Tibial Plateau Fracture Characteristics: Reliability and Diagnostic Accuracy

CT scan-based 3D fracture mapping in civilian gunshot intracapsular fractures of the femur neck

INTRODUCTION

Displaced intracapsular neck of femur (NOF) fractures secondary to civilian gunshots are rare injuries with universally poor outcomes following surgical fixation. No studies have been published on fracture mapping in NOF fractures secondary to civilian gunshots.

OBJECTIVES

We performed CT scan-based fracture mapping to identify the most common fracture patterns in these injuries.

METHODS

Design: Retrospective search of prospectively collected data.

SETTING

Single Level 1 Trauma hospital. Patient selection criteria: All patients presenting with gunshot fractures to the femur neck between 01 January 2009 and 31 December 2022 were identified. Once identified from Picture Archiving and Communication System (PACS), computed tomography (CT) scans in Digital Imaging and Communication in Medicine (DICOM) format were imported into Mimics 16 software and fracture fragments were segmented and three-dimensional (3D) reconstruction was generated. The reduced fractures were exported to 3-Matic software to merge the fragments and adjust the orientation in three planes. An uninjured femur model was used as a template for reduction. Fracture lines and heat maps were then generated. Our outcome measures were successful mapping of the identified fracture lines.

RESULTS

A total of 25 intracapsular femur neck fractures were identified and suitable for CT scan mapping. All patients were male with an average age of 22 (range 18-32). Once generated, fracture maps were used to show the location, distribution and frequency of the fracture lines. In all but two cases the fracture line propagation remained within the confines of the hip joint capsule. In three cases there was fracture extension into the superior aspect of the femur head, and in one case extension into the inferior aspect.

CONCLUSION

This is the first study to perform 3D fracture mapping for intracapsular femur neck fractures secondary to civilian gunshot injuries. The exercise has helped us better understand the commonest fracture patterns and assisted us with surgical planning and execution.

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.

Extension of the Medial Approach to the Tibial Plateau via an Osteotomy of the Tibial Insertion of the Superficial Medial Collateral Ligament

The treatment of medial tibial plateau fractures can be challenging due to poor exposure of the articular surface. Therefore, a medial epicondyle osteotomy may be needed. Current methods describe osteotomy of the medial femoral epicondyle. However, this method requires additional detachment of the medial meniscus in order to ensure proper visualization. The aim of this study is to present a new technique using distal osteotomy of the superficial medial collateral ligament and to analyze the area of the exposed articular surface area. On each of eight fresh-frozen human cadaveric knees (mean age: 79.4 ± 9.4 years), an osteotomy and proximal reflection of the distal insertion of the superficial medial collateral ligament combined with a submeniscal arthrotomy was performed, followed by a medial epicondyle osteotomy. Using a three-dimensional measurement arm (Absolute Arm 8320-7, Hexagon Metrology GmbH), the exposed area was analyzed and compared to the entire medial articular surface using ANOVA (p < 0.05). Through the medial epicondyle osteotomy, 39.9 ± 9.7% of the anteromedial articular surface was seen. This area was significantly smaller compared to the osteotomy of the distal insertion of the superficial collateral ligament with an exposed articular surface of 77.2 ± 16.9% (p = 0.004). Thus, the distal osteotomy exposed 37.3% more of the articular surface compared to the medial epicondyle osteotomy. None of these techniques were able to adequately expose the posteromedial- and medial-most aspects of the tibial plateau. A distal superficial collateral ligament osteotomy may be superior to a medial epicondyle osteotomy when an extension of the anteromedial approach to the tibial plateau is required. A distal superficial medial collateral ligament osteotomy combines the advantages of better exposure of the medial articular surface with preservation of the blood supply to the medial meniscus. However, surgeons should carefully consider whether such an extended approach is necessary, as it significantly increases invasiveness.

The influence of pre-operative Computed Tomography (CT) on surgical approach and fixation for fractures of the tibial plateau

Background

It is well known that a computed tomography (CT) scan improves the classification of tibial plateau fractures (TPF) compared with radiographs. However, it is less clear how this translates into clinical practice. The aim of this study is to establish to what extent a pre-operative CT scan alters the approach, setup and fixation choice in TPF compared to radiographs.

