TWO AND THREE-DIMENSIONAL COMPUTED TOMOGRAPHY FOR THE CLASSIFICATION AND MANAGEMENT OF DISTAL HUMERAL FRACTURES

Management of Pediatric Elbow Fractures and Dislocations

Pediatric elbow fractures and dislocations have always been a challenge from a diagnostic and therapeutic point of view, primarily due to the complex nature of the pediatric elbow, especially its developmental anatomy. They must be diagnosed and treated on time to prevent numerous complications with long-term consequences. With the development of radiology and pediatric surgery and orthopedics, as well as the development of modern osteosynthesis materials, concerning current scientific and professional knowledge, the outcomes are getting better, with fewer acute and chronic complications. This comprehensive review aims to provide clinicians current knowledge about pediatric elbow fractures and dislocations so that in daily practice they have as few doubts as possible with the best possible treatment outcomes.

The Kappa Paradox Explained

Observer reliability studies for fracture classification systems evaluate agreement using Cohen's κ and absolute agreement as outcome measures. Cohen's κ is a chance-corrected measure of agreement and can range between 0 (no agreement) and 1 (perfect agreement). Absolute agreement is the percentage of times observers agree on the matter they have to rate. Some studies report a high-absolute agreement but a relatively low κ value, which is counterintuitive. This phenomenon is referred to as the Kappa Paradox. The objective of this article was to explain the statistical phenomenon of the Kappa Paradox and to help readers and researchers to recognize and prevent this phenomenon.

Reproducibility of the Mayo and Schatzker classification systems in proximal ulna fractures

INTRODUCTION

A fracture classification system should provide a reliable and reproducible means of communication between different parties. It should be logical and understandable, with few categories to memorize. The aim of this study was to determine the intra- and interobserver reliability of the Schatzker and Mayo classification systems for the assessment of proximal ulna fractures.

MATERIALS AND METHODS

Intra- and interobserver reliability studies were conducted on 39 X-rays of injured elbows drawn randomly from 74 cases previously used in a series on predictors of ulnohumeral osteoarthritis in proximal ulna fractures. Ten observers independently reviewed these X-rays on 2 separate occasions 3 months apart. The fracture type was assessed according to the Schatzker and Mayo classification systems during each reading session. Cohen's and Fleiss' kappa were used to measure the intra- and interobserver reliability.

RESULTS

The Schatzker classification had a fair interobserver reliability for the first (Schatzker R1, Fleiss' κ: 0.394) and second (Schatzker R2, Fleiss' κ: 0.351) readings. The mean intraobserver reliability value between the 10 reviewers for the Schatzker classification was rated as substantial (0.61). The Mayo classification had a fair interobserver reliability for the first (Mayo R1, Fleiss' κ: 0.278) and second (Mayo R2, Fleiss' κ: 0.292) readings. The mean intraobserver reliability value between the 10 reviewers for the Mayo classification was rated as fair (0.52).

DISCUSSION

The classification systems for proximal ulna fractures showed poor reproducibility between the different observers since they had low interobserver agreement values. Nevertheless, their use remained reliable since the measured intraobserver agreement value was deemed substantial.

LEVEL OF EVIDENCE

IV; retrospective.

Coronal Plane Articular Shear Fractures of the Distal Humerus

Coronal plane articular shear fractures of the distal humerus are a rare injury, comprising 6% of distal humerus fractures. The fracture can be easily missed on initial radiographs; therefore, a high index of suspicion is warranted. Radiographically obvious fractures are often more complex than initially appreciated, with plain radiographs often underestimating the extent of posterior comminution and trochlear involvement. Associated bony and ligamentous injuries are common. Anatomic reduction and internal fixation of displaced fractures is the standard of care because poor results have been described with nonsurgical treatment. However, the regional anatomy and the often-limited bone stock can make open reduction and internal fixation challenging. The lateral approach, with headless compression screws placed from anterior to posterior, is commonly used for simpler fracture patterns, but exposure and fixation of trochlea extension can be difficult. In the absence of posterior comminution, the anterolateral approach can enhance trochlea exposure and allow for a better trajectory for screw placement. Posterior comminution often requires locking plate fixation. Better results and lower complication rates have been reported for fractures with less fragmentation of the articular surface and those without posterior comminution. Contracture and symptomatic implants are the most common reasons for revision surgery.

Functional outcomes of elbow injuries managed according to the Wrightington classification of elbow fracture-dislocations

Background

This study aims to review the functional outcomes of patients managed by the application of the Wrightington elbow fracture-dislocation classification system and its corresponding management algorithms.

Methods

This is a retrospective consecutive case series of patients over the age of 16 with an elbow fracture-dislocation managed according to the Wrightington classification. The primary outcome was the Mayo Elbow Performance Score (MEPS) at the last follow-up. Range of movement (ROM) and complications were collected as a secondary outcome.

Results

Sixty patients qualified for inclusion (32 female, 28 male) with a mean age of 48 years (19-84). Fifty-eight (97%) patients completed a minimum of three months follow-up. Mean follow-up was six months (3-18). The median MEPS at the final follow-up was 100 (interquartile range [IQR] 85-100) and median ROM of 123° (IQR 101-130) degrees. Four patients underwent secondary surgery and had improved outcomes with the average MEPS score improving from 65 to 94 following the second surgery.

Conclusions

The results of this study show that good outcomes can be achieved for complex elbow fracture-dislocations through pattern recognition and management with an anatomically based reconstruction algorithm as described by the Wrightington classification system.

The role of three dimension computed tomography in Lisfranc injury diagnosis

PURPOSE

To evaluate the intra/inter observer and diagnostic reliability of 3-dimensional (3D) model reconstruction computed tomography (CT) compared to the traditional two-dimensional (2D) CT when evaluating Lisfranc (LF) injuries.

METHODS

A retrospective study was performed on CT studies of patients with clinically suspected LF injuries examined in the emergency department at medium size medical center. Each CT study was evaluated for metatarsal fractures and subluxations employing both standard 2D and 3D CT model reconstruction. Four orthopaedists, 2 senior and 2 residents, were assigned to review and evaluate each CT. Each CT study was reviewed twice by each reader in a randomized order. Descriptive statistics were calculated for all measured variables. The intra-observer and inter-observer agreement Kappa coefficients were calculated to evaluate reliability and reproducibility between and within readers for each modality.

