Biomedical subjects

A Katzer

Publications and source records attributed to A Katzer.

At least 19 recordsLinked to original sources

PubMed2006

[Chronic cobalt poisoning in endoprosthetic replacement].

This article outlines symptoms and therapeutic options in chronic cobalt poisoning including a case report in which metallosis caused by a ceramic-metal articular pairing led to almost complete loss of sight and hearing after revision of a total hip prosthesis. At primary revision the firmly incorporated stem was left in place. For a better offset only the head was exchanged from a ceramic to a metal model which articulated with a socket containing a ceramic inlay. Postoperatively, movement of the hip joint became increasingly uncomfortable and painful. After 2 years, the patient started complaining about increasing impairment of his eyesight followed by a gradual loss of hearing. In a second revision, examination of the explanted material showed almost complete deterioration of the metal femoral head and a partially fractured ceramic inlay with extensive contamination of the bone and surrounding soft tissue by metal debris. At the time of revision increasing concentrations of the alloy elements cobalt, chromium, and molybdenum were measured in the serum and liquor. The concentration of cobalt, in particular, was remarkably high. Treatment options in cases with chronic cobalt poisoning include chelation therapy with EDTA or BAL/DMPS.

Arthralgia↗

PubMed2006

Single-stage revision of peri-prosthetic infection following total elbow replacement.

This study reviews the predisposing features, the clinical, and laboratory findings at the time of diagnosis and the results of single-stage revision of prosthetic replacement of the elbow for infection. Deep infection occurred in six of 305 (1.9%) primary total elbow replacements. The mean follow-up after revision was 6.8 years (6 months to 16 years) and the mean age at the time of revision was 62.7 years (56 to 74). All six cases with infection had rheumatoid arthritis and had received steroid therapy. The infective organism was Staphylococcus aureus. Four of the six elbows had a developed radiolucency around one component or the other. Successful single-stage exchange arthroplasty was carried out with antibiotic-loaded cement in five of the six cases. In one, the revision prosthesis had to be removed following recurrence of the infection. The functional result was good in three elbows, fair in one, poor in one and fair in the resection arthroplasty.

Aged↗

PubMed2005

One-stage exchange shoulder arthroplasty for peri-prosthetic infection.

There are few reports in the literature of the diagnosis and treatment of the infected shoulder arthroplasty. Most deal with resection arthroplasty and two-stage exchange surgery. We present our results of one-stage exchange operation as treatment for the infected shoulder arthroplasty. Our group comprised 16 patients (ten men, six women) with 16 infected arthroplasties. By the time of follow-up, two patients had died (mean 5.8 years), two could not be located and three had already undergone revision surgery. Nine patients were thus available for clinical examination and assessment. The infections were largely caused by staphylococci, Propionibacterium species and streptococci. Two were early infections (within three months of surgery) and 14 were late infections. The mean follow-up was 5.8 years (13 months to 13.25 years) when the mean Constant-Murley score was 33.6 points and the mean University College of Los Angeles score 18.3 points. Further revision was performed in three patients. One sustained a peri-prosthetic humeral fracture, another developed an acromial pseudarthrosis after transacromial surgery and the third suffered recurrent dislocations. No patient had a recurrence of infection. A one-stage exchange procedure using antibiotic-loaded bone cement eradicated infection in all our patients and we suggest that such a procedure is at least as successful as either a resection arthroplasty or a two-stage exchange in the management of the infected shoulder arthroplasty.

Aged↗

PubMed2004

Is "aseptic" loosening of the prosthetic cup after total hip replacement due to nonculturable bacterial pathogens in patients with low-grade infection?

