calcaneal fractures occurring at one trauma center were reviewed. The CT images were presented to eight observers (two orthopaedic surgery chief residents, two foot and ankle fellows, two fellowship-trained orthopaedic trauma surgeons, and two fellowship-trained foot and ankle surgeons) on two separate occasions 8 weeks apart. On each viewing, observers were asked to classify the fractures according to both the Sanders and Crosby-Fitzgibbons systems. Interobserver reliability and intraobserver reproducibility were assessed with computer-generated kappa statistics (SAS software; SAS Institute Inc., Cary, North Carolina). RESULTS: Total unanimity (eight of eight observers assigned the same fracture classification) was achieved only 24% (six of 25) of the time with the Sanders system and 36% (nine of 25) of the time with the Crosby-Fitzgibbons scheme. Interobserver reliability for the Sanders classification method reached a moderate (kappa = 0.48, 0.50) level of agreement, when the subclasses were included. The agreement level increased but remained in the moderate (kappa = 0.55, 0.55) range when the subclasses were excluded. Interobserver agreement reached a substantial (kappa = 0.63, 0.63) level with the Crosby-Fitzgibbons system. Intraobserver reproducibility was better for both schemes. The Sanders system with subclasses included reached moderate (kappa = 0.57) agreement, while ignoring the subclasses brought agreement into the substantial (kappa = 0.77) range. The overall intraobserver agreement was substantial (kappa = 0.74) for the Crosby-Fitzgibbons system. CONCLUSIONS: Although intraobserver kappa values reached substantial levels and the Crosby-Fitzgibbons system generally showed greater agreement, we were unable to demonstrate excellent interobserver or intraobserver reliability with either classification scheme. While a system with perfect agreement would be impossible, our results indicate that these classifications lack the reproducibility to be considered ideal.     

Sanders Ⅱ型跟骨骨折螺钉微创治疗的有限元优化分析

目的:探讨Sanders Ⅱ型跟骨骨折微创治疗时螺钉不同固定方式后的生物力学特点.方法:将CT 扫描后的跟骨Dicom 数据输入Mimics 21.0 软件及Ansys 15.0 软件中构建跟骨三维有限元数字模型;将此模型导入UG NX 10.0 软件中,根据Sanders 分型切割跟骨,建立后关节面塌陷的Sander...     

Surgical treatment of displaced intraarticular calcaneal fractures by a minimally invasive technique using a locking nail: A preliminary study

BackgroundThe aim of this retrospective study was to evaluate the outcome of patients with intra-articular calcaneal fractures treated using a minimally invasive locking nail (Calcanail^®).MethodsBetween January 2016 and April 2017, 15 patients (9 men and 6 women) with a calcaneal fracture were consecutively treated with Calcanail^®. The Böhler angle was recorded on standard X-rays pre- and post-operatively. The articular reduction of the posterior facet was evaluated with the Goldzak index in a CT scan 3 months post-operatively. The mean age of the patients was 53 years (range, 24–78). Mean final follow-up was 18 months (range, 12–24).ResultsSix fractures were classified as Sanders II, 7 as Sanders III and 2 as Sanders IV. In 13 out of the 15 patients treated, the post-operative Böhler angle was of more than 20°. Goldzak index was deemed as excellent in 73.5% of the cases (11 patients), good in 20% of cases (3 patients), and poor in 6.5% (1 patient). Post-operative mean AOFAS score was 85 (range, 60–96).ConclusionsThe Calcanail^® provides good restoration of the subtalar joint and the calcaneal angles with the advantages of a minimally invasive approach. It was effectively used in Sanders types II and III, even in the presence of poor cutaneous conditions.     

