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Biomedical subjects

M Libicher

Publications and source records attributed to M Libicher.

At least 19 recordsLinked to original sources
PubMed2006

Osseous integration of calcium phosphate in osteoporotic vertebral fractures after kyphoplasty: initial results from a clinical and experimental pilot study.

INTRODUCTION: This study evaluated the radiological changes at the bone-cement interface of calcium phosphate cement (CPC) and polymethylmethacrylate (PMMA) 12 months after kyphoplasty. In a pilot experiment, we additionally performed a histomorphometric analysis in osteopenic foxhounds to analyze the process of osseous integration of CPC and PMMA. METHODS: Twenty postmenopausal female patients with 46 vertebral compression fractures (VCF) were treated by kyphoplasty, utilizing CPC (N=28) or PMMA (N=18) for intravertebral stabilization. After a 12-month follow-up, we measured the density changes of border voxels at the bone-cement interface by computed tomography (CT) using dedicated software algorithms. We defined the border-voxel density (BVD) as a parameter of cement resorption at the interface. We also investigated the bone-implant interface in three osteopenic foxhounds by histomorphometry 3, 6, and 12 months after cement implantation. RESULTS: Twelve months after kyphoplasty, only CPC showed a significant decrease of the BVD compared to PMMA (p<0.01), indicating a slow progress of resorption at the interface. Histomorphometry of the dog vertebrae showed near total bone coverage of CPC implants, whereas the PMMA surface exhibited only 30% direct bone contact (p<0.01). We also observed a time-dependent increase in the number of discernable osteons close to the interface of CPC, but no bone tissue within PMMA (p<0.01). CONCLUSIONS: The decrease of the BVD 12 months after kyphoplasty may indicate osseous integration of CPC by: (1) the ingrowth of bone tissue and (2) osteonal penetration close to the interface.

Animals↗
PubMed2006

Transarterial embolization of primary and secondary tumors of the skeletal system.

Percutaneous transcatheteral embolizations of primary and secondary bone tumors are important minimal invasive angiographic interventions of the skeletal system. In most of the cases embolization is performed for preoperative devascularization or as a palliative measure to treat tumor-associated pain or other tumor bulk symptoms. The transarterial embolization of primary and secondary tumors of the skeletal system has been developed to a safe and very effective method. Indications, techniques, results and complications of this minimal invasive interventional therapy for treatment of primary and secondary bone tumors are described and discussed and compared with the newer literature and our own results.

Adult↗
PubMed2006

[Balloon kyphoplasty in the treatment of vertebral fractures].

Approximately 500,000 vertebral fractures occur as a result of osteoporosis every year in Europe. One third of the patients thus affected complain of severe back pain and seek treatment. In the past, the treatment of such fractures was limited to conservative methods, such as the use of braces and analgesics and long-term immobilisation followed by physiotherapy. Since 1998 balloon kyphoplasty, a minimally invasive procedure, has also been available for their treatment. During balloon kyphoplasty a balloon system is introduced into the fractured vertebral body to achieve bitranspedicular augmentation, after which low-viscosity bone cement is injected into the vertebral body, where it sets very quickly. In general the patient can be fully mobilized 24-48 h after the procedure and in most cases the symptoms are then considerably attenuated; many patients are actually free of pain. Published studies and our own experience indicate that balloon kyphoplasty is a safe method of treating painful vertebral compression fractures sustained in various ways and that complications are rare with this procedure.

Back Pain↗
PubMed2006

[Balloon kyphoplasty in the treatment of back pain].

BACKGROUND: Experience of just under 5 years has shown that balloon kyphoplasty can be just as successfully employed as the longer-stablished vertebroplasty for the treatment of back pain due to recent or prior osteoporotic fractures as well as new traumatic fractures. MATERIAL AND METHOD: Among 345 patients with a total of 690 treated vertebral bodies, the change in pain symptomatology was analyzed for a follow-up period of 12 months in 40 study patients who underwent kyphoplasty and a control group of 20 patients. In addition, the pain experienced by a further 29 patients with new traumatic vertebral body fractures was monitored over a 12-month period. These fractures were partly managed by fixateur interne alone and by a combination of fixateur interne and kyphoplasty. RESULTS: The 40 patients treated by kyphoplasty had a baseline VAS score of 26.2+/-2.00, which increased to 44.4+/-3.11 after 12 months, while the respective scores for the control group were 33.6+/-4.21 and 34.3+/-4.35. In the 29 patients with new traumatic vertebral body fractures, the initial VAS score was 62 and after 12 months a distinct reduction of pain was noted with a score of 20 (100 = maximum pain, 0 = no pain). The number of times that the 40 patients managed by kyphoplasty had to consult their general practitioner was significantly reduced by the pain therapy. CONCLUSION: Balloon kyphoplasty verifiably improved the pain symptomatology after vertebral fracture over a period of 12 months. Comparison with the control group, which received the same osteoporosis drug therapy, confirmed the effect of this minimally invasive treatment form.