RESULTS

The study included 44 patients. Median age was 41.4 years (interquartile range, 23-58). The intra-observer and inter-observer reliability was good (intra-observer; 3D Kappa; 0.76 and 2D Kappa 0.73 p<0.001, inter-observer; 3D Kappa 0.68, 2D Kappa 0.63 and combined 2D and 3D kappa 0.68, p<0.001). Three dimensional CT was found to be more sensitive than 2D CT, specifically when evaluating for second metatarsal dislocation (sensitivity: 70% vs 47%). Combined evaluation of 2D and 3D CT, greatly improved sensitivity rate to 85.7%. In terms of fracture diagnosis, combined evaluation of 2D and 3D CT showed higher sensitivity and specificity rates as compared to 2D or 3D alone.

CONCLUSION

The employment of 3D CT in LF injury diagnosis, in isolation and in combination with 2D CT, seems to improve the diagnostic accuracy and reliability between and within observers compared to 2D CT alone.

Artificial intelligence and computer vision in orthopaedic trauma : the why, what, and how

Artificial intelligence (AI) is, in essence, the concept of 'computer thinking', encompassing methods that train computers to perform and learn from executing certain tasks, called machine learning, and methods to build intricate computer models that both learn and adapt, called complex neural networks. Computer vision is a function of AI by which machine learning and complex neural networks can be applied to enable computers to capture, analyze, and interpret information from clinical images and visual inputs. This annotation summarizes key considerations and future perspectives concerning computer vision, questioning the need for this technology (the 'why'), the current applications (the 'what'), and the approach to unlocking its full potential (the 'how'). Cite this article: Bone Joint J 2022;104-B(8):911-914.

Distal Humerus Traction Radiographs: Is the Interobserver and Intraobserver Reliability Comparable With Computed Tomography?

OBJECTIVES

To compare the interobserver and intraobserver reliability of traction radiographs with 2-dimensional computed tomography (2D CT) in distal humerus fracture classification and characterization.

DESIGN

Randomized controlled radiographic review of retrospectively collected data.

SETTING

Academic Level 1 trauma center.

PATIENTS/PARTICIPANTS

Skeletally mature patients with intra-articular distal humerus fractures with both traction radiographs and CT scans were reviewed by 11 orthopaedists from different subspecialties and training levels.

INTERVENTION

The intervention involved traction radiographs and 2D CT.

MAIN OUTCOME MEASUREMENTS

The main outcome measurements included interobserver and intraobserver reliability of fracture classification by the OTA/AO and Jupiter-Mehne and determination of key fracture characteristics.

RESULTS

For the OTA/AO and Jupiter-Mehne classifications, we found a moderate intraobserver agreement with both 2D CT and traction radiographs (κ = 0.70-0.75). When compared with traction radiographs, 2D CT improved the interobserver reliability of the OTA/AO classification from fair to moderate (κ = 0.3 to κ = 0.42) and the identification of a coronal fracture from slight to fair (κ = 0.2 to κ = 0.34), which was more pronounced in a subgroup analysis of less-experienced surgeons. When compared with 2D CT, traction radiographs improved the intraobserver reliability of detecting stable affected articular fragments from fair to substantial (κ = 0.4 to κ = 0.67).

CONCLUSIONS

Traction radiographs provide similar diagnostic characteristics as 2D CT in distal humerus fractures. For less-experienced surgeons, 2D CT may improve the identification of coronal fracture lines and articular comminution.

Assessment of Usefulness of CT Scan in AO Classification of Intertrochanteric Fractures: A Prospective Observational Study

OBJECTIVE

The sliding hip screw (SHS) is the gold standard for the management of stable intertrochanteric (IT) fractures. However, intramedullary implants are now being increasingly used for management of unstable IT fractures especially those with a compromised or vulnerable lateral wall. Therefore, accurate classification of fracture is important to ensure proper surgical planning and choice of implant. The AO classification for IT fractures is based on plain radiographs alone and many authors have reported it to have poor inter- and intra-observer agreement. Therefore, the objectives of the study were to assess the improvement in inter- and intra-observer agreement of the AO classification after addition of CT scan to plain radiographs, to assess the change in pattern of AO classification on addition of CT scan to plain radiographs and to assess percentage of times, stable lateral wall seen on plain radiographs is classified as unstable or broken on CT scans.

METHOD

Fifty-four patients of intertrochanteric fracture were included in study. Plain radiographs of patients were shown to three orthopedic surgeons. They were asked to document the AO classification of the fracture, and comment on the integrity of the lateral wall. Then, CT scans with 3D reconstructions of the same patients were provided along with the radiographs and they were asked to classify the fracture again. Inter- and intra-observer agreement of the AO classification based on plain radiographs alone and once CT scan with 3D reconstruction was added to the plain radiographs was determined using Kappa coefficients. Pattern of change in classification on addition of CT scan to plain radiographs was also assessed.

RESULT

The mean kappa value for inter- and intra-observer agreement for AO classification on plain radiographs alone were 0.58 (moderate) and 0.66 (substantial), respectively. Upon addition of CT scan to plain radiographs, both improved to 0.70 (substantial) and 0.77 (substantial), respectively. The AO classification of the fracture changed 28.70% times (93 of 324 observations) upon addition of CT scan to plain radiographs. 96.77% times (90 of 93 observations) the classification was upgraded to higher group, while it was downgraded in only 3.22% times (3 of 93). 55.91% times this change was observed in AO 31 A 2 group (52 of 93 observations). In 17.59% cases (57 of 324 observations), fractures which were classified as stable (A1.1-A2.1) on radiographs alone, were reclassified as unstable (A2.2-3.3) upon addition of CT scan to plain radiographs. In 11.4% cases (37 of 324 observations), the lateral wall was classified as vulnerable or broken on CT scans where it was classified intact on plain radiographs.