Interobserver and Intraobserver Reliability Assessment of Calcaneal Fracture Classification Systems

The aim of the present study was to assess the reliability of commonly used intra-articular calcaneal fracture classification systems and to compare them with the newer AO Integral Classification of Injuries (ICI) system. Forty computed tomography and radiographic images of 40 intra-articular calcaneal fractures were reviewed independently by 3 reviewers on 2 separate occasions and classified according to the Essex-Lopresti, Atkins, Zwipp and Tscherne, Sanders, and AO-ICI classification systems. The reviewers were unaware of the patients' identity and all aspects of clinical care. The data were analyzed using kappa (κ) statistics to assess the intra- and interobserver reliability. The κ values were calculated for Essex-Lopresti (κ = 0.85 intraobserver, κ = 0.78 interobserver), Atkins (κ = 0.42 intraobserver, κ = 0.73 interobserver), Zwipp and Tscherne (κ = 0.40 intraobserver, κ = 0.47 interobserver), Sanders (κ = 0.31 intraobserver, κ = 0.35 interobserver), and AO-ICI (κ = 0.41 intraobserver, κ = 0.33 interobserver). The AO-ICI classification system had levels of reproducibility similar to that of the Sanders classification, currently the most widely used system. The Essex-Lopresti classification demonstrated improved reliability compared with that reported in previous studies. This can be attributed to using sagittal computed tomography images, in addition to the originally described plain radiographs, for assessment. This improvement is relevant because of its accepted prognostic predictability.     

Improved Interobserver Reliability of the Sanders Classification in Calcaneal Fractures Using Segmented Three-Dimensional Prints

We examined the added value of 3-dimensional (3D) prints in improving the interobserver reliability of the Sanders classification of displaced intraarticular calcaneal fractures. Twenty-four observers (radiologists, trainees, and foot surgeons) were asked to rate 2-dimensional (2D) computed tomography images and 3D prints of a series of 11 fractures, selected from cases treatment at our level I trauma center between 2014 and 2016. The interobserver reliability for the Sanders classification was assessed using kappa coefficients. Three versions of the Sanders classification were considered: Sanders classification with subclasses, Sanders classification without subclasses, and the combination of Sanders types III and IV because of the high incidence of comminution in both types. The reference standard for classification was the perioperative findings by a single surgeon. The 3D print always yielded higher values for agreement and chance-corrected agreement. The Brennan-Prediger–weighted kappa equaled 0.35 for the 2D views and 0.63 for the 3D prints for the Sanders classification with subclasses (p?=?.004), 0.55 (2D) and 0.76 (3D) for the classification without subclasses (p?=?.003), and 0.58 (2D) and 0.78 (3D) for the fusion of Sanders types III and IV (p?=?.027). Greater agreement was also found between the perioperative evaluation and the 3D prints (88% versus 65% for the 2D views; p?<?.0001). However, a greater percentage of Sanders type III-IV were classified with 2D than with 3D (56% versus 32%; p?<?.0001). The interobserver agreement for the evaluation of calcaneal fractures was improved with the use of 3D prints after “digital disarticulation.”     

How Does Mechanism of Injury Relate to Similar Fracture Patterns in Bilateral Displaced Intra-articular Calcaneal Fractures?

Several biomechanical/cadaver studies have established a correlation between mechanism of injury and fracture classification in calcaneal fractures. However, this has never been backed up by clinical studies. In this study, the hypothesis is tested whether the alleged similar mechanism of injury for both feet in bilateral calcaneal fractures leads to similar fracture types. In this retrospective cross-sectional cohort study, patients with unilateral and bilateral calcaneal fractures treated between 2000 and 2017 were classified according to Essex-Lopresti and Sanders. Positive predictive values were computed, signifying the chance that the fracture type in the left foot corresponded to that in the right foot. These were compared to the a priori chance of a fracture type (percentage of fracture type in unilateral fractures) by constructing 95% confidence intervals of the positive predictive value of each fracture type. Of the 451 patients, 413 (91.6%) had unilateral and 38 (8.4%) bilateral calcaneal fractures. Mechanisms of injury were similar for uni- and bilateral fractures. Using the Essex-Lopresti fracture classification, 34 cases (90%) had the same classification in both feet, compared with 24 (63%) in the Sanders classification. The chance of a fracture type in the left, with the right foot as reference, was significantly larger than expected from a priori chance in the unilateral population. This leads to a new hypothesis, that, more than mechanism of injury, the magnitude of the impact and the position of the foot are important in predicting fracture classification in the calcaneus.     

