The Impact of Three-Dimensional CT Imaging on Intraobserver and Interobserver Reliability of Proximal Humeral Fracture Classifications and Treatment Recommendations

The effect of addition of 2DCT scans and 3DCT scans for the classification of tibial plateau fractures: a systematic review

PURPOSE

In this systematic review, we evaluate the effect of radiographs and 2D and 3D imaging techniques on the interobserver agreement of six commonly used classification systems for tibial plateau fractures.

METHODS

In accordance with PRISMA guidelines, PubMed, Cochrane, Embase and Web of Science were searched for studies regarding the effect of 2D and 3D imaging techniques on the interobserver agreement of tibial plateau classification systems. Studies validating new classification systems, not providing own data or only providing information on the interobserver agreement for radiographs were excluded. Studies were scored based on the ROBINS-I risk of bias tool.

RESULTS

Our review analysed 14 studies on different classification systems used for tibial plateau fractures in clinical practice, with the Schatzker classification being the most commonly used classification system. The results showed that the addition of 2D CT led to a significant improvement of interobserver agreement for one study. However, other included studies showed varying levels of interobserver agreement, ranging from fair to substantial according to the interpretation by Landis and Koch. The addition of 3D CT resulted in a significant deterioration in one study for the Schatzker classification. Similar to the addition of 2D CT, the interobserver agreement for the Schatzker classification with the addition of 3D CT were heterogeneous ranging from fair to almost perfect according to the interpretation by Landis and Koch.

CONCLUSIONS

The use of 2D CT can be recommended for classifying tibial plateau fractures with the Schatzker classification, AO/OTA classification and Hohl classification. The value of 3D CT on the interobserver agreement of commonly used classification systems remains uncertain and unproven. Therefore, we do not recommend the use of 3D CT for the classification of tibial plateau fractures. Overall, the advancement of imaging techniques is not in line with the advancement in interobserver agreement on fracture classification.

Mechanisms of shoulder trauma: Current concepts

Acute traumatic injuries to the glenohumeral articulation are common. The types of injuries depend on age, muscle strength, bone density, and biomechanics of the traumatic event. Understanding the different mechanisms of trauma and how they affect the functional anatomical structures of the shoulder joint is crucial for the treatment of these lesions. Therefore, when clinicians have knowledge of these mechanisms they can accurately diagnose and treat shoulder pathology and predict distinct injury patterns. Here, we have described the fundamentals of the mechanisms of injury of the glenohumeral dislocation, dislocation with fracture of the humeral head, and the proximal humerus fracture. We have focused on common injury mechanisms and the correlation with radiological diagnostics. Radiological and laboratory findings of distinct types of injury were also discussed.

A prognostic classification of proximal humerus fractures: the cephalic extension staging

PURPOSE

Recent publications emphasized the role of dorsomedial metaphyseal extension of humeral head as predictor of ischemia after complex proximal humerus fractures (PHFs). We evaluated on preoperative 3D CT scan of PHFs the surface of this metaphyseal extension and its prognostic value on the occurrence of avascular necrosis (AVN).

METHODS

We followed a series of 25 fixations of complex PHF which had a preoperative 3D CT scan and measured the surface area of the posterior metaphyseal extension (PME) of the head. Using approximations, we calculated the ratio between the PME surface area (PMS) and the articular surface area of the head (HS). The PMS/HS ratio was analyzed against the risk of AVN.

RESULTS

The measurement of the PMS/HS ratio emphasizes the significance of PME. The incidence of AVN is correlated with the magnitude of PME. Therefore, we include the PME as a fifth element in the characterization of complex PHFs and we propose a 4-stage prognostic classification based on the number of extensions of the humeral head. The head may have 3 extensions: posteromedial (PME), lesser tuberosity (LTE) and greater tuberosity (GTE). The risk of AVN decreases with the number of extensions of the head.

CONCLUSION

Our study demonstrates a correlation between the occurrence of AVN and the size of PME in complex PHF cases. We propose a four-stage classification system to facilitate treatment decision-making between fixation and prosthesis.

Efficacy of fracture stem in reverse shoulder arthroplasty for 3- or 4-part proximal humerus fractures

BACKGROUND

This study compared the clinical results of fracture stems and conventional stems using the same glenoid component in reverse shoulder arthroplasty for proximal humerus fractures in the elderly.

METHODS

This retrospective study included 35 patients who underwent Grammont-type reverse shoulder arthroplasty for proximal humerus fractures from 2014 to 2020. The average age at surgery was 79.2 (range, 65-92) years, with 33 female shoulders. Fracture types per Neer classification were 3-part fracture, 4-part fracture, in 13 and 22 shoulders, respectively. The final follow-up period was 35 (range, 24-81) months. The Constant score, American Shoulder and Elbow Surgeons score, shoulder range of motion, and healing of greater tuberosities at the final follow-up of AEQUALIS™ REVERSED (Conventional stem group: n = 15) and AEQUALIS™ REVERSED FX (Fractured stem group: n = 20) were retrospectively investigated.

RESULTS

There were no statistically significant differences in age at surgery, sex, body mass index, fracture type, waiting time from injury to surgery, or preoperative general condition between the groups. The Constant and American Shoulder and Elbow Surgeons scores of the fractured stem group were significantly higher than those of the conventional stem group (P = 0.038 and P = 0.023, respectively). The anterior elevation and external rotation at the side of the fractured stem group also showed significantly higher values than those of the conventional stem group (fractured stem group vs. conventional stem group: anterior elevation 127° ± 25° vs. 105° ± 35°, P = 0.041; external rotation 28° ± 13° vs. 13° ± 12°, P = 0.015). The greater tuberosity healing rate was 46.7% (7/15) in the conventional stem group and 85.0% (17/20) in the fractured stem group (P＝0.027).