BACKGROUND: Loosening of the prosthetic cup is the limiting factor in the service life of total hip prostheses (THPs). Despite effective culture methods, the detection of low-grade infection in patients with loose implants still presents a challenge. It is crucial to distinguish between "aseptic" loosening and loosening due to periprosthetic infection, so that appropriate treatment can be administered. We investigated whether aseptic loosening of the acetabular components of THPs is due to unrecognized infection. METHODS: From October through December 2002, a total of 24 patients with acetabular cup loosening were investigated. Only patients without clinical signs of infection and with negative results of bacteriologic culture of synovial fluid (obtained by preoperative aspiration) were included in the study. Intraoperative biopsy samples obtained from the neocapsule and synovia (e.g., the interface membrane) were examined by means of routine culture methods and by polymerase chain reaction (PCR) for detection of 16S ribosomal RNA (rRNA). Control subjects included 9 patients undergoing primary hip arthroplasty. RESULTS: C-reactive protein levels and erythrocyte sedimentation rates were slightly elevated in the group with loosening, compared with the control group, but the difference was not statistically significant. PCR and routine culture showed no microorganisms in either group, with the exception of 1 patient in the loosening group. CONCLUSIONS: PCR for detection of 16S rRNA in tissue specimens obtained from hip joints is not superior to routine bacteriologic culture techniques for detection of low-grade infections. However, these results demonstrate that the loosening of cups in THPs do not usually result from nonculturable periprosthetic infection, if the microbiological processing is adequate.

Aged↗

PubMed2003

In vitro toxicity and mutagenicity of CoCrMo and Ti6Al wear particles.

Contact of wear particles with body fluids can result in widespread dissemination of extractable constituents from joint implants. The aim of this in vitro study is to clarify whether there is a mutagenic and/or carcinogenic risk from CoCrMo and Ti6Al wear particles. Particles of a representative size were produced by fretting; toxicity and mutagenicity were investigated using the salmonella/microsome test according to AMES and the V79-HGPRT Test (Chinese Hamster Fibroblasts). To obtain the greatest possible elution of all constituents the metallic wear particles were extracted with dimethylsulfoxyd and water and the resulting eluates mixed together. Neither the bacterial assay nor the mammalian cell system after repeated test series under standardised conditions produced evidence of a toxic or mutagenic effect in the concentration range under study. It is therefore not to be expected that CoCrMo or Ti6Al alloys initiate carcinogenesis in the human organism.

Aluminum↗

PubMed2003

[In vitro toxicity and mutagenicity of CoCrMo and TiAl wear particles].

Contact of wear particles with body fluids can result in widespread dissemination of extractable constituents from joint implants. The aim of this in vitro study is to clarify whether there is a mutagenic and/or carcinogenic risk from Co(28)Cr(6)Mo and Ti(6)Al(4)V wear particles. Particles of a representative size were produced by fretting; toxicity and mutagenicity were investigated using the Ames Salmonella/microsome test and the V79-HGPRT Test (Chinese hamster fibroblasts). To obtain the greatest possible elution of all constituents, the metallic wear particles were extracted with DMSO and water and the resulting eluates mixed together. After repeated test series under standardized conditions, neither the bacterial nor the mammalian cell assays produced evidence of toxic or mutagenic effects in the concentration range under study. It is therefore not to be expected that CoCrMo or TiAl alloys initiate carcinogenesis in the human organism.

Alloys↗

PubMed2003

[Endoprosthetic surgery of the elbow].

Artificial joint replacement has found a firm place in orthopaedic surgery since its first introduction in the late 1960s. While the initial fixed bearing implants tended to progress to early loosening, the development of so-called "sloppy joints" has seen a major advance in the survival and success rate of this arthroplasty. The surgical approach and technique have also been modified in such a way as to allow a complete ventral release of a flexion contracture, while at the same time preserving the integrity of the extensor mechanism. In this way, the improvement of the biomechanics of the implant combined with diligent surgical technique have enhanced this procedure dramatically. Between 1978 and 1999, 305 GSB 3-type prosthesis were implanted, with the underlying pathologies being rheumatoid arthritis (77%), posttraumatic arthritis (21%) and degenerative arthritis (2%). The range of motion could be significantly improved from the pre-operative state for extension as well as flexion. This was even more obvious in the rheumatoid than in the posttraumatic situation. The survival rate for this type of implant was 90% at 10 years, with the implants after rheumatoid surgery faring somewhat better than those of the posttraumatics. Alternative treatment options, such as resection arthroplasty, distraction arthroplasty, or arthrodesis, are nowadays employed only in rare cases where a previous infection, personal preference or an inability by the patient to co-operate in a rehabilitation program have to be considered. The overall functional results of these types of treatments seem to be inferior to that of elbow arthroplasty. Therefore, this procedure is recommended not only for advanced degenerative and rheumatoid pathologies, but also in cases of posttraumatic arthrosis.