CONCLUSION

Addition of CT scans with 3D reconstructions to plain radiographs improves the intra- and inter-observer agreement of the AO classification. Addition of CT scan results in change in classification of the fracture in about one out of three cases. This most commonly happens in the AO 31 A 2 group. Most of the times, this results in the classification of fracture being upgraded. Many fractures which are initially classified as stable (A1.1-A2.1) on radiographs are reclassified as unstable (A2.2-3.3) on addition of CT scans. The lateral wall is also classified as vulnerable or broken more number of times on CT scans than plain radiographs alone. Therefore, we conclude that CT scan with 3 D reconstructions definitely helps in better pre-operative classification of intertrochanteric fractures especially in select group of fractures (AO 31 A 2) where stability and integrity of lateral wall is difficult to assess.

Coronal shear fractures of the capitellum and trochlea: interobserver variability in classifying the fracture and the need for a computed tomography scan for the correct surgical planning

Background

To determine interobserver agreement in the classification by X-rays and by computed tomography (CT) scan of the coronal shear fractures of the capitellum and trochlea as well as the agreement between these two tests.

Methods

Patients with coronal shear fractures of the capitellum who were managed at our center between January 2008 and December 2017 were included. This retrospective cohort study was carried out with the approval of the ethics committee of our institution (Nº: IIBSP-Cod-2019-02, Ref. 19/070). Clinical, radiographic, and elbow-specific outcomes, including the Mayo Elbow Performance Index, were evaluated. Three observers analyzed the preoperative X-rays from all the cases. Each one of them independently classified the fractures according to the Bryan and Morrey classification (with the modification of McKee et al). The interobserver agreement was calculated by Cohen kappa coefficient. The same methodology was used to analyze the CT scan. Thereafter, one single value was determined for each X-ray and CT scan, from the good interobserver agreements. Finally, the agreement between the global X-ray classification and the global CT scan classification was calculated using the agreement percentage and the Cohen kappa coefficient.

Results

There were 3 males and 6 females, with a mean age of 47 years (range, 18-83). The mean follow-up period was 18 months (12-40). The average Mayo Elbow Performance Index score was 85 (range, 65-100) points. The complications were nonunion in one patient (11 %), degenerative arthritis in 7 (78 %), joint step-off in 5 (55%), and heterotopic ossification in 7 (78%). The agreement analysis between the global X-ray classification and the global CT scan classification showed a 57.1% agreement, with a kappa coefficient of −0.167. These values imply the absence of agreement.

Conclusion

Our results demostrated that simple X-rays do not allow for the adequate interpretation of distal humeral coronal plane fractures. Although an acceptable interobserver agreement was found, there is no agreement when the same fractures were analyzed by CT scan. The authors routinely recommend CT scan to assess the extent of the fracture and perform surgical planning.

Do 3-D Printed Handheld Models Improve Surgeon Reliability for Recognition of Intraarticular Distal Radius Fracture Characteristics?

BACKGROUND

For fracture care, radiographs and two-dimensional (2-D) and three-dimensional (3-D) CT are primarily used for preoperative planning and postoperative evaluation. Intraarticular distal radius fractures are technically challenging to treat, and meticulous preoperative planning is paramount to improve the patient's outcome. Three-dimensionally printed handheld models might improve the surgeon's interpretation of specific fracture characteristics and patterns preoperatively and could therefore be clinically valuable; however, the additional value of 3-D printed handheld models for fractures of the distal radius, a high-volume and commonly complex fracture due to its intraarticular configuration, has yet to be determined.

QUESTIONS/PURPOSES

(1) Does the reliability of assessing specific fracture characteristics that guide surgical decision-making for distal radius fractures improve with 3-D printed handheld models? (2) Does surgeon agreement on the overall fracture classification improve with 3-D printed handheld models? (3) Does the surgeon's confidence improve when assessing the overall fracture configuration with an additional 3-D model?

METHODS

We consecutively included 20 intraarticular distal radius fractures treated at a Level 1 trauma center between May 2018 and November 2018. Ten surgeons evaluated the presence or absence of specific fracture characteristics (volar rim fracture, die punch, volar lunate facet, dorsal comminution, step-off > 2 mm, and gap > 2 mm), fracture classification according to the AO/Orthopaedic Trauma Association (OTA) classification scheme, and their confidence in assessing the overall fracture according to the classification scheme, rated on a scale from 0 to 10 (0 = not at all confident to 10 = very confident). Of 10 participants regularly treating distal radius fractures, seven were orthopaedic trauma surgeons and three upper limb surgeons with experience levels ranging from 1 to 25 years after completion of residency training. Fractures were assessed twice, with 1 month between each assessment. Initially, fractures were assessed using radiographs and 2-D and 3-D CT images (conventional assessment); the second time, the evaluation was based on radiographs and 2-D and 3-D CT images with an additional 3-D handheld model (3-D printed handheld model assessment). On both occasions, fracture characteristics were evaluated upon a surgeon's own interpretation, without specific instruction before assessment. We provided a sheet demonstrating the AO/OTA classification scheme before evaluation on each session. Multi-rater Fleiss's kappa was used to determine intersurgeon reliability for assessing fracture characteristics and classification. Confidence regarding assessment of the overall fracture classification was assessed using a paired t-test.

