Imaging of sports-related knee injuries

Selective Unique Signs of Meniscus Tears as Visualized by Magnetic Resonance Imaging

The meniscus is an organized collection of fibrocartilaginous tissue that is located between the femoral condyles and the tibial plateau of the knee which primarily assists with load transmission. The complex composition of articulating soft-tissue structures in the knee causes the menisci to become a common source of injury, especially in the realm of athletic trauma. Magnetic resonance imaging (MRI) has become the imaging modality of choice for evaluating patients with suspected meniscal pathology because of its numerous advantages over plain radiographs. Most forms of meniscal tears have classic MRI findings and are used in correlation with physical examination findings to confirm or rule out a diagnosis. These imaging findings are referred to as signs and have been well studied, and the associated eponyms for each sign are well published throughout the literature. This article will review and describe a unique selection of meniscal pathology as visualized by MRI that is more commonly published in musculoskeletal radiology literature when compared with orthopedics and sports medicine literature.

Presentation, examination, investigation and early treatment of acute knee injuries

Acute knee injuries are common presentations that frequently occur during sporting activities and can result in permanent disability. However, they often result in a single visit, seldom receive surgical intervention and, in the main, are cared for entirely by General Practitioners or Emergency Department physicians. Thorough clinical assessment and appropriate early treatment at the primary presentation is vital in order to offer the best chance of maximal functional recovery and to minimize long-term disability. This requires a sound knowledge of basic knee anatomy, careful assessment of the mechanism of injury, detection and consideration of physical ndings and the results of adjunctive investigations. This article aims to give a comprehensive review of the examination, investigation and early treatment of acute knee injuries at the primary presentation. In addition, comments on important epidemiological and aetiological factors and a brief description of basic knee anatomy are also provided.

A Current Review of the Meniscus Imaging: Proposition of a Useful Tool for Its Radiologic Analysis

The main objective of this review was to present a synthesis of the current literature in order to provide a useful tool to clinician in radiologic analysis of the meniscus. All anatomical descriptions were clearly illustrated by MRI, arthroscopy, and/or drawings. The value of standard radiography is extremely limited for the assessment of meniscal injuries but may be indicated to obtain a differential diagnosis such as osteoarthritis. Ultrasound is rarely used as a diagnostic tool for meniscal pathologies and its accuracy is operator-dependent. CT arthrography with multiplanar reconstructions can detect meniscus tears that are not visible on MRI. This technique is also useful in case of MRI contraindications, in postoperative assessment of meniscal sutures and the condition of cartilage covering the articular surfaces. MRI is the most accurate and less invasive method for diagnosing meniscal lesions. MRI allows confirming and characterizing the meniscal lesion, the type, the extension, its association with a cyst, the meniscal extrusion, and assessing cartilage and subchondral bone. New 3D-MRI in three dimensions with isotropic resolution allows the creation of multiplanar reformatted images to obtain from an acquisition in one sectional plane reconstructions in other spatial planes. 3D MRI should further improve the diagnosis of meniscal tears.

Genu Recurvatum Deformity in a Child due to Salter Harris Type V Fracture of the Proximal Tibial Physis Treated with High Tibial Dome Osteotomy

Salter-Harris type V fracture is a very rare injury in the immature skeleton. In most cases, it remains undiagnosed and untreated. We report a case of genu recurvatum deformity in a 15-year-old boy caused by a Salter-Harris type V fracture of the proximal tibial physis. The initial X-ray did not reveal fracture. One year after injury, genu recurvatum deformity was detected associated with significant restriction of knee flexion and limp length discrepancy (2 cm) as well as medial and posterior instability of the joint. Further imaging studies revealed anterior bone bridge of the proximal tibial physis. The deformity was treated with a high tibial dome osteotomy combined with a tibial tubercle osteotomy stabilized with malleolar screws and a cast. Two years after surgery, the patient gained functional knee mobility without clinical instability. Firstly, this case highlights the importance of early identification of this rare lesion (Salter-Harris type V fracture) and, secondly, provides an alternative method of treatment for genu recurvatum deformity.