CONCLUSIONS

The findings suggest that use of a fracture-specific stem rather than a conventional stem in Grammont-type reverse shoulder arthroplasty for proximal humerus fractures improves tuberosity healing, postoperative range of motion, and clinical scores.

Statistical Morphology and Fragment Mapping of Complex Proximal Humeral Fractures

Background and Objectives: Proximal humerus fractures (PHFs) are common in the elderly, but the treatment results are often poor. A clear understanding of fracture morphology and distribution of cortical bone loss is important for improved surgical decision making, operative considerations, and new implant designs. The aim of this study was to develop a 3D segmentation fracture mapping technique to create a statistical description of the spatial pattern and cortical bone loss of complex PHFs. Materials and Methods: Fifty clinical computed tomography (CT) scans of complex PHFs and their contralateral intact shoulders were collected. In-house software was developed for semi-automated segmentation and fracture line detection and was combined with manual fracture reduction to the contralateral template in a commercial software. A statistical mean model of these cases was built and used to describe probability maps of the fracture lines and cortical fragments. Results: The fracture lines predominantly passed through the surgical neck and between the tuberosities and tendon insertions. The superior aspects of the tuberosities were constant fragments where comminution was less likely. Some fracture lines passed through the bicipital sulcus, but predominantly at its edges and curving around the tuberosities proximally and distally. Conclusions: A comprehensive and systematic approach was developed for processing clinical CT images of complex fractures into fracture morphology and fragment probability maps and applied on PHFs. This information creates an important basis for better understanding of fracture morphology that could be utilized in future studies for surgical training and implant design.

Computed Tomography Does Not Improve Intra- and Interobserver Agreement of Hertel Radiographic Prognostic Criteria

Background and Objectives: Proximal humerus fractures are the second most frequent site of avascular necrosis (AVN), occurring in up to 16% of cases. The Hertel criteria have been used as a reference for the prediction of humerus head ischemia. However, these are based solely on the use of radiographs, which can make interpretation extremely difficult due to several reasons, such as the overlapping fragments, severity of the injury, and noncompliant acute pain patients. The objectives of the study were to evaluate the role of computed tomography (CT) in the interpretation of the Hertel criteria and to evaluate the intra- and interobserver agreement of orthopedic surgeons, comparing their area of expertise. Materials and Methods: The radiographs and CT scans of 20 skeletally mature patients who had fractures of the proximal humerus were converted to jpeg and mov, respectively. All images were evaluated by eight orthopedic surgeons (four trauma surgeons and four shoulder surgeons) in two different occasions. The intra- and interobserver agreement was assessed by using the Kappa coefficient. The level of significance was 5%. Results: There was a weak-to-moderate intraobserver agreement (κ < 0.59) for all examiners. Only the medial metaphyseal hinge greater than 2 mm was identified by 87.5% of evaluators both in the radiographic and CT examinations in the two rounds of the study (p < 0.05). There was no significant interobserver agreement (κ < 0.19), as it occurred only in some moments of the second round of evaluation. Conclusions: The prognostic criteria for humeral head ischemia evaluated in this study showed weak intra- and interobserver agreement in both the radiographic and tomographic evaluation. CT did not help surgeons in the primary interpretation of Hertel prognostic criteria used in this study when compared to the radiographic examination.

Validation of the modified AO sternum classification system

INTRODUCTION

The Arbeitsgemeinschaft für Osteosynthesefragen (AO) foundation along with the Orthopaedic. Trauma Association (OTA) introduced a new classification for sternal fractures in 2018 aiming to provide greater uniformity and clinical utility for the surgical community. A previous validation study identified some critical issues such as the differentiation between type A and B fractures and localization of the fracture either in the manubrium or in the body. Due to the moderate agreement in inter- and intra-observer variability, some modifications were proposed in order to improve the performance of the classification. The aim of this study was to re-assess the inter- and intra-observer variability after adding modifications to the classification. Our hypothesis was that a significative improvement of inter- and intra-observer variability could be achieved.

MATERIAL AND METHODS

Twenty computed tomography (CT) scans of patients with sternal fractures were analyzed by six. Junior and six senior surgeons independently. Two assessments were performed with an interval of 6 weeks. The kappa (K) value was calculated in order to assess inter- and intra-observer variability.

RESULTS

The overall mean kappa value for inter-observer variability improved from 0.364 to 0.468 (p < 0.001). Inter-observer variability mean for location was 0.573 (SD 0.221) and for type was 0.441 (SD: 0.181). Intra-observer variability showed a mean of 0.703 (SD: 0.153) with a statistic significant improvement when compared to the previous study (mean 0.414, SD: 0.256, p < 0.001).

CONCLUSIONS

By modifying the AO/OTA classification of sternal fractures, the inter- and intra-observer variability improved and now shows moderate to substantial agreement.

The reliability of the Neer classification for proximal humerus fractures: A survey of orthopedic shoulder surgeons

Background

The Neer classification is among the most widely used systems to describe proximal humerus fractures (PHF) despite the poor interobserver agreement. The purpose of this study was to verify whether or not blinded shoulder surgeons and trainees agree with the authors of articles published in the highest impact-factor orthopedic journals.

Methods

All articles regarding PHF published between 2017 and 2019 in the top 10 orthopedic journals as rated by impact factor were searched. Articles were included if the authors used the Neer classification to describe at least 1 PHF in the figures. Figures were extracted without the legend, and X-rays ± computed tomography scan images were included when available. An international survey was conducted among 138 shoulder surgeons who were asked to record the Neer classification for each de-identified radiograph in the publications. The type of fracture mentioned in the legend of the published figure was considered as the gold standard.