Adult↗
PubMed2006

[Balloon kyphoplasty in the therapy of vertebral fractures].

Approximately 500,000 vertebral fractures occur as a result of osteoporosis every year in Europe. One third of the patients thus affected complain of severe back pain and seek treatment. In the past, the treatment of such fractures was limited to conservative methods, such as the use of braces and analgesics and long-term immobilisation followed by physiotherapy. Since 1998 balloon kyphoplasty, a minimally invasive procedure, has also been available for their treatment. During balloon kyphoplasty a balloon system is introduced into a fractured vertebral body to achieve bitranspedicular augmentation, after which low-viscosity bone cement is injected into the vertebral body, where it sets very quickly. In general the patient can be fully mobilized 24-48 h after the procedure and in most cases the symptoms are then considerably attenuated; many patients are actually free of pain. Published studies and our own experience indicate that balloon kyphoplasty is a safe method of treating painful vertebral compression fractures sustained in various ways and that complications are rare with this procedure.

Bone Cements↗
PubMed2006

Wound complications following kidney and liver transplantation.

Advances in surgical techniques and immunosuppression (IS) have led to an appreciable reduction in postoperative complications following transplantation. However, wound complications as probably the most common type of post-transplantation surgical complication can still limit these improved outcomes and result in prolonged hospitalization, hospital readmission, and reoperation, consequently increasing overall transplant cost. Our aim was to review the literature to delineate the evidence-based risk factors for wound complications following kidney and liver transplantation (KTx, LTx), and to present the preventive and therapeutic modalities for this bothersome morbidity. Generally, wound complications are categorized as superficial and deep wound dehiscences, perigraft fluid collections and seroma, superficial and deep wound infections, cellulitis, lymphocele and wound drainage. The results of several studies showed that the most important risk factors for wound complications are IS and obesity. Additionally, there are surgical and/or technical factors, including type of incision, reoperation, and surgeon's expertise, as well as comorbidities such as advanced age, diabetes mellitus, malnutrition, and uremia. Preventive management of wound complications necessitates defining their etiological factors so that their detrimental effects on healing processes can be addressed and reduced. IS modalities and agents, especially sirolimus (SRL), and steroids (ST) should be adjusted according to the patient's co-existing risk factors. SRL should be administered three months after transplantation and ST should be tapered as soon as possible. A body mass index (BMI) lower than 30 kg/m2 is advisable for inclusion in a transplantation program, but higher BMIs do not exclude recipients. Surgical risk factors can be prevented by applying precise surgical techniques. Therapeutic modalities must focus on the most efficient and cost-effective medications and/or interventions to facilitate and improve wound healing.

Humans↗
PubMed2005

CT volumetry of intravertebral cement after kyphoplasty. Comparison of polymethylmethacrylate and calcium phosphate in a 12-month follow-up.

This study was intended to measure the volume of intravertebral cement after balloon kyphoplasty with high resolution computed tomography (CT) and dedicated software. Volume changes of biocompatible calcium phosphate cement (CPC) were detected during a follow-up of 12 months. Measurements were compared with a control group of patients treated with polymethylmethacrylate (PMMA). Twenty-three vertebrae (14 CPC, 9 PMMA) of 12 patients were examined with CT using an identical imaging protocol. Dedicated software was used to quantify intravertebral cement volume in subvoxel resolution by analyzing each cement implant with a density-weighted algorithm. The mean volume reduction of CPC was 0.08 ml after 12 months, which corresponds to an absorption rate of 2 vol%. However, the difference did not reach significance level (P>0.05). The mean error estimate was 0.005 ml, indicating excellent precision of the method. CT volumetry appears a precise tool for measurement of intravertebral cement volume. CT volumetry offers the possibility of in vivo measurement of CPC resorption.

Bone Cements↗
PubMed2005

[Treatment of malignant biliary obstructions via the percutaneous approach].

This paper gives an overview of experience and success of percutaneous transhepatic interventions in malignant biliary obstruction. Even after exhaustion of surgical and endoscopic therapy options, the percutaneously inserted stents provide effective palliation. The palliative treatment of malignant jaundice using a stent is an established procedure in clinical practice, particularly whenever the endoscopic, transpapillary approach is not possible due to high obstructions or previous surgery. The technical success rate is very high (about 95-100%), and the complication rate is about 10-30%. Since the patency rate of stents is higher than that of plastic endoprostheses, their primary use is justified despite higher costs, provided the patients are adequately selected.

Drainage↗
PubMed2004

[The evaluation of balloonkyphoplasty for osteoporotic vertebral fractures. An interdisciplinary concept].

