MR imaging of tibial plateau fractures

Incidence and Radiological Predictors of Concomitant Meniscal and Cruciate Ligament Injuries in Operative Tibial Plateau Fractures: A Prospective Diagnostic Study

The aim of this prospective study was to determine the incidence of meniscal and cruciate ligament injuries in operative tibial plateau fractures detected using knee arthroscopy, and to identify the radiological predictors observed on CT images. From January 2016 to February 2017, a total of 102 closed tibial plateau fractures were enrolled in this prospective protocol. Each patient underwent arthroscopic examination following the tibial plateau internal fixation. Univariate analysis and multivariable logistic regression were used to assess the association between imaging parameters and soft-tissue injuries. The menisci were traumatically injured in 52.9% of subjects (54 of 102) and the cruciate ligaments injured in 22.5% (23 of 102). Significantly higher injury rates for bucket-handle meniscal tears were observed in Schatzker type VI fractures (P = 0.04). Greater risk of lateral meniscus injury was observed in patients with >6.3 mm of lateral joint depression. Greater risk of ACL injury when the volumetric lateral joint depression was ≤209.5 mm2 and/or with >5.7 mm lateral joint widening. Associated meniscal and ligament injuries were commonly seen among operative tibial plateau fractures. Preoperative CT measurements might help predict a higher risk of meniscus and ACL injury, providing guidance to the surgeon to look for and to be prepared to treat such injuries.

A systematic literature review of tibial plateau fractures: What classifications are used and how reliable and useful are they?

INTRODUCTION

Classification systems such as the Schatzker and AO/OTA have been proposed for standardised assessment of tibial plateau fractures and to guide clinical decision making. However, there has been no comprehensive literature review of all classification systems for tibial plateau fractures, including assessment of their reliability. The aim of this systematic review was to identify and appraise previously established classification systems for tibial plateau fractures and determine their reliability for fracture classification.

METHODS

Six databases were searched from inception until October 2016. Classification systems for tibial plateau fractures were identified. No restriction was placed on imaging modality (plain film X-ray, CT, MRI). Data synthesis was performed to identify common features of the systems, their prevalence within the literature and studies of intra and inter-rater reliability of fracture classification using Kappa coefficient (κ).

RESULTS

Thirty-eight classification systems were identified, five of which were a sub-classification of a single fracture type from a previous tool. The Schatzker and AO/OTA classification systems were the most commonly reported. Of the tools identified only five have been tested for inter and intra-observer reliability (Schatzker, AO/OTA, Duparc, Hohl and Luo). Reliability of more simplistic classification systems, such as that by Luo et al. (three-column) was typically high (intra-κ = 0.67-0.81, inter-κ = 0.71-0.87), but with the disadvantage of providing less information on fracture patterns and morphology. Intra and inter-observer reliability using plain film X-ray was frequently moderate (κ = 0.40-0.60), with 2D and 3D CT typically improving reliability of classification. Only 11 of the 32 complete classification systems identified association of fracture classification with clinical outcome.

DISCUSSION

Frequently used systems for classification of tibial plateau fractures display moderate intra and inter-observer reliability. More sophisticated imaging modalities such as 2D and 3D CT typically improve reliability estimates. Using fracture classification based on imaging findings to predict clinical outcome was not a commonly reported goal of newly developed systems. More detailed assessment of fracture patterns and morphology, in conjunction with information on surgical fixation, may be desirable for predicting outcomes and to guide clinical decision making.

Comparison of CT and MRI in patients with tibial plateau fracture: can CT findings predict ligament tear or meniscal injury?

OBJECTIVE

(1) To determine the accuracy of computed tomography (CT) in the evaluation of ligament tear and avulsion in patients with tibial plateau fracture. (2) To evaluate whether the presence or severity of fracture gap and articular depression can predict meniscal injury.

DESIGN AND PATIENTS

A fellowship-trained musculoskeletal radiologist retrospectively reviewed knee CT and MRI examinations of 41 consecutive patients presenting to a level 1 trauma center with tibial plateau fractures. Fracture gap, articular depression, ligament tear and footprint avulsions were assessed on CT examinations. The MRI studies were examined for osseous and soft tissue injuries, including meniscal tear, meniscal displacement, ligament tear, and ligament avulsion.

RESULTS

CT demonstrated torn ligaments with 80% sensitivity and 98% specificity. Only 2% of ligaments deemed intact on careful CT evaluation had partial or complete tears on MRI. Although the degree of fracture gap and articular depression was significantly greater in patients with meniscal injury compared with those without meniscal injury, ROC analysis demonstrated no clear threshold for gap or depression that yielded a combination of high sensitivity and specificity.

CONCLUSIONS

In the acute setting, CT offers high sensitivity and specificity for depicting osseous avulsions, as well as high negative predictive value for excluding ligament injury. However, MRI remains necessary for the preoperative detection of meniscal injury.