Grouping of intraarticular calcaneal fractures relative to treatment options

None of the classifications of intraarticular calcaneal fractures are comprehensive enough to accommodate all types of fractures. Of the 150 intraarticular calcaneal fractures, 37 could not be placed in the commonly used Sanders classification. These then were grouped according to where their primary fracture line was located in relation to the posterior calcaneal facet. Twenty-three fractures were anteromedial to the facet; 75% of these were of the tongue type and were amenable to being treated with the Essex-Lopresti method of reduction and placement of two screws. The joint depression type in this group required open reduction and internal fixation through the lateral approach. Eight fractures were located posterolateral to the facet. They were treated from the lateral or the medial approach. Six fractures crossed the facet transversely; these were treated percutaneously with placement of two lag screws. Clinically this grouping was helpful because it provided a guideline to appropriate treatment strategies for fractures that could not be accommodated in the Sanders classification.     

Sanders IIeIII calcaneal fractures fixed with locking plate in elderly patients

Purpose: To evaluate the clinical outcomes of locking calcaneal plate in treating calcaneal fracture (Sanders IIeIII) in elderly patients. Methods: From October 2012 to December 2013, 23 elderly patients suffering from calcaneal fracture (Sanders IIeIII) were treated and followed up. There were 15 males and 8 females with the mean age of 68.5 years (range: 65e79 years). According to Sander''s classification, 16 cases (16 feet) were type II fractures and 7 cases (7 feet) were type III fractures. Anteroposterior, lateral and axial views of X-ray were taken to detect the calcaneum. CT scan was done to assess the amount of comminution and articular depression. Radiological assessment was performed using Bohler''s angle and Gissane''s angle. Functional outcome was assessed using the Maryland foot score. Results: All the patients were followed up for 13.7 months on average (10e20 months). The mean time of bone union was 3.2 months (3e4 months). The mean time of complete weight bearing was 3.2 months (3.1e4.0 months). The soft tissue necrosis was found in 1 case. The mean Bohler''s angle and Gissane''s angle were 25.31 and 117.5 respectively. The overall excellent to good rate was 82.6%. Conclusion: Open reduction and internal fixation with locking calcaneal plate can obtain good functional outcome for Sanders IIeIII calcaneal fractures in elderly patients.     

基于Faster R-CNN及增强CT图像自动检测肝血管瘤

目的 基于快速区域卷积神经网络（Faster R-CNN）构建肝血管瘤自动检测系统,观察其检出增强CT图像中的肝血管瘤的效能。方法 收集经腹部增强CT诊断的128例肝血管瘤患者、共2 304幅增强CT图像,按8∶2比例将其分为训练集（n=102）和测试集（n=26）,分别含1 836幅及468幅增强CT图像。利用Faster R-CNN、针对增强CT图像构建自动检测肝血管瘤系统,基于迁移学习方案,采用Resnet50预训练分类网络作为提取特征模块的基础骨架,以区域提议网络提取训练集增强CT图像特征,以边界框分类回归模块输出预测边框的精确位置坐标和类别的概率分数。训练过程中绘制Loss曲线,评估模型对训练集的训练效果及其稳定性;采用随机梯度下降法作为优化器对参数进行调整,以提升模型性能。通过平均精度均值（mAP）评估系统检出测试集增强CT图像中的肝血管瘤的效能。结果 训练集训练过程损失函数Loss曲线中,自动检测系统呈快速下降趋势,提示模型学习能力良好,预测性能稳定。mAP曲线显示,迭代次数epoch为40~80时,系统对测试集468幅增强CT图像检出肝血管瘤的mAP为0.962~0.973,波动小,提示模型已收敛,自动检测效果良好。结论 基于Faster R-CNN的增强CT图像自动检测系统可有效检出肝血管瘤。     