RESULTS

We found that 3-D printed models of intraarticular distal radius fractures led to no change in kappa values for the reliability of all characteristics: volar rim (conventional kappa 0.19 [95% CI 0.06 to 0.32], kappa for 3-D handheld model 0.23 [95% CI 0.11 to 0.36], difference of kappas 0.04 [95% CI -0.14 to 0.22]; p = 0.66), die punch (conventional kappa 0.38 [95% CI 0.15 to 0.61], kappa for 3-D handheld model 0.50 [95% CI 0.23 to 0.78], difference of kappas 0.12 [95% CI -0.23 to 0.47]; p = 0.52), volar lunate facet (conventional kappa 0.31 [95% CI 0.14 to 0.49], kappa for 3-D handheld model 0.48 [95% CI 0.23 to 0.72], difference of kappas 0.17 [95% CI -0.12 to 0.46]; p = 0.26), dorsal comminution (conventional kappa 0.36 [95% CI 0.13 to 0.58], kappa for 3-D handheld model 0.31 [95% CI 0.11 to 0.51], difference of kappas -0.05 [95% CI -0.34 to 0.24]; p = 0.74), step-off > 2 mm (conventional kappa 0.55 [95% CI 0.29 to 0.82], kappa for 3-D handheld model 0.58 [95% CI 0.31 to 0.85], difference of kappas 0.03 [95% CI -0.34 to 0.40]; p = 0.87), gap > 2 mm (conventional kappa 0.59 [95% CI 0.39 to 0.79], kappa for 3-D handheld model 0.69 [95% CI 0.50 to 0.89], difference of kappas 0.10 [95% CI -0.17 to 0.37]; p = 0.48). Although there appeared to be categorical improvement in kappa values for some fracture characteristics, overlapping CIs indicated no change. Fracture classification did not improve (conventional diagnostics: kappa 0.27 [95% CI 0.14 to 0.39], conventional diagnostics with an additional 3-D handheld model: kappa 0.25 [95% CI 0.15 to 0.35], difference of kappas: -0.02 [95% CI -0.18 to 0.14]; p = 0.81). There was no improvement in self-assessed confidence in terms of assessment of overall fracture configuration when a 3-D model was added to the evaluation process (conventional diagnostics 7.8 [SD 0.79 {95% CI 7.2 to 8.3}], 3-D handheld model 8.5 [SD 0.71 {95% CI 8.0 to 9.0}], difference of score: 0.7 [95% CI -1.69 to 0.16], p = 0.09).

CONCLUSIONS

Intersurgeon reliability for evaluating the characteristics of and classifying intraarticular distal radius fractures did not improve with an additional 3-D model. Further studies should evaluate the added value of 3-D printed handheld models for teaching surgical residents and medical trainees to define the future role of 3-D printing in caring for fractures of the distal radius.

LEVEL OF EVIDENCE

Level II, diagnostic study.

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

BACKGROUND

With 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 METHODS

There 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.

RESULTS

The 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.

CONCLUSION

Inter-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.

Impact of Transverse Ultrasound Images on the Classification and Treatment of Pediatric Lateral Humeral Condyle Fractures

BACKGROUND

Pediatric lateral humeral condyle fractures (LHCFs) are sometimes misdiagnosed and inappropriately treated on the basis of x-ray radiographs because cartilage cannot be seen on radiographs. However, as a useful technique, transverse ultrasonography can accurately and readily determine the integrity of the cartilage hinge in pediatric LHCFs. The purpose of this study was to assess the reliability of the Jakob classification, the treatment plan, and the necessity for further examination of pediatric LHCFs with the use of x-ray with and without transverse ultrasound images.

METHODS

Five pediatric orthopaedic surgeons with different levels of experience evaluated 62 cases on the basis of the use of x-ray alone and x-ray combined with transverse ultrasound images. These 2 types of evaluations were repeated after an interval of 4 to 6 weeks. At the time of each evaluation, all observers were asked to classify the fractures according to the Jakob classification, to formulate treatment plans, and to determine whether further examinations were required.

RESULTS

After the training of transverse ultrasound image interpretation, the interobserver reliability of the Jakob classification significantly improved from fair (a kappa of 0.54) to moderate (a kappa of 0.71) with the addition of transverse ultrasound images. The treatment plan was changed from conservative treatment to surgical treatment in 7% of the ratings but from surgical treatment to conservative treatment in 15% of the ratings after reviewing the ultrasound images, and the difference was statistically significant (P=0.003).

CONCLUSIONS

The use of the Jakob classification and a treatment plan for pediatric LHCFs can be optimized by the addition of transverse ultrasound images, especially after training for transverse ultrasound image interpretation.

LEVEL OF EVIDENCE

Level III-diagnostic study.

Coronal shear fractures of the distal humerus: Current concepts and surgical techniques

Coronal shear fractures of the distal humerus are a unique subset of distal humeral fractures which entail partial or complete articular fractures of the distal humerus without involvement of the columns. The very distal nature of these fragments, their small size and propensity for comminution render them challenging to treat surgically. The purpose of this article is to describe the classification, outcomes and surgical techniques currently used for the treatment of these fractures using the available literature and authors' clinical experience.

Three-dimensional computed tomography reconstruction improves the reliability of tibial pilon fracture classification and preoperative surgical planning

PURPOSE

In the present study, we aimed to evaluate the impact of two-dimensional multi-planar computed tomography (2D-MP-CT) scans and three-dimensional surface rendering computed tomography reconstruction (3D-SR-CT) on the inter- and intra-observer reliability of four commonly used classification systems for tibial pilon fractures, and on the reliability and validity of surgical treatment planning for fracture fixation.

METHODS

Four observers evaluated computed tomography images of 35 cases with pilon fractures according to the classifications of Rüedi and Allgöwer, AO/OTA, Topliss, and Tang, and recommended a surgical treatment plan, including the surgical approach, implant position, and need for bone graft augmentation. Fractures were first evaluated using 2D-MP-CT, followed by 3D-SR-CT. We calculated the Kappa values for the correlation between the fracture classifications, types of surgical approaches, implant positions, and bone graft recommendations by the observers. Furthermore, we assessed the correlation between the treatment plans recommended by the observers and the actual surgical procedure performed.

RESULTS

All classifications showed poor inter-observer reliability and moderate intra-observer reliability with 2D-MP-CT scans. The inter-observer reliability of the Rüedi and Allgöwer, AO/OTA, and Tang classifications improved to moderate, whereas the intra-observer reliability of the AO/OTA classification improved to good with additional 3D-SR-CT. The correlation between the suggested and the actually performed surgical approaches was poor with 2D-MP-CT, but improved to moderate with 3D-SR-CT. The suggested plate positions showed a moderate correlation with the actually performed plating; although the correlation improved significantly, it remained moderate with 3D-SR-CT.

