Biomedical subjects
Publications and source records attributed to J D Laredo.
This article details many of the latest developments in the field of musculoskeletal interventional radiology. Some of the topics included in this discussion are percutaneous biopsy of musculoskeletal lesions, automated percutaneous discectomy, facet joint arthrography, percutaneous vertebroplasty, and percutaneous drainage of abscesses.
A randomized clinical trial was conducted to compare the results of automated percutaneous discectomy with those of chemonucleolysis in 141 patients with sciatica caused by a disk herniation; 69 underwent automated percutaneous discectomy and 72 were subjected to chemonucleolysis. The principle outcome was the overall assessment of the patient 6 months after treatment. Treatment was considered to be successful by 61% of the patients in the chemonucleolysis group compared with 44% in the automated percutaneous discectomy group. At 1-year follow-up, overall success rates were 66% in the chemonucleolysis group and 37% in the automated percutaneous group. Within 6 months of treatment, 7% of the patients in the chemonucleolysis group and 33% in the discectomy group underwent subsequent open surgery. The complication rates of both treatment groups were low, with the exception of a high rate of low-back pain in the chemonucleolysis group (42%). The results of this trial confirm previous controlled studies on chemonucleolysis and suggest that controlled studies should be carried out before automated percutaneous discectomy can be considered a useful intervention.
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Long-term radiologic follow-up, from the age of 1 year to 27 and 28 years respectively, was performed for two patients with the XXXXY chromosome anomaly. The patients remained sexually immature; the major abnormality observed radiologically was delayed maturation of the skeleton, the growth plates persisting into adulthood. Early degeneration of the articular cartilage, particularly at the elbows, was observed, along with hypertrophy of the epiphyses and radiohumeral dislocation. One of the patients had intra-articular osteochondroma of the left elbow of unknown cause. Cerebral computed tomography showed enlargement of the lateral ventricles in both patients and the formation of pneumatic cavities in the parietal bones in one.
The prevalence of neurological complications in patients with osteoporotic vertebral collapse and the risk factors for neurological compromise were studied retrospectively in 138 inpatients. Six per cent of patients had objective neurological loss. Patients with neurological loss were more likely to have changes suggestive of malignant disease on roentgenograms, computed tomography, and magnetic resonance imaging. Diagnosis was based on magnetic resonance imaging and examination of vertebral biopsy specimens. Comparison of patients with and without neurological loss suggested that an intravertebral vacuum phenomenon and/or a cortical osteoporosis may cause fracture of the posterior wall and therefore compression of neurological structures.
Erdheim-Chester disease is an endogenous, non-genetically-determined lipidosis characterized by infiltrates of foamy, lipid-laden histiocytes and by bilateral symmetric foci of sclerosis in appendicular long bones. The clinical spectrum ranges from focal bone lesions to systemic disease with life-threatening visceral involvement. In one third of patients, roentgenograms show focal osteolysis within areas of sclerosis. Authors report a new case of Erdheim-Chester disease documented by two bone biopsies in different sites. Features in their patient included: 1) osteolysis and sclerosis of the long bones of the limbs and maxillas, with CT scan evidence of cortical rupture; 2) on magnetic resonance imaging studies, heterogeneous foci of decreased signal intensity on T1 images and heterogeneous areas of moderately increased signal intensity on T2-weighted images; 3) increased serum osteocalcin levels; 4) laboratory evidence of chronic inflammation with no extraosseous manifestations. The clinical, radiological, and pathological features of Erdheim-Chester disease are different from those of Langerhans cell histiocytosis. However, three cases of patients with both conditions have been reported in the literature, suggesting that there may be links between the two diseases.
Imaging of the knee is one of the main indications of MRI in musculo-skeletal diseases. Some of the most recent papers dealing with MR imaging of the knee are discussed in this review article. Abnormal conditions reviewed are meniscal injuries including those occurring in previously operated menisci, osteochondral fractures, osteochondritis dissecans and rheumatoid arthritis.