Results

Survey participants agreed with the published article authors in 55% of cases overall (range 6%-96%, n = 35). The most common response disagreed with the article authors in 13 cases (37%), underestimating the number of parts in 11 of 13 cases. The interobserver agreement between the 138 responders was fair (k = 0.296). There was an association between the percentage of concordant answers and greater experience (number of years of shoulder surgery practice) of the responders (P = .0023). The number of parts, the number or type of available imaging modalities, and the geographic origin of participants did not influence the agreement between responders and authors.

Discussion

In more than one-third of cases, specialized shoulder surgeons disagree with article authors when interpreting the Neer classification of de-identified images of PHF in published manuscripts. Morphologic classification of PHF as the sole basis for treatment algorithms and surgical success should be scrutinized.

Inter-rater agreement among shoulder surgeons on treatment options for proximal humeral fractures among shoulder surgeons

Background

The treatment approach for proximal humeral fractures is determined by various factors, including patient age, sex, dominant arm, fracture pattern, presence of osteoporosis, preexisting arthritis, rotator cuff status, and medical comorbidities. However, there is a lack of consensus in the literature regarding the optimal treatment for displaced proximal humeral fractures. This study aimed to assess and quantify the decision-making process for either conservative or surgical treatment and the choice of surgical method among shoulder surgeons when treating proximal humeral fractures.

Methods

Forty sets of true anteroposterior view, scapular Y projection view, and three-dimensional computed tomography of proximal humeral fractures were provided to 12 shoulder surgeons along with clinical information. Surveys regarding Neer classification, decisions between conservative and surgical treatments, and chosen methods were conducted twice with an interval of 2 months. The factors affecting the treatment plans were also assessed.

Results

The inter-rater agreement was fair for Neer classification (kappa=0.395), moderate for the decision between conservative and surgical treatments (kappa=0.528), and substantial for the chosen method of surgical treatment (kappa=0.740). The percentage of agreement was 71.1% for Neer classification, 84.6% for the decision between conservative and surgical treatment, and 96.4% for the chosen method of surgical treatment. The fracture pattern was the most crucial factor in deciding between conservative and surgical treatments, followed by age and physical activity.

Conclusions

The decision between conservative and surgical treatment for proximal humeral fractures showed good agreement, while the chosen method between osteosynthesis and arthroplasty showed substantial agreement among shoulder surgeons.

3D-printed Handheld Models Do Not Improve Recognition of Specific Characteristics and Patterns of Three-part and Four-part Proximal Humerus Fractures

BACKGROUND

Reliably recognizing the overall pattern and specific characteristics of proximal humerus fractures may aid in surgical decision-making. With conventional onscreen imaging modalities, there is considerable and undesired interobserver variability, even when observers receive training in the application of the classification systems used. It is unclear whether three-dimensional (3D) models, which now can be fabricated with desktop printers at relatively little cost, can decrease interobserver variability in fracture classification.

QUESTIONS/PURPOSES

Do 3D-printed handheld models of proximal humerus fractures improve agreement among residents and attending surgeons regarding (1) specific fracture characteristics and (2) patterns according to the Neer and Hertel classification systems?

METHODS

Plain radiographs, as well as two-dimensional (2D) and 3D CT images, were collected from 20 patients (aged 18 years or older) who sustained a three-part or four-part proximal humerus fracture treated at a Level I trauma center between 2015 and 2019. The included images were chosen to comprise images from patients whose fractures were considered as difficult-to-classify, displaced fractures. Consequently, the images were assessed for eight fracture characteristics and categorized according to the Neer and Hertel classifications by four orthopaedic residents and four attending orthopaedic surgeons during two separate sessions. In the first session, the assessment was performed with conventional onscreen imaging (radiographs and 2D and 3D CT images). In the second session, 3D-printed handheld models were used for assessment, while onscreen imaging was also available. Although proximal humerus classifications such as the Neer classification have, in the past, been shown to have low interobserver reliability, we theorized that by receiving direct tactile and visual feedback from 3D-printed handheld fracture models, clinicians would be able to recognize the complex 3D aspects of classification systems reliably. Interobserver agreement was determined with the multirater Fleiss kappa and scored according to the categorical rating by Landis and Koch. To determine whether there was a difference between the two sessions, we calculated the delta (difference in the) kappa value with 95% confidence intervals and a two-tailed p value. Post hoc power analysis revealed that with the current sample size, a delta kappa value of 0.40 could be detected with 80% power at alpha = 0.05.

RESULTS

Using 3D-printed models in addition to conventional imaging did not improve interobserver agreement of the following fracture characteristics: more than 2 mm medial hinge displacement, more than 8 mm metaphyseal extension, surgical neck fracture, anatomic neck fracture, displacement of the humeral head, more than 10 mm lesser tuberosity displacement, and more than 10 mm greater tuberosity displacement. Agreement regarding the presence of a humeral head-splitting fracture was improved but only to a level that was insufficient for clinical or scientific use (fair to substantial, delta kappa = 0.33 [95% CI 0.02 to 0.64]). Assessing 3D-printed handheld models adjunct to onscreen conventional imaging did not improve the interobserver agreement for pattern recognition according to Neer (delta kappa = 0.02 [95% CI -0.11 to 0.07]) and Hertel (delta kappa = 0.01 [95% CI -0.11 to 0.08]). There were no differences between residents and attending surgeons in terms of whether 3D models helped them classify the fractures, but there were few differences to identify fracture characteristics. However, none of the identified differences improved to almost perfect agreement (kappa value above 0.80), so even those few differences are unlikely to be clinically useful.