Methods

50 consecutive TPF with a preoperative CT and radiographic imaging available, were assessed by 4 consultant surgeons. First, anonymised radiographs were classifying according to the column classification and the planned setup, approach, and fixation technique documented. At a 1-month interval, randomised matched CT scans were assessed and the same data collected. A tibial plateau disruption score (TPDS) was derived for all 4 quadrants (no injury = 0, split = 1, split/depression = 2 and depression = 3). Radiograph and CT TPDS were assessed using an unpaired T-test.

Results

26 female and 24 male patients, mean age 50.3, were included. Mean TPDS on radiographs and CT scans were 2.77 and 3.17 respectively. A significantly higher CT TPDS, of 0.4 (95%CI 0.10-0.71)[P = 0.0093] was observed, demonstrating that radiographs underestimate the extent of injury. The surgical approach changed in 28.5% of cases, thus influencing a change in the patient setup in theatre in 27% of cases. Identification of fractures within a column changed in 34% of cases. A high intra-observer reliability was observed when surgeons were asked to repeat their assessment in a third round at a further one month interval.

Conclusion

A pre-operative CT scan has a significant effect on the approach required to fix TPF. This therefore influences the setup of the patient and can justifiably be requested as part of pre-operative planning.

Imposter Syndrome Among Surgeons Is Associated With Intolerance of Uncertainty and Lower Confidence in Problem Solving

BACKGROUND

Feelings of imposter syndrome (inadequacy or incompetence) are common among physicians and are associated with diminished joy in practice. Identification of modifiable factors associated with feelings of imposter syndrome might inform strategies to ameliorate them. To this point, though, no such factors have been identified.

QUESTION/PURPOSE

Are intolerance of uncertainty and confidence in problem-solving skills independently associated with feelings of imposter syndrome after accounting for other factors?

METHODS

This survey-based experiment measured the relationship between feelings of imposter syndrome, intolerance of uncertainty, and confidence in problem-solving skills among musculoskeletal specialist surgeons. Approximately 200 surgeons who actively participate in the Science of Variation Group, a collaboration of mainly orthopaedic surgeons specializing in upper extremity illnesses primarily across Europe and North America, were invited to this survey-based experiment. One hundred two surgeons completed questionnaires measuring feelings of imposter syndrome (an adaptation of the Clance Imposter Phenomenon Scale), tolerance of uncertainty (the Intolerance of Uncertainty Scale-12), and confidence in problem-solving skills (the Personal Optimism and Self-Efficacy Optimism questionnaire), as well as basic demographics. The participants were characteristic of other Science of Variation Group experiments: the mean age was 52 ± 5 years, with 89% (91 of 102) being men, most self-reported White race (81% [83 of 102]), largely subspecializing in hand and/or wrist surgery (73% [74 of 102]), and with just over half of the group (54% [55 of 102]) having greater than 11 years of experience. We sought to identify factors associated with greater feelings of imposter syndrome in a multivariable statistical model.

RESULTS

Accounting for potential confounding factors such as years of experience or supervision of trainees in the multivariable linear regression analysis, greater feelings of imposter syndrome were modestly associated with higher intolerance of uncertainty (regression coefficient [β] 0.34 [95% confidence interval (CI) 0.16 to 0.51]; p < 0.01) and with lower confidence in problem-solving skills (β -0.70 [95% CI -1.0 to -0.35]; p < 0.01).

CONCLUSION

The finding that feelings of imposter syndrome may be modestly to notably associated with modifiable factors, such as difficulty managing uncertainty and lack of confidence in problem-solving, spark coaching opportunities to support and sustain a surgeon's mindset, which may lead to increased comfort and joy at work.

CLINICAL RELEVANCE

Beginning with premedical coursework and throughout medical training and continuing medical education, future studies can address the impact of learning and practicing tactics that increase comfort with uncertainty and greater confidence in problem solving on limiting feelings of imposter syndrome.

Development and external validation of automated detection, classification, and localization of ankle fractures: inside the black box of a convolutional neural network (CNN)

Purpose

Convolutional neural networks (CNNs) are increasingly being developed for automated fracture detection in orthopaedic trauma surgery. Studies to date, however, are limited to providing classification based on the entire image—and only produce heatmaps for approximate fracture localization instead of delineating exact fracture morphology. Therefore, we aimed to answer (1) what is the performance of a CNN that detects, classifies, localizes, and segments an ankle fracture, and (2) would this be externally valid?