CONCLUSION

The use of 3D-SR-CT reconstruction can improve the reliability of the Rüedi and Allgöwer, AO/OTA, and Tang classifications. Furthermore, three-dimensional imaging enables a more valid planning of the surgical approach and implant position.

Sonographic morphometry of abductor pollicis brevis: can direct contact yield images comparable with those obtained by the water bath technique?

PURPOSE

This study sought to compare ultrasound-guided measurements of the abductor pollicis brevis (APB) using the water bath technique (WBT) and the direct contact method (DM) and investigate whether the DM can reproduce the measurements that would be obtained with a non-contact method, such as the WBT.

METHODS

The APB muscles of 80 hands (40 healthy adults) were measured. The WBT was performed in a plastic container filled with water. The probe was placed adjacent to the skin surface without contact. In the DM, sonographic images were obtained with the probe and skin separated by sufficient transmission gel. The muscle thickness and cross-sectional area (CSA) were calculated with both methods. All subjects were examined three times by two examiners to estimate the inter- and intra-observer reliability. Bland-Altman analysis was performed to examine the agreement between the methods.

RESULTS

No significant differences in the thickness or CSA of the APB were found. The interclass correlation coefficients for the WBT and DM showed almost perfect intra- and inter-observer reliability (range 0.87-0.94). There was no systematic bias between the techniques in the Bland-Altman analysis.

CONCLUSION

Similar to the WBT, the DM provides measurements of the APB thickness and CSA without causing morphometric changes.

Can objective criteria for poor tolerance of proximal humerus malunion be identified?

BACKGROUND

Malunion of the proximal humerus is common and variably tolerated. Classifications developed for proximal humerus malunion (PHM) rely on standard radiographs, which underestimate bone fragment displacement and lack accuracy. The clinical tolerance of PHM is subjective, and revision surgery is not always necessary. The primary objective of this study was to assess the reproducibility and relevance of four CT angle measurements for objectively quantifying the morphological disharmony caused by PHM in a control population then in a population with PHM. The secondary objectives were to identify angle cut-offs and to assess the correlations between angle values and the clinical tolerance of PHM.

HYPOTHESIS

Objective criteria for assessing proximal humerus malunion can be identified using CT scans.

MATERIALS AND METHODS

Four angles were chosen to quantify proximal humerus disharmony: the angles between the humeral head and the glenoid in the coronal plane (HGCo) and axial plane (HGAx), the angle of tuberosity divergence in the axial plane (TDAx), and the centrum collum diaphyseal angle (CCD). The reproducibility of measurements of the four angles on computed tomography (CT) views was evaluated in a control population and in 46 patients with PHM. To this end, the reproducibility of reference slice selection was determined and intra- and interobserver reproducibility of the angle measurements was then assessed. Patients with PHM were divided into two groups based on clinical tolerance to allow testing for disharmony parameters associated with poor clinical tolerance, which was defined as functional impairment and surgical revision.

RESULTS

Slice selection was found to be reproducible. The Bland-Altman plot indicated that the angle measurements in both the controls and the patients were reproducible within ±2 SDs. Intraclass correlation coefficient values ranged from fair to excellent for all angles in both the controls and the patients. The mean TDAx was higher in the patients than in the controls (72.0° vs. 56.1°, P<0.05) and, within the PHM group, was higher in the subgroup with good vs. poor clinical tolerance (75.8° vs. 69.5°, P<0.05). The CCD angle was greater in the controls than in the patients (129.8° [range, 128.3°-131.3°] vs. 125.9° [range, 122.9°-128.9], respectively) and was significantly greater in the PHM subgroup with good vs poor clinical tolerance (131.4° vs. 122.3°, respectively; P=0.007). The HGCo and HGAx angles were significantly greater in the patients than in the controls (HGCo: 66.6° vs. 52.2°, respectively; HGAx: 17.5° vs. 13.3°, respectively, P=0.55).

DISCUSSION

The measurement method described here provides a quantitative assessment of postfracture disharmony based on four angles, the HGCo, HGAx, and TDAx. Measurement of these four angles on CT images was found to have good intra- and interobserver reproducibility. The angle values were significantly greater in the patients with PHM than in the controls. Within the patient group, the subgroup with poor clinical tolerance had smaller values of the TDAx, CCD, and HGAx angles and a greater value of the HGCo angle.

LEVEL OF EVIDENCE

IV, retrospective observational study.

Surgical treatment for terrible triad injury of the elbow with anteromedial coronoid fracture through a combined surgical approach

Objective

To report the results of the surgical treatment of terrible triad injury with anteromedial coronoid fracture through a combined surgical approach.

Methods

This retrospective study evaluated data from patients who underwent surgery to repair terrible triad injuries and anteromedial coronoid fractures. Surgical treatment involved radial head repair or replacement, medial and lateral collateral ligament repair, and coronoid fracture fixation through combined approaches. Evaluations were performed using the Mayo Elbow Performance Score (MEPS) and anteroposterior and lateral radiographs of the elbow.

Results

Twenty-two patients (15 males, seven females; mean ± SD age, 47.5 ± 11.4 years) were enrolled in this study. Fracture union and concentric reduction of both the ulnotrochlear and radiocapitellar articulations were achieved in all patients. The mean ± SD follow-up was 31.6 ± 11.9 months. The mean ± SD arc of flexion–extension was 110.3° ± 26.3° and arc of forearm rotation was 139.5° ± 17.1°. The mean ± SD MEPS was 88.1 ± 12.2 points, with results classified as excellent in eight elbows, good in ten, and fair in four. Six patients had radiographic signs of post-traumatic arthritis. Three patients required secondary surgeries.

Conclusion

Combined surgical approaches can be considered for the treatment of terrible triad injuries in association with anteromedial coronoid fractures.

Ultralow-Dose CT (REDUCTION Protocol) for Extremity Fracture Evaluation Is as Safe and Effective as Conventional CT: An Evaluation of Quality Outcomes

OBJECTIVES

To assess clinical and hospital quality outcomes of patients receiving the previously reported Reduced Effective Dose Using Computed Tomography In Orthopaedic Injury (REDUCTION) imaging protocol.