CONCLUSION

Using 3D-printed handheld fracture models in addition to conventional onscreen imaging of three-part and four-part proximal humerus fractures does not improve agreement among residents and attending surgeons on specific fracture characteristics and patterns. Therefore, we do not recommend that clinicians expend the time and costs needed to create these models if the goal is to classify or describe patients' fracture characteristics or pattern, since doing so is unlikely to improve clinicians' abilities to select treatment or estimate prognosis.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Imaging of traumatic shoulder injuries – Understanding the surgeon’s perspective

Imaging plays a key role in the assessment and management of traumatic shoulder injuries, and it is important to understand how the imaging details help guide orthopedic surgeons in determining the role for surgical treatment. Imaging is also crucial in preoperative planning, the longitudinal assessment after surgery and the identification of complications after treatment. This review discusses the mechanisms of injury, key imaging findings, therapeutic options and associated complications for the most common shoulder injuries, tailored to the orthopedic surgeon’s perspective.

Inter- and intraobserver reliability of morphological Mutch classification for greater tuberosity fractures of the proximal humerus: A comparison of x-ray, two-, and three-dimensional CT imaging

BACKGROUND

The objective of this study was to investigate inter- and intraobserver reliability of the morphological Mutch classification for greater tuberosity (GT) fragments in consecutive proximal humerus fractures (PHF) regardless of the number of parts according to the Codman classification system for three different imaging modalities (plain radiographs, two-dimensional [2-D] computed tomography [CT], and reformatted, three-dimensional [3-D] CT reconstruction).

MATERIALS AND METHODS

One hundred thirty-eight consecutive PHF with GT involvement were identified between January 2018 and December 2018 in a supraregional Level 1 trauma center. GT morphology was classified by three blinded observers according to the morphological Mutch classification using the picture archiving and communication software Visage 7.1 (Visage Imaging Inc., San Diego, CA, USA). Fleiss' and Cohens' kappa were assessed for inter- and intraobserver reliability. Strength of agreement for kappa (k) values was interpreted according to the Landis and Koch benchmark scale.

RESULTS

In cases of isolated GT fractures (n = 24), the morphological Mutch classification achieved consistently substantial values for interobserver reliability (radiograph: k = 0.63; 2-D CT: k = 0.75; 3-D CT: k = 0.77). Moreover, use of advanced imaging (2-D and 3-D CT) tends to increase reliability. Consistently substantial mean values were found for intraobserver agreement (radiograph: Ø k = 0.72; 2-D CT: Ø k = 0.8; 3-D CT: Ø k = 0.76). In cases of multi-part PHF with GT involvement (n = 114), interobserver agreement was only slight to fair regardless of imaging modality (radiograph: k = 0.3; 2-D CT: k = 0.17; 3-D CT: k = 0.05). Intraobserver agreement achieved fair to moderate mean values (radiograph: Ø k = 0.56; 2-D CT: Ø k = 0.61; 3-D CT: Ø k = 0.33).

CONCLUSION

The morphological Mutch classification remains a reliable classification for isolated GT fractures, even with 2-D or 3-D CT imaging. Usage of these advanced imaging modalities tends to increase interobserver reliability. However, its reliability for multi-part fractures with GT involvement is limited. A simple and reliable classification is missing for this fracture entity.

Application of Three-Dimensional Computed Tomography Improved the Interrater Reliability of the AO/OTA Classification Decision in a Patellar Fracture

We investigated whether interrater reliabilities of the AO/OTA classification of patellar fracture change with the imaging modalities applied, including plain radiography and two- and three-dimensional (2-D and 3-D) computed tomography (CT). Seven orthopedic specialists and four orthopedic residents completed a survey of 50 patellar fractures to classify the fractures according to the AO/OTA classification for patellar fractures. Initially, the survey was conducted using plain radiography only, then with 2-D CT introduced three weeks later and 3-D CT introduced six weeks later. Fleiss’ Kappa coefficients were calculated to determine interrater reliability. The overall interrater reliability of the AO/OTA classifications was 0.40 (95% CI, 0.38–0.42) with plain radiography only and 0.43 (95% CI, 0.41–0.45) with the addition of 2-D CT. With the addition of 3-D CT, the reliability was significantly improved to 0.54 (95% CI, 0.52–0.56). In specialists, interrater reliability of the classifications was moderate with all three imaging modalities. With the use of 3-D CT, interrater reliability of the classification was 0.53 (95% CI, 0.50–0.56), which was significantly higher than that with the use of 2-D CT (κ = 0.45; 95% CI, 0.42–0.48). In residents, interrater reliability of the classification was 0.30 (95% CI, 0.24–0.36) with plain radiography. The reliability improved to 0.49 (95% CI, 0.43–0.56) with the addition of 2-D CT, which was significantly higher than that with plain radiography only. The use of 3-D CT imaging improved interrater reliability of the classification. Therefore, surgeons, especially residents, may benefit from using 3-D CT imaging for classifying and planning the treatment of patellar fractures.

Interobserver and intraobserver agreement of three-dimensionally printed models for the classification of proximal humeral fractures

Hypothesis

This study aimed to examine whether three-dimensionally printed models (3D models) could improve interobserver and intraobserver agreement when classifying proximal humeral fractures (PHFs) using the Neer system. We hypothesized that 3D models would improve interobserver and intraobserver agreement compared with x-ray, two-dimensional (2D) and three-dimensional (3D) computed tomography (CT) and that agreement using 3D models would be higher for registrars than for consultants.

Methods

Thirty consecutive PHF images were selected from a state-wide database and classified by fourteen observers. Each imaging modality (x-ray, 2D CT, 3D CT, 3D models) was grouped and presented in a randomly allocated sequence on two separate occasions. Interobserver and intraobserver agreements were quantified with kappa values (κ), percentage agreement, and 95% confidence intervals (CIs).