Methods

The training set included 326 isolated fibula fractures and 423 non-fracture radiographs. The Detectron2 implementation of the Mask R-CNN was trained with labelled and annotated radiographs. The internal validation (or ‘test set’) and external validation sets consisted of 300 and 334 radiographs, respectively. Consensus agreement between three experienced fellowship-trained trauma surgeons was defined as the ground truth label. Diagnostic accuracy and area under the receiver operator characteristic curve (AUC) were used to assess classification performance. The Intersection over Union (IoU) was used to quantify accuracy of the segmentation predictions by the CNN, where a value of 0.5 is generally considered an adequate segmentation.

Results

The final CNN was able to classify fibula fractures according to four classes (Danis-Weber A, B, C and No Fracture) with AUC values ranging from 0.93 to 0.99. Diagnostic accuracy was 89% on the test set with average sensitivity of 89% and specificity of 96%. External validity was 89–90% accurate on a set of radiographs from a different hospital. Accuracies/AUCs observed were 100/0.99 for the ‘No Fracture’ class, 92/0.99 for ‘Weber B’, 88/0.93 for ‘Weber C’, and 76/0.97 for ‘Weber A’. For the fracture bounding box prediction by the CNN, a mean IoU of 0.65 (SD ± 0.16) was observed. The fracture segmentation predictions by the CNN resulted in a mean IoU of 0.47 (SD ± 0.17).

Conclusions

This study presents a look into the ‘black box’ of CNNs and represents the first automated delineation (segmentation) of fracture lines on (ankle) radiographs. The AUC values presented in this paper indicate good discriminatory capability of the CNN and substantiate further study of CNNs in detecting and classifying ankle fractures.

Level of evidence

II, Diagnostic imaging study.

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.

A lateral fracture step-off of 2mm increases intra-articular pressure following tibial plateau fracture

INTRODUCTION

The aim of this study was to evaluate the effects of increasing posttraumatic step-offs after lateral tibial plateau fracture reduction on the intra-articular pressure.

MATERIALS AND METHODS

In eight fresh-frozen human cadaveric knees with intact menisci, a standardized sagittal osteotomy of the lateral tibial condyle was performed as an OTA/AO type 41-B1 fracture-model. The fragment was fixed by a customized sled including an angular stable tibia plate to evaluate step-offs from 0 mm to 8 mm in 1mm increments. In a servo-hydraulic testing machine, an axial force was applied to the tibial plateau in 0° (700N), 15° (700N), 30° (700N), 60° (350N), and 90 ° (350N) of flexion while the joint pressure was recorded by two pressure sensors.

RESULTS

A 1mm step-off did not result in an increased joint pressure. At 60° of flexion a 2mm step-off increased the lateral joint pressure by 61.84kPa (P = 0.0027). In 30° of flexion, a 3mm step raised the lateral joint pressure by 66.80kPa (p = 0.0017), whereas in 0°, 15° and 90° of flexion, a 4mm step increased the pressure by >50kPa (P < 0.05). Concomitant medial joint pressure increments were lower than those in the lateral plateau. A significant increase of 19-24kPa in the medial joint pressure was detected in 90° of flexion with a 1mm lateral step (P = 0.0075), in 15° and 60° of flexion with a 2mm step (P < 0.05), in 0° of flexion with a 4mm step (P = 0.0215) and in 30° of flexion with a 7mm step (P = 0.0487).

CONCLUSION

Lateral fracture step-offs of 2mm or larger should be reduced intraoperatively to avoid large increases in lateral joint pressure.

Proximal tibia fracture dislocations: Management and outcomes of a severe and under-recognized injury

INTRODUCTION

Proximal tibia fracture dislocations (PTFDs) are a subset of plateau fractures with little in the literature since description by Hohl (1967) and classification by Moore (1981). We sought to evaluate reliability in diagnosis of fracture-dislocations by traumatologists and to compare their outcomes with bicondylar tibial plateau fractures (BTPFs).

METHODS

This was a retrospective cohort study at 14 level 1 trauma centers throughout North America. In all, 4771 proximal tibia fractures were reviewed by all sites and 278 possible PTFDs were identified using the Moore classification. These were reviewed by an adjudication board of three traumatologists to obtain consensus. Outcomes included inter-rater reliability of PTFD diagnosis, wound complications, malunion, range of motion (ROM), and knee pain limiting function. These were compared to BTPF data from a previous study.

