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M Richter

Publications and source records attributed to M Richter.

At least 37 records · Page 2Linked to original sources
PubMed2006

Computer-assisted analysis of lower limb geometry: higher intraobserver reliability compared to conventional method.

Exact radiographic evaluation of lower limb alignment, joint orientation and leg length is crucial for preoperative planning and successful treatment of deformities, fractures and osteoarthritis. Improvement of the accuracy of radiographic measurements is highly desirable. To determine the intraobserver reliability of conventional analysis of lower extremity geometry, 59 long leg radiographs were randomly analyzed 5 times by a single surgeon. The measurements revealed a standard deviation between 0.36 degrees and 1.17 degrees for the angles mLPFA, mLDFA, MPTA, LDTA, JLCA and AMA (nomenclature according to Paley), and 0.94 mm and 0.90 mm for the MAD and leg length, respectively. Computer-assisted analysis with a special software significantly reduced the standard deviation of the mLDFA, MPTA, LDTA, JLCA (each p < 0.001), AMA (p = 0.032) and MAD (p = 0.023) by 0.05-0.36 degrees and 0.14 mm, respectively. Measuring time was reduced by 44% to 6:34 +/- 0:45 min (p < 0.001). Digital calibration by the software revealed an average magnification of conventional long leg radiographs of 4.6 +/- 1.8% (range: 2.7-11.9%). Computer-assisted analysis increases the intraobserver reliability and reduces the time needed for the analysis. Another major benefit is the ease of storage and transfer of digitized images. Due to the varying magnification factors on long leg radiographs, the use of magnification markers for calibration is recommended.

Adult↗
PubMed2005

[Osteonecrosis of the jaws and bisphosphonates].

Widely prescribed, bisphosphonates inhibit bone resorption. They are not metabolised and have long half-lives. Two cases of osteonecrosis of the jaws have recently been attributed to bisphosphonates at the University Hospital of Geneva. The recent literature reveals more than a hundred similar cases throughout the world. Bone exposure appears spontaneously or after dental care. Treatment of the osteonecrosis is controversial and cure very difficult. This pathology is usually seen in patients on chemotherapy, steroids and i.v. bisphosphonates, but is sometimes seen with low-dose p.o. bisphosphonates. In view of the strong association between bisphosphonate therapy and osteonecrosis of the jaw, specialists have recommended dental and oral evaluation during bisphosphonate therapy as well as for several years after drug discontinuation.

Age Factors↗
PubMed2005

Proton beam therapy and iris neovascularisation in uveal melanoma.

PURPOSE: Local treatment of uveal melanoma by radiotherapy involves the use of brachytherapy with radioactive plaques attached to the sclera, or proton irradiation. Both treatments induce growth arrest within the tumour and its slow involution over several years. Although ocular retention rates are excellent, regrowth of tumours due to resistance and neovascular glaucoma leads to enucleation of up to 10% of affected eyes. Proton irradiation involves part of the iris in most cases and we noticed that neovascularisation only occurred in the part of the iris that was not irradiated. We therefore conducted this study to determine the relationship between the development of iris neovascularisation and iris irradiation. METHODS: A total of 21 enucleation specimens from patients who had previously had proton irradiation were collected from the files of the Department of Pathology, Moorfields Eye Hospital during the 5-year period from 1994 to 1999. Sections of these eyes were assessed for VEGF-A, bFGF, and von Willebrand Factor (vWF) by immunohistochemistry. Ophthalmic notes and radiotherapy records were reviewed to assess the extent of iris irradiation. RESULTS: In all, 11 cases showed clinical evidence of iris neovascularisation and were selected for further study. Three of these eyes also showed clinical evidence of regrowth of the tumour. Histological evidence of iris neovascularization was noted in all 11 of the eyes examined, and was only present in the nonirradiated side of the iris in 8/11 eyes. NVI was present on both sides of the iris in three cases, but was less severe in the irradiated part. Expression of VEGF-A was at most weak within the tumour, but was present in the detached retina and in the epithelium of both ciliary body and iris. Some bFGF staining was noted around vessels in the iris stroma. CONCLUSIONS: Our results suggest that irradiation leads to iris atrophy, and that atrophic, irradiated iris is resistant to the development of neovascularisation.