Results

Seven orthopedic registrars and seven orthopedic consultants classified 30 fractures on one occasion (interobserver). Four registrars and three consultants additionally completed classification on a second occasion (intraobserver). Interobserver agreement was greater with 3D models than with x-ray (κ = 0.47, CI: 0.44-0.50, 66.5%, CI: 64.6-68.4% and κ = 0.29, CI: 0.26-0.31, 57.2%, CI: 55.1-59.3%, respectively), 2D CT (κ = 0.30, CI: 0.27-0.33, 57.8%, CI: 55.5-60.2%), and 3D CT (κ = 0.35, CI: 0.33-0.38, 58.8%, CI: 56.7-60.9%). Intraobserver agreement appeared higher for 3D models than for other modalities; however, results were not significant. There were no differences in interobserver or intraobserver agreement between registrars and consultants.

Conclusion

Three-dimensionally printed models improved interobserver agreement in the classification of PHFs using the Neer system. This has potential implications for using 3D models for surgical planning and teaching.

Classification of tibial plateau fractures using 3DCT with and without subtraction of unfractured bones

BACKGROUND

The addition of 3D CT scans for observers evaluating tibial plateau fractures decreases agreement and diagnostic accuracy, possibly due to obstruction of the view by unfractured bones (i.e., patella, fibula, and femur) in 3D reconstructions.

QUESTIONS/PURPOSES

This study compared (1) the interobserver agreement between (subgroups of) observers classifying 3DCT reconstructions of tibial plateau fractures according to Schatzker, Luo, and AO/OTA, (2) recognition of different fracture characteristics, and (3) the level of confidence on a scale from 0 to 10 with and without subtraction of the unfractured bones.

METHODS

We selected twenty consecutive 3DCT reconstructions of tibial plateau fractures treated in a level I trauma center between 2013 and 2014. Members of the Science of Variation Group were randomized (1:1) to evaluate reconstructions with or without subtraction of the unfractured bone. Forty-nine surgeons completed the survey. The interobserver agreement was determined using Fleiss' kappa, and bootstrapping (resamples = 1000) was used to calculate the standard error, z statistic, and confidence intervals.

RESULTS

Overall, subtraction of unfractured bones did not affect interobserver agreement in Schatzker, Luo, and AO/OTA classification systems, agreement on the presence of fracture characteristics, and level of confidence. In subgroup analysis, non-trauma surgeons had significantly higher agreement in the three classification systems with subtraction. For fracture characteristics, some subgroups had higher agreement while others had lower agreement with subtraction.

DISCUSSION

The finding that agreement on classification of tibial plateau fractures is limited on 3DCT scan and is not improved by subtraction of unfractured bones suggests that disagreement may be based on variations in understanding and bias. Reliability of these classification systems might benefit from a focus on accounting for these pre-existing conceptualizations rather than further emphasis on imaging detail.

LEVEL OF EVIDENCE

Diagnostic, level 1.

Reproducibility of the modified Neer classification defining displacement with respect to the humeral head fragment for proximal humeral fractures

Background

Although the Neer classification is widely used for the assessment of proximal humeral fractures, its reproducibility has been challenged. The purpose of this study was to evaluate the reproducibility of the conventional Neer classification and a modified classification that defined fracture displacement with respect to the humeral head fragment.

Methods

The fracture patterns in 80 cases of proximal humeral fractures were independently assessed by 6 observers. The cases were grouped according to the conventional Neer classification using radiographs followed by computed tomography (CT) scans by each examiner twice with a 1-month interval. The fractures were then classified with the modified Neer classification, which defined displacement of the fragment as separation of more than 1 cm or angulation of more than 45° from the humeral head fragment, twice with a 1-month interval. Kappa coefficients of the conventional and modified Neer classifications were compared.

Results

The modified classification showed significantly higher intra-observer agreement than the conventional classification, both for radiographs (P = .028) and for CT scans (P = .043). Intra-observer agreement was also significantly higher for the modified classification than for the conventional classification, both for radiographs (P = .001) and for CT scans (P < .001).

Conclusions

The present study showed that agreement for the Neer classification could be improved when fracture displacement was defined as separation or angulation from the humeral head. Considering vascularity to the humeral head, furthermore, the modified method might be more helpful for predicting patients’ prognosis than the conventional Neer classification.

Imaging of Acute Shoulder Trauma

Acute injuries to the shoulder girdle are common and frequently encountered by the practicing radiologist. The type of injury is highly dependent on the age of the patient and mechanism of trauma with injuries occurring at the site of greatest mechanical weakness. In this review, we discuss the main clinical features and key imaging findings for the most common shoulder injuries. For each injury, we also provide a section on the important features that the orthopedic surgeon needs to know in order to guide surgical versus nonsurgical management.

Follow-up radiographs in isolated Greater Tuberosity fractures lead to a change in treatment recommendation; an online survey study

INTRODUCTION

It is common practice to obtain follow-up radiographs of non-operatively treated isolated greater tuberosity (GT) fractures 1 to 2 weeks after trauma. However, the majority of non-operatively treated GT fractures remain stable and do not require reconsideration of the initial treatment decision. Radiological follow-up therefore might be unnecessary. Our primary objective was to study whether radiological folow-up changes the initial treatment recommendation, hypothesizing no change.

MATERIALS AND METHODS

Radiographs of 25 patients diagnosed with an isolated GT fracture were selected from our hospital database and presented on a web-based platform. Sixty-eight trauma- and orthopedic surgeons evaluated these radiographs. First the radiographs directly post-trauma and then, in random order, the radiographs 5-14 days post-trauma alongside the first radiographs. Each observer evaluated each set of radiographs once. The observers answered which treatment they would recommend (non-operative/operative), and how certain they were about their advice (absolutely certain, certain, some doubt, very uncertain). Recommendation-consistency and inter-observer agreement are presented as percentages and intra class correlation coefficients (ICC).

RESULTS

Overall, 84% (95% CI 82.1-85.8) of treatment recommendations was unchanged after evaluation of the second radiograph. Agreement within each observer ranged from 60 to 98%. The mean proportion of patients about whom the observers were (absolutely) certain of their recommendation increased from 70% at the first evaluation to 83% at the second evaluation (12.8; 95% CI 9.8-15.9). Furthermore, the ICC between the surgeons improved from 0.37 (95% CI 0.26-0.54) for the first evaluation to 0.60 (95% CI 0.47-0.74) for the second.