RESULTS

Of 278 submitted cases, 187 were deemed PTFDs representing 4% of all proximal tibia fractures reviewed and 67% of those submitted. Inter-rater agreement by the adjudication board was good (83%). Sixty-one PTFDs (33%) were unicondylar. Eleven (6%) had ligamentous repair and 72 (39%) had meniscal repair. Two required vascular repair. Infection was more common among PTFDs than BTPFs (14% vs 9%, p = 0.038). Malunion occurred in 25% of PTFDs. ROM was worse among PTFDs, although likely not clinically significant. Knee pain limited function at final follow-up in 24% of both cohorts.

CONCLUSIONS

PTFDs represent 4% of proximal tibia fractures. They are often unicondylar and may go unrecognized. Malunion is common, and PTFD outcomes may be worse than bicondylar fractures.

Clinical and radiographic results after arthroscopic repair of lateral meniscus tear in lateral-depression tibial plateau fracture

INTRODUCTION

To evaluate the clinical and radiographic results of AR/IF and meniscus repair for treating lateral meniscus (LM) tears associated with lateral tibial plateau fractures and to identify the factors associated with LM tear.

MATERIALS AND METHODS

Forty-two patients with lateral plateau fractures (Schatzker types II and III) treated by AR/IF were included retrospectively. Radiographic evaluations using the Rasmussen system and computerized tomography (CT) were performed. Clinical evaluations were also conducted at final follow-up. Second-look arthroscopy was applied during metal removal.

RESULTS

All fractures were healed after 46.3 months of follow-up. The mean Tegner activity level was not decreased significantly, going from 7.1 ± 2.1 pre-injury to 6.6 ± 2.3 at final follow-up (p = 0.301). However, the amount of depression noted on CT imaging was significantly decreased from 8.9 mm ± 4.4 to 1.2 mm ± 1.3 (p = 0.000). The mean Rasmussen radiologic score at final follow-up was 14.5 ± 5.3 points. Osteoarthritis was progressed in six patients (14.3%). Twenty-five patients had concomitant LM tear, with 18 cases treated by repair and the remaining ones treated by partial meniscectomy. Preoperative joint depression (> 11 mm) was significantly associated with the risk of LM tear (p = 0.024; odds ratio (OR): 9.0, 95% confidence interval (CI): 1.018-79.545) and most of those lesions could be repaired (p = 0.001). Postoperatively, 16 repaired patients were evaluated by second-look arthroscopy; 15 had healed completely and one had healed partially.

CONCLUSION

LM tears are frequently combined with lateral tibial plateau fracture, especially in correlation with more than 11 mm of joint depression, though most of those lesions can be repaired at the time of fracture fixation. AR/IF with arthroscopic meniscus repair could achieve good clinical and radiographic outcomes when treating Schatzker types II and III tibial plateau fractures.

STUDY DESIGN

Level IV retrospective cohort study.

3D modelling of tibial plateau fractures: Variability in fracture location and characteristics across Schatzker fracture types

INTRODUCTION

Numerous classifications have been developed to assess tibial plateau fractures (TPF). Of these, the Schatzker system is the most widely reported in the literature yet this system is limited in its characterisation of morphological fracture features underlying the fracture location. The purpose of this study was to compare 3D morphological features of TPFs across different Schatzker types.

METHODS

This study retrospectively analysed preoperative TPF imaging data to reconstruct 3D models of the fractures. Ninety-one fractures (29 female, 62 male) were analysed and classified using Schatzker. Fracture location across Schatzker types was compared based on division of the articular surface into six 'zones'. Additionally, morphological characteristics of the fractures were compared based on fracture type, including; the number, volume and shape of the fragments.

RESULTS

Schatzker II, IV and VI fractures were most common, making up 41%, 16% and 20%, respectively. Type II fractures commonly involved both the lateral and central aspect of the tibial plateau, similarly, type IV fractures incorporated the lateral condyle in most cases. Considering the morphological metrics, statistically significant differences were observed between Schatzker types for the number of; total, articular, cortical and volumetrically significant (all P < 0.001) fragments along with the volume of both primary (P < 0.001) and secondary (P = 0.02) fragments.

DISCUSSION

Assessment of underlying fracture characteristics in addition to fracture location can serve to provide greater detail relating to fracture morphology, which has the potential to assist with both surgical decision making and assessment of postoperative outcomes. Incorporating this information as part of a hierarchical or multifactorial framework for classifying fractures may help distinguish subtle differences between fracture types that are classifiable using the most current systems.

