Bone and joint complications related to Gaucher disease.

There is a broad spectrum of Gaucher disease-related skeletal complications, ranging from asymptomatic osteopenia to osteonecrosis (of the shoulders and hips) with secondary degenerative joint disease. Characterization of the pattern and severity of bone involvement in the individual patient requires the application of conventional and advanced radiographic techniques. The introduction of enzyme replacement therapy (ERT) for this inborn error of glycosphingolipid metabolism has focused great interest in determining the nature and extent of the bone responses with this mode of treatment. The multifactorial etiology of the bone complications necessitates a multifaceted approach, combining pharmacologic strategies with physical therapy and orthopedic intervention. As bone disease can lead to chronic pain and debility with a resultant adverse impact on quality of life, it is important that patients be monitored closely and that early intervention with ERT prior to established bone disease (infarction and fibrosis) be considered.

Tetraparesis following dental extraction: case report and discussion of preventive measures for cervical spinal hyperextension injury.

This concerns a patient with compression myelopathy following passive hyperextension of the cervical spine during a dental procedure. Although he had been asymptomatic prior to the procedure, subsequent cervical spinal imaging revealed advanced spondylosis and spinal stenosis. Spinal stenosis is often asymptomatic for a long time. However, when radiculomyelopathy occurs after minor trauma to the head or neck, the patient is often found to have spinal stenosis. Specifically, hyperextension of a cervical spine with spondylotic changes can lead to compression myelopathy. Acquired spinal stenosis correlates positively with aging. As the size of the elderly population continues to increase the prevalence of cervical spondylotic radiculo-myelopathy will likely increase as well. Since appropriate precautions against potential neurologic damage can be undertaken, we suggest radiographic screening for pre-existing spinal stenosis prior to a procedure requiring hyperextension of the neck. Preventive measures for individuals with asymptomatic spondylotic changes and education of all health-care professionals to avoid abrupt or prolonged hyperextension of the cervical spine is emphasized.

MR imaging of glenohumeral instability.

Familiarity with normal anatomy and pathologic features of the capsulolabral complex as well as high resolution imaging are important factors in achieving a consistently high accuracy rate in diagnosis of glenohumeral instability by conventional MR imaging. In this article, the pathophysiology of glenohumeral instability and the various MR imaging findings are discussed and illustrated.

Insufficiency fracture of the femoral head: MR imaging in three patients.

OBJECTIVE: The purpose of this report is to describe three patients in whom a presumptive diagnosis of insufficiency fracture of the femoral head was made on the basis of clinical and MR imaging findings. CONCLUSION: Femoral head insufficiency fracture should be included in the differential diagnosis of hip pain in the osteopenic elderly patient.

Avascular necrosis of carpal bones.

MR imaging is extremely well suited to detection of early phases of avascular necrosis, permitting diagnosis before collapse of the carpal bones has occurred. The sensitivity of this imaging modality allows differentiation of subtle changes in the bone marrow signal. This is used as criteria for a new stage classification of Kienböck's disease based on MR imaging appearance. The prognosis of scaphoid fractures and estimation of likelihood of avascular necrosis of the proximal fragment can be inferred by using gadolinium enhancement to evaluate the bone marrow vascularity.

MR imaging of the menisci. Fundamentals of anatomy and pathology.

This article discusses the anatomy of the menisci and various signal abnormalities. Morphologic changes indicative of degenerative disease, degenerative tear, intra- and para-meniscal cysts, and traumatic tear are also covered.

Magnetic resonance imaging of glenohumeral instability.

Familiarity with normal anatomy and pathologic features of the capsulolabral complex as well as high resolution imaging are important factors in achieving a consistently high accuracy rate in diagnosis of glenohumeral instabilities by conventional MR imaging. The various types of glenoid labrum lesions and features that are most often associated with glenohumeral instability are defined.

Rotator cuff lesions: signal patterns at MR imaging.