Prediction of Soft-Tissue Injuries in Schatzker II Tibial Plateau Fractures based on Measurements of Plain Radiographs

BACKGROUND

Split-depression fractures of the lateral tibial plateau (Schatzker II) are associated with a significant risk of capsuloligamentous and meniscal injury. We hypothesized that the amount of fracture depression and widening on anteroposterior (AP) plain radiographs would correlate with the incidence of injury to these structures on magnetic resonance imaging (MRI).

METHODS

Sixty-two consecutive patients with Schatzker II tibial plateau fractures had a knee x-ray series and MRI preoperatively. AP plain radiographs were measured for lateral joint line depression and condylar widening, and MRIs were evaluated for injury to soft-tissue structures around the knee. For each structure, the threshold of depression and widening that led to the greatest disparity in soft-tissue injury was determined. Multiple logistic regressions were applied to calculate whether depression and/or widening above the thresholds were predictive for injury to individual soft-tissue structures.

RESULTS

When depression was greater than 6 mm and widening was greater than 5 mm, lateral meniscal injury occurred in 83% of fractures, compared with 50% of fractures with less displacement (p < 0.05). When either depression or widening was at least 8 mm, medial meniscal injury occurred more frequently (depression 53%, p < 0.05; widening 78%, p < 0.05; versus neither 15%). Lateral collateral ligament and posterior cruciate ligament tears were not seen with minimally displaced fractures (< 4 mm), but the incidence of injury approached 30% with increasing displacement.

CONCLUSIONS

Due to the limited availability of MRI in some centers, correlation of lateral condylar depression and widening, as measured on plain radiographs, to injury of various soft-tissue structures may be extremely helpful in planning open or arthroscopic treatment methods. Using these guidelines, Schatzker II fractures with depression or widening approaching 5 mm deserve heightened vigilance in diagnosing and treating these concomitant soft-tissue injuries.

High-energy tibial plateau fractures

The severity of a tibial plateau fracture and the complexity of its treatment depend on the energy imparted to the limb. Low-energy injuries typically cause unilateral depression-type fractures, whereas high-energy injuries can lead to comminuted fractures with significant osseous, soft-tissue, and neurovascular injury. Evaluation includes appropriate radiographs and careful clinical assessment of the soft-tissue envelope. Treatment is directed at safeguarding tissue vascularity and emphasizes restoration of joint congruity and the mechanical axis of the limb. Temporary joint-spanning external fixation facilitates soft-tissue recovery, whereas minimally invasive techniques and anatomically contoured plates can limit damage to the soft tissues and provide stable fixation. Alternatively, the use of limited internal fixation and definitive external fixation can minimize soft-tissue disruption, avoid complications, and allow fracture union. Complications, including infection, loss of fixation, and malalignment, are best avoided by following these biologically respectful treatment principles.

The incidence of soft tissue injury in operative tibial plateau fractures: a magnetic resonance imaging analysis of 103 patients

OBJECTIVES

The goal of this study was to determine the incidence of injury to soft tissue structures of the knee in tibial plateau fractures scheduled for surgery.

DESIGN

Prospective cohort.

SETTING

Level I academic medical center.

PATIENTS/PARTICIPANTS

One hundred three consecutive patients with acute tibial plateau fractures indicated for operative intervention.

INTERVENTION

Standard x-ray examinations, including anteroposterior, lateral, and oblique views, were performed in the emergency department. Subsequently all patients had magnetic resonance imaging performed. The Schatzker and AO/OTA classifications were used to classify each fracture pattern based solely on the x-rays. Soft tissue injuries were assessed by magnetic resonance imaging.

MAIN OUTCOME MEASUREMENTS

Fifteen categories of injury were determined as positive or negative on each magnetic resonance imaging, which included tears of the cruciates, collateral ligaments, menisci, and posterolateral corner.

RESULTS

The overall incidence of injury to soft tissues was higher than previously reported. Only 1 patient (1%) in the series had complete absence of any soft tissue injury. Seventy-nine patients (77%) sustained a complete tear or avulsion of 1 or more cruciate or collateral ligaments. Ninety-four patients (91%) had evidence of lateral meniscus pathology. Forty-five patients (44%) had medial meniscus tears. Seventy patients (68%) had tears of 1 or more of the posterolateral corner structures of the knee. The most frequent fracture pattern was a lateral plateau split-depression (Schatzker II) (60%). No pure depression injuries (Schatzker III, AO/OTA 41-B2) were seen.

CONCLUSIONS

The incidence of complete ligamentous or meniscal disruption associated with operative tibial plateau fractures was higher than previously reported. Though the clinical importance of injury to each of these structures is unknown, the treating surgeon should be aware that a variety of soft tissue injuries are common in these fractures. In addition, all fractures had at least 1 cortical split visible on magnetic resonance imaging, implying that pure depression patterns are very rare or may not exist.

The value of current developments in radiology to the accident and emergency department--a pictorial review

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