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Biomedical subjects

B Ghelman

Publications and source records attributed to B Ghelman.

At least 19 recordsLinked to original sources
PubMed2001

Bone density adjacent to press-fit acetabular components. A prospective analysis with quantitative computed tomography.

BACKGROUND: The status of periprosthetic bone stock is an important concern when revision total hip arthroplasty is undertaken. Remodeling of periprosthetic femoral bone after total hip arthroplasty has been studied extensively, and the phenomenon of femoral stress-shielding has been well characterized. Finite element analysis and computer-simulated remodeling theory have predicted that retroacetabular bone-mineral density decreases after total hip arthroplasty; however, remodeling of periprosthetic pelvic bone in this setting has yet to be well defined. This study was conducted to evaluate the short-term natural history of periacetabular bone-mineral density following primary total hip arthroplasty. METHODS: Periacetabular bone-mineral density was studied prospectively in a group of twenty-six patients who underwent primary hybrid total hip arthroplasty for the treatment of advanced osteoarthritis. Density within the central part of the ilium (directly cephalad to a press-fit acetabular component) was assessed with serial quantitative computed tomography. Baseline density was measured within the first five days following the total hip arthroplasty. Ipsilateral density measurements were repeated at an average of 1.28 years postoperatively. Density values at corresponding levels of the contralateral ilium were obtained at both time-points in all patients to serve as internal controls. RESULTS: Bone-mineral density decreased significantly (p< or =0.001) between the two time-points on the side of the operation. The mean absolute magnitude of the interval density reduction (75 mg/cc) was greatest immediately adjacent to the implant (p<0.001), but it was also significantly reduced (by 35 mg/cc) at a distance of 10 mm cephalad to the implant (p = 0.001). Relative declines in mean density ranged from 33% to 20% of the baseline values. No focal bone resorption (osteolysis) was detected at the time of this short-term follow-up study. With the numbers available, no significant interval alteration in bone-mineral density was found on the untreated (internal control) side (p> or =0.07). CONCLUSIONS: We suggest that the observed decline in bone-mineral density represents a remodeling response to an altered stress pattern within the pelvis that was induced by the presence of the acetabular implant. This finding corroborates the predictions of finite element analysis and computer-simulated remodeling theory. It remains to be seen whether this trend of atrophy of retroacetabular bone stock will continue with longer follow-up or will ultimately affect the long-term stability of press-fit acetabular components.

Acetabulum↗
PubMed2000

Association between findings of provocative discography and vertebral endplate signal changes as seen on MRI.

Provocative discography is a controversial diagnostic tool for pathologic discs. Modic has identified vertebral endplate signal changes on magnetic resonance imaging (MRI) that are thought to signify advanced discogenic degeneration. These two distinct diagnostic tools are examined to determine if there is association between them. Fifty-three consecutive patients who underwent both investigations were retrospectively reviewed. In discs that had negative T1 MRI findings, 28.2% of patients had concordant pain and 17.3% had discordant pain. In discs with positive T1 MRI findings, 34.8% of patients had concordant pain and 17.4% had discordant pain. 79.5% and 74.4% of levels with patient concordant pain on discography had no endplate changes on T1- and T2 weighted MR images, respectively (compared with 84.5% and 81.7%, respectively, for levels with no patient pain on discography). Our data showed no significant relationship between these distinct diagnostic tools. Further investigation of their relative roles in this application is recommended.

Adult↗
PubMed1998

Biopsies of the musculoskeletal system.

Percutaneous biopsies of musculoskeletal lesions are a safe, economical, and reliable method of obtaining a diagnosis. Most of these biopsies are done under CT guidance, but fluoroscopy is an alternative. Conditions that can be discovered through percutaneous biopsies include metastases, primary benign tumors, infection, and metabolic disease. Experience with invasive procedures and with imaging equipment are the requirements for a physician interested in performing these biopsies.

Aftercare↗
PubMed1998

Ultrasound screening for deep venous thrombosis after total knee arthroplasty. 2-year reassessment.