The Pararectus approach provides secure access to the deep circumflex iliac vessel for harvest of a large sized and vascularized segment of the iliac crest

BackgroundThe feasibility of harvesting a vascularized iliac crest utilizing the Pararectus approach was assessed in cadavers and then this new technique was implemented in a clinical case.MethodsBilaterally in five cadavers the branches of both external iliac arteries were injected with colored silicone to assess their position to each other and to harvest a bone graft vascularized by the deep circumflex iliac artery (DCIA) through the Pararectus approach. This technique was implemented in a 68-years-old female patient, initially admitted to a level-I-trauma center after sustaining multiple injuries by falling from great height. For definitive treatment of a severely contaminated medially open (Gustilo-Anderson Type 3A) calcaneal luxation fracture (Sanders type IIIBC) in this patient a vascularized iliac crest autograft harvest by the Pararectus approach was used for reconstructive surgery.ResultsThe DCIA and the deep inferior epigastric vessels (DIEV: vascularizing the rectus abdominis muscle and main pedicle of the inferiorly based rectus abdominis myocutaneous flap) are very close on the lateral and medial border of the external iliac artery, respectively. As a consequence, the retrograde dissection of the DIEV towards the DCIA through the Pararectus approach made the dissection of the vascularized iliac crest more amenable, preserving both the lateral femoral cutaneous and the genitofemoral nerves. Four months after the surgery the patient was able to fully weight-bear in orthopedic shoes. Radiographs and CT scans showed correct hind foot alignment and bony integration of the vascularized iliac crest graft into the residual calcaneal body.ConclusionThe Pararectus approach allowed for secure collection of large vascularized iliac grafts. The presented technique was successful as a salvage procedure in a clinical case with substantial bone loss after an open calcaneal fracture.     

解剖接骨板治疗SandersⅡ～Ⅳ型跟骨骨折的临床疗效

目的评价解剖接骨板治疗SandersⅡ～Ⅳ型跟骨骨折的临床疗效。方法2008年9月至2010年10月行解剖接骨板内固定治疗并获得随访的SandersⅡ-Ⅳ型跟骨骨折29例（33足）,男19例,女10例;年龄18—58岁,平均37岁。双侧跟骨骨折4例,合并骨盆骨折3例,合并胸腰段压缩性骨折3例;闭合性跟骨骨折27例,开放性跟骨骨折2例;术前根据影像学检查分为SandersⅡ型16例（16足）,SandersⅢ型9例（11足）,SandersⅣ型4例（6足）。按照Maryland Foot Score标准进行患足功能评价。结果29例（33足）获得随访,随访时间为9—21个月,平均11．3个月。跟骨骨折达骨性愈合时间为2—4个月,平均2．9个月;患足完全负重时间为2．5—4个月,平均3．2个月;无一例发生延迟愈合及不愈合。闭合性跟骨骨折术前准备时间为5～12天,平均8天。术后2例（2足）出现切口边缘皮肤坏死。2例开放性跟骨骨折患者中1例（1足）因软组织损伤严重,最终行局部旋转皮瓣植皮术治疗。术后患足Bohler角及Gissane角均得到显著改善（P〈0．05）。SandersⅡ型优良率为87．5％,SandersⅢ型优良率为81．8％,SandersⅣ型优良率为50％。结论切开复位解剖接骨板内固定术是治疗SandersⅡ～Ⅳ型跟骨骨折的有效方法。     

CT-Based Classification Systems for Intra-Articular Calcaneal Fractures: The Inter- and Intraobserver Variations as well as Integrality