Adult↗
PubMed2005

Cement leakage during vertebroplasty: an underestimated problem?

Overall, vertebroplasty has a low complication rate. Nevertheless, severe complications can occur. The majority of these are related to cement extrusion. The rate of cement leakage is often obtained by X-ray, with only a single leak registration per vertebra. Detection rate of leaks in comparison with CT and inter-observer reliability for X-ray is, in large parts, unknown. We conducted this study to determine the value of fluoroscopy and X-ray used to detect cement leakage as compared to CT scans. Intraoperative findings in lateral fluoroscopy by the surgeon, and postoperative findings in X-rays by two orthopaedic surgeons, were compared with CT scans for the same study group. Multiple cement leakage was considered, and agreement rate was determined. The detection rate for leaks was 34% for lateral X-ray and 48% for lateral and AP view. Additional AP views only enhanced the detection of leaks in the segmental veins. The agreement rate between fluoroscopy/X-ray and CT scans ranged between 66% and 74%, while inter-observer reliability showed only fair agreement. The rate of cement leaks in vertebroplasty is high if multiple leaks are considered in CT scans. Detection rates using X-rays are low and complicated by only fair inter-observer agreement. Leaks in the basivertebral veins are frequently misinterpreted and can lead to severe complications. Therefore, CT scans should be obtained to calculate the exact leakage rate and to assess persistent or new pain occurring postoperatively.

Aged↗
PubMed2005

Multi-frequency EPR and Mössbauer spectroscopic studies on freeze-quenched reaction intermediates of nitric oxide synthase.

It is believed by analogy to chloroperoxidase (CPO) from Caldariomyces fumago that the electronic structure of the intermediate iron-oxo species in the catalytic cycle of nitric oxide synthase (NOS) corresponds to an iron(IV) porphyrin-pi -cation radical. Such species can also be produced by the reaction of ferric NOS with external oxidants within the shunt pathway. We present multi-frequency EPR (9.6, 94, 285 GHz) and Mössbauer spectroscopic studies on freeze-quenched intermediates of the oxygenase domain of nitric oxide synthase which has reacted with peroxy acetic acid within 8-200 ms. The intermediates of the oxygenase domain of both the cytokine inducible NOS (iNOSox) and the neuronal NOS (nNOSox) show an organic radical signal in the 9.6-GHz spectrum overlapping with the spectrum of an unknown species with g-values of 2.24, 2.23 and 1.96. Using 94- and 285-GHz EPR the organic radical signal is assigned to a tyrosine radical on the basis of g-values (i.e. Tyr*562 in nNOSox and Tyr*341 in iNOSox). Mössbauer spectroscopy of (57)Fe-labeled unreacted nNOSox shows a ferric low-spin heme-iron (delta = 0.38 mms(-1), deltaE(Q) = 2.58 mms(-1)). The reaction of nNOSox with peroxy acetic acid for 8 ms leads to the disappearance of the magnetic background characteristic for native nNOSox and a new species with delta = 0.27 mms(-1) and deltaE(Q) = 2.41 mms(-1) is detected at 4.2 K which does not resemble the parameters typical for a Fe(IV) center. It is proposed that this intermediate species corresponds to a ferric low-spin species which magnetically couples to an amino acid radical (presumably Trp*409).

Binding Sites↗
PubMed2005

[Indication for removal of tibial nails].