The efficacy of ultrasound compared with ascending venography for the detection of deep venous thrombosis immediately after total knee arthroplasty was assessed after a 2-year interval. One hundred thirty-seven patients were eligible for the study; however, 31 patients received only one of the screening methods and a color Doppler examination was inconclusive in six patients. Therefore, 100 patients had a Doppler examination and a venogram. Overall, the sensitivity of ultrasound was 85%, the specificity 97%, the positive predictive value 85%, the negative predictive value 97%, and the accuracy 95%. The sensitivity in the calf was 83%, in the popliteal vein 86%, and in the femoral vein 100%. Two years ago, the initial assessment of ultrasound for the detection of deep venous thrombosis after surgery in patients who had total joint arthroplasty revealed a 75% sensitivity, 99% specificity, 91% positive predictive value, 97% negative predictive value, and 97% accuracy. The sensitivity in the calf was 83%; the sensitivity in the popliteal vein was 40%; and the sensitivity in the femoral vein was 50%. After 2 years of using this screening test with one technician and one radiologist, an improvement with this noninvasive technique was shown. However, it was found that Doppler imaging is not as sensitive as venography for detecting calf thrombi. Any imaging technique should be validated by each institution to determine the validity of the instrument and the learning curve of the technician administering the examination.

Adult↗
PubMed1995

Computerized tomography for the evaluation of posttraumatic multiplane deformities of the tibia.

Traditional assessment of posttraumatic multiplane deformities of the tibia includes radiographic evaluation with anteroposterior, lateral, and oblique radiographs for assessment of the coronal and sagittal deformities, and scanograms, teleroentgenograms, or orthoroentgenograms for the determination of limb length. Standard clinical measurements are used for the determination of rotational deformity. We report our technique and experience using a selected computerized tomography examination that provides accurate information necessary for the exact determination of the tibial deformity, and the preoperative planning of its correction. The technique is accurate, cost-effective, and safe, with less radiation exposure to the patient.

Costs and Cost Analysis↗
PubMed1994

Recurrent disk versus scar in the postoperative patient: the role of computed tomography (CT)/diskography and CT/myelography.

The purpose of this study was to compare computed tomography (CT)/myelography and CT/diskography images, in a given patient, as a method of distinguishing postoperative fibrosis from recurrent herniated disk material. The study population consisted of 20 patients who had undergone lumbar diskectomy and subsequently developed recurrent radicular pain. All patients underwent CT/myelography and CT/diskography, each procedure performed within 72 h of the other. Comparison of transaxial images from CT/myelography and CT/diskography at a given disk space level yielded the following results: in 12 patients the extradural mass seen via CT/myelography corresponded entirely to the contrast-filled disk fragment seen via CT/diskography (recurrent herniated disk); in three patients the extradural mass seen via CT/myelography was larger than the disk fragment seen via CT/diskography (recurrent herniated disk and fibrosis); and in five patients CT/diskography images appeared normal, but CT/myelography showed an extradural mass (fibrosis). Fifteen patients underwent surgical reexploration with the following results: in three of three patients, the suspicion of recurrent herniated disk and fibrosis by radiologic evaluation was confirmed by surgical reexploration; in nine of 12 patients, solely recurrent herniated disk shown by radiologic criteria was similarly confirmed. The remaining five patients presumed to have fibrosis by radiologic criteria were treated nonoperatively.

Adult↗
PubMed1993

Synovial plicae and chondromalacia patellae: correlation of results of CT arthrography with results of arthroscopy.

The purpose of this study was to compare computed tomographic (CT) arthrography with arthroscopy in the evaluation of patients with anterior knee pain. The authors studied 23 patients with patellar plicae at CT arthrography. Twenty of 21 patients presumed to have medial plicae at arthroscopy had similar findings at CT arthrography (sensitivity, 95%; specificity, 100%). However, 10 of 12 suprapatellar plicae and 11 of 11 lateral plicae seen at CT arthrography were not seen at arthroscopy. All 11 patients with a diagnosis of no or mild chondromalacia patellae at arthroscopy had similar CT arthrographic findings, whereas seven of 11 patients presumed to have moderate or severe chondromalacia patellae at arthroscopy had matching CT arthrographic results (sensitivity, 100%; specificity, 73%). CT arthrography was much more accurate in classifying plicae as thick (66%) as opposed to classifying plicae as thin (17%). The authors conclude that CT arthrography is an accurate and specific modality for distinguishing patients with anterior knee pain due to plicae from those with anterior knee pain due to differing causes.

Adult↗
PubMed1992

Imaging of the patellofemoral joint.

Abnormalities of the patellofemoral joint are one of the main problems in internal derangement of the knee. The role of different imaging modalities (plain radiographs, CT, CT/arthrograms, radionuclide scans, and MR imaging) is discussed in this article.

Femur↗
PubMed1991

Percutaneous computed-tomography-guided biopsy of the thoracic and lumbar spine.