CONCLUSION

In 16% of the patients the treatment recommendation for an isolated GT fracture changed after the evaluation of radiographs 1 to 2 weeks post-trauma. In addition, surgeons were more certain about their recommendation and there was less inter-observer variation. Radiological follow-up of a non-operatively treated isolated GT fracture therefore seems justifiable.

LEVEL OF EVIDENCE

III, diagnostic study.

Reliability and reproducibility of the new AO/OTA 2018 classification system for proximal humeral fractures: a comparison of three different classification systems

BACKGROUND

The classification systems for proximal humeral fractures routinely used in clinical practice include the Neer and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) 2007 systems. Currently used systems have low inter- and intraobserver reliability. In 2018, AO/OTA introduced a new classification system with the aim of simplifying the coding process, in which the Neer four-part classification was integrated into the fracture description. The aim of the present work is to assess the inter- and intraobserver agreement of the new AO/OTA 2018 compared with the Neer and AO/OTA 2007 classifications.

MATERIALS AND METHODS

A total of 116 radiographs of consecutive patients with proximal humeral fracture were selected and classified by three observers with different levels of experience. All three observers independently reviewed and classified the images according to the Neer, AO/OTA 2007, and new AO/OTA 2018 systems. To determine the intraobserver agreement, the observers reviewed the same set of radiographs after an interval of 8 weeks. The inter- and intraobserver agreement were determined through Cohen's kappa coefficient analysis.

RESULTS

The new AO/OTA 2018 classification showed substantial mean inter- (k = 0.67) and intraobserver (k = 0.75) agreement. These results are similar to the reliability observed for the Neer classification (interobserver, k = 0.67; intraobserver, k = 0.85) but better than those found for the AO/OTA 2007 system, which showed only moderate inter- (k = 0.57) and intraobserver (k = 0.58) agreement. The two more experienced observers showed better overall agreement, but no statistically significant difference was found. No differences were found between surgical experience and agreement regarding specific fracture types or groups.

CONCLUSIONS

The results showed that the Neer system still represents the more reliable and reproducible classification. However, the new AO/OTA 2018 classification improved the agreement among observers compared with the AO/OTA 2007 system, while still maintaining substantial descriptive power and simplifying the coding process. The universal modifiers and qualifications, despite their possible complexity, allowed a more comprehensive fracture definition without negatively affecting the reliability or reproducibility of the classification system.

LEVEL OF EVIDENCE

Level III, diagnostic studies.

Imaging to improve agreement for proximal humeral fracture classification in adult patient: A systematic review of quantitative studies

Proximal humeral fracture classification has low reproducibility. Many studies have tried to increase inter- and intra-observer agreement with more sophisticated imaging. The aim of this review was to determine which imaging modality produces the best inter- and intra-observer agreement for proximal humeral fracture classification in adults and to determine if this varies with observer experience or fracture complexity. OvidMEDLINE, The Cochrane Library, EBSCO CINAHL and Elsevier Scopus were searched on July 22nd, 2018. Quantitative studies comparing at least two imaging modalities for inter- or intra-observer agreement of proximal humeral fracture classification in adults were eligible for inclusion in this systematic literature review. Two reviewers independently screened and extracted data. Study quality was appraised using a modified Downs and Black checklist. The search strategy identified 1987 studies, of which 15 met the eligibility criteria. All included studies addressed inter-observer agreement and 8 provided results for intra-observer agreement. A narrative synthesis was performed. Trends were compared between studies as clinical heterogeneity and the statistical measures used by included studies prevented meta-analysis. Inter- and intra-observer agreement was found to increase from radiographs (x-ray) to two-dimensional (2D) computed tomography (CT) to three-dimensional (3D) CT. 2D and 3D CT may improve inter-observer agreement to a greater extent in less experienced observers and in more complex fractures. Future studies should compare 2D and 3D CT with subgroups categorising surgeon experience and fracture complexity. X-ray should be used for initial assessment; however doctors should have a low threshold for ordering CT. PROSPERO number: CRD42018094307.

Impact of two- and three-dimensional computed tomography use on intraobserver and interobserver reliabilities of pilon fracture classification and treatment recommendation

BACKGROUND

Two-dimensional (2D) and three-dimensional (3D) computed tomography (CT) have been increasingly used in various intra-articular fractures including pilon fracture. However, no study has investigated intraobserver and interobserver reliabilities of pilon fracture classification using 3D CT images.

HYPOTHESIS

(1) Intraobserver and interobserver agreements of fracture classifications and treatment recommendations will improve by using 2D CT images compared to using plain radiographs only; (2) agreements will improve by adding 3D CT images compared to adding 2D CT images; and (3) agreements of orthopedic residents rather than specialists will be influenced more by imaging modality.

MATERIALS AND METHODS

Ten orthopedic specialists and 10 residents completed a survey to classify the fractures according to the Rüedi-Allgöwer and AO/OTA classifications and to select treatment options using 25 pilon fracture images. The survey was conducted using plain radiographs, with 2D and 3D CT images introduced 3 and 6weeks later, respectively. Kappa coefficients were calculated to determine reliabilities.

RESULTS

Intraobserver reliabilities for fracture classifications in specialists significantly improved by using 2D images compared to using plain radiographs only. Addition of 3D CT did not significantly improve intraobserver reliabilities compared to those with 2D CT. Use of 2D CT images significantly improved overall interobserver agreement of both classifications, with the improvement being greater for residents. Use of 3D CT images did not improve the interobserver reliability of both classifications. Overall interobserver reliabilities for treatment recommendations did not significantly differ according to the imaging modality. However, interobserver agreement among residents significantly improved from slight agreement using radiographs only to fair agreement using 2D CT images.