BACKGROUND: Tibial nail removal has been suggested as a routine procedure for both symptomatic and asymptomatic patients. The aim of this study was to define guidelines for the removal of tibial nails. PATIENTS AND METHODS: A retrospective study on the isolated removal of 69 tibial nails after fracture consolidation was done. A review of the patient charts and radiographs was performed. Forty-four patients (64%) were available for the follow-up interview. RESULTS: Preoperatively, 26 patients (59%) had local complaints. Of these 26 patients, 73% reported an improvement, and 8% reported an aggravation of their local complaints. Of the 18 patients who were asymptomatic before surgery, 17% reported long-term complaints at follow-up. CONCLUSION: We conclude that routine removal of tibial nails should be discussed critically in asymptomatic patients.

Adolescent↗
PubMed2005

[Rhabdomyolysis after administration of diclofenac].

Rhabdomyolysis may develop after various traumatic and nontraumatic circumstances. The use of lipid-lowering statins as well as the abuse of stimulants such as methylendioxymethamphetamine (ecstasy) can lead to fatal rhabdomyolysis with acute renal failure. We describe a case of diclofenac-induced rhabdomyolysis after a cumulative dose of 200 mg per os with consecutive critical increase of the creatine kinase and myoglobin. Prescription of diclofenac should therefore be done with caution. In cases of emergent myalgias, immediate testing of creatine kinase and myoglobin is mandatory to exclude fatal rhabdomyolysis with acute renal failure.

Acute Kidney Injury↗
PubMed2005

[Diabetic muscle infarction-an orthopedic disease pattern?].

Diabetic muscle infarction (DMI) is a largely unfamiliar disease. It affects mainly patients around 40 years of age with long-standing diabetes and concomitant end-organ complications. The symptoms represent a classic pattern of a musculoskeletal disease with muscle pain without trauma, swelling, and functional impairment. Although its short-term prognosis is good, with improvement of the symptoms over weeks or months under analgesia and rest, a high recurrence rate of up to 60% can be observed. Additionaly, the long-term survival of patients after DMI is reduced mostly due to major vascular complications. Since many diabetic patients are in orthopedic care for musculoskeletal disorders, the orthopedic surgeon should be aware of this disease to avoid unnecessary invasive diagnostic procedures and initiate suitable therapy. Furthermore, a better knowledge of the disease could lead to definite conclusions regarding its real incidence and aid in establishing new therapeutic measures for prophylaxis and better long-term survival.

Diabetic Angiopathies↗
PubMed2005

C0h/C2h monitoring of the pharmacodynamics of cyclosporin plus mycophenolate mofetil in human heart transplant recipients.

UNLABELLED: Pharmacokinetic (PK) parameters like C2h have improved efficacy of immunosuppressive therapy. However, drug interactions, toxicities, and individual differences to drug effects still remain challenging. Therefore, this study was designed to assess pharmacodynamic (PD) effects of the combination cyclosporin (CsA) plus mycophenolate mofetil (MMF) on lymphocyte functions in peripheral blood of stable heart transplant recipients (HTx) using our established FACS assays. METHODS: Blood from 25 HTx patients was drawn before (C0h) and 2 hours after dosing (C2h). CsA and mycophenolic acid (MPA) concentrations were measured by EMIT. FACS assessed expression of cytokine production (IL-2, TNF-alpha), lymphocyte proliferation (PCNA), and T-cell activation (CD25, CD95). RESULTS: Evening doses of CsA (25/50/75 or 100 mg) and MMF (250/500 or 1000 mg) produced C0h levels as follows: CsA, 162 +/- 12 ng/mL; MPA, 1.7 +/- 0.2 mg/L. Morning doses of CsA (50/75 or 100 mg) and MMF (250/500/1000 or 1500 mg) produced C2h-levels as follows: CsA, 589 +/- 56 ng/mL and MPA, 7.4 +/- 1.3 mg/L. PD effects at C0h/C2h (% expression +/- SEM, all P < .05) were IL-2, 18 +/- 3/10 +/- 2; TNF-alpha, 12 +/- 2/7 +/- 1; PCNA, 8 +/- 1/5 +/- 1; CD25, 26 +/- 4/13 +/- 2; CD95, 23 +/- 4/11 +/- 2). Correlations (r2) at time point C2h between inhibition of lymphocyte functions (PD) with drug concentrations (PK) and with drug doses were CsA-PK, 0.71 to 0.91; MMF-PK, 0.55 to 0.76; CsA-dose, 0.73 to 0.87; MMF-dose, 0.61 to 0.80. CONCLUSION: For the first time, the immunosuppressive effects of the combination CsA plus MMF were quantified in whole blood of human HTx at different time points. PD assays may offer the opportunity to optimize clinical immunosuppressive drug therapy.

