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Biomedical subjects

J D Laredo

Publications and source records attributed to J D Laredo.

At least 19 recordsLinked to original sources
PubMed2002

[Diagnostic approach to the rheumatoid wrist from plain radiographs].

OBJECTIVE: Monitor a reproducible analysis method based on a simple algorithm. DIAGNOSIS OF RHEUMATOLOGIC DISEASE IN WRISTS: The first step is to examine the joint space. When the space is preserved, diagnosis may be established on the presence of bony defects, demineralization or erosions. DIAGNOSIS OF RHEUMATOLOGIC DISEASE IN FINGERS: The first step is to determine whether the patient has degenerative or inflammatory joint disease involving the joint space or bone disease where bony lesions predominate.

Algorithms↗
PubMed2002

Hip fracture risk and proximal femur geometry from DXA scans.

In this retrospective study of hip fracture risk evaluation from hip dual-energy X-ray absorptiometry (DXA) scans, our objectives were to determine which part of the femoral neck length contributes most to the fracture risk and to define a geometric parameter better than hip axis length (HAL) for discriminating hip fracture patients. Forty-nine Caucasian women with a nontraumatic femoral neck fracture were matched on age to 49 normal women and on both age and femoral neck bone mineral density (BMD) to 49 unfractured women. In addition to BMD, geometric parameters including neck-shaft angle, neck width and several HAL segments were evaluated by discriminant analysis to determine which was the best hip fracture discriminator. Neck-shaft angle had a limited influence on the hip fracture risk. Age-related bone loss was associated with a neck width increase in unfractured and fractured patients. HAL was significantly longer in fractured patients and was a significant discriminator between fractured patients and normal controls. HAL was not significant as a discriminator between fractured and low-BMD unfractured patients. The intertrochanter-head center distance (from the intertrochanteric line to the femoral head center) coincides with the femoral lever arm and includes no segments that adapt to BMD changes, such as the greater trochanter-intertrochanter distance. Among all tested lengths, this segment was the part of HAL that discriminated best between fractured and low-BMD unfractured patients. A longer intertrochanter-head center distance increased the risk of femoral neck fracture among low-BMD patients. Including automatic measurement of this segment in standard DXA protocols may prove useful in identifying patients at high risk for hip fracture. At present, HAL remains the easier neck length to measure, but automatic evaluation of the intertrochanter-head center distance must be a goal for future image analysis development.

Absorptiometry, Photon↗
PubMed2001

Vertebral tumors and pseudotumors.

This article discusses lesions that may present as vertebral tumors at radiologic examination. Conditions are discussed in order of decreasing frequency: pseudotumoral lesions, vertebral metastases, bone marrow diseases, and primary vertebral tumors, which are relatively uncommon. The differential diagnosis between nontraumatic benign and malignant vertebral collapses is also discussed.

Adolescent↗
PubMed2001

Distribution of intracortical porosity in human midfemoral cortex by age and gender.

The purpose of this study was to describe the age-specific distribution of midfemoral intracortical porosity throughout the cortical width in males and females. Microradiography and an automated image analysis system were used to study midfemoral cortical bone specimens from 163 white people, including 77 males and 86 females, in a recent anthropological collection covering a broad age range. In each specimen, porosity (percentage of the cortical bone area occupied by pores), pore number, and pore size were measured throughout the entire cortex and in three cortical subregions of equal width labeled the periosteal, midcortical, and endosteal subregions. For each gender, relationships linking age to porosity, pore number, and mean pore size were assessed using regression analysis. In addition, age- and site-related changes in these three variables were tested for significance using two-way analysis of variance (ANOVA). Age explained 52% of the porosity variance in females and 13.5% in males. In each gender, there were significant age- and site-related differences in porosity, pore number, and pore size. In adults aged 60 years or younger, both pore size and pore number increased with increasing age, whereas in adults older than 60 years, pore size continued to increase but pore number decreased. In males, the age-related changes in pore size and pore number were proportionally similar in the three cortical subregions. In females, in contrast, the changes predominated in the endosteal subregion and resulted in significant cortical thinning.

Adolescent↗
PubMed2001

[Imaging of the wrist and of the hand: what is the best modality?].

The authors describe the indications for radiologic explorations in case of traumatic as well as non-traumatic conditions. In case of trauma of the wrist, the radiologic exploration looks for a fracture, a dislocation or a ligament injury. Initially, postero-antérior and lateral views must be completed with an antero-posterior view, a scaphoid incidence and an oblique view. This initial examination can be completed secondarily by specific views for the carpal bones, dynamic X-Rays, CT scan or arthro CT scan. In non-traumatic cases, radiologic explorations look for osteo-articular or soft tissue abnormalities specific of a inflammatory or degenerative disease. The initial incidence is a postero-anterior view of both hands. It can be completed secondarly by other explorations (other X-Rays, Ultra-sound, CT scan or MRI).