The aim of this study was to measure the inter- and intraobserver variations as well as integrality of the Zwipp, Crosby-Fitzgibbons, Sanders, and Eastwood-Atkins classification systems based on more accurate CT scans. Five hundred and forty-nine patients with intra-articular calcaneal fractures from January 2018 to December 2019 taken from a database in our level-I trauma center (3 affiliated hospitals) were included. For each case, normative CT (1 mm slices) scans were available. Four different observers reviewed all CT scans 2 times according to these 4 most prevalent fracture classification systems (FCSs) within a 2-month interval. For these 4 FCSs, the kappa [κ] coefficient was used to evaluate interobserver reliability and intraobserver reproducibility, and the percentage that can be classified was used to indicate integrality. The κ values were measured for Zwipp (κ = 0.38 interobserver, κ = 0.61 intraobserver), Crosby-Fitzgibbons (κ = 0.48 interobserver, κ = 0.79 intraobserver), Sanders (κ = 0.40 interobserver, κ = 0.57 intraobserver), and Eastwood-Atkins (κ = 0.44 interobserver, κ = 0.72 intraobserver). Furthermore, the integralities were calculated for Zwipp (100%), Crosby-Fitzgibbons (100%), Sanders (92%) as well as Eastwood-Atkins (89.6%). Compared with previous literatures, CT scanning with higher accuracy can significantly improve intraobserver reproducibility of Zwipp and Eastwood-Atkins FCSs, but it has no positive effect on variability of Sanders FCS and interobserver reliability of Crosby-Fitzgibbons FCS. In terms of integrality, Zwipp and Crosby-Fitzgibbons FCSs appear to be superior to the other 2 FCSs.     

经跗骨窦入路结合型解剖板治疗SandersⅡ/Ⅲ型跟骨骨折

目的探讨经跗骨窦切口联合跟骨结合型微创解剖板治疗SandersⅡ/Ⅲ型跟骨骨折的短期临床疗效。方法回顾性研究分析自2016年6月至2018年6月我院骨科中心收治的18例(19足)闭合性跟骨骨折患者,其中男11例,女7例;年龄范围22-65岁,平均(38.1±5.6)岁。Sanders分型:Ⅱ型8足,Ⅲ型11足。全部患者均采用经跗骨窦入路,联合使用跟骨结合型微创解剖板进行治疗。结果本组病例术后均获得随访,随访时间12-18个月,平均(13.5±1.5)个月。根据美国足踝外科协会(American orthopaedic foot and ankle society,AOFAS)踝-后足评分标准对患足功能进行评价,优16足,良2足,可1足,优良率94.7%。结论经跗骨窦切口入路联合跟骨结合型微创解剖板治疗SandersⅡ/Ⅲ型跟骨骨折,可有效恢复跟骨的形态,有利于足踝功能地恢复,可作为SandersⅡ/Ⅲ型跟骨骨折手术治疗的一种选择。     

Does 3D CT reconstruction help the surgeon to preoperatively assess calcaneal fractures?

BackgroundWith the advent of 3D volume rendered CT scans, more information is potentially available to aid the surgeon in complex calcaneal fractures. The primary aim was to determine if there is a difference in inter-observer and intra-observer reliability of 3D CT reconstructions compared to 2D CTs of calcaneus fractures based on classification, identification of specific fracture characteristics and proposed treatment. It is hypothesized that the correlation will be greater between experienced surgeons and trainees when using 3D CT. As a secondary aim, the authors wished to investigate the surgeons’ satisfaction with 3D CT.Patients and methodsThere were six raters, split into 2 groups: high and low surgical experience. Both 2D and 3D scans (10 patients) were reviewed by each rater by filling out a validated questionnaire. This sitting was over a period of six months and all scans were sent separately and randomly by our research coordinator. This process was repeated after a four-week break.ResultsThe overall evaluation and satisfaction of CT scans of calcaneal fractures was improved by the additional use of volume rendered 3D images. Inexperienced surgeons benefited more than experienced surgeons in terms of reliabilities with fracture configuration. 3D CTs were more likely to change the surgeons’ operative strategy. The consistency of deciding on the fracture classification and satisfaction was more uniform between all the raters when 3D CT was used.ConclusionInter-observer and intra-observer reliability of 3D CT reconstructions compared to 2D CTs of calcaneus fractures was greater based on classification, identification of specific fracture characteristics and proposed treatment. Inexperienced surgeons were more consistent when interpreting the scans using 3D CTs (improved inter-observer reliability) and were always more satisfied using the 3D CTs. As there is no extra cost or radiation exposure, we propose that 3D CTs may be valuable with preoperative teaching and planning.     