Axial computed tomographic scans were used to guide percutaneous needle biopsies in 76 patients with thoracic and lumbar spinal lesions. Prebiopsy evaluation included spine radiographs, radionuclide bone scans, computed tomographic scans, magnetic resonance imaging scans in some cases, and coagulation studies. Forty-five patients were diagnosed as having metastatic lesions, 11 infection, and 12 primary bone tumors. Of all patients, 34 had lytic vertebral lesions with significant collapse and questionable spinal stability. Six of those had a concomitant paravertebral mass. A clinical and pathologic correlation was completed for each of the cases studied. Histologic diagnosis confirming the clinical suspicion was obtained on the first biopsy attempt in 65 (86%) of the 76 cases.

Biopsy, Needle↗
PubMed1991

Multiple giant cell tumors and Paget disease of bone: radiographic and clinical correlations.

The clinical and radiographic findings of four patients with multicentric giant cell tumor (GCT) of bone and Paget disease were retrospectively reviewed. Three patients underwent magnetic resonance (MR) imaging evaluation; all patients underwent computed tomography (CT). The MR characteristics of the bone component in pagetic GCT appeared to reflect the pagetic phase; a sclerotic pattern was largely represented by hypointense marrow signal intensity on images obtained with both long and short repetition times (TRs) and echo times (TEs). Conversely, a tumor appearing in a mixed pagetic phase demonstrated more heterogeneous signal intensity with all pulse sequences. Extensive soft-tissue components, noted in all cases, showed largely intermediate signal intensity on short TR/TE images and foci of increased signal intensity on longer TR/TE images. In most cases, dramatic reduction in tumor bulk was noted with the use of steroids alone. An awareness of this entity is important because the appearance of lytic lesions with soft-tissue extension in patients with Paget disease does not necessarily imply a grave prognosis. Serial CT or MR imaging is helpful in monitoring the remissions and exacerbations that reflect response to therapy in Paget disease and GCT.

Aged↗
PubMed1991

Progression and regression of deep vein thrombosis after total knee arthroplasty.

In this study, patients indicated for primary total knee arthroplasty were prospectively evaluated with serial ascending venography in the index extremities to elucidate the incidence, timing, and evidence of propagation or diminution of any associated deep vein thrombosis. One of 30 limbs evaluated with preoperative venography was positive. Seventy-six knees in 59 patients were evaluated with early and late postoperative venograms. Overall, 47% of limbs were positive at early venography and 54% were positive at late venography. Comparison of early and late results revealed that, in the unilateral arthroplasty group, 86% of eventually positive limbs were already positive within one day after surgery. In the bilateral arthroplasty group, 85% of eventually positive limbs and 87% of eventually positive patients were already positive within one day after surgery. Five percent of unilateral arthroplasty patients and 12% of knees in bilateral arthroplasty patients demonstrated thrombosis proximal to the deep veins of the calf at the early venogram. Late venography demonstrated thrombus formation proximal to the deep veins of the calf in 12% of knees in the unilateral and bilateral groups. No limbs with thrombi less than 9 cm in length at early venography demonstrated thrombosis in or proximal to the popliteal vein at late venography. All thromboses demonstrating propagation into or above the popliteal vein between the early and late venograms did so despite warfarin therapy that had been initiated at the time of the initial positive venogram.

Aged↗
PubMed1991

Bilateral femoral retroversion associated with acetabular dysplasia. A case report.

Retroversion of the proximal femur is associated with a number of acquired conditions but is unusual in a congenital form. It is even more unusual to be associated with acetabular dysplasia. A 38-year-old woman with bilateral hip pain had roentgenographic evidence of acetabular dysplasia with valgus neck-shaft angles. Physical findings were consistent with femoral retroversion, and computed tomography demonstrated 28 degrees of retroversion on both sides. Symptomatic relief was obtained with bilateral varus internal rotation osteotomies of the proximal femur. To date, a case of retroverted femora associated with acetabular dysplasia seems not to have been reported in the literature.

Acetabulum↗
PubMed1990

Posterior limbus vertebrae: a cause of radiating back pain in adolescents and young adults.

Four cases of posterior limbus vertebrae are presented, three in the lumbar spine and one in the lower thoracic spine. All four patients have myelographic documentation of herniated disc material affecting the spinal canal. One patient underwent an additional discogram that confirms the pathophysiology of the limbus vertebra by demonstrating that contrast material injected into the nucleus pulposus tracks between the body and the detached fragment.

Adolescent↗