Acute traumatic knee radiographs: beware of lesions of little expression but of great significance

A Review of Current Concepts of the Anterolateral Complex of the Knee

The anterolateral complex (ALC) of the knee has gained increased interest over the last decades due to the high revision rates of anterior cruciate ligament reconstruction (ACLR). Furthermore, in patients with an ACL tear, the injury of at least one of the ALC's anatomic structures has been shown to be significantly higher, thus affecting its secondary stabilizing role at the knee joint. As such, ACLR augmentation techniques, that embrace the ALC, have been proposed recently, and indications for these procedures are still evolving. This review aims to present and discuss the most current anatomical, biomechanical, and imaging data, current reconstruction techniques, and the clinical results of ALC reconstruction.

Comparison of diagnostic accuracy of point-of-care ultrasonography and X-ray of bony injuries of the knee

PURPOSE

We aimed to compare the accuracy of point-of-care ultrasonography (POCUS) and X-ray (XR) in the diagnosis of knee bone fractures and fracture characteristics in cases of injuries to the knee.

METHODS

The study was conducted in the emergency department (ED) of a tertiary hospital between March 2017 and March 2019. It included patients who presented to the ED with isolated knee injuries, were suspected to have a bony lesion based on clinical examinations, and were ultimately referred for XR. Five emergency physicians (EPs) who had at least three years of ED experience participated in the study. Before the study, these EPs received training on knee examination and radiographic investigation of the knee joint. They were also trained on how to assess the knee joint using POCUS. The knee bones, patella, femur, tibia, and fibula were evaluated. A POCUS examination of the knee bones was carried out according to the eight-step Kozaci Protocol.

RESULTS

This study included 92 patients with knee trauma. The mean age of the patients was 34 ± 16 years (6-55 years). Using POCUS and XR, fractures were detected in 40 (43%) and 32 patients (35%), respectively. Relative to XR, for detecting fractures, POCUS showed sensitivity, specificity, positive predictive value, and negative predictive value of 97%, 85%, 78%, 98%, respectively, and the kappa value was 0.774. POCUS examination revealed hematoma and edema in the soft tissue in 34 (37%) patients and hemarthrosis in 33 patients (36%).

CONCLUSION

XR is the first and most widely used imaging modality to identify fractures of the knee bone trauma. However, POCUS examination can successfully diagnose bony lesions of the knee in patients with stable vital signs and without life-threatening injuries. It can also easily diagnose hematoma and hemarthrosis. Therefore, POCUS can be used as a diagnostic tool in emergency situations where XR is not available.

Comparison of X-Ray Imaging and Computed Tomography Scan in the Evaluation of Knee Trauma

Background and objectives: The aim of the study was to compare the accuracy of X-ray (XR) imaging according to computed tomography (CT) scanning in the diagnosis of knee bone fractures, and in the determination of fracture characteristics, and to identify CT scan indications in patients with knee trauma. Materials and methods: The patients who presented to the emergency department (ED) due to knee trauma between January 2017 and December 2018 and who underwent XR imaging and CT scans were included in the study. XR images were reinterpreted by an emergency physician. The official reports, which had been interpreted by a radiologist in the hospital automation system for CT images, were considered valid. Results: Five hundred and forty-eight patients were included in the study. Of the patients, 200 (36.5%) had fractures in XR imaging and 208 (38.0%) had fractures in CT scans. Compared to CT scanning, XR imaging was found to have 89% sensitivity, 95% specificity, 92% positive predictive value, and 92% negative predictive value in identifying the fracture. The sensitivity of XR imaging in identifying growth plate fracture, angulation, stepping off, and extension of the fracture into the joint space was determined as 78% and less. According to the kappa value, there was determined a perfect concordance between the XR imaging and CT scans in angulation, stepping off, and extension of the fracture into the joint space. This concordance was moderate in growth plate fractures. Conclusions: XR imaging has a low sensitivity in identifying knee fractures. There is a moderate concordance between XR imaging and CT scanning in identifying growth plate fractures. Therefore, CT scanning should be performed in patients whose fracture type and fracture characteristics are not able to be determined exactly with XR imaging in knee injury.

Acute presentation of Sinding-Larsen-Johansson disease simulating patella sleeve fracture: A case report

OBJECTIVES

Diagnosis of Sinding-Larsen-Johansson disease may not be an easy task. Several sport-related conditions affect the distal pole of the patella in the adolescent, and treatment varies considerably. The article describes a patient that had radiographic features of Sinding-Larsen-Johansson disease associated with an atypical acute presentation.

METHODS

Case report and literature review.

RESULTS

A 10-year-old boy presented with a sudden pain after a noncontact soccer injury. He had tenderness and swelling over the patella. Radiographs showed minimally displaced distal patellar ossicle. Magnetic resonance imaging excluded sleeve cartilaginous injury and documented Sinding-Larsen-Johansson disease. The knee was immobilized briefly. There was complete healing of the injury in 4-week follow-up radiographs.

CONCLUSION

Emergency physicians, radiologists, and orthopedic surgeons should be aware of the acute presentation of Sinding-Larsen-Johansson disease after knee injuries.

Bone abnormalities of the knee: MRI features

The knee is one of the most studied anatomical structures by magnetic resonance imaging (MRI). Bone abnormalities are very frequently detected, whether or not related to the symptoms for which imaging was indicated. The aim of this pictorial study is to review the most commonly observed bone abnormalities of the knee, bearing in mind that the interpretation of MR images should always take into consideration both clinical and laboratory data, as well as the results of conventional X-ray imaging.

What’s in a name? Lower extremity fracture eponyms (Part 2)

Eponymous extremity fractures are commonly encountered in the emergency setting. Correct eponym usage allows rapid, succinct communication of complex injuries. We review both common and less frequently encountered extremity fracture eponyms, focusing on imaging features to identify and differentiate these injuries. We focus on plain radiographic findings, with supporting computed tomography (CT) images. For each injury, important radiologic descriptors are discussed which may need to be communicated to clinicians. Aspects of management and follow-up imaging recommendations are included. This is a two-part review: Part 1 focuses on fracture eponyms of the upper extremity, while Part 2 encompasses fracture eponyms of the lower extremity.