Arthrography↗
PubMed2000

Multifocal osteogenic sarcoma in Paget's disease.

The most serious complication of Paget's disease is sarcomatous degeneration of pagetic bone. Multifocal sarcomatous degeneration occurs mainly in polyostotic Paget's disease. Multifocal Paget's sarcoma is uncommon and can arise in any site. We report two cases of synchronous multifocal sarcomatous degeneration. The two patients were elderly women (aged 77 and 86 years, respectively) who developed sarcomatous lesions concomitantly, in the first case report in left ilium, left tibia, and first lumbar vertebra and in the second case report in the skull, right ilium, and sacrum. Whether these cases are due to the simultaneous development of several primaries or to metastases from a single primary remains unclear.

Aged↗
PubMed2000

Type II autosomal dominant osteopetrosis (Albers-Schönberg disease): clinical and radiological manifestations in 42 patients.

Type II autosomal dominant osteopetrosis (ADO II, Albers-Schonberg disease) is a genetic condition characterized by generalized osteosclerosis predominating in some skeletal sites such as the spine and pelvis. ADO II is rare, and most available clinical descriptions are based on small numbers of patients. We report the clinical and radiological manifestations in 42 ADO II patients. To our knowledge, this is the largest series reported so far. Our inclusion criterion was presence on radiographs of the spine of vertebral endplate thickening, producing the classic sandwich vertebra appearance. We found various patterns of sandwich vertebra, of which we provide a description to assist physicians in diagnosing ADO II. The classic bone-within-bone appearance was present in most but not all skeletal sites. The radiological penetrance of the disease was high (90%) and increased after 20 years of age. As many as 81% of our patients experienced clinical manifestations. Fractures were common (78% of patients) and healed slowly. Hip osteoarthritis developed in 27% of patients and required arthroplasty in 9 of the 16 affected hips. Nonmandibular osteomyelitis occurred in 4 cases (11%). Twenty-four percent of patients had thoracic or lumbar scoliosis. Orthopedic surgery was performed in 52.8% of patients, of whom half had at least three surgical procedures for internal fracture fixation, arthroplasty, limb deformity correction, or treatment of surgical complications. There was a high rate of surgical complications including nonunion, infection, prosthesis loosening, and intraoperative fractures. Nearly two-thirds of patients (64%) had stomatologic manifestations, including mandibular osteomyelitis in 4 patients (11%). Cranial nerve involvement responsible for hearing loss, bilateral optic atrophy, and/or facial palsy was present in 14 patients but was clearly attributable to ADO II in only 6 cases (16%). This large series sheds new light on several aspects of ADO II, most notably the possibility of severe clinical complications. Although other forms of osteopetrosis are considerably more severe, the name "benign osteopetrosis" previously used for ADO II is probably a misnomer.

Adolescent↗
PubMed2000

CT of the middiaphyseal femur: cortical bone mineral density and relation to porosity.

PURPOSE: To determine whether computed tomography (CT) can be used to quantify age- and site-related changes in cortical bone mineral density (cBMD) at the middiaphyseal femur and whether cBMD differences are related to intracortical porosity. MATERIALS AND METHODS: Cortical bone specimens from 163 femurs were studied with CT and microradiography. Femurs were from 77 males and 86 females in a white anthropologic collection covering a broad age spectrum. In each sample, the cBMD was measured in the entire cortical width and in periosteal, midcortical, and endosteal subregions of interest. Age- and site-related changes in cBMD were tested for significance by using a two-way analysis of variance for both sexes. By using linear regression, cBMD was compared with porosity in the entire cortical width and in each subregion. RESULTS: There were significant age-related differences in cBMD (P <.001 in females, P =.008 in males). In addition, cBMD values were significantly different between the three cortical subregions (P <.001 for both sexes), decreasing from the periosteum to the midcortex to the endosteum. The cBMD values were closely related to porosity, and porosity contributed to 71.6% of the variance in cBMD in the overall population. CONCLUSION: CT is effective in the measurement of age- and site-related changes in cBMD. Decreases in cBMD are closely correlated with increased cortical porosity.

Adolescent↗
PubMed2000

[Differential diagnosis of infective spondylodiscitis and erosive degenerative disk disease].

PURPOSE: To assess the value of imaging in the differential diagnosis of erosive intervertebral osteochondrosis (EIVO) versus infectious discitis (ID). MATERIALS AND METHODS: Twelve cases of EIVO and 30 cases of ID were reviewed to define the usefull signs for differential diagnosis on plain films, CT, and MR. RESULTS: No single sign is sufficient, but the association of several signs is suggestive of EIVO: discal vacuum phenomenom, well-defined sclerosis and erosions of vertebral endplates, high signal strip surrounding low signal of vertebral endplates on T1-weighted images. CONCLUSION: Imaging is helpful in difficult differential diagnosis of EIVO versus ID.

