Unique musculoskeletal trauma

Pelvic and lower extremity insufficiency fracture in the osteoporotic individual, an approach to posttraumatic wrist instabilities, and certain upper and lower extremity pediatric fractures are discussed. The case material concentrates upon the clinical/radiographic recognition of subtle trauma and the multimodality approach to these unique traumatic musculoskeletal conditions. The impact that computed tomography has had on some of these traumatic conditions also is presented.     

Imaging of musculoskeletal infections

Imaging studies play a critical role in the diagnosis and management of musculoskeletal infections in children. Conventional radiography is usually the first imaging study performed with other imaging modalities as needed. Ultrasound is helpful in detecting joint effusions and fluid collections in the soft tissue and subperiosteal regions, and may guide localization for aspiration or drainage. CT can demonstrate osseous and soft tissue abnormalities and is ideal for detecting gas in soft tissues. Nuclear scintigraphy and MR imaging are valuable because of their high sensitivity. Scintigraphy is particularly useful in identifying multifocal involvement, which is an important consideration in neonatal osteomyelitis and CRMO. MR imaging provides accurate information on both the soft tissues and bones and is our imaging study of choice for evaluating the local extent of musculoskeletal infections.     

Computed tomography of musculoskeletal trauma

Radiology plays a crucial role in the evaluation of the acutely traumatized patient by providing information that allows timely and appropriate management to be instituted. With few exceptions, notably the skull, plain films remain the primary imaging technique for the diagnosis of skeletal trauma. Computed tomography (CT) has become an important adjunctive procedure in the evaluation and diagnosis of trauma, particularly in complex anatomic areas, including the sternoclavicular joint, the pelvis, and the spine, and in many hospitals has virtually replaced conventional tomography. It may be combined with arthrography or enhanced by intravenous or intrathecal contrast material. This article reviews the uses of CT in the diagnosis and evaluation of musculoskeletal trauma and its complications.     

Conventional tomography in musculoskeletal trauma

Conventional tomography utilizes controlled blurring of overlying structures, in effect, to remove these possible obscuring overlying structures and permit improved evaluation of anatomic detail within the specific layer or focal plane of interest. Although it has largely been replaced by true sectional imaging modalities such as CT and MR imaging, it remains a valuable tool in specific settings as in musculoskeletal trauma. It is particularly useful when the orientation of the pathology requires coronal or sagittal planes for optimal evaluation.     

Scintigraphic techniques in musculoskeletal trauma

Scintigraphic techniques play an important role in the diagnosis and evaluation of a wide variety of musculoskeletal injuries. They provide physiologic and pathophysiologic information but do not provide the exquisite resolution of computed tomography or magnetic resonance imaging. Thus, scintigraphy studies should be ordered only when they would be expected to provide data that will establish a diagnosis or help in planning therapy.     

Imaging features of musculoskeletal tuberculosis

The purpose of this article is to review the imaging characteristics of musculoskeletal tuberculosis. Skeletal tuberculosis represents one-third of all cases of tuberculosis occurring in extrapulmonary sites. Hematogenous spread from a distant focus elsewhere in the body is the cornerstone in the understanding of imaging features of musculoskeletal tuberculosis. The most common presentations are tuberculous spondylitis, arthritis, osteomyelitis, and soft tissue involvement. The diagnostic value of the different imaging techniques, which include conventional radiography, CT, and MR imaging, are emphasized. Whereas conventional radiography is the mainstay in the diagnosis of tuberculous arthritis and osteomyelitis, MR imaging may detect associated bone marrow and soft tissue abnormalities. MR imaging is generally accepted as the imaging modality of choice for diagnosis, demonstration of the extent of the disease of tuberculous spondylitis, and soft tissue tuberculosis. Moreover, it may be very helpful in the differential diagnosis with pyogenic spondylodiscitis, as it may easily demonstrate anterior corner destruction, the relative preservation of the intervertebral disk, multilevel involvement with or without skip lesions, and a large soft tissue abscess, as these are all arguments in favor of a tuberculous spondylitis. On the other hand, CT is still superior in the demonstration of calcifications, which are found in chronic tuberculous abscesses.     

Imaging of musculoskeletal fibromatosis.

The musculoskeletal fibromatoses comprise a wide range of lesions with a common histopathologic appearance. They can be divided into two major groups: superficial and deep. The superficial fibromatoses are typically small, slow-growing lesions and include palmar fibromatosis, plantar fibromatosis, juvenile aponeurotic fibroma, and infantile digital fibroma. The deep fibromatoses are commonly large, may grow rapidly, and are more aggressive. They include infantile myofibromatosis, fibromatosis colli, extraabdominal desmoid tumor, and aggressive infantile fibromatosis. Radiographs typically reveal a nonspecific soft-tissue mass, and calcification is common only in juvenile aponeurotic fibroma. Advanced imaging (ultrasonography, computed tomography, and magnetic resonance [MR] imaging) demonstrates lesion extent. Involvement of adjacent structures is common, reflecting the infiltrative growth pattern often seen in these lesions. MR imaging may show characteristic features of prominent low to intermediate signal intensity and bands of low signal intensity representing highly collagenized tissue. However, fibromatoses with less collagen and more cellularity may have nonspecific high signal intensity on T2-weighted images. Local recurrence is frequent after surgical resection due to the aggressive lesion growth. It is important for radiologists to recognize the imaging characteristics of musculoskeletal fibromatoses to help guide the often difficult and protracted therapy and management of these lesions.     

