The acutely limping child

Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.     

Atraumatic fractures of the femur

Atraumatic fractures of femur, although not as common as traumatic fractures, are frequently encountered in the clinical practice. They present with non-specific symptoms and can be occult on initial imaging making their diagnosis difficult, sometimes resulting in complications. Overlapping terminologies used to describe these fractures may hamper effective communication between the radiologist and the clinician. In this article, we review various atraumatic fractures of femur, terminologies used to describe them, their imaging findings and differential diagnosis. The article also describes the aetiology, pathophysiology and relevant biomechanics behind these fractures. An approach to atraumatic femoral fractures has been outlined.     

Easily missed thoracolumbar spine fractures

Thoracolumbar spine fractures are common and can be difficult to diagnose. Many of these fractures are associated with extraspinal injuries and are subtle on imaging further contributing to diagnostic delay or misdiagnosis. Missed fractures are associated with increased neurologic injury and resulting morbidity. Careful and thorough workup of the multitrauma patient with dedicated spinal imaging is necessary to identify these injuries. This article reviews the major thoracolumbar spine fractures and imaging findings with attention drawn to subtle and easily overlooked features of these injuries.     

Fractures of the talus and calcaneus: evaluation by computed tomography

Fractures of the talus and calcaneus may be difficult to evaluate using conventional imaging modalities. Failure to recognize these fractures or to appreciate their extent may result in severe deformity or disability. Patients with talar and calcaneal fractures had computed tomography to assess its role in the management of these fractures. Computed tomography is superior to other imaging modalities in showing the position of the fracture fragments, the number of fragments, the relation of the fracture to the articular surfaces, residual articular changes, and evidence of healing.     

颌骨骨折的常规X线、CT和三维CT对比研究

研究常规Ｘ线，ＣＴ和三维ＣＴ对显示颌骨骨折 缺点和互补点。材料与方法，对６１例不同类型的上、下颌骨骨折常规Ｘ线、ＣＴ和三维ＣＴ显示情况进行对比分析，同时与手术结果对照。结论３种影像学检查对凳骨骨折的显示各有优缺点，三者相互结合可以提高对颌骨骨折显示的准确率。     

Occult fractures of extremities

Recent advances in cross-sectional imaging, particularly in CT and MR imaging, have given these modalities a prominent role in the diagnosis of fractures of the extremities. This article describes the clinical application and imaging features of cross-sectional imaging (CT and MR imaging) in the evaluation of patients who have occult fractures of the extremities. Although CT or MR imaging is not typically required for evaluation of acute fractures, these modalities could be helpful in the evaluation of the occult osseous injuries in which radiographic findings are equivocal or inconclusive.     

Isolated greater tuberosity fractures of the proximal humerus: anatomy,injury patterns,multimodality imaging,and approach to management

The greater tuberosity is an important anatomic structure and its integrity is important for shoulder abduction and external rotation. Isolated fractures of the greater tuberosity are often subtle and may not be detected on initial radiographs. Clinically, these patients display symptoms which mimic a full thickness rotator cuff tear. It is important to differentiate these two entities, as their treatment is different (typically nonsurgical management for minimally displaced fractures versus rotator cuff repair for acute full thickness rotator cuff tears). When greater tuberosity fractures are significantly displaced and allowed to heal without anatomic reduction, they can lead to impingement. This article will review greater tuberosity anatomy and function, as well as the clinical presentation and multimodality imaging findings of greater tuberosity fractures. Imaging optimization, pitfalls, and clinical management of these fractures will also be discussed.     

Imaging of stress injuries of the pelvis

Stress fractures are common, representing the final stage in a continuum of bone response to continued mechanical damage. Encompassing fatigue- and insufficiency-type fractures, stress fractures of the pelvis are likely underreported. Radiographs are insensitive to stress injuries, particularly those in the pelvis, whereas scintigraphy and magnetic resonance imaging are exquisitely sensitive. In this article we discuss the pathophysiology and imaging appearances of stress injuries of the pelvis and sacrum. Relevant literature regarding risk factors, problem-solving issues, and an imaging algorithm are discussed, with the goal of improving accuracy in the diagnosis of these common injuries.     