BACKGROUND DATA: Patients with osteoporotic vertebral compression fractures frequently complain of pain and a loss of function and mobility. Such fractures are associated with an increased mortality. The common treatment with bed rest, bracing or osteosynthesis does not lead to satisfying results. With two new surgical techniques, vertebroplasty and kyphoplasty, an internal stabilisation of osteoporotic vertebral fractures is possible. METHODS: All patients were treated by kyphoplasty. With a minimal invasive dorsal approach, an inflatable bone tamp is placed in the fractured vertebral body. This tamp can restore the vertebral body height and create a cavity, which is filled with bone cement under low pressure. The advantage of kyphoplasty compared to vertebroplasty is the restoration of the vertebral height and a decreased cement leakage rate. We performed a prospective, interdisciplinary study with a follow-up of 12 months. We treated 192 vertebral fractures in 102 patients. Augmentation was performed with polymethylmethacrylate in 138 cases and with a new injectable calcium phosphate-cement in 54 vertebral bodies. Outcome data were obtained with two different spine-scores and by the radiomorphometric evaluation of x-rays before and after treatment. RESULTS: We noticed a significant improvement in pain and function in 89% of the patients. All patients showed a regain of vertebral height of on average 17%. In 7% of all treated vertebral bodies, we noticed cement leakage, which was, however, far below the rates published for vertebroplasty (20-70%). There were two complications, bleeding due to an unknown coagulopathy and a violation of the myelon by malpunction. CONCLUSION: Kyphoplasty is a reliable and minimally invasive method for stabilizing fractured osteoporotic vertebral bodies. Improvement of pain and function and a regain in height of the treated vertebral body can be accomplished.

Aged↗
PubMed2004

[Evaluation of tibial torsion--comparison of clinical methods and computed tomography].

PURPOSE: To determine variability between clinical goniometric methods and computed tomography (CT) in measuring posttraumatic malrotation of the tibia. MATERIALS AND METHODS: In a prospective study, absolute tibial torsion of both legs after unilateral fracture of the tibia as well as the difference between both legs (intra-individual torsional difference) was postoperatively determined with two goniometric and two CT methods in 40 patients (female : male = 16 : 24, mean age = 46 +/- 34 years). RESULTS: The mean difference between goniometric and CT methods in determining intra-individual torsional difference was not significant. Nevertheless, variance of values was higher in goniometric measurement (up to +/- 11 degree), with the measurements of torsional difference showing two times greater standard deviation in interobserver variability of goniometric methods as compared to CT. CONCLUSION: Goniometric methods do not significantly differ from the CT methods for determination of intraindividual torsional difference. The higher variance of interobserver values limits accuracy of goniometric methods. Therefore, goniometric determination of tibial torsion can only be considered an estimate but not a precise measurement.

Adolescent↗
PubMed2003

[MRI-guided musculoskeletal biopsy].

MRI-guided musculoskeletal biopsy has been mentioned to be a minimally invasive method to obtain specimens for diagnostic purposes in bone tumors. To evaluate the viability, to assess the accuracy, and to record possible complications of this method, clinical data of 19 MRI-guided biopsies were analyzed. Interventions were performed on 18 patients (1-78 years) as an outpatient procedure: 15 skeletal and 4 soft tissue biopsies were taken from the pelvis, upper limb,or lower limb. We used T1-weighted gradient echoes (GE) for locating the puncture site and T2-weighted turbo spin echoes (TSE) for visualization of needle position. In 14 of 18 MRI-guided biopsies, a definite histological diagnosis was obtained. According to the pathologist, the inadequate size of the specimen was the main reason for missing the diagnoses in four cases.Long intervention time and inappropriate biopsy tools proved to be the main disadvantages of MRI-guided biopsy, but technical improvement might solve these technical problems in future.A postbiopsy hematoma was the only complication observed. Once technically improved, MRI-guided biopsy could be a precise alternative routine method for musculoskeletal biopsies in future.

Adolescent↗
PubMed2002

[CT staging of malignant lymphoma. How to avoid misinterpretations].

Therapeutic strategy and prognosis of malignant lymphoma are influenced by staging. Therefore, evaluation of pattern of lymphatic involvement is highly relevant. There are numerous pitfalls possible in detection and description when malignant lymphomas are visualized by computed tomography (CT). Normal anatomic structures may be interpreted as pathologic lymph nodes by inexperienced radiologists. Assessment and detection of lymphomas require precise knowledge of normal anatomic structures as well as roentgenological criteria and adequate methods of imaging. This report provides an overview of the relevant pitfalls and often overlooked areas in staging of malignant lymphomas.

Diagnosis, Differential↗
PubMed2002

[Value of CT-guided biopsy in malignant lymphoma].