Antigens, CD↗
PubMed2005

[Vertebroplasty--basic science, indications and technique].

INTRODUCTION: Vertebroplasty is a relatively new procedure for the treatment of vertebral body fractures of different origin. Due to early promising results the rate of performed procedures increases constantly. Indeed an increasing number of partially severe complications are reported. A summary of the existing findings seems therefore necessary. METHODS: On the basis of a medline inquiry important aspects of vertebroplasty in the fields of basic science, diagnostics, indications, contraindications, technique, results and complications were compiled. RESULTS: Especially for the field of indications, possible longterm effects and for the "ideal" technique open questions exist, mainly due to missing prospective, randomized long-term clinical trials. CONCLUSIONS: A final assessment of the significance of vertebroplasty for osteoporotic fractures in comparison to conservative treatment is actually not possible. In contrast vertebroplasty is a therapeutical option for malignomas in selected cases.

Biomechanical Phenomena↗
PubMed2005

[Prevention of school sport injuries--an analysis of ballsports with 2234 injuries].

PURPOSE: Ball sport school injuries account for a significant morbidity among children and adolescents. MATERIALS AND METHODS: During a school year 2234 school sport injuries have been reported to the Gemeinde Unfall Versicherung (GUV) Niedersachsen, Germany. RESULTS: Regarding the non-gender-specific distribution of the ball sport disciplines, basketball leads with 32 % (n = 431), followed by soccer (24 %, n = 316), volleyball (17 %, n = 232), handball (8.3 %, n = 110) and hockey (4.9 %, n = 65). Sprains (27 %) dominate in basketball, followed by ligament distorsions and ruptures (23 %) and fractures (21 %), with frequent finger injuries (61 %) without contact of an opponent, and injuries of the lower extremity (28 %). Soccer leads to contusions (29 %), in 52 % of the lower extremity frequently after collision with an opponent (22 %) or the ball (20 %). In volleyball upper extremity injuries (71 %) dominate with 53 % finger sprains in individual volleyball play. CONCLUSION: Ball school sport injuries account for a significant morbidity with frequent finger injuries. Proprioceptive deficits may play a role in those finger injuries in basketball, volleyball and handball. During hockey, severe dental and facial injuries were apparent. A prospective proprioceptive training program aiming on fingers and the ankle region may therefore be a preventive measure such as helmets with facial protection in hockey school sport.

Adolescent↗
PubMed2005

[Health Behaviour in school-aged children--results of the international study "Health Behavior in School-aged Children"].

INTRODUCTION: Childhood and adolescence are critical periods in the development and stabilisation of health behaviour and risk behaviour. Typically, individual health behaviour developed during this phase of life is carried into adulthood. The goal of this data analysis was to conduct an international comparison of adverse health behaviour among adolescents, to interpret differences between countries, and to make recommendations for future health promotion and prevention programmes. METHODS: The international comparative study "Health Behaviour in School-aged Children" (HBSC) serves as the basis for this data analysis. HBSC is conducted by the WHO (World Health Organization) every four years. The four health behaviour indicators selected from the HBSC study for this analysis include tobacco consumption, alcohol consumption, physical activity, and eating behaviour. RESULTS AND DISCUSSION: Large differences in adolescent health behaviour were identified among the countries of the EU and the USA. German youth when compared with youth in other countries, have higher rates for most selected indicators. To enhance success, prevention and health promotion programmes in Germany should adopt effective strategies from other countries, and include gender-specific and comprehensive programming aspects. Based on this comparison, it is recommended that health interventions should be tailored to the cultural, social, economic and political conditions of a particular country.