Occult fractures of the carpals and metacarpals: demonstration by CT

Occult fractures of the carpals and metacarpals occur frequently and are associated with major disability. The cross-sectional display and superior resolution of CT are well suited to the demonstration of these fractures. Sixteen patients with pain and negative conventional radiographs were chosen for further evaluation by CT. Imaging was performed in two planes and showed 21 fractures. The transaxial plane was the most revealing imaging plane. Coronal imaging was equal or superior to the transaxial plane in most fractures of the scaphoid, lunate, capitate, and pisiform bones and of the bases of the metacarpal bones. The direct sagittal plane was the best imaging plane in one patient with fractures of the scaphoid and lunate bones. After discovery of the fracture on CT, surgical removal of the avulsed fracture fragment was recommended in seven patients and fusion was recommended in three. Eight patients had a marked decrease in pain after the surgical procedure. The accuracy of CT for the demonstration of occult fractures may result in earlier recognition of these fractures and a reduction in the associated disability.     

Greater trochanter fractures: MR assessment and its influence on patient management

Eight patients with nondisplaced greater trochanteric (GT) fractures diagnosed by conventional radiographs were evaluated with magnetic resonance (MR) imaging. MR imaging demonstrated unsuspected intertrochanteric (IT) extension in each of the eight patients. This resulted in unanticipated surgical intervention in six of eight patients. Nondisplaced GT fractures are often more extensive and complex than they appear on conventional radiographs. MR imaging is useful in determining the extent and morphology of these fractures, information valuable for orthopedic management, and should be considered for definitive assessment in these patients.     

Imaging of insufficiency fractures

This review focuses on the occurrence, imaging and differential diagnosis of insufficiency fractures. Prevalence, the most common sites of insufficiency fractures and their clinical implications are discussed. Insufficiency fractures occur with normal stress exerted on weakened bone. Postmenopausal osteoporosis is the most common cause of insufficiency fractures. Other conditions which affect bone turnover include osteomalacia, hyperparathyroidism, chronic renal failure and high-dose glucocorticoid therapy. It is a challenge for the radiologist to detect and diagnose insufficiency fractures, and to differentiate them from other bone lesions. Radiographs are still the most widely used imaging method for identification of insufficiency fractures, but sensitivity is limited, depending on the location of the fractures. Magnetic resonance imaging (MRI) is a very sensitive tool to visualize bone marrow abnormalities associated with insufficiency fractures. Thin section, multi-detector computed tomography (MDCT) depicts subtle fracture lines allowing direct visualization of cortical and trabecular bone. Bone scintigraphy still plays a role in detecting fractures, with good sensitivity but limited specificity. The most important differential diagnosis is underlying malignant disease leading to pathologic fractures. Bone densitometry and clinical history may also be helpful in confirming the diagnosis of insufficiency fractures.     

Osteoporosis imaging: state of the art and advanced imaging

Osteoporosis is becoming an increasingly important public health issue, and effective treatments to prevent fragility fractures are available. Osteoporosis imaging is of critical importance in identifying individuals at risk for fractures who would require pharmacotherapy to reduce fracture risk and also in monitoring response to treatment. Dual x-ray absorptiometry is currently the state-of-the-art technique to measure bone mineral density and to diagnose osteoporosis according to the World Health Organization guidelines. Motivated by a 2000 National Institutes of Health consensus conference, substantial research efforts have focused on assessing bone quality by using advanced imaging techniques. Among these techniques aimed at better characterizing fracture risk and treatment effects, high-resolution peripheral quantitative computed tomography (CT) currently plays a central role, and a large number of recent studies have used this technique to study trabecular and cortical bone architecture. Other techniques to analyze bone quality include multidetector CT, magnetic resonance imaging, and quantitative ultrasonography. In addition to quantitative imaging techniques measuring bone density and quality, imaging needs to be used to diagnose prevalent osteoporotic fractures, such as spine fractures on chest radiographs and sagittal multidetector CT reconstructions. Radiologists need to be sensitized to the fact that the presence of fragility fractures will alter patient care, and these fractures need to be described in the report. This review article covers state-of-the-art imaging techniques to measure bone mineral density, describes novel techniques to study bone quality, and focuses on how standard imaging techniques should be used to diagnose prevalent osteoporotic fractures.     