Management of diagnosing malignant lymphomas has changed with development of CT-guided techniques and reliable biopsy tools. Pathologists can use representative tissue samples for sub classification in more than 90%. Evaluation of residual lymphoma or relapse can be nearly as effective. Therefore percutaneous biopsy can be considered as primary diagnostic tool in the absence of peripheral lymphadenopathy. CT-guided biopsies can be performed on an outpatient basis under conscious sedation considering contraindications as well as regional complications. Acceptance of percutaneous biopsy by the pathologist and oncologist is based on diagnostic effectiveness that is significantly improved if more than 3 dagger solid tissue samples are taken. This article reviews the value of CT-guided biopsy in comparison to surgical procedures in patients with malignant lymphoma. Essential aspects that lead to a diagnostic percutaneous biopsy are discussed on grounds of the current literature.

Ambulatory Surgical Procedures↗
PubMed2001

[Characteristic perfusion pattern of osseous giant cell tumor in dynamic contrast-enhanced MRI].

PURPOSE: To describe the perfusion pattern of giant cell tumor (GCT) of bone with Gd-enhanced dynamic MR imaging. To compare time-intensity-curves in patients with local recurrence and postoperative alterations without recurrence. METHODS: Nine patients (5 women, 4 men) with GCT of bone underwent 19 dynamic MRI examinations. Mean age was 34 years (range 24-64 years). All diagnoses were proven by pathology. Dynamic contrast-enhanced MRI was performed at 1.0 T using T1-weighted gradient echo sequences. GCT was located in the distal radius (4x), tibia (3x), fibula (1x) and humeral head (1x). RESULTS: All giant cell tumors showed a uniform perfusion pattern with a steep slope and maximum intensity value followed by an early and rapid washout phase. The same pattern appeared in five local recurrences of GCT in four patients. In nine follow-up examinations without local recurrence dynamic MRI yielded in uncharacteristic perfusion patterns. CONCLUSION: These results demonstrate a uniform perfusion pattern of GCT of bone obtained by dynamic MRI. It is characterized by a steep slope followed by an early and rapid washout phase. This characteristic pattern can also be obtained in local recurrences. Dynamic contrast-enhanced MRI appears a helpful method for primary diagnosis of GCT of bone and detection of local recurrences after surgery.

Adult↗
PubMed2001

[Radiological diagnosis in contracted elbow joint. Value of CT and MRI].

A contracture of the elbow joint is a challenge for diagnostic radiology. Radiographs remain the method of choice for primary diagnosis, however, diagnostic confidence can be limited if periarticular ossifications or contracture do not permit evaluation of the whole joint. In these cases, CT or MRI can be used for specific diagnostic problems. Additional multiplanar or three-dimensional reformations can be used by the orthopedic surgeon for planning the surgical procedure. MRI has a great advantage in allowing visualization of muscles, capsula-ligamentous complex and articular cartilage. The main disadvantages are duration of examination time and artifacts. CT is superior in terms of spatial resolution and visualization of bony structures. MRI and CT examinations of the elbow will increase with the number of minimal invasive surgical procedures. Protocols must therefore be optimized with attention to positioning, sequence selection and image processing. This article reviews the current standards of high resolution imaging with CT and MRI, including arthrographic techniques. The pros and cons of both methods are discussed in the setting of a contracture of the elbow joint.

Arthrography↗
PubMed2000

[Hypercalcemia caused by generalized sarcoidosis].

HISTORY AND ADMISSION FINDINGS: A 70-year-old man with a 23-year history of recurrent nephrolithiasis was admitted for evaluation of hypercalcaemia (maximal calcium concentration 3.24 mmol/l). Physical examination on admission was unremarkable except for sensory neuropathy in the right foot. INVESTIGATIONS: Chest radiogram, subsequent transbronchial lung biopsy, gallium scintigraphy and magnetic resonance imaging (MRI) of the vertebrae indicated generalized sarcoidosis, predominantly affecting the mediastinum, lumbar vertebrae and nerves of the distal limbs. Parathormone level was reduced, while the levels of vitamin D metabolites were normal. TREATMENT AND COURSE: Serum calcium level became normal within 2 weeks of starting glucocorticoid treatment. CONCLUSION: Hypercalcaemia can occur in the course of sarcoidosis even in the absence of a elderly increased level of 1,25-dihydroxyvitamin D3. In this case the cause of the hypercalcaemia of a year's duration may have been due to lymphomacrophagocytic infiltration of the bone of several vertebrae as demonstrated by MRI of the vertebral columns but not by conventional radiography. In this case an increase in cytokine secretion by macrophages may have played an important role in addition to the level of 1,25-dihydroxyvitamin D3 at the upper limit of normal that, in view of the renal failure, could only have been caused by extrarenal production. Cytokines (e.g. interleukin-1 beta and tumour necrosis factor alpha) secreted by activated macrophages are among the most powerful stimulators of bone reabsorption.

Aged↗