Biomedical subjects

M Runkel

Publications and source records attributed to M Runkel.

At least 19 recordsLinked to original sources

PubMed1998

[Efficacy of ultrasound controlled direct reposition of fragments of the posterior vertebral body facet].

To calculate canal compromise and decrease of midsagittal diameter caused by retropulsion of fragments into the spinal canal we analyzed the pre- and postoperative computed tomographies of 32 patients with unstable thoracolumbar burst fractures treated by USS (universal spine system). Our intention was to examine the efficiency of ultrasound guided repositioning of the dispaced fragments which was performed in all 32 cases. We found a clear postoperative enlargement of canal area (ASP preoperatively 55%, postop. 80%) and midsagittal diameter (MSD preop. 58%, postop. 78%). 10 of 13 patients presented a postoperative improvement of neurological deficit, no neurological deterioration occurred. Fractures with neurological deficit showed more canal compromise (52%) and less midsagittal diameter (MSD compromise 51%) than those without (40% or 39%). There was no correlation between the percentage of spinal canal stenosis and the severity of neurological deficit. Below L 1 the spinal canal is greater than between Th 11 and L 1, so a more important spinal stenosis is tolerated. In case of unstable burst fractures with neurological deficit the ultrasound guided spinal fracture reposition is an effective procedure concerning the necessary improvement of spinal stenosis: an additional ventral approach for the revision of the spinal canal is unneeded. In fractures without neurologic deficit the repositioning of the displaced fragments promises an avoidance of long-term damages such as myelopathia and claudicatio spinalis.

Adolescent↗

PubMed1998

[Low-field MR arthrography of the shoulder: early results using an open 0.2T MR system].

PURPOSE: To assess the practicability and image quality of doing MR arthrography of the shoulder using a 0.2T system. PATIENTS AND METHOD: 60 patients (24 with chronic instability, 36 with impingement syndrome) were examined in an open 0.2T MR apparatus (Magnetom Open, Siemens). After the intra-articular injections of 15-20 ml of a 2 mmol Gd-DTPA solution, coronary STIR, T1-weighted, sagittal and axial T2*-weighted FLASH 2D sequences were performed. 21 patients subsequently underwent surgery. RESULTS: Image quality of the T1- and T2*-weighted FLASH 2D sequences was regarded as good or adequate and movement artifacts were minor or moderate. STIR sequences were statistically significantly worse in respect of image quality and movement artifacts (p < 0.001, p < 0.005). The sensitivity and specificity in the diagnosis of rotator cuff rupture as confirmed by surgery was 100% (labrum lesions 100%, 93%). Agreement in the diagnosis of rupture of the supraspinatus and infraspinatus tendons was 0.93 and 0.65. CONCLUSION: MR arthrography of the shoulder using an open 0.2 T MR system provides adequate information concerning the intra articular structures of the joint. The disadvantage is the prolonged duration of the examination with the risk of poor image quality resulting from movement artifacts.

Adult↗

PubMed1998

Retrograde nailing of humeral shaft fractures.

The use of intramedullary nailing in the upper extremity is still controversial. Those who have experience with antegrade nailing have either great enthusiasm