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Biomedical subjects

M A Scherer

Publications and source records attributed to M A Scherer.

At least 19 recordsLinked to original sources
PubMed2006

[On informed patient consent].

One third of all lawsuits against doctors include statements of insufficient or lacking informed consent. The objectives of this prospective study in 104 patients were to elucidate the actual clinical routine of obtaining informed consent (process quality), collect information on active and passive recall 3 to 7 days p.op., and to investigate whether patient age, sex, education, profession, and cognitive function using the Mini Mental State Test, the time from obtaining consent to interview, acuity (emergency vs elective cases), and quantity of patient/doctor interaction would influence the patient's recall capabilities. In clinical routine, obtaining informed consent is a very variable procedure, and between two and 18 items were documented by the physician. Of the patients, 12.6% recalled actively and 43.5% passively. They named between 1.1 and 3.7 items on average, with "infection" as the leading complication, followed by "pain" and "lesion of nerves". Of all parameters investigated, only the number of initially documented items exhibit a significant effect on the patients' recall. The quantity of patient/physician interaction not only guarantees an increased effect on recall but also means improves patient interaction, thereby reducing the probability of imminent accusations.

Adolescent↗
PubMed2006

[Positive screening for MRSA--clinical consequences?].

BACKGROUND: The worldwide rise of MRSA is equivalent to an increase of nasal colonization with MRSA. The objectives of this study were to investigate the rate of occult nasal MRSA colonization in trauma patients, to elucidate the role of MRSA carriers for endogenous infection (nose --> wound) and to check the efficiency of mupirocin therapy. PATIENTS AND METHODS: A total of 643 consecutive trauma patients underwent MRSA screening (nasal swabs) on admission. At the same time all MRSA wound infections were registered and all isolates were analysed with PFGE (pulsed-field gel electrophoresis) to detect cross-infection between individuals. RESULTS: In 13 patients (2.0%) we found MRSA in the nose and limited isolation as well as therapy with mupirocin were performed. No endogenous transmission of MRSA from the nose to the wound could be seen, and no cross-infection to other patients could be detected. CONCLUSION: Our findings suggest that in our patients with nasal colonization the risk of intra- and interindividual transmission of MRSA is very small. Therefore, in trauma patients screening on admission does not seem to be absolutely necessary either for clinical or for epidemiological reasons.

Aged↗
PubMed2002

[Skin burns under application of electro-surgical devices: aspects of liability and medicine].

Under established jurisdiction,burn damage to the skin in connection with the use of coagulating current is not regarded as unavoidable. On the contrary, a breach of duty by the surgeon will be assumed.He is responsible for acquainting himself with the techniques and the risks of the high-frequency surgical devices he is using.He has to prevent injuries on the basis of controllable risks, even those which only appear as a result of cooperation with other specialist. The evaluation of judicial decisions, the literature, damage reports and expert opinions confirms that most injuries could have been avoided by compliance with the recommended precautions.

Burns↗
PubMed2001

C-reactive protein in patients who had operative fracture treatment.

C-reactive protein as an indicator of infection, may help to detect surgical complications early and provide a better outcome for patients. To obtain a baseline for the use of C-reactive protein, the kinetics of C-reactive protein levels of 330 patients who had operative fracture treatment were studied before and after surgery. All patients who had an uneventful postoperative course had similar evolution in their C-reactive protein values: the peak level, which occurred on the second postoperative day, depended on the region of trauma (femoral fractures, 15.4 mg/dL versus ankle fractures, 3.5 mg/dL) and reflected the extent of surgical trauma. Of 47 patients with complicated courses, C-reactive protein proved helpful as a marker in risk stratification and as an early indicator for infection. Of nine patients with a deep wound infection, a high rise of C-reactive protein was recorded, and seven patients showed a rise in the C-reactive protein level before the onset of clinical symptoms. A cut-off level of 14 mg/dL on the fourth day after surgery was recorded for the patients with deep wound infection.

Adolescent↗
PubMed1999

[Significance of combined anterior cruciate ligament and meniscus injury].

The combined lesion of the anterior cruciate ligament (ACL) with simultaneous or secondary meniscal tears has severe consequences for the knee joint. By a synopsis of the literature and own experimental investigations in sheep it can be shown that in ACL deficient knees secondary meniscal lesions occur, what finally ends in osteoarthrosis. The combined lesion of the ACL and the meniscus results in a more severe damage of the joint than the sum of the single lesions. ACL reconstruction in these cases is very important, because meniscal tears cannot heal in unstable knees. On the other hand resections of the menisci have to be avoided, because the loss of these secondary stabilizers and synergists of the ACL increases the risk of joint degeneration.