Arthritis↗

PubMed2002

Polyetheretherketone--cytotoxicity and mutagenicity in vitro.

The results of the incubation of polyetheretherketone (PEEK) fibre material with seven different genotype variants of salmonella bacterium showed with and without an external metabolic activation system (S9) with no mutagenic or cytotoxic activity of the test material. In the so-called "plate incorporation test" in which the PEEK raw material is finely cut and applied direct to the agar plate without the addition of solvent there was, as expected, no evidence of cytotoxic or mutagenic effects. In the HPRT test there was a significant increase in the number of mutants per dish, both after addition of N-acetylaminofluorene and N-methyl-N'-nitro-N-nitrosoguanidine (with and without an external metabolic activation system = +S9), but not after treatment of the cells with PEEK-DMSO-eluate. This means that the PEEK material under study did not release any substances that cause V79 cells to mutate. The investigation of the toxic reaction on the material under study revealed that the number of surviving colonies per 10(5) surviving cells lay within the range of or below the solvent control even in the presence of high PEEK concentrations (5.0 microg/ml). Therefore, in summary, the study produced no evidence of cell damage caused by PEEK.

2-Acetylaminofluorene↗

PubMed2001

[Carpo-metacarpal dislocation injuries].

Carpometacarpal dislocations are rare. In most cases, the dislocation is caused by a violent injury, e.g. the crash of a motorcyclist or a fall from great height. A considerable swelling of the back of the hand may mask the characteristic lump at the root of the hand. The diagnosis can be easily missed due to serious associated injuries. The lesion is also often overlooked in the routine X-ray diagnostic. Lateral and oblique views are important for the recognition of the true extent of the lesion. Anatomical reposition is difficult if the dislocation is not fresh and open reposition is necessary. Between 1990 and 1999, altogether 16 patients who had suffered a carpometacarpal dislocation were treated. One patient had a rare dislocation of the III. to V. joints. Simultaneous dislocation of all five carpometacarpal joints was seen in three cases. The treatment mostly consists of closed reduction and temporary Kirschner wire transfixation. Fourteen patients were controlled (clinical examination and X-ray control) after an average follow-up time of three years. In addition, the DASH questionnaire was used. After an average time of 3 years the patients showed in 64% of the cases excellent and good results (eight excellent, one good). The subjective function of the hand was moderate in 29% (four patients), in one patient the subjective function was poor (7%). Five patients had a diminished range of motion of the hand. The average points in the DASH questionnaire were 24. We recommend as therapy of choice after primary closed repositioning, primary surgery by means of short Kirschner wires introduced from distal-dorsal to proximal-palmar. In cases of impossible closed reduction or in cases with local additional injuries, open treatment for fixation, is indicated.

Adult↗

PubMed1998

[Attempted suicide--a challenge for the trauma surgeon?].

The data from 767 patients after a suicide attempt or suicide were analyzed retrospectively. Skeletal damage was present in 52% of the patients. This was also the highest percentage in the breakdown of the injury patterns, followed by damage of the central nervous system (26.6%). Injuries to parenchymatous organs (20.1%) took third place. Extensive soft tissue injuries were diagnosed in 18.1% and relevant vascular lesions in 16% of suicide cases. At the same time, the high percentage of multiple trauma patients (22.9%) reflects the severity and the extent of injuries suffered in the application of "violent methods". Injuries of suicide cases involving violence often resemble those of serious road traffic accidents. In contrast to unselected patients, the injury pattern of suicide cases with multiple trauma is dominated by jumps from a great height and being run over by a train. However, when unusual suicide techniques are used, the surgeon's experience may soon become insufficient. To our knowledge, special traumatology wards provide the best available diagnosis and emergency care for these patients unless they have suffered purely trivial injuries.