Eight cases of spinal sarcoma complicating Paget's disease seen in different centers were reviewed. Clinical and radiological features of this condition were determined on the basis of these 8 cases and of 51 previously published cases. In the current series as well as in previous reports, most cases involved the lumbar and sacral spine and manifested as low back pain with sciatica and early development of neurological deficits. Roentgenographic diagnosis proved difficult because of the anatomic complexity of the spine and architectural changes characteristic of the pagetic bone. The most common radiological features was a mixed pattern with both sclerosis and central osteolysis. Computed tomography performed in one patient of current series disclosed osteolysis of the sacrum (not visible on plain roentgenograms) with tumor spread to adjacent soft tissues. Features shared by spinal and nonspinal sarcomas complicating Paget's disease include advanced mean age of patients, predominance of osteogenic sarcomas among histologic forms, increased risk of sarcoma in polyostotic Paget's disease, and a very grim prognosis. Development of a neurological deficit in a patient with Paget's disease is an unusual occurrence which should suggest sarcomatous transformation. Roentgenographic changes are difficult to identify on plain films of the spine and consequently CT scan studies are warranted whenever a sarcoma is suspected.
This study of the topographic distribution of tumoral and pseudotumoral lesions of the proximal femur shows that certain lesions have a preferential site, for example osteoid osteoma affects the internal cortex of the neck and diaphysis or the intertrochanteric zone; chondroblastoma occurs in zones of epiphyseal ossification of the head; fibrous dysplasia affects the femoral neck, while sparing the epiphyseal femoral head and trochanters. The island of osteosclerosis is situated, at least partially, in the support fan; so-called physiological cysts are situated on or above the midline of the neck and below the basicapital line. Osteolytic or mixed metastases preferentially involve Ward's triangle in the femoral neck and the intertrochanteric region. The sites of these lesions therefore appears to depend on the bony architecture which, in turn, is dependent on mechanical stresses. However, this purely morphological study fails to demonstrate whether mechanical stresses influence the development of these lesions.
The authors review the embryology of the hip joint with its pathological implications. The radioanatomy is presented in an elementary fashion, with the appearance of each component as seen on the various imaging techniques (conventional X-rays, CT scan, MRI). The authors also describe the views used in conventional radiology and the invasive techniques of arthrography and arthroscanning.
Nuclear magnetic resonance has shed new light on our understanding of osteonecrosis of the femoral head. It is at present the most sensitive and most specific imaging technique for the diagnosis of this condition. Studies involving correlations between MR images and anatomical findings have facilitated the understanding of tissue changes responsible for magnetic appearances. However, all problems are not resolved. At an early stage, fortunately almost always asymptomatic, false negative MRI or MR findings similar to those of algoneurodystrophy of the hip can be encountered. The aim of this article is to pinpoint the current status of these questions on the basis of a review of the recent literature. The contribution of MRI with injection of Gadolinium and future prospects are also discussed.
A 69-year-old woman with a 25-year history of recurrent sciatica presented with an expanding lytic lesion of the right side of the first sacral vertebra. Histological examination proved the lesion to be a DF. DF is usually diagnosed in young patients and is very rarely located in the spine and sacrum. The growth rate of the tumor was presumed to be very low because it had not progressed from radiological studies performed 9 years previously. The clinical, radiological, and pathological features of DF are described, and the differential diagnoses are discussed. The most difficult problem is to distinguish DF from a low-grade fibrosarcoma or chordoma.
The understanding of carpal instability and their radiological signs are based on a knowledge of the anatomy and complex physiology of the wrist. This article successively deals with the physiological anatomy, radiological technique, normal static and dynamic radiological features, radiographic signs of various types of instability and therapeutic principles.
In 21 patients with computed tomography-diagnosed lumbar herniated nucleus pulposus, nerve root pain resolved after conservative treatment. A subsequent computed tomography scan was performed 6 months or more after presentation. This follow-up computed tomography scan was compared with the initial one. A definite decrease in size of the herniated nucleus pulposus was observed in 14 patients: disappearance in 5, obvious decrease in 5, and moderate decrease in 4. No definite change was observed in seven patients. Major computed tomography scan changes occurred significantly more frequently in large herniated nucleus pulposus than in small ones (p. less than 0.05). This study suggests that large lumbar herniated nucleus pulposus can decrease and even disappear in some patients treated successfully with conservative care.
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We report a case of chondrosarcoma of the femoral neck wrongly considered as a normal variant during a long time due to the initial aspect on the plain films and its location. Precise radiological criteria must allow the differential diagnosis and will be detailed.
Many significant papers in the current literature on musculoskeletal trauma deal with new advances in MR imaging. The increasing role of MR imaging in the evaluation of traumatic lesions of the knee explains the number of papers dealing with the differentiation of true traumatic lesions from normal variants or clinically insignificant changes. Other contributions on musculoskeletal trauma deal with more conventional imaging techniques, such as arthrography, plain films, and even complex tomography.
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