The signal intensity patterns of rotator cuff lesions at magnetic resonance (MR) imaging were evaluated in 80 patients who had surgical correlation and in 13 asymptomatic individuals (14 shoulders). Six cadaver shoulders were examined with MR, and histologic correlation was obtained in four. All studies were performed at 1.5 T with a flexible circular surface coil. The accuracy of MR imaging in detection of full-thickness cuff tears (31 patients) was 0.95 and of partial thickness tears (16 patients), 0.84. The most common and accurate pattern for full-thickness cuff tears (22 of 31 tears) was a region of intense signal seen on T2-weighted images. Less often the torn region consisted of an extremely degenerated and attenuated tendon with moderate signal intensity or was obscured by low-signal-intensity scar. The intense signal pattern on T2-weighted images was also accurate, although a less common finding (seven of 16 cases), in the diagnosis of partial tears. Tendinitis was recognized as focal or diffuse regions of increased signal intensity or a nonhomogeneous pattern of increased signal often associated with tendinous enlargement. In some patients, manifestations of subacromial-subdeltoid bursitis was present. Tendon degeneration was also manifested as regions of increased signal intensity. Some similarity and overlap of signal patterns of partial interstitial tears, tendinitis, and tendon degeneration are observed.

Tears of the triangular fibrocartilage of the wrist: MR imaging.

Magnetic resonance (MR) imaging of the wrist was performed in 35 patients with specific complaints of pain and soft-tissue swelling in the medial side of the wrist. Twenty of the 35 subsequently underwent surgery. In 14 of the patients who underwent surgery, a diagnosis of triangular fibrocartilage (TFC) tear was made at MR imaging; in 13 of the 14 the tear was confirmed by surgical findings. In the six patients with an MR diagnosis of an intact TFC, surgical findings confirmed the diagnosis. These patients were operated on for an abnormality in the vicinity of the TFC (avascular necrosis, ganglion cyst, xanthoma). On the basis of findings from the 20 patients with surgical correlation, the accuracy of MR imaging in the detection of TFC tears was 95%. MR imaging is a valuable noninvasive method in the study of pathologic conditions of the TFC.

Volumetric rendering of MR images.

The authors developed new techniques for three-dimensional display of magnetic resonance (MR) images that preserve soft-tissue definition, are fully automatic, and work with routinely used section thicknesses. MR images are segmented, selectively enhanced, and displayed by means of a volumetric rendering algorithm. These techniques were used to illustrate normal anatomy of the brain, knee, and liver. Three-dimensional rendering of balanced spin-echo images shows the ventricles and extracerebral veins and of T1-weighted images, the sulci and gyri. The large hepatic and portal vessels can be seen with these enhancement techniques. Three-dimensional views of the knee reveal articular surfaces of the tibia and clearly depict menisci and posterior and anterior cruciate ligaments. These techniques make it possible to image multiple soft tissues simultaneously while preserving the detail contained in the original images. Three-dimensional presentation of complex, overlapping anatomic regions is helpful in surgical planning and should lead to improved diagnosis.

Computed tomography (CT) arthrography of shoulder instabilities in athletes.

Sixty professional and recreational athletes underwent CT arthrography of the shoulder for evaluation of suspected shoulder joint derangement. These athletes, 46 males and 14 females ranging in age from 15 to 60 years (mean, 32 years), all had persistent pain that interfered with their sports activity and was resistant to conservative treatment. Seventeen patients had shoulder instability based on clinical manifestations and CT arthrographic findings. An additional five patients, also based on clinical manifestations and CT arthrographic findings, were considered to have an unobtrusive degree of anterior joint laxity. Patients with anterior instability (20 cases) all had an anteroinferior tear or detachment of the glenoid labrum, as well as some violation of the insertion of the joint capsule onto the scapula. Those with posterior instability (two cases) had a combination of labral and capsular tears. Two other major patterns of labral tears, both unaffiliated with shoulder instability, were identified. These included total or partial detachment of superior segments of the labrum, and anterior labral tears at the midglenoid level. Moreover, various degrees of labral attenuation (or, less often, enlargement), osteophyte formation, and alterations in articular cartilage were observed. Surgical correlation was obtained in 25 patients, with 95% accuracy of CT arthrographic findings. CT arthrography is a minimally invasive and highly accurate technique for investigation of glenohumeral derangement. Specifically, the extent of pathologic changes associated with instability can be determined and differentiated from other intraarticular causes of incapacity, such as labral tears caused by throwing, or degenerative changes.

Radiation induced fractures of sacrum: CT diagnosis.