Adolescent↗
PubMed2005

[The role of social inequality for adolescent health].

PURPOSE: The aim of the study was to investigate socioeconomic differences in adolescent health in Germany. METHODS: Findings are based on data from 5650 11- to 15-year-old German pupils participating in the cross-national study "Health Behaviour in School-age Children" in 2002. RESULTS: Extend and occurrence of health inequalities depended largely on the selected health out comes. Moreover, there were marked gender-specific differences in respect of socioeconomic differences in health. For both, boys and girls, results showed a strong effect of socioeconomic status (parental occupation and family affluence) on overweight. Allergies yielded comparable results in respect of socioeconomic differences. On the other hand, social inequalities had an influence on psychological health mainly in girls. This effect was found for the number as well as for the extent of socioeconomic health differences. No health inequalities were found in respect of injuries, life satisfaction and underweight, independent of gender. CONCLUSIONS: The influence of social inequalities on adolescents' health was considerably more complex and more stratified than expected. The analysis indicates that the special characteristics of adolescence need to be taken into account in the discussion of social inequalities in health. The fact that young people's health is probably less influenced by social inequality then it is during other parts of the life course points attention to adolescence as an important stage for preventive efforts.

Adolescent↗
PubMed2004

Absidia posttraumatic infection: successful treatment with posaconazole.

The class zygomycetes is a large group of filamentous fungi found ubiquitously in nature, primarily in humid soil. Their virulence in immunocompetent hosts is low; therefore, they are usually considered to be contaminants of cultures. In the present study, we describe a patient who had severe traumatic injury with an Absidia infection, who developed intolerance to antifungal treatment with amphotericin B, but responded to posaconazole treatment.

Absidia↗
PubMed2004

Nasopharynx paraganglioma with extension in the clivus.

Paraganglioma is a rare benign tumor arising from the sympathetic nervous system. Here we describe an exceptional case of a paraganglioma located in the nasopharynx with an extension through the clivus up to the dura. Atypically, no contact with any major vessels was found. A radical resection of the mass was performed by an anterior transmaxillary approach through a Le Fort I osteotomy. One year follow up reveals no signs of local or distant recurrence. No cosmetic changes can be observed after the surgery and nasal and masticatory functions are unmodified. We review the clinical presentation, workup of paraganglioma, as well as the surgical approaches to the clivus.

Adult↗
PubMed2004

A new dorsal modular fixation device allows a modified approach in cervical and cervico-thoracic neoplastic lesions.

INTRODUCTION: The aim of this study was to improve the management of cervical tumor osteolysis. A new modular rod-screw implant system for the posterior instrumentation of the occipito-cervical, cervical and cervico-thoracic spine (neon occipito cervical system, Ulrich, Germany) is available since 2000. K-wire guided pedicle screws are used, CT-guided instrumentation is possible. Previous studies have demonstrated increased biomechanical stability compared to established posterior cervical systems. METHODS: The cervical and cervico-thoracic spine of 8 patients (6 males, 2 females, mean age 62 years, range 48-77 years) with osteolysis due to plasmocytoma (n=2), bronchial (n=2), mammary (n=2), esophageal (n=1) and pancreatic (n=1) carcinoma were instrumentated since June 2001. RESULTS: A stable fixation without loosening or failure of the fixation system was achieved in all cases. No impairment of the neurogical status was observed. CONCLUSION: Posterior instrumentation of the cervical spine including the occipito-cervical and the cervico-thoracic region with a new modular angle-stable rod-screw implant system offers good stabilization and allows simultaneous decompression. Since tumor masses are predominantly located in the anterior portion of the spine blood loss can be reduced.

Aged↗