DISCUSSION

Intraobserver and interobserver reliabilities of pilon fracture classification and treatment recommendations did not improve between using 3D and 2D CT. Using 2D CT images improved the intraobserver and interobserver reliabilities of the fracture classifications in specialists and the interobserver reliabilities of the fracture classifications and the treatment recommendations in residents.

LEVEL OF EVIDENCE

IV, case control study.

Intraobserver and Interobserver Reliability of Radiographic Analysis of Proximal Humerus Fractures in Adolescents

BACKGROUND

Multiple studies have shown low intrarater and interrater agreement of radiographic classification systems for proximal humerus fractures (PHFs) in adults. There is no standardized method of measuring angulation of pediatric PHFs, nor is there consensus as to the amount of angulation and displacement that require operative fixation of adolescent PHFs. We propose a new standardized method to measure fracture angulation that is similar to the method used to measure the epiphyseal-shaft angle for slipped capital femoral epiphysis. The primary purpose of this study was to evaluate the intraobserver and interobserver reliability of our proposed method compared with a nonstandardized method. The secondary purpose was to evaluate the intrarater and interrater agreement of the Neer and Horowitz (NH), and Salter-Harris (SH) classification systems.

METHODS

Seven raters evaluated 26 deidentified anteroposterior shoulder radiographs of patients 10 to 16 years of age with PHFs. Raters classified each fracture using the NH and SH systems, and used their own method to measure fracture angulation. This process was repeated 2 weeks later. During the second round, raters also measured fracture angulation using our proposed standardized method. Two weeks after the second round, raters reevaluated the radiographs using the standardized method. Intraclass correlation coefficients were calculated.

RESULTS

Excellent intraobserver and interobserver agreement was achieved for the standardized method of measuring fracture angulation. All of the raters had an intrarater reliability classified as excellent (>0.80) using the standardized method. Good intrarater and excellent interrater agreement was achieved when raters used their own fracture angulation measurement method but wide confidence intervals suggested that the results were less precise. Fair to moderate intrarater and interrater reliability was seen for the NH and SH classifications.

CONCLUSIONS

Our standardized method for measuring angulation in adolescent PHFs demonstrated excellent intrarater and interrater reliability. We propose that this technique may be a more precise method of measuring fracture angulation and this method should be used in future studies that evaluate indications for operative management of adolescent PHFs.

LEVEL OF EVIDENCE

Level III-diagnostic.

New Imaging, Diagnostic, and Assessment Techniques in Orthopedic Trauma

This article examines new imaging, diagnostic, and assessment techniques that may affect the care of patients with orthopedic trauma and/or infection. Three-dimensional imaging has assisted in fracture assessment preoperatively, whereas improvement in C-arm technology has allowed real-time evaluation of implant placement and periarticular reduction before leaving the operating room. Advances in imaging techniques have allowed earlier and more accurate diagnosis of nonunion and infection. Innovations in bacteriologic testing have improved the sensitivity and specificity of perioperative and peri-implant infections. It is critical that surgeons remain up to date on the options available for optimal patient care.

3D reconstruction does not improve agreement and results in an increase in surgical indications in proximal humeral fractures

The objective of this study is to analyze the effect of different imaging modalities in treatment decision making in proximal humeral fractures. After evaluation of 116 consecutive proximal humeral fractures, observers were asked to give treatment recommendation (conservative vs. surgery). If surgery was proposed, they were told to select surgery of choice. When 3D imaging was added, complexity of fractures significantly increased (p < 0.001), number of surgeries significantly increased (p < 0.000) and number of ORIF treatments significantly increased (p < 0.0004). Addition of 3D imaging of proximal humeral fractures significantly increases number of surgical decisions when compared to radiographs alone or together with CT.

A morphovolumetric study of head malposition in proximal humeral fractures based on 3-dimensional computed tomography scans: the control volume theory

BACKGROUND

This study regards a volumetric analysis of proximal humeral fractures. The main purpose was to investigate the head displacement in relation to the shaft and its link to volume reductions ("bone loss") of the anatomic segments interposed between the head and the shaft: the tuberosities and the calcar. We call this area "control volume."

METHODS

In 20 fractures, we used 3-dimensional virtual reconstruction to create a reference system that divides geometrically the control volume and allows the evaluation of displacement angles of the humeral head. We calculated the volumetric reduction of control volume segments for each fracture through a specific mathematical protocol.

RESULTS

The measurement of the head displacement angles in 20 fractures led to following results: in the coronal plane, 10 varus, 6 valgus, 4 neutral; in the sagittal plane, 6 anterior tilt, 9 posterior tilt, 5 neutral position. There was a reduction of control volume in 19 of 20 fractures. Only in 1 fracture was the control volume intact and the fracture was nonimpacted. In 19 impacted fractures, the volume reduction was variable (4% minimum loss, 98% maximum loss). In head varus position, loss was greater in the medial area than in the lateral area. There was generally a clear correspondence between the positions assumed by the head and the volumetric losses of the respective control volume segments.

CONCLUSIONS

The control volume is an important anatomic and functional area of the proximal humerus. A morphovolumetric 3-dimensional approach improves knowledge about pathomorphology of proximal humeral fractures.

Difficulty in decision making in the treatment of displaced proximal humerus fractures: the effect of uncertainty on surgical outcomes

BACKGROUND

Decision making in the management of proximal humerus fractures can be difficult in situations in which the surgeon is uncertain of the ideal treatment.