Sacral insufficiency fracture due to bone atrophy may develop as a complication of irradiation of pelvic malignancies. Pain is the presenting symptom and the clinical diagnoses most often considered are recurrence of the original malignancy and metastatic disease. Computed tomography provides the most specific information helpful for the detection of these fractures and for exclusion of recurrent malignancy.

The role of computed tomography in evaluation of skeletal metastases.

Computed tomography was performed in 100 patients for additional evaluation of suspected skeletal metastases following radionuclide bone scanning in 86 patients and conventional radiography in all. A retrospective review of these cases revealed that the majority (78%) involved the spine and pelvis. Computed tomography contributed to the diagnosis of a malignancy by revealing a definite destructive lesion of bone in 27 patients who had an abnormal radionuclide bone scan, a normal or inconclusive radiograph, or both. It excluded a malignant lesion in 19 patients. In 38 patients, computed tomography provided additional information that contributed to such aspects of patient care as obtaining tissue diagnosis, determining the extent of lesions, and evaluating the response to treatment. False diagnoses were made in two patients. Detection by computed tomography of a skeletal lesion and histologic documentation, frequently by computed tomography-guided percutaneous needle aspiration biopsy, greatly curtailed an otherwise extensive search for the primary site. Furthermore, this information altered the treatment plan by obviating the need for radical resection or biopsy of the primary tumor and by directing the choice of an appropriate chemotherapeutic regimen.

Lumbar spine after surgery: examination with intravenous contrast-enhanced CT.

Computed tomography (CT) of the lumbar spine without and with intravenous administration of contrast medium was performed in 143 consecutive patients who had previously had spine surgery for disk herniation and had persistent or recurrent symptoms. Fifty-two patients underwent surgical reexploration. It was possible to make the diagnosis of normal postoperative status, disk herniation, or scarring in 31 (60%) of the 52 patients with the use of CT scans without intravenous contrast medium. CT with intravenous contrast enhancement was useful in 12 of the remaining patients (23%). Enhancement of the margins of a herniated disk occurred in 37 (71%) of the patients. There was near-homogeneous enhancement of postoperative scarring in 34 (65%) patients. Intravenous contrast medium was particularly helpful when disk herniation and scarring were both present, by delineating the margins of a herniated disk and enhancing the entire substance of the scar. In symptomatic postoperative patients, CT of the lumbar spine without intravenous contrast medium should be performed initially. If a definitive diagnosis is not established, CT with intravenous contrast enhancement should be considered.

Athlete shoulder injuries: CT arthrographic findings.

Forty-three professional and amateur athletes with persistent shoulder pain that interfered with their sports activities were evaluated by computed tomographic (CT) arthrography. In 19 patients, glenohumeral instability (14 anterior, two posterior, three multidirectional) was diagnosed with CT arthrography based on the simultaneous presence of labral and capsular lesions. The findings were crucial in establishing the diagnosis of instability in six patients in whom the condition was not suggested or could not be confirmed clinically. Another significant injury consisted of labral lesions not associated with glenohumeral instability. These tears often involved the anterior and parasuperior segments of this structure. Other, less frequently detected lesions included segmental labral enlargement and several labra with abnormal orientation (everted labrum). Early onset of degenerative disease was present in many athletes, especially those with a long history of sports activity. CT arthrographic findings were correlated with arthroscopic or surgical results in 19 patients.

Tibial plateau fractures: CT evaluation and classification.

Fractures of the tibial plateau consist of two important components. One is depression of the plateau surface and the other a detached and peripherally displaced component referred to as the split fragment. The classification of these fractures is based on the morphologic appearance as well as the location of the above components. The surgical treatment of these fractures is dependent upon several factors, including the type of fracture, the degree of the fracture depression, and fracture fragment separation as well as the patient's age and physical condition. The degree of the plateau depression is a particularly important criteria for surgical-treatment planning. However, the anatomic configuration of the proximal tibia is such that the fractures of these regions are not adequately visualized on conventional radiographs. In the past, conventional tomography was routinely employed for evaluation of tibial plateau fractures. Recently, computed tomography (CT) has shown to be a more accurate and easier method for evaluation of these fractures. CT can be performed without removal of the knee brace or cast and usually requires less than 12 axial images. Furthermore, the degree of fracture separation and depression can be measured by computerized technique. CT scanning is a reliable method for evaluation and an accurate classification of tibial plateau fractures.