Adolescent↗

PubMed1997

[Rotator cuff rupture. Vascular supply and collagen fiber processes as pathogenetic factors].

Light and polarization microscopic appraisal of the pathways of fibers and blood vessels in the region of the rotator cuff shows branches of the suprascapular artery. These initially radiate into the insertion tendon parallel to the muscle fibers. They do not continue there, i.e. the vessel branches have blind endings, or they branch and anastomose with each other. Outliers of the transverse branch of the anterior circumflex artery of the humerus come from lateral (from the direction of the deltoid muscle). They pass from the bony insertion of the supraspinatus tendon into the tendon plate, but only run together with the fibers for a short distance. Consequently, a zone low in vessels or free of vessels can be constantly demonstrated under a magnifying glass in the course of the supraspinatus and to a small extent also of the infraspinatus in the fetus or neonate as well as in the adult in the region of the zone of interweaving of the tendinous muscle outlier with the capsule at length magnification. In the genesis of rotator cuff rupture, the presence of hypovascularity must be considered to be a predisposing factor which is present from birth onwards. It affects the clinical course during the process of aging as the point of least resistance in consequence of arteriosclerosis, collagen degeneration physiological wear and tear friction at the lower surface of the acromion and inflammatory swellings of the subacromial bursa.

Aged↗

PubMed1997

[Self-induced injuries--surgical aspects].

So far, psychiatric-psychoanalytic theories have been able to explain the phenomenon "self-injury" only unsatisfactorily. Moreover, the patients do not turn to a psychiatrist in the first place, but to surgeons, dermatologists, gynecologists or general practitioners. This is therefore an interdisciplinary problem. Since general medical knowledge is relatively unhelpful in diagnosing self-inflicted disease and its treatment, these patients often do not receive adequate psychiatric co-management or further care or indeed often get the chance to delegate the act of self-injury to the physician. In view of the sustained tendency for the disorder to chronify, this frequently results in severe, partly irreversible and sometimes iatrogenically co-induced physical impairments. In the final analysis, it also leads to enormous financial burdens for the agencies which bear the costs.

Adult↗

PubMed1997

[Perioperative antibiotic prophylaxis in hip operations. Penetration into bone, capsule tissue and cartilage exemplified by cefuroxime].

The most serious complication of accident surgery is postoperative osteitis. At the same time, perioperative antibiotic prophylaxis is generally recommended in order to reduce the rate of infection in joint surgery. The criteria for the suitability of a substance as prophylaxis include inter alia the activity spectrum with respect to the expected microorganisms, its retention time in the body and its ability to penetrate the endangered tissue. In the present study, the systemic and local activity levels after a single i.v. dose of 1500 mg cefuroxime was investigated in relation to the time of administration in 30 patients who had to undergo total hip replacement owing to a medial fracture of the neck of the femur. The tissue and serum samples were analyzed by high pressure liquid chromatography (HPLC). The results show that the tissue levels of the intermediary cephalosporin after an i.v. single shot dose are on average still several times higher than the minimum inhibitory concentration (MIC) of the most frequent bacterium. Staphylococcus aureus, as late as 4 hours after application. The optimal time for the administration form selected was immediately prior to the operation and the concentrations measured suggest that several repeat doses of cefuroxime for short-term prophylaxis are not necessary.

Aged↗

PubMed1997

[Pathologic humeral fracture in secondary osteosarcoma of the humerus: a rare complication of osteodystrophia deformans Paget].

Pathological fracture in histologically proven post-Paget osteosarcoma of the humerus is a rare complication. Due to individual requests as well as age and comorbidity, a course of primary palliative treatment was chosen in the present case. Survival time after diagnosis was 9 months and the patient died of a tumor-independent disease. Even in combined treatment, consisting of surgery and (neo-)adjuvant radio-/chemotherapy, prognosis of osteosarcomas secondary to Paget's disease remains very disappointing. Therefore, in treatment of this highly lethal tumor the patient's individual requests and personal situation often require more consideration than in many other malignancies.