DESIGN

Retrospective Chart review.

SETTING

Level I Trauma Center and affiliated Tertiary Care Hospital Center.

PATIENTS/PARTICIPANTS

Fifty patients who received this protocol for acute traumatic fracture evaluation and met the inclusion criteria were compared with a cohort of 50 patients matched for age and fracture type who previously received conventional CT scanning for acute traumatic fracture evaluation.

INTERVENTION

Reduced Effective Dose Using Computed Tomography In Orthopaedic Injury (REDUCTION) protocol for diagnostic fracture evaluation.

MAIN OUTCOME MEASURES

Estimated effective radiation doses were calculated and compared using Digital Imaging and Communications in Medicine (DICOM) information from all included studies. Patient outcomes between groups were compared with time to fracture union as the primary outcome. Secondary outcome measures included the presence of complication defined as infection, malunion, nonunion, failure of nonoperative treatment, painful implants, and implant failure. Other secondary quality outcomes that were recorded included readmission within 30 days and hospital length of stay. Functional quality measures included joint range of motion. Statistical analyses were conducted to identify significant differences between cohorts (significance designated as P < 0.05).

RESULTS

Patient characteristics between cohorts were not significantly different with respect to age, sex, body mass index, comorbidities, injury mechanism, or injury location. Fractures of the elbow, hip, knee, and foot/ankle were evaluated. Mean clinical follow-up was 9.5 ± 4.9 months for the REDUCTION cohort and 12.4 ± 5.3 months for the conventional CT cohort. Mean estimated effective dose for all REDUCTION scans was 0.15 milliSieverts (mSv) as compared to 1.50 mSv for the conventional CT cohort (P = 0.037). Preoperative diagnosis was confirmed intraoperatively in 49/50 cases in the REDUCTION cohort compared with 48/50 cases in the conventional CT cohort (P = 0.79). Outcomes including time to union, range of motion, complications, readmission, treatment failure, reoperation, and length of stay were not significantly different between groups.

CONCLUSIONS

The REDUCTION protocol represents ultralow-dose CT developed for minimizing radiation exposure to patients presenting with traumatic fractures. This protocol resulted in a 10-fold reduction in radiation exposure. No difference in clinical or hospital quality outcomes was detected between patients who received this protocol as compared to those receiving automated dose CT. The REDUCTION protocol is a safe and effective method of performing CT for extremity fractures with significantly reduced radiation risk.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Ulnohumeral dislocation despite intact radiocapitellar joint: a rare Monteggia variant

We treated one patient with a mid-diaphyseal radius fracture and concomitant anteromedial facet fracture of the coronoid. The ulnohumeral joint was severely unstable by complete ligament detachment and interosseous membrane rupture. Despite this gross instability, the radiocapitellar was congruent and stable. The possible mechanism of radiocapitellar stability is discussed and the concept of concavity-compression stability across the radiocapitellar joint is emphasized.

Tibial Plateau Fracture Characteristics: Reliability and Diagnostic Accuracy

OBJECTIVES

The purpose of this study was to assess the interobserver reliability and diagnostic accuracy for 2-dimensional (2D) and 3-dimensional (3D) computed tomography (CT)-based evaluation of tibial plateau fracture characteristics. We hypothesized that recognition of specific tibial plateau fracture characteristics is equally reliable and accurate in 2DCT and 2D- and 3DCT.

METHODS

Eighty-one orthopedic trauma surgeons and residents were randomized to either 2DCT or 2D- and 3DCT evaluation of 15 complex tibial plateau fractures using web-based platforms to recognize 4 tibial plateau fracture characteristics: (1) a posteromedial component, (2) a lateral component, (3) a tibial tubercle component, and (4) a tibial spine (central) component. Interobserver reliability was evaluated by Siegel and Castellan's multirater kappa measure and kappa values were interpreted according to the categorical rating by Landis and Koch. Diagnostic accuracy was calculated according to standard formulas.

RESULTS

Interobserver reliability of tibial plateau fracture characteristics ranged from "fair" to "substantial". The addition of 3DCT reconstructions did not improve agreement between observers or diagnostic accuracy, because kappa values and diagnostic accuracy were significantly better for evaluation of tibial plateau fractures using 2DCT alone. Diagnostic accuracy of fracture characteristics ranged from 70% to 89% and was better for more frequently encountered components (ie, the posteromedial and lateral component).

CONCLUSIONS

The recognition of tibial plateau fracture characteristics prove accurate and reliable on CT-based evaluation in this study and may be useful besides current classification systems, which do not account for all fracture components, in daily practice to help clinical decision making. Further research is needed to evaluate whether the use of distinct fracture components helps preoperative planning of surgical approach and specific fixation techniques.

Tibial Plateau Fracture Characteristics: Computed Tomography Mapping of Lateral, Medial, and Bicondylar Fractures

BACKGROUND

Computed tomography (CT) is seen as a useful diagnostic modality in preoperative planning for tibial plateau fractures. The purpose of this study was to characterize patterns of tibial plateau fractures with use of CT mapping. We hypothesized that CT mapping of fractures of the tibial plateau would reveal recurrent patterns of fragments and fracture lines, including patterns that do not fit into Schatzker's original classification.

METHODS

One hundred and twenty-seven tibial plateau fractures were retrospectively included in this study. Fracture lines and zones of comminution were graphically superimposed onto an axial template of an intact subarticular tibial plateau to identify major patterns of fracture and comminution. This fracture map of the tibial plateau was subsequently divided into lateral (Schatzker types I, II, and III), medial (Schatzker type IV), and bicondylar (Schatzker types V and VI) fracture maps.

RESULTS

This study included seventy-three female and fifty-four male patients (average age, forty-seven years [range, seventeen to ninety-one years]) with a tibial plateau fracture. Sixty-four of the fractures were Schatzker type I, II, or III; fifteen were Schatzker type IV; and forty-eight were Schatzker type V or VI. Analysis of the fracture maps suggested patterns in the Schatzker type-IV, V, and VI fractures beyond those described in Schatzker's original classification. The maps of the 127 fractures revealed four recurrent major fracture features: the lateral split fragment (A), found in 75%; the posteromedial fragment (B), seen in 43%; the tibial tubercle fragment (C), seen in 16%; and a zone of comminution that included the tibial spine and frequently extended to the lateral condyle (D), seen in 28%.