Animals↗
PubMed1998

[Glycosaminoglycans as markers of post-traumatic gonarthrosis?].

Osteoarthritis (OA) influences the levels of free intraarticular glucosaminoglycans (GAG). Little is known about the direction--decrease/increase--of these changes, and information on the correlation between GAG levels and the degree of OA is sparse. Objectives of this study were to investigate the correlation between intraarticular levels of sulphated and unsulphated GAG and the degree of experimental OA, the time course of these changes and whether GAG might be useful as a marker for OA. Twenty-one sheep were randomly assigned to three groups: (1) transsection of the posterolateral bundle of the anterior cruciate ligament, ACL (TD), (2) medial meniscectomy (ME), and (3) meniscectomy and resection of the ACL (MV). During follow-up clinical and radiological examinations were done. After screening for intraarticular effusions, a joint tab was performed and the levels of hyaluronic acid and chondroitin sulphate were measured. The radiological scores differ significantly between group TD and groups ME and MV (P < 0.01). Hyaluronic acid levels in ME and MV are significantly higher than in the controls. Significantly increased levels (P < 0.01) of chondroitin sulphate are found 6 months after ME and 1 year following TD. Clinical consequences: Hyaluronic acid levels--at least in the experimental setting--correspond to a certain degree with osteoarthrotic changes: increasing levels were found along with increasing postoperative interval and increasing grade of OA. Chondroitin sulphate, on the other hand seems, to lend itself as a marker for chondromalacia, in other words for prearthrotic deformities and early stages of OA.

Animals↗
PubMed1997

Incorporation of devitalised autografts in dogs.

Segments of the tibial diaphysis from 24 adult dogs were reimplanted after extracorporeal autoclaving or gamma-irradiation. Fixation was by interlocking intramedullary nailing, or plating. The dogs were killed after 36 weeks and the tibias examined. Bony union was seen in 46 of the 48 contact areas. Microangiography and Tc-perfusion scans demonstrated complete revascularisation of all the grafts. Biomechanical tests showed defective union with increased bending and decreased stiffness compared to normal controls. Fluorescent microscopy confirmed restitution of Haversian systems and slow replacement of the graft by lamellar bone containing viable osteocytes.

Angiography↗
PubMed1997

[Diagnostic and therapeutic standard in meniscus lesions--results of a survey].

With a survey among surgeons and orthopaedic surgeons in German speaking countries the presently applied diagnostic and therapeutic schemes of meniscus lesions were investigated. In 322 questionnaires altogether 43.958 meniscus lesions were reported. In over 90% arthroscopy serves as diagnostic and therapeutic tool. Two thirds of the surgeons suture a longitudinal tear of the outer zone of the meniscus, all the other meniscus lesions were foremost treated by partial resection. The postoperative treatment after meniscus surgery is very inconsistent. Altogether less preserving meniscus operations were performed than it would be possible according to the literature. On one hand new therapy regimens are acknowledged by clinical practice with considerable delay, on the other hand the importance of menisci for the integrity of the knee-joint necessitates a further improvement of reconstructive techniques for preservation of the menisci.

Adult↗
PubMed1996

[Development of replacement meniscus of autogenous tissue].

At present no established therapy for the complete loss of meniscus is available. An attempt is made to create a transplant out of autogeneic tissue resembling the meniscus in its morphological and functional aspects. The middle third of the patellar tendon with proximal and distal bone blocks serves as a basis and is coated with a fascia lata strip. After temporary subcutaneous transfer, the meniscus substitute is intended for later transplantation. The theoretical ideas for the imitation of a meniscus in view of fibre architecture and biomechanical validity were tested in 14 sheep. In principal this model succeeds in imitating the fibre architecture of the menisci. After a conditioning period of 8-10 weeks in the subcutaneous tissue, the neomeniscus seems to be suitable for transplantation. The tensile strength of the grafts decreases slightly but the bone blocks stay viable.

Animals↗
PubMed1996

[Lesions of the popliteus system and their significance for the stability of the knee joint].