Evaluation of Sanders Type 2 Joint Depression Calcaneal Fractures in 197 Patients from a Single Center Using Three-Dimensional Mapping

BACKGROUND This study aimed to evaluate Sanders type 2 calcaneal fractures in 197 patients from a single center using the 3D (three-dimensional) CT (computed tomography) mapping method. MATERIAL AND METHODS A consecutive series of 197 Sanders type 2 joint depression calcaneal fractures was used. The segment and split functions were used to create each calcaneal fragment using Mimics Research 20.0 software. The fracture fragments were reduced in 3-matic Research 12.0 software. In the E-3D Medical 18.01 software, after superimposing the fractured calcaneus entity with the calcaneus template, we drew the fracture line on the template. Finally, the heatmap was obtained by fracture statistical analysis function. Simultaneously, the distribution of the fracture lines in the anterior part of the calcaneus (APC) and middle talar joint was recorded. RESULTS There were 109 cases of Sanders type 2A, 46 cases of Sanders type 2B, and 42 cases of Sanders type 2C. Based on the data, we drew the characteristic fracture map of type 2A 2B and 2C. This study found that the most common types of Sanders type 2A in APC and middle talar articular surface are type AC and type AD. In Sanders type 2B, the most common type is type AC, and in Sanders type 2C it is type ACD. CONCLUSIONS The findings from this study showed that 3D CT imaging and reconstruction of the calcaneus was a useful diagnostic method to evaluate and classify joint depression calcaneal fractures. The calcaneal fracture map can be used to guide surgical planning and optimize the design of internal fixation.

Medial sided articular impaction in tibial plateau fractures

INTRODUCTION

Tibial plateau fractures are a heterogenous group of injuries with a variable amount of articular injury and are commonly associated with lateral sided articular impaction. Previous work has focused on describing the morphology of tibial plateau fractures, but has neglected description of medial sided articular impaction. The aim of this investigation was to assess the morphology of medial sided articular impaction in tibial plateau fractures, with specific attention directed toward the frequency, location, size, and associated fracture patterns.

METHODS

Skeletally mature patients presenting to a Level I trauma center from 2008-2018 with a tibial plateau fracture (AO/OTA 41B-C) were identified retrospectively. Fractures were classified by AO/OTA and Schatzker type. Radiographs and computed tomography (CT) scans were reviewed to identify and localize medial sided articular impaction. The location and surface area of impaction was characterized by creating frequency diagram heat maps from axial CT scans. Descriptive statistics were performed using standard measures.

RESULTS

Of the 1032 tibial plateau fractures included, 82 (7.9%) were noted to have medial sided articular impaction. Rate of impaction varied by fracture type (p = 0.03): Schatzker II, 2% (7 of 381); Schatzker IV, 21% (19 of 96); and Schatzker VI, 11% (56 of 524). Average total surface area of impaction was 9% of the total and 19% of the medial plateau area. Area of impaction varied by fracture type (p = 0.004): Schatzker II, 6% (95% confidence interval [CI], 4%-7%); Schatzker IV, 11% (95% CI, 9%-13%), and Schatzker VI, 9% (95% CI, 7%-11%). The area of impaction occurred primarily along the lateral aspect of the medial plateau in Schatzker II fractures, in the anteromedial quadrant of Schatzker IV fractures, and was evenly distributed across the medial plateau in Schatzker VI fractures.

CONCLUSIONS

Surgeons should be aware that medial articular impaction is present in approximately 8% of tibial plateau fractures. Schatzker IV fractures are most likely to have medial impaction and a larger proportion of the joint surface involved in these injuries.

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.

The effect of coronal splits on the structural stability of bi-condylar tibial plateau fractures: a biomechanical investigation

INTRODUCTION

Surgical treatment of bi-condylar tibial plateau fractures is still challenging due to the complexity of the fracture and the difficult surgical approach. Coronal fracture lines are associated with a high risk of fixation failure. However, previous biomechanical studies and fracture classifications have disregarded coronal fracture lines.

MATERIALS AND METHODS

This study aimed to develop a clinically relevant fracture model (Fracture C) and compare its mechanical behavior with the traditional Horwitz model (Fracture H). Twelve samples of fourth-generation tibia Sawbones were utilized to realize two fracture models with (Fracture C) or without (Fracture H) a coronal fracture line and both fixed with lateral locking plates. Loading of the tibial plateau was introduced through artificial femur condyles to cyclically load the fracture constructs until failure. Stiffness, fracture gap movements, failure loads as well as relative displacements and rotations of fracture fragments were measured.