Étude prospective sur les accidents de décompression ostéomyoarticulaires en plongée de loisir : leurs facteurs de risque et leur potentiel évolutif en ostéonécrose dysbarique

Objectives

Dysbaric osteonecrosis is a complication that can result from repetitive and prolonged hyperbaric exposures and the correlation with a previous type 1 decompression sickness described as a joint pain remains a controversial subject. The study was designed to determine the risk factors of type 1 decompression sickness in recreational divers and their potential to shortly evolve into osteonecrosis.

Methods

All the osteoarthromuscular decompression sickness treated between October 2004 and November 2005 in one of three hyperbaric centers assigned in the Provence-Alpes-Côte d'Azur region were analyzed in a prospective way of standardized collections, and the majority was explored with MRI in order to screen ischaemic osteomedullar damages.

Results

Eleven cases (8,5%) were inventoried amongst the 129 diving accidents treated during this period. These joint pains were mainly located in the shoulder area (81%) and involved a majority of male experienced divers after performing deep and long dives (90%) furthermore more than 50% of these divers had greater than one dive within a twelve hour period. The average age was 38,5 years with a body mass index of 27,5 kg/m². All dives were performed with a dive computer without omitted decompression. Ten injured divers (90%) were examined by MRI shortly after the accident, but only one diver (10%) had lesions compatible with osteonecrosis.

Conclusion

This preliminary study shows that osteoarthromuscular decompression sickness in recreational diving are essentially involved in dives considered to carry a high risk for bubble production. The conditions of occurence appear also to be related with some individual factors that must be specified in other studies. Nevertheless, the risk of early underlying dysbaric osteonecrosis development is quite low.     

缺血性椎体压缩骨折的影像分析

目的分析缺血性椎体压缩骨折的影像变化及特点。方法随访11例初诊为骨质疏松性压缩骨折,复诊确定为缺血性椎体压缩骨折的病例。复诊时采用不同体位行X线摄影,并于透视下观察病变椎体在不同体位下的形态和变化特点,其中8例并同时行螺旋CT扫描。对初诊及复诊的X线及CT图像进行对比观测分析。结果11例病例的影像动态变化特点均表现为进行性椎体塌陷及后凸畸形;萎陷的椎体呈扁平状或薄骨板样(8例)、鱼椎状(3例),萎陷的椎体内均可见真空裂隙征。结论缺血性椎体压缩骨折的影像学具有一定特征性。     

Atypical diaphyseal femoral fractures—new aspects

Post menopausal osteoporotic fractures are a major public health concern worldwide with oral bisphosphonates favored for their prevention and treatment. Recent interest has centered on clinically observed, unusually sited femoral diaphyseal fractures, particularly attributed to alendronate. Their imaging presentations on routine radiographs, alternate imaging modalities, and associated pitfalls in nine fractures in six patients are selectively illustrated by seven fractures in four patients that serve to emphasize the following: (1) Bisphosphonates other than alendronate have been used for treating various bone diseases in children and men as well as osteoporotic women. (2) Effects may differ with each bisphosphonate’s route of administration and prolongation of activity, despite discontinuation. Prior investigations and theoretical mechanisms of bisphosphonates as a class rather than with a specific alendronate association are reviewed to provide a broader basis for evaluating their recently observed clinical and radiographic complications.     