Aged↗

PubMed1997

[Intrahepatic pressure, oxygen partial pressure and pain in chronic pancreatitis].

We investigated the relationship between pain, intraductal and parenchymal pancreatic pressures and oxygen partial pressure in 39 patients who underwent surgery for chronic pancreatitis with intractable pain. Acute pain was correlated with parenchymal pressure; correlation between pain and oxygen pressure could not be found. Since no strong correlation exists between pain and parenchymal pressure, we hypothesise that pressure and parenchymal factors contribute to the pathogenesis of pain in chronic pancreatitis.

Abdomen, Acute↗

PubMed1996

[Electromyography studies of surgically managed knee ligament ruptures. A retrospective analysis of defined injury patterns].

In 52 patients (5 groups, average age 32.8 years) with operative treatment of knee ligament injuries cutaneous electromyograms (EMG) under dynamic and isometric conditions (100 N, 200 N, 300 N) were performed in an average of 61.2 weeks postoperatively. The subgroups consisted of 13 patients with operative reconstruction of the anterior cruciate ligament (ACL), 12 after reconstruction of the medial collateral ligament (MCL), 21 after combined ACL and MCL reconstruction and 6 patients with autologous or alloplastic ligament replacement, respectively. The control group consisted of seventeen young adults without a history of knee joint injuries. The intensified and filtered analogous signals of 8 investigated thigh muscles were digitalized and analysed with help of a specially developed computer program. In summary, group specific EMG-criteria reveal distinct ligamentomuscular inhibitory reflexes and, vice versa, EMG activities of thigh muscles may indicate tendencies for group specific criterion after operatively treated knee ligament injuries.

Adult↗

PubMed1996

[Detection of the tendon of the musculus plantaris longus--diagnostic imaging and anatomic correlate].

Using ultrasound as well as magnetic resonance imaging (MRI) and computed tomography (CT), the plantaris tendon can be identified between the top of the calcaneus and the upper third of the lower leg in cross sections. Due to the surrounding fat tissue, the best proof of plantaris tendon existence and diameter can be obtained on sections at the level of syndesmosis and ankle joint. This allows to avoid unnecessary incisions during plastic and reconstructive surgery using this tendon as an autologeous transplant. For the experienced examiner ultrasound seems to be the easiest way to show plantaris tendon existence; in case of doubt, MRI or CT will give further information.

Ankle Injuries↗

PubMed1996

Influence of cardiac dysfunction on fast sodium current regulation by Forskolin.

There are several reports of an altered beta-adrenergic pathway in heart failure. Since the fast cardiac sodium current (INa+) is also subject to beta-receptor dependent regulation, we investigated its regulation in a model of cardiac dysfunction. Adenylyl cyclase was stimulated directly with forskolin as one step in the beta-adrenergic pathway. Twelve-week-old Wistar rats were infarcted by ligation of the left anterior descending coronary artery. Eight weeks later, the induced hemodynamic changes were evaluated. The left ventricular end-diastolic pressure (LVEDP) was used as a measure of the hemodynamic effects of the myocardial infarction. With the loose patch clamp technique, INa+ was measured in intact papillary muscles at an external sodium concentration of 150 mmol/L. Potential dependent availability was tested with pulses to 0 mV from various conditioning potentials. In animals with minor infarction (n = 7, LVEDP = 7.7 +/- 0.9 mmHg), forskolin (3 mumol/L) increased the maximal available INa+ to 109% +/- 13% of baseline values. This increase was nearly the same in the group with significant infarctions (n = 7, LVEDP = 15.7 +/- 1.6 mmHg) to 113% +/- 6%. Thus, although we previously observed a reduction of the isoproterenol induced increase of INa+ in rats with significant myocardial infarctions, this increase remains the same when adenylyl cyclase is stimulated directly. This is consistent with a direct beta-receptor down-regulation or desensitization.

Action Potentials↗