RESULTS

The presence of a coronal fracture line reduced fracture construct stiffness by 43% (p = 0.013) and decreased the failure load by 38% from 593 ± 159 to 368 ± 63 N (p = 0.016). Largest displacements were observed at the medial aspect between the tibial plateau and the tibial shaft in the longitudinal direction. Again, the presence of the coronal fracture line reduced the stability of the fragments and created increased joint incongruities.

CONCLUSIONS

Coronal articular fracture lines substantially affect the mechanical response of tibia implant structures specifically on the medial side. With this in mind, utilizing a clinically relevant fracture model for biomechanical evaluations regarding bi-condylar tibial plateau fractures is strongly recommended.

Quantitative 3D measurements of tibial plateau fractures

Fracture gap and step-off measurements on 2DCT-slices probably underestimate the complex multi-directional features of tibial plateau fractures. Our aim was to develop a quantitative 3D-CT (Q3DCT) fracture analysis of these injuries. CT-based 3D models were created for 10 patients with a tibial plateau fracture. Several 3D measures (gap area, articular surface involvement, 3D displacement) were developed and tested. Gaps and step-offs were measured in 2D and 3D. All measurements were repeated by six observers and the reproducibility was determined by intra-class correlation coefficients. Q3DCT measurements demonstrated a median gap of 5.3 mm, step-off of 5.2 mm, gap area of 235 mm², articular surface involvement of 33% and 3D displacement of 6.1 mm. The inter-rater reliability was higher in the Q3DCT than in the 2DCT measurements for both the gap (0.96 vs. 0.81) and step-off (0.63 vs. 0.32). Q3DCT measurements showed excellent reliability (ICC of 0.94 for gap area, 1 for articular surface involvement and 0.99 for 3D displacement). Q3DCT fracture analysis of tibial plateau fractures is feasible and shows excellent reliability. 3D measurements could be used together with the current classification systems to quantify the true extent of these complex multi-directional fractures in a standardized way.

Immediate arthroscopy following ORIF for tibial plateau fractures provide early diagnosis and treatment of the combined intra-articular pathologies

PURPOSE

To evaluate the effectiveness of immediate arthroscopy and clinical outcomes following open reduction and internal fixation (ORIF) of tibial plateau fractures.

METHODS

Sixty patients (36 men and 24 women, median age 56 (20-78) years) were divided into Group I (ORIF only: 26 patients, median age 58 (25-78) years) or Group II (ORIF with immediate arthroscopy: 34 patients, median age 55 (20-75) years) in tibial plateau fractures (Schatzker Type II-VI fractures). In the first part of this study, ORIF only was performed without arthroscopic treatment. In the second part, ORIF with immediate arthroscopic examination and treatment was performed. Clinical outcomes, utilizing range of motion (ROM), International Knee Documentation Committee (IKDC) score and hospital for special knee score (HSS) were assessed.

RESULTS

At the final follow-up, HSS score was 81 ± 11 points in Group I and 83 ± 9 points in Group II. The IKDC score was 85 ± 8 points in Group I and 86 ± 6 points in Group II. In Group II, concomitant intra-articular lesions in 10 patients (29%) were found and treated simultaneously. However, there were no significant differences in clinical scores or ROM between the two groups.

CONCLUSION

Immediate arthroscopy following ORIF for tibial plateau fracture is an effective procedure that provides accurate information for fracture reduction, leading to immediate treatment of concomitant intra-articular lesions without complications.

LEVEL OF EVIDENCE

III.

Preliminary application of three-dimension printing technology in surgical management of bicondylar tibial plateau fractures

OBJECTIVE

Surgical management of bicondylar tibial plateau fractures, which is frequently associate with high wound complication rates and functional impairment, remains a challenge for orthopedic surgeons. Recently, the emergence of three-dimension(3D) printing provided orthopedic surgeons with a new technology which has revolutionary impacts on surgical planning, operative guidance and custom-made implants manufacture. The aim of this study is to explore the clinical feasibility and application value of 3D printing in the surgical management of bicondylar tibial plateau fractures.

METHOD

Data of this retrospective study was collected from 11 patients suffering bicondylar tibial plateau fracture from October 2015 to August 2016. All of them underwent surgical treatment with the assistance of 3D printing technology. Real-size solid models and screw guide templates were printed for preoperative planning, surgical simulation and intraoperative guidance. Patients' Demographics, surgery duration, intraoperative blood loss, the accuracy of preoperative planning were recorded and evaluated.