CONCLUSIONS

Tibial plateau fracture maps show recurrent patterns of fracture lines, revealing four major fracture characteristics. An understanding of these recurrent features of tibial plateau fractures can aid surgeons during diagnosis, preoperative planning, and execution of surgical strategies.

Utility of three-dimensional computed tomography for the surgical management of rib fractures

BACKGROUND

Surgical stabilization of flail chest is increasingly recognized as a valid approach to improve pulmonary mechanics in selected trauma patients. The use of two-dimensional (2D) computed tomography (CT) has become almost universal in the assessment of blunt chest trauma and multiple rib fractures. We hypothesized that three-dimensional (3D) CT adds valuable information to the preoperative plan for fixation of rib fractures.

METHODS

Using a retrospective cohort of 35 consecutive adult patients with flail chest requiring surgery, we evaluated the intraobserver and interobserver reliability of plain radiographs, 2D CT and 3D CT, for the identification of rib fractures and identified how often the surgical plan changed with the addition of the information provided by the 3D CT. Two fellowship-trained orthopedic trauma surgeons who regularly operate on rib fractures in their clinical practice and were not involved in the treatment of the study population evaluated the radiographic data.

RESULTS

Intraobserver and interobserver reliability was excellent for both 2D CT and 3D CT and was the highest for 2D CT. Overall, 2D CT had the highest diagnostic accuracy for detecting rib fractures as compared with plain radiographs and 3D CT. However, 3D CT changed the surgical tactic in 65.7% of the cases.

CONCLUSION

We conclude that 3D CT is not as accurate as 2D CT for rib fracture diagnostic purposes; it seems to be an important tool for the preoperative planning of rib fracture fixation.

LEVEL OF EVIDENCE

Diagnostic study, level II.

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

BACKGROUND

The classification systems for fractures of the proximal part of the humerus provide low interobserver and intraobserver reliability when radiographs or two-dimensional computed tomography scans are used. The purpose of this investigation was to determine whether the use of three-dimensional computed tomography scans could improve interobserver and intraobserver reliability of AO/OTA (Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association) and Neer classifications and treatment recommendations.

METHODS

Two trauma surgeons, one shoulder surgeon, two senior orthopaedic residents, and two junior orthopaedic residents reviewed the radiographs and two and three-dimensional computed tomography scans of forty fractures of the proximal part of the humerus. Each imaging modality was reviewed in isolation, and fractures were classified according to the Neer and AO/OTA classifications and treatment recommendations were provided. This process was repeated for intraobserver analysis. Interobserver agreement was calculated within and between levels of training for each classification and treatment recommendation with respect to radiographs and two and three-dimensional computed tomography scans.

RESULTS

Among attending orthopaedic surgeons and senior residents, the use of three-dimensional computed tomography did not improve agreement compared with the use of two-dimensional computed tomography for the Neer classification based on planes, the AO/OTA classification, or the treatment recommendation, but it did improve agreement among junior residents. Comparing between levels of training, three-dimensional computed tomography increased agreement only between junior residents and more experienced reviewers for the Neer classification based on planes and for the AO/OTA classification but not for the treatment recommendation. Intraobserver agreement for each reviewer for classification and treatment ranged from slight to fair and was not improved through the use of three-dimensional computed tomography.

CONCLUSIONS

In this investigation, the use of three-dimensional computed tomography imaging did not offer improved interobserver and intraobserver agreement compared with the use of two-dimensional computed tomography imaging with regard to classification and treatment of fractures of the proximal part of the humerus, except among reviewers with limited clinical experience.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Biomechanical testing of a novel osteosynthesis plate for the ulnar coronoid process

BACKGROUND

The present study aimed to biomechanically evaluate a novel locking plate intended for osteosynthesis of coronoid fracture compared to mini L-plates and cannulated screws.

METHODS

Biomechanical tests were performed on a fracture model in synthetic bones. Three groups, each with eight implant-bone-constructs, were analyzed in quasi-static and dynamic tests. Finally, samples were tested destructively for maximum strength.

RESULTS

The mean (SD) highest stiffness was measured for the novel plate [693 (18) N/mm], followed by the mini L-plate [646 (37) N/mm] and the cannulated screws [249 (113) N/mm]. During the cycling testing of the novel plate and the mini L-plate, no failures occurred, although three of the eight samples of cannulated screws failed during the test. The mean (SD) maximum strength during the destructive testing was 1333 (234) N for the novel plate, 1338 (227) N for the mini-L-plate and 459 (56) N for the cannulated screws. No statistical differences were found during the destructive testing between the two plates (p = 0.999), although statistical differences were found between both plates and the cannulated screws (p = 0.000 each).

CONCLUSIONS

Osteosynthesis of the coronoid process using the novel plate is mechanically similar to the mini L-plate. Both plates were superior to osteosynthesis with cannulated screws.

The Roles of Mechanical Stresses in the Pathogenesis of Osteoarthritis: Implications for Treatment of Joint Injuries

Excessive joint surface loadings, either single (acute impact event) or repetitive (cumulative contact stress), can cause the clinical syndrome of osteoarthritis (OA). Despite advances in treatment of injured joints, the risk of OA following joint injuries has not decreased in the last 50 years. Cumulative excessive articular surface contact stress that leads to OA results from post-traumatic joint incongruity and instability, and joint dysplasia, but also may cause OA in patients without known joint abnormalities. In vitro investigations show that excessive articular cartilage loading triggers release of reactive oxygen species (ROS) from mitochondria, and that these ROS cause chondrocyte death and matrix degradation. Preventing release of ROS or inhibiting their effects preserves chondrocytes and their matrix. Fibronectin fragments released from articular cartilage subjected to excessive loads also stimulate matrix degradation; inhibition of molecular pathways initiated by these fragments prevents this effect. Additionally, injured chondrocytes release alarmins that activate chondroprogentior cells in vitro that propogate and migrate to regions of damaged cartilage. These cells also release chemokines and cytokines that may contribute to inflammation that causes progressive cartilage loss. Distraction and motion of osteoarthritic human ankles can promote joint remodeling, decrease pain and improve joint function in patients with end-stage post-traumatic OA. These advances in understanding of how altering mechanical stresses can lead to remodeling of osteoarthritic joints and how excessive stress causes loss of articular cartilage, including identification of mechanically induced mediators of cartilage loss, provide the basis for new biologic and mechanical approaches to the prevention and treatment of OA.