INTRODUCTION: Stäubli postulated a clinical significance of lesions to the popliteus system because of a 95% incidence in acute and 85.7% in chronic ruptures of the cruciate ligaments. The sparse clinical literature on this topic favours conservative or operative treatment as well. OBJECTIVE OF THE STUDY: What is the significance of isolated lesions of the popliteus tendon on translational stability of the knee joint? MATERIAL AND METHODS: The popliteus tendon was severed in six sheep. One year postop. the knee joints were evaluated by means of x-ray, biomechanical testing, computed tomography osteoabsorptiometry (CTOAM) and micromorphology. RESULTS: There were no pathological findings on x-ray. The simulation of the trauma situation ex vivo showed no instability whereas increased translation and progressive loosening of secondary stabilizers was found after one year (posterior and total aptranslation, compliance index p < 0.05). The position of the density maxima of the subchondral mineralization are about the same on the operated and the non-operated knee joint. All tendons healed macroscopically, but micromorphology exhibited a persisting increase of cross-sectional areas, a low differentiated ultrastructure of the tendon and an increased cellularity (p < 0.01). CONCLUSIONS EXPERIMENTAL: 1. intraarticular, extrasynovial tendons heal spontaneously even within the synovial environment; 2. healing is defective even one year postop.; 3. the postulate of the significance of the popliteus system for the stability of the knee is proven. Clinical: 1. (isolated) lesions of the popliteus go undetected with clinical and instrumented examination; 2. conservative treatment eventually results in increased posterior translational instability; 3. this will increase strain and load on the menisci and ACL- reconstructions.

Animals↗
PubMed1995

[Biomechanics of healing of cortical autotransplants after intramedullary nailing and device removal].

The aim of the study was to investigate the biomechanical properties of segmental cortical autografts subjected to extracorporeal treatment. For this purpose, 12 beagle dogs were submitted to tibial osteotomy, when 25 mm-long diaphyseal segments of bone were removed and treated outside the body by autoclaving or gamma radiation (Co, 5 kGy). Subsequently, osteosynthesis involving the use of medullary nailing was performed. After 36 weeks, the dogs were killed painlessly and, after removing the nails, the tibias were tested for the biomechanical properties. In comparison with the contralateral tibia, a mean stiffness of 47% and 32% was measured for tibia treated by irradiation and autoclaving, respectively, while bending showed an increase of up to 590%. These results show the need to allow plenty of time for healing in the case of weightbearing transplants. When bealing is undisturbed, no biomechanical differences are found between proximal and distal osteotomies, although in the X-ray image the osteotomy gap (fracture line) remains visible, and scintigraphic activity persists for a longer period. This means that the radiological aspect of the former does not necessarily reflect actual biomechanical strength.

Animals↗
PubMed1994

[Change in subchondral mineralization after reconstruction of the anterior cruciate ligament of the sheep].

The cruciate ligaments are generally regarded as regulators of the joint kinematics, but also increasingly as a "Sensory organ" regulating the periarticular musculature, which influences the position of the contact surfaces and the direction and magnitude of the resultant forces. Indirectly, therefore, they influence the long-term stress distribution, which is itself reflected in the distribution of the subchondral mineralisation. An experimental investigation was therefore undertaken to see whether, in terms of this distribution, the distribution of the stress alters postoperatively, since this could be regarded as an early cause of degenerative change. We examined the distribution of the subchondral mineralisation of six tibiae from six adult Merino sheep 1 year after anterior cruciate ligament reconstruction with patellar tendon. The contralateral tibia we used as controls. Maximum subchondral mineralisation of both the medial and the lateral joint surfaces in all the control joints was found to be central. In the treated knees, however, the medial joint surface maxima were found to have been displaced towards the dorsomedial edge of the surface in every case. If the density pattern on the control side is accepted as the expression of a normal stress distribution, the distribution patterns on the treated side must indicate a pathologic distribution of stress. Reconstruction of the anterior cruciate ligament is therefore--at least in the animal model--not able to prevent the development of a pathologic stress distribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Missed injuries of the musculoskeletal system in multiple trauma--a retrospective study].

In order to quantify frequency, localisation and consequences of missed musculoskeletal injuries in multiple injured patients, 323 cases were retrospectively analyzed. 40 primarily missed injuries were found, 12 of them in patients, who had been transferred from another hospital. This rate of 12.4% corresponds with the literature. Four regions are mainly affected: 1. the cervical spine, especially the cervicothoracic transition, 2. the shoulder, 3. the ligaments of the knee especially with femur or tibia fractures at the same time, and 4. the forefoot. About half of the primary missed injuries are ligament lesions. Whereas spine injuries were diagnosed within the first 2 weeks (average 4 days), ligament injuries (average 28 days) and foot injuries (average 38 days) were discovered at the patient's mobilization phase. Reasons for non detecting the injuries are: Missing or inadequate x-rays, not consistently continued diagnostic steps, inaccurate or not repeated clinical examination, apparent insignificance of peripheral injuries in multiple trauma. The potential danger of neurologic deficits of vertebral fractures, delay of rehabilitation due to secondary correction surgery (e.g. secondary ligament reconstructions) and imminent permanent damage (e.g. posttraumatic foot deformities) show the importance of a quick diagnosis of all injuries, even those appearing at the first glance as unimportant.