Orthopedic trauma: office management of major joint injury

Orthopedic injuries are common reasons for visits to primary care physicians. Careful history and physical examination with intelligent use of imaging technology will arrive at the correct diagnosis in most patients. Many conditions may be definitively managed by the office internist. Others maybe initially stabilized and referred to orthopedic surgeons for definitive care. Nondisplaced fractures, tendon injuries, sprains, and overuse syndromes are entities within the purview of the primary care physician. Familiarity and confidence with diagnosis and management of these conditions in the office is optimal for the care of the adult patient.

Avulsion fractures of the lateral tibial condyle in children

Avulsion fractures of the lateral tibial condyle are very rare in children and adolescents. Seven patients were treated between 1986 and 2000. They were all involved in sporting activities and an acute contraction of the fibres of the iliotibial band was considered to be their common pathogenetic factor. A subdivision in two types of avulsion fractures according to the anatomic location of the lesion was used. The Segond fracture, a small vertical avulsion fracture involving the midportion of the lateral tibial condyle distal to the plateau but proximal to the physis, was diagnosed in five patients. In two of them it was associated with a fracture of the anterior intercondylar eminence. The avulsion fracture of the Gerdy's tubercle was diagnosed in two other patients. The detached fragment was bigger, more anterior and involved a part of the articular surface of the lateral tibial plateau as well as a part of the physeal plate. All patients were treated conservatively and were free of symptoms after a mean follow-up of 9 years.

[Muscle and tendon injuries of the knee joint]

Muscles and tendons contribute greatly to stabilization of the knee joint and are crucial elements for normal joint function. Therefore, injuries of those structures cause variable degrees of disability, depending on the severity of the lesion. Due to the characteristic structural changes and alterations of signal intensities, MR imaging allows accurate identification and staging of acute injuries of muscles and tendons, as well as assessment of chronic or degenerative disease. The knowledge of anatomy and normal function of muscles and tendons, together with a thorough understanding of the mechanism and usual combinations of their injuries (e.g., posterolateral structures) allows an exact evaluation of injury-induced functional impairments to the knee joint. A detailed and exact radiological report is of the greatest importance for the referring clinician and the patient to determine optimal therapeutic strategies.

LOW-FIELD MAGNETIC RESONANCE IMAGING OF BONE MARROW IN THE LUMBAR SPINE, PELVIS, AND FEMUR IN THE ADULT DOG

The purpose of this study was to describe the appearance of normal bone marrow in seven adult dogs using low-field (0.3T) magnetic resonance (MR) imaging. The areas imaged included the lumbar spine, pelvis, and femur. T1-weighted, fast spin-echo T2-weighted, and short tau (T1) inversion recovery (STIR) sequences were obtained at all locations. Histopathology was performed on sections from the sixth lumbar vertebral body, the wing of the ilium, and the femur (head and neck, mid-diaphysis, and condyle) for evaluation of cellularity and fat content. The lumbar spine and pelvic marrow MR images were similar in all dogs. The lumbar vertebral bone marrow was uniform, intermediate signal intensity, and isointense to muscle on all sequences. There was variation between dogs in the bone marrow distribution with MR imaging of the femur. In the proximal and mid-diaphysis of the femur there was patchy high-signal intensity on T1- and T2-weighted images, and hypointense foci on the STIR images. The distal femoral metaphysis had a variable pattern ranging from intermediate-to-high signal on T1- and T2-weighted images and intermediate-to-low signal on STIR images. The femoral condyles were uniformly high signal on T1- and T2-weighted images and hypointense on STIR images. Histopathologically there was a normal variation in the bone marrow cellularity. The marrow was normocellular (25-75% cellularity) for all sites examined except the femoral condyles, which were hypocellular (<25% cellularity).

Protocols in sports magnetic resonance imaging

Magnetic resonance imaging, with its multiplanar imaging capability and superior soft-tissue contrast, has become the preferred method for imaging sports-related injuries. Advances in gradient technology, receiver coils, and imaging software have allowed the imaging of the injured athlete to take place quickly and at high resolution. Understanding the tissues being imaged, the underlying anatomy, and the capabilities of today's scanners is crucial to the design of intelligent and efficient protocols.