Effect of three-dimensional computed tomography reconstructions on reliability

BACKGROUND

This study evaluated the impact of three-dimensional (3D) volume-rendering computed tomography (CT) reconstructions on the inter- and intraobserver reliability of six commonly used classification systems in the assessment of calcaneal fractures.

METHODS

Four independent observers with different levels of clinical training evaluated 64 fractures according to the classifications of the Orthopaedic Trauma Association (OTA), Essex-Lopresti, Sanders, Crosby, Zwipp, and Regazzoni, using two-dimensional (2D) CT scans with multiplanar reconstructions and 3D volume-rendering reconstructions.

RESULTS

Interobserver reliability was moderate for the OTA, Essex-Lopresti, Sanders, Crosby, and Regazzoni classifications with 2D CT scans and 3D CT reconstructions. The Zwipp classification was poor with 2D CT scans and improved to moderate with 3D reconstructions. Intraobserver reliability with 2D CT scans was good for the Essex-Lopresti classification and moderate for the OTA, Sanders, Crosby, Zwipp, and Regazzoni classifications. After the addition of 3D reconstructions, all classifications showed moderate intraobserver reliability.

CONCLUSION

According to the findings of this study, the additional use of 3D reconstructions is of minor value when used in conjunction with the classifications of the OTA, Sanders, Crosby, Regazzoni, and Essex-Lopresti. If calcaneal fractures are assessed with the Zwipp classification, 3D reconstructions could be used to achieve comparable reproducibility compared to other classifications.

CLINICAL RELEVANCE

3D reconstructions may have other benefits not evaluated in the presented study and may give useful information not captured by current classification systems.

Distal humeral fractures in adults

Distal humeral fractures in adults are relatively uncommon injuries that require operative intervention in the majority of cases. Dual plate fixation, with placement of a separate strong plate on each column and orientation of the plates either at 90° or 180° to each other, is indicated for all adult fractures involving both columns of the distal part of the humerus. Acute total elbow arthroplasty is the preferred treatment for elderly patients with a displaced, comminuted, intra-articular distal humeral fracture that is not amenable to stable internal fixation. Displaced coronal shear fractures of the distal humeral articular surface require operative fixation, most typically via a lateral approach.

Agreement between Initial Classification and Subsequent Reclassification of Fractures of the Distal Radius in a Prospective Cohort Study

We tested the hypothesis that the original surgeon-investigator classification of a fracture of the distal radius in a prospective cohort study would have moderate agreement with the final classification by the team performing final analysis of the data. The initial post-injury radiographs of 621 patients with distal radius fractures from a multicenter international prospective cohort study were classified according to the Comprehensive Classification of Fractures, first by the treating surgeon-investigator and then by a research team analyzing the data. Correspondence between original and revised classification was evaluated using the Kappa statistic at the type, group and subgroup levels. The agreement between initial and revised classifications decreased from Type (moderate; Κ(type) = 0.60), to Group (moderate; Κ(group) = 0.41), to Subgroup (fair; Κ(subgroup) = 0.33) classifications (all p < 0.05). There was only moderate agreement in the classification of fractures of the distal radius between surgeon-investigators and final evaluators in a prospective multicenter cohort study. Such variations might influence interpretation and comparability of the data. The lack of a reference standard for classification complicates efforts to lessen variability and improve consensus.

A minimally invasive anterior approach to reduction and screw fixation of coronoid fractures

We investigated a minimally invasive anterior approach to reduce and fix coronoid fractures with a screw in eight consecutive patients and evaluated seven patients at a minimum of 1 year (mean, 78 weeks; range, 61-89 weeks). It was only possible to repair seven of eight coronoid fractures. The average time to radiographic healing was 12 weeks and all healed without the screw loosening, migration or breakage. Endoscopy permitted an excellent view of coronoid fractures, allowing anatomic fixation, and as it avoided extensive soft tissue dissection, this method preserved soft tissue attachments of small coronoid fragments. This method was safe and minimally invasive.

The impact of stereo-visualisation of three-dimensional CT datasets on the inter- and intraobserver reliability of the AO/OTA and Neer classifications in the assessment of fractures of the proximal humerus

We evaluated the impact of stereo-visualisation of three-dimensional volume-rendering CT datasets on the inter- and intraobserver reliability assessed by kappa values on the AO/OTA and Neer classifications in the assessment of proximal humeral fractures. Four independent observers classified 40 fractures according to the AO/OTA and Neer classifications using plain radiographs, two-dimensional CT scans and with stereo-visualised three-dimensional volume-rendering reconstructions. Both classification systems showed moderate interobserver reliability with plain radiographs and two-dimensional CT scans. Three-dimensional volume-rendered CT scans improved the interobserver reliability of both systems to good. Intraobserver reliability was moderate for both classifications when assessed by plain radiographs. Stereo visualisation of three-dimensional volume rendering improved intraobserver reliability to good for the AO/OTA method and to excellent for the Neer classification. These data support our opinion that stereo visualisation of three-dimensional volume-rendering datasets is of value when analysing and classifying complex fractures of the proximal humerus.

Coronoid fixation using suture anchors

Fractures of the coronoid process of the ulna generally occur in relatively high-energy injuries and are commonly associated with injuries to other structures around the elbow. Damage to the coronoid process in addition to other elbow structures may complicate treatment. Several approaches have been used in the management of coronoid process fractures. This paper reports a method of coronoid process fracture fixation using suture anchors.