RESULT

The 3D printed models successfully provided the omni-directional exhibition of the fracture morphology. Model-based surgical simulation procedures and pre-selection of implants were generally consistent with the results of actual surgeries. There were no significant differences between the length of the osteosynthesis screws and that of actual surgeries (59.43 ± 11.13 mm vs 60.14 ± 12.05 mm). Beyond that, other parameters, such as surgical duration, intraoperative blood loss and HSS scores was satisfactory according to the surgical records and follow-up.

CONCLUSIONS

According to our experience, the assistance of 3D printing technology in the surgical management of bicondylar tibial plateau fractures provides a comprehensive understanding of fracture features, an accurate patient-specific preoperative planning and an intraoperative guidance for real surgeries, thus leading to the optimization of clinical outcomes.

Articular coronal fracture angle of posteromedial tibial plateau fragments: A computed tomography fracture mapping study

OBJECTIVES

The purpose of this study is to analyze posteromedial fragment morphology using two-dimensional computed tomography fracture mapping and to compare posteromedial fragment morphology in various Schatzker type tibial plateau fractures.

MATERIALS & METHODS

One hundred twenty-seven consecutive AO/OTA B- and C-type tibial plateau fractures were retrospectively analyzed using 2DCT fracture mapping. The posteromedial articular fracture angle and articular surface areas of all fractures with posteromedial fragments were calculated. Based on biomechanical studies, posteromedial fragments with coronal fracture angles >68° were considered amenable for anterolateral stabilization with standardized plating. Kruskall-Wallis non-parametric test was used for statistical comparison of morphological features of posteromedial fragments between the various Schatzker types.

RESULTS

Forty-seven out of 127 tibial plateau fractures included a posteromedial fragment. The mean posteromedial articular fracture angle was 44° (range: 2°-90^o, standard deviation: 23°). Forty fragments (85%) had a fracture angle of <68°, increasing the risk for insufficient stabilization with standardized anterolateral plating. The mean articular surface area was 34% of the entire tibial plateau (range: 7%-53%, SD: 12%). There were no significant differences in posteromedial fragment morphology between Schatzker type IV, V, and VI fractures.

DISCUSSION AND CONCLUSION

Posteromedial fragments commonly occur not only in Schatzker type V and VI, but also in Schatzker type IV tibial plateau fractures. Eighty-five percent of tibial plateau fractures with a posteromedial fragment may benefit from non-standard customized lateral plating, or may require an additional medial or posterior surgical approach for fracture-specific fixation to optimize screw purchase and biomechanical stability.

Computed tomography of bicondylar tibial plateau fractures after distraction with a bridging external fixation

BACKGROUND

The goal of this study was to compare the inter- and intra-observer reliabilities of computed tomography (CT) scans of bicondylar tibial plateau fractures (Bi-TPFs) with or without distraction with a bridging external fixation (EF) as interpreted by inexperienced surgeons.

METHODS

Patients that underwent CT after distraction with a bridging EF were allocated to group 1 (n = 18), and patients that underwent CT before distraction with a bridging EF were allocated to group 2 (n = 18). Five observers were given plain radiographs and CT images to assess (survey 1) and this assessment was repeated six weeks later (survey 2). Agreements regarding fracture classification and pre-operative planning were evaluated using kappa coefficients. In addition, to evaluate fracture severity, we designed a severity score.

RESULTS

Inter-observer reliabilities for fracture classification and pre-operative planning were higher in group 1 than in group 2. Surveys 1 and 2 revealed similar kappa coefficients in the two study groups. The mean absolute difference (MAD) in severity scores allocated at the two surveys was significantly different between the two groups (P = 0.045). Intra-observer reliabilities of fracture classification and pre-operative planning were also higher in group 1 than in group 2. In addition, level of training was found to have a significant impact on the MAD in severity scores (P = 0.007).

CONCLUSIONS

Inter- and intra-observer reliabilities for fracture classification and pre-operative planning were better for inexperienced surgeons when CT was performed after distraction with a bridging EF for Bi-TPFs. Thus, when staged treatment using EF is selected in Bi-TPF patients, the authors suggest that CT scans be performed after distraction with a bridging EF especially for inexperienced surgeons.

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.