Diagnostic Errors↗
PubMed1993

[Biomechanical studies of change in the patellar tendon after transplant removal].

The reconstruction of the anterior cruciate ligament deficient knee with the patellar tendon is the "gold standard". Dislocation of the patella, rupture of the patellar tendon and fracture of the patella were reported to occur. In this biomechanical investigation on the changes of the patellar tendon following harvesting of a graft, 51 sheep knee underwent destructive testing at t0 (n = 11), 4 weeks p.op. (n = 5), 3 months p.op. (n = 14), 6 months p.op. (n = 15), and 12 months p.op. (n = 6). Harvesting of a graft produces a stiffness and strength of the patellar tendon of 50-70% of normal. There was no significant change of free patellar tendon length up to 12 months p.op. The cross-sectional area is definitely increased (p < 0.05). The tensile stress is always above normal, nevertheless the strength shows a massive decline until 6 months p.op. and does not regain normal strength by one year p.op. Stiffness shows comparable biomechanical pattern like tensile stress. There are time-dependent changes, the structural weakness is compensated by an increase of cross-sectional area. There is no restitution of the patellar tendon ad integrum, the remainder is a defect with scar tissue and alterated biomechanical properties. Revision surgery using the same host patellar tendon cannot be recommended.

Animals↗
PubMed1993

[Importance of ultrasound in postoperative follow-up after reconstruction of the anterior cruciate ligament].

Eighty-eight male patients following reconstruction of the anterior cruciate ligament (ACL; mean 24 months since operation) had a thorough clinical examination including instrumented measurement of laxity using the KT 1000. These results were correlated with an ultrasound (US) grading that evaluates the reconstruction itself as well as its functional behaviour during the anterior drawer test. Thirty-four magnetic resonance (MR) studies of 33 patients were available. Undoubtedly postoperative visualization of the reconstructed ACL is superior to that of both normal control ACL and acute trauma cases. Especially operative procedures which use the patellar or semitendinosus tendon lend themselves to accurate evaluation of the intraarticular reconstruction. The sensitivity, specificity, positive and negative predictive values and overall accuracy of US/MR versus the clinical laxity measurement are calculated to be 66.7%/96.0%, 71.2%%/23.8%, 59.5%/60.0%, 77.1%/83.3% and 69.4%/63.0% respectively. US has a satisfactory diagnostic value and performs similarly well on all these parameters. MR, on the other hand, correctly diagnoses nearly all unstable knees but is associated with a high number of false positives. There is no statistically significant, linear correlation between MR and US; r = -0.0769, P = 0.6706. Only three times did the reconstructed ACL appear normal on MR, whereas 48.5% of the reconstructions were graded type I (normal) on US. Clinical Consequences: Ultrasound and MRT should not be considered rival but rather complementary methods: ultrasound is a good method for documenting changes within the knee joint on an outpatient basis, while the indications for MR in the postoperative course are any occurrences of pain, instability or reinjury.

Adult↗
PubMed1993

[Radioactivity of bone cement].

A total of 14 samples of different types of bone cement from five different manufacturers were examined for their radioactivity. Each of the investigated bone cements showed a low radioactivity level, i.e. between < 1 and 100 Bq/kg. The content of U-238 and K-40 always was below the limit of detection (< 1-< 10 Bq/kg). Significant differences were detected in the amount of Ra-226, Pb-210, and Ra-228 detected between different samples of the same product from the same manufacturer, as well as between various types of cements. The highest radioactivity level was measured for Ra-226. Although stochastic radiation effects can not totally be excluded, it is extremely unlikely that the small amount of radioactive substances additionally transferred into the body by the bone cement has negative effects on the recipient's organism or on the fate of the alloplastic implant: "The risk factor and extrapolation in a low dosage range ... do not lead to an underestimation but more likely to an overestimation of the radiation hazard" [18].

Bone Cements↗