Distinguishing stress fractures from pathologic fractures: a multimodality approach

Whereas stress fractures occur in normal or metabolically weakened bones, pathologic fractures occur at the site of a bone tumor. Unfortunately, stress fractures may share imaging features with pathologic fractures on plain radiography, and therefore other modalities are commonly utilized to distinguish these entities. Additional cross-sectional imaging with CT or MRI as well as scintigraphy and PET scanning is often performed for further evaluation. For the detailed assessment of a fracture site, CT offers a high-resolution view of the bone cortex and periosteum which aids the diagnosis of a pathologic fracture. The character of underlying bone marrow patterns of destruction can also be ascertained along with evidence of a soft tissue mass. MRI, however, is a more sensitive technique for the detection of underlying bone marrow lesions at a fracture site. In addition, the surrounding soft tissues, including possible involvement of adjacent muscle, can be well evaluated with MRI. While bone scintigraphy and FDG-PET are not specific, they offer a whole-body screen for metastases in the case of a suspected malignant pathologic fracture. In this review, we present select examples of fractures that underscore imaging features that help distinguish stress fractures from pathologic fractures, since accurate differentiation of these entities is paramount.     

Pelvic stress fracture in female runners

Stress fractures are a common injury in long-distance runners, and typically involve the lower extremities. Although relatively rare, pubic ramus stress fractures also occur, primarily in female runners. Bone imaging visualized a pubic stress fracture and a tibial stress fracture in a female long-distance runner with groin pain. Pubic stress fractures should be considered in female runners who present with groin pain. Radionuclide bone imaging is useful in diagnosing these lesions.     

Imaging and treatment of scaphoid fractures and their complications

The scaphoid is the most commonly fractured carpal bone, with frequent complications that are predisposed by its anatomical location, anatomical configuration (shape and length), and vascular supply. The most common mechanism of injury is a fall onto an outstretched hand. Imaging plays a significant role in the initial evaluation and treatment of scaphoid fractures and their complications. Radiography should be the first imaging modality in the initial evaluation and follow-up of scaphoid fractures. Computed tomography with its superb spatial resolution enables better visualization and characterization of the fracture line, and the amount of displacement and angulation of the fracture fragments. Using the metal reduction artifact with computed tomography allows good follow-up of scaphoid fractures despite surgical hardware. Magnetic resonance imaging without contrast is the imaging modality of choice for depiction of radiographically occult scaphoid fracture, bone contusion, and associated soft tissue injury; contrast-enhanced imaging aids assessment of scaphoid fracture nonunion, osteonecrosis, fracture healing after bone grafting, and revitalization of the necrotic bone after bone grafting. Proper identification and classification of scaphoid fracture and its complications is necessary for appropriate treatment. This article describes the normal anatomy, mechanism of injury, and classification of stable and unstable fractures, together with the imaging and treatment algorithm of scaphoid fractures and their complications with an emphasis on magnetic resonance imaging.     

Imaging of the acetabulum in the era of multidetector computed tomography

Acetabular fractures are often complex injuries and the result of high-energy trauma with associated injuries. Understanding and classification of these rare injuries using radiography can be difficult and are much facilitated by the addition of computed tomography (CT). The purpose of this paper is to briefly review some of the underlying physical principles and technical factors for multidetector CT (MDCT) and to describe its use and imaging findings in the evaluation of acetabular fractures. Using MDCT with two-dimensional multiplanar reformatted (MPR) images and three-dimensional volume rendered images, the supplemental oblique radiographic Judet views can be omitted. MDCT is now an indispensable tool in preoperative imaging of acetabular fractures and also in postoperative imaging in complicated cases. Not only is MDCT excellent for a general overview but also for detailed imaging of fracture extent, joint congruency, step-offs or gaps in the joint surface, and entrapped osteochondral fragments.