Revisit of Broden's View for Intraarticular Calcaneal Fracture

Background

This study was performed to investigate the relationship between coronal computed tomography (CT) and Broden''s view in terms of location of the fracture line and fracture pattern.

Methods

Forty-five feet of 45 patients with intraarticular calcaneal fractures were evaluated. The mean age of the patients was 46.3 years (standard deviation, 18.1; range, 15 to 80 years), and there were 34 men and 11 women. The Broden''s views were acquired using the ray sum projection, reviewed, and correlated with the coronal CT image to determine the location of the fracture on the posterior facet and fracture pattern described by the Sanders classification. The quantified location of the fracture line was defined as the distance between the medial margin of posterior facet and the fracture line divided by the whole length of the posterior facet, which was expressed as a percentage.

Results

The fracture line on the Broden''s view was positioned at 22.3% (standard deviation, 29.6) laterally compared to that on coronal CT (p < 0.01). Although all cases showed posterior facet involvement on the CT scan, the fracture line was positioned lateral to the posterior facet in 6 cases (13.3%) in the Broden''s view. The coronal CT and Broden''s view showed a low level of agreement in the fracture pattern according to the Sanders classification, with kappa values of 0.23.

Conclusions

Surgeons should consider that the fracture line on the Broden''s view shows positioning laterally compared to coronal CT and they should consider that the fracture line at the lateral to posterior facet on the Broden''s view might be an intraarticular fracture line. There are some limitations when applying the Sanders classification with the Broden''s view.     

Interobserver reliability of a CT-based fracture classification system

OBJECTIVES: This study was designed to determine whether the interobserver reliability of a fracture classification scheme applied based on a single, carefully defined, computed tomography (CT) cut is greater than those previously reported for systems designed for use with plain radiographs. DESIGN: Observer review of selected cases. SETTING: Four, level one, trauma centers. PATIENTS: Pretreatment CT scans of patients with calcaneus fractures were screened by the authors. Thirty cases were selected that had an appropriate semicoronal CT image. Ten orthopaedic traumatologists who were members of the Orthopaedic Trauma Association and had a minimum of 5 years postresidency experience were selected as reviewers. INTERVENTION: The reviewers were provided with a digital CT image for each case as well as written and diagrammatic representations of the Sanders classification system. The observers then classified each fracture according to the Sanders classification. RESULTS:: The mean kappa value for interobserver reliability for fracture types I-IV was 0.41 +/- 0.02 (mean +/- standard error of the mean; range, 0.07-0.64). Observers disagreed by more than 1 fracture type (ie, I vs. III or II vs. IV) in 10% of the cases. Observers agreed on the location of the fracture lines (A, B, C) in 90% of type II fractures and 52% of type III fractures. CONCLUSIONS: The results indicate that in a carefully controlled paradigm, the interobserver reliability with a classification system based on interpretation of a single, carefully defined CT image was no better than the results reported for the same classification system used with full CT data or for other classification systems used for various fractures in the skeleton. Agreement in identifying the location of the fracture lines was very good for simple fractures but much worse for complex injuries. Additional study may determine whether the use of a full complement of CT images can improve reliability in classification of complex injuries.