Magnetic resonance imaging of musculoskeletal trauma

Magnetic resonance imaging has unique capabilities for evaluating musculoskeletal trauma. It can clearly delineate tears and hemorrhage in muscles, ligaments, and tendons and can provide clinically useful information in patients with joint injuries. Other developing applications include evaluation of compartment syndromes, injuries of peripheral nerves and blood vessels, and chronic sequelae of trauma. If a correct technical approach is employed, MRI has a clinical role that is complementary to other imaging modalities.     

Imaging of musculoskeletal complications of hemophilia

In patients with hemophilia, hemarthrosis often occurs in one or several joints and may progress to a destructive, disabling arthropathy. Treatment includes continuous or on-demand clotting factor replacement and radionuclide or open synovectomy. The radiographic findings of hemophilic arthropathy depend on the stage of disease, the age of the patient at onset, and the joint involved. These findings include joint effusion, soft tissue swelling, epiphyseal overgrowth, subchondral cysts, osseous erosion, and secondary degenerative changes. Magnetic resonance imaging (MRI) is the most accurate imaging modality for assessing hemophilic arthropathy and may have a significant impact on patient management. MRI is anticipated to be useful in documenting early joint changes when treatment may be most effective. Hemophilic pseudotumor is a chronic, encapsulated, hemorrhagic fluid collection that usually destroys bone and may become quite large. Both computed tomography and MRI are useful in determining the extent of this lesion.     

Imaging of musculoskeletal disorders in children

A review of the year's literature on musculoskeletal disorders in infants and children includes many advances in imaging principles, especially MR imaging pulse sequences. We have not attempted to review these advances because the principles are essentially the same in children as in adults. We have confined this review to several topics including the importance of differentiating the findings in osteogenesis imperfecta from those in the abused child, limb-lengthening procedures in infants and children, the treatment of slipped upper femoral capital epiphysis, spinal anomalies, and skeletal abnormalities associated with cloacal exstrophy. A brief comment on cervical spine films in pediatric trauma patients is also included.     

Imaging of musculoskeletal and spinal tuberculosis

The diagnosis of tuberculosis of the musculoskeletal system is difficult for many reasons. As Walker states, to diagnose tuberculosis one must consider the possibility. The uncommonness of osteoarticular MTb results in clinician inexperience, which leads to overlooking the diagnosis. Subtle early manifestations may elude detection. Negative skin tests and normal chest films do not exclude the consideration of tuberculosis. The most conclusive means of reaching the diagnosis (biopsy and culture) necessitate invasive procedures that are not always definitive, and may require repeated attempts. Management and surgical decisions, however, rely on prompt diagnosis; diagnostic delay has prognostic implications and results in significant morbidity. Musculoskeletal tuberculosis produces no pathognomonic imaging signs, and in advanced stages mimics other disease processes. Despite these difficulties, the diagnostician's goal is to catch the disease as early as possible, because antibiotic treatment can lead to resolution and obviate more radical management. The radiologist must be aware of the groups at greatest risk, and typical and atypical presentations at imaging. The eventual eradication of MTb is conceivable, although not presently within our grasp. Maintaining reasonable suspicion and developing cognizance of the patterns of presentation allow the radiologist to diagnose efficiently the patient who presents with osteoarticular tuberculosis.     

Imaging of musculoskeletal trauma in three dimensions. An integrated two-dimensional/three-dimensional approach with computed tomography

Transaxial computed tomographic (CT) data can be used to generate images rapidly in the coronal and sagittal planes (two-dimensional CT) and create simulated three-dimensional images. The techniques and advantages of an integrated two-dimensional/three-dimensional CT approach to musculoskeletal trauma are illustrated and discussed.     

Imaging of lymphoma of the musculoskeletal system

Imaging plays a crucial role in staging and the assessment of treatment response in patients who have lymphoma of the musculoskeletal system. This article reviews imaging features of lymphoma of bone, muscles, cutaneous, and subcutaneous tissue. At radiography, lymphoma of the bone is most commonly lytic, but the affected bone also can appear deceptively normal, even when a large tumor is present. At CT, lymphoma of muscle can be homogenous in attenuation, and it may not show contrast enhancement, making tumor detection more difficult. Post-treatment changes often are encountered at MR imaging and positron emission tomography, and when considered in light of the patient's therapy regimen (eg, radiation therapy and granulocyte-colony stimulating factor), they usually can be differentiated from tumor. Post-treatment changes include diffuse FDG uptake in marrow after chemotherapy, indicating rebound of normal marrow, and MR imaging signal abnormalities that may persist for anywhere from a few months to years after treatment.     

Imaging of renal trauma

Trauma is a major cause of death and disability and renal injuries occur in up to 10% of patients with significant blunt abdominal trauma. Patients with penetrating trauma and hematuria, blunt trauma with shock and hematuria, or gross hematuria warrant imaging of the urinary tract specifically and CT is the preferred modality. If there is significant perinephric fluid, especially medially, or deep laceration, delayed images should be obtained to evaluate for urinary extravasation. Most renal injuries are minor, including contusions, subcapsular and perinephric hematoma, and superficial lacerations. More significant injuries include deep lacerations, shattered kidney, active hemorrhage, infarctions, and vascular pedicle and UPJ injuries. These injuries are more likely to need surgery or have delayed complications but may still often be managed conservatively. The presence of urinary extravasation and large devitalized areas of renal parenchyma, especially with associated injuries of intraperitoneal organs, is particularly prone to complication and usually requires surgery. Active hemorrhage should be recognized because it often indicates a need for urgent surgery or embolization to prevent exsanguination.     

Imaging of pancreatic trauma

This pictorial review discusses the imaging findings in acute pancreatic injury and its delayed complications. These findings are related to key decisions in surgical management. Emphasis is placed on the difficulty of acute diagnosis using CT and the pivotal role of endoscopic retrograde pancreatography (ERP) in the definition of ductal anatomy with delayed diagnosis.