Adult↗
PubMed1999

Unusual longitudinal stress fractures of the femoral diaphysis: report of five cases.

We present five cases of a distinctive type of longitudinal stress fracture of the upper femoral shaft in which the fracture line is parallel to the outer surface of the bone, in contrast to the perpendicular orientation to the cortical surface in previously reported cases of diaphyseal stress fractures. In two cases the fracture recurred after 15 and 18 months, respectively.

Aged↗
PubMed1999

Symptomatic lumbar facet joint synovial cysts: clinical assessment of facet joint steroid injection after 1 and 6 months and long-term follow-up in 30 patients.

PURPOSE: To study the results of facet joint intraarticular steroid injections in patients with symptomatic lumbar facet joint synovial cysts. MATERIALS AND METHODS: Data from 30 patients (age range, 44-82 years; mean age, 67 years) with nerve root pain due to a lumbar facet joint synovial cyst and treated with facet joint steroid injection were retrospectively studied. On the basis of MacNab criteria, the clinical course of nerve root pain was evaluated after 1 (n = 30) and 6 (n = 28) months. Data from long-term follow-up (mean, 26 months) were also available in 14 nonsurgically treated patients. RESULTS: After 1 month, the nerve root pain outcome was excellent or good in 20 patients (67%) and fair or poor in 10 (33%). After 6 months, 10 (50%) of these 20 patients still had excellent or good results, and 18 (60%) of the 30 patients had a fair or poor clinical status, 14 of whom underwent surgery; two patients (7%) were lost to follow-up. Excellent and good results were maintained at further follow-up (range, 9-50 months). CONCLUSION: One-third of patients with symptomatic lumbar facet joint synovial cysts had long-lasting acceptable benefit from facet joint steroid injections in this study. Steroid injection should be indicated before surgery.

Aged↗
PubMed1999

Hyperextension vertebral body fractures in diffuse idiopathic skeletal hyperostosis: a cause of intravertebral fluidlike collections on MR imaging.

OBJECTIVE: We describe an intravertebral fluidlike collection observed on MR images in five of six patients who sustained vertebral body fracture through a segment of the spine ankylosed by diffuse idiopathic skeletal hyperostosis. The mechanism of injury, clinical course, conventional radiographs, CT scans, and other MR imaging findings are analyzed. CONCLUSION: Intravertebral fluidlike collections were associated with hyperextension injury of the spine. Well-delineated borders, anterior widening, and associated posterior-element injury are the main MR imaging characteristics of this trauma-related intravertebral fluidlike collection.

Aged↗
PubMed1999

Osteonecrosis-like syndrome of the medial tibial plateau can be due to a stress fracture. MR findings in 13 patients.

OBJECTIVE: To demonstrate the contribution of magnetic resonance imaging to the elucidation of mechanisms involved in "osteonecrosis-like syndrome of the medial tibial plateau". PATIENTS AND METHODS: A magnetic resonance study with sagittal and coronal sections was done in 13 patients (age range, 57-95 years) two weeks to four months into a painful syndrome meeting the definition of "osteonecrosis-like syndrome of the medial tibial plateau". Gadolinium injection was used in nine patients. Clinical symptoms resolved within a few weeks in all 13 cases. RESULTS: T1-weighted images without gadolinium showed diffuse low signal from the epiphysis (n = 12) containing an area of even lower signal seen either as a crescent-shaped subchondral image (n = 3/12) or as a linear image (n = 9/12). On postgadolinium images, the low signal was abolished except for a line of low signal parallel to the subchondral bone. T2-weighted images demonstrated diffuse high signal from the medial tibial plateau with persistence of the line of low signal (n = 8/12). CONCLUSION: Magnetic resonance imaging allows to analyze the anatomic lesion responsible for "osteonecrosis-like syndrome of the medial tibial plateau". Our magnetic resonance findings were similar to those seen in stress fractures at other sites.

Aged↗
PubMed1999

Osteoid osteoma of the acetabulum. Three cases treated by percutaneous resection.

The acetabulum is a rare location for osteoid osteoma. Conventional surgery of such lesions may require either a large bone resection, an arthrotomy, or a hip dislocation. This report describes the technique and results of percutaneous lesion removal using computed tomography guidance in three osteoid osteomas of the acetabulum. Histologic confirmation was obtained in the three cases. The three patients experienced complete pain relief with a mean followup of 36 months.

Acetabulum↗