METHODS

Two shoulder surgeons operatively treated 476 proximal humerus fractures from 1998-2014 with open reduction-internal fixation (ORIF), hemiarthroplasty, or reverse shoulder arthroplasty. Operative treatment was stratified by year to determine the evolution of technological influences on treatment over time. To evaluate the effect of uncertainty, 274 clinical vignettes were created for all patients with 1 year of follow-up or more and reviewed by 3 fellowship-trained shoulder surgeons to determine the type of treatment for each case. To evaluate the effect of certainty, range of motion for each patient with unanimous agreement on treatment was analyzed.

RESULTS

ORIF treatment increased from 40% to 62% after release of the proximal humerus locking plate. Introduction of the fracture stem in 2011 increased reverse shoulder arthroplasty for fractures from 8.8% to 44.3%. Unanimous agreement on either operative or nonoperative treatment occurred 70.5% of the time. Only 63.5% of patients received the actual treatment selected (P = .001). Patients for whom unanimous agreement matched actual treatment in the ORIF treatment group showed improvement of forward elevation (144° vs 123°, P = .005) and abduction (129° vs 103°, P = .002).

CONCLUSION

Successful management of displaced proximal humerus fractures requires both technical and decision-making abilities. The difficulty in making these decisions is reflected by the agreement of experienced shoulder surgeons only 63.5% of the time regarding the treatment performed. When uncertainty occurs, patients may have reduced outcomes as seen in the ORIF treatment group.

Online Studies on Variation in Orthopedic Surgery: Computed Tomography in MPEG4 Versus DICOM Format

The purpose of this study was to compare the observer participation and satisfaction as well as interobserver reliability between two online platforms, Science of Variation Group (SOVG) and Traumaplatform Study Collaborative, for the evaluation of complex tibial plateau fractures using computed tomography in MPEG4 and DICOM format. A total of 143 observers started with the online evaluation of 15 complex tibial plateau fractures via either the SOVG or Traumaplatform Study Collaborative websites using MPEG4 videos or a DICOM viewer, respectively. Observers were asked to indicate the absence or presence of four tibial plateau fracture characteristics and to rate their satisfaction with the evaluation as provided by the respective online platforms. The observer participation rate was significantly higher in the SOVG (MPEG4 video) group compared to that in the Traumaplatform Study Collaborative (DICOM viewer) group (75 and 43%, respectively; P < 0.001). The median observer satisfaction with the online evaluation was seven (range, 0-10) using MPEG4 video compared to six (range, 1-9) using DICOM viewer (P = 0.11). The interobserver reliability for recognition of fracture characteristics in complex tibial plateau fractures was higher for the evaluation using MPEG4 video. In conclusion, observer participation and interobserver reliability for the characterization of tibial plateau fractures was greater with MPEG4 videos than with a standard DICOM viewer, while there was no difference in observer satisfaction. Future reliability studies should account for the method of delivering images.

The Effect of Two Factors on Interobserver Reliability for Proximal Humeral Fractures

INTRODUCTION

The purpose of this study was to assess whether training observers and simplifying proximal humeral fracture classifications improve interobserver reliability among a large number of orthopaedic surgeons.

METHODS

One hundred eighty-five observers were randomized to receive training or no training in a simple classification for proximal humeral fractures before evaluating preoperative radiographs of a consecutive series of 30 patients who were treated with open reduction and internal fixation.

RESULTS

The overall interobserver reliability of the simple proximal humeral fracture classification system was low and not significantly different between the training and the no training group (κ = 0.20 and κ = 0.18, respectively; P = 0.10). Subgroup analyses showed that training improved the agreement among surgeons who have been in independent practice ≤5 years (κ = 0.23 versus κ = 0.14; P < 0.001), surgeons from the United States (κ = 0.23 versus κ = 0.16; P = 0.002), and general orthopaedic surgeons (κ = 0.42 versus κ = 0.15; P = 0.021).

DISCUSSION

Simplifying classifications and training observers did not improve the interobserver reliability for the diagnosis of proximal humeral fractures. However, training observers improved interobserver reliability of a simple proximal humeral fracture classification system among surgeons from the United States and, in particular, younger and less specialized surgeons. This finding may suggest that our interpretations of radiographic information might become more fixed and immutable with experience.

Interobserver reliability of the Schatzker and Luo classification systems for tibial plateau fractures

INTRODUCTION

Tibial plateau fracture classification systems have limited interobserver reliability and new systems emerge. The purpose of this study was to compare the reliability of the Luo classification and the Schatzker classification for two-dimensional computed tomography (2DCT) and to study the effect of adding three-dimensional computed tomography (3DCT).

MATERIALS AND METHODS

Eighty-one observers, orthopedic surgeons and residents, were randomized to either 2DCT or 2D- and 3DCT evaluation of a spectrum of 15 complex tibial plateau fractures using web-based platforms in order to classify according to the Schatzker and according to Luo's Three Column classification. Reliability was calculated with the use of Siegel and Castellan's multirater kappa measure. Kappa values were interpreted according to the categorical rating by Landis and Koch.

RESULTS

Overall interobserver reliability of the Schatzker classification was significantly better compared to the Luo classification (kSchatzker=0.32 and kLuo=0.28, P=0.021), however, 'fair' for both fracture classification systems. For the Schatzker classification observers agreed significantly better on 2DCT compared to 2D- and 3DCT (k2DCT=0.37 and k2D+3DCT=0.29, P<0.001). The addition of 3DCT did not improve the overall interobserver reliability for the Luo classification as well, as kappa values were not significantly different on 2DCT and 2D- and 3DCT (k2DCT=0.31 and k2D+3DCT=0.25, P=0.096).

CONCLUSIONS

The agreement between observers was significantly better for the Schatzker classification compared to Luo's Three Column classification, however agreement was fair for both classification systems. Furthermore, the addition of 3DCT reconstructions did not improve the reliability of CT-based evaluation of tibial plateau fractures. Considering that new classification systems and 3DCT do not seem to improve agreement between surgeons, other efforts are needed that lead to more reliable diagnosis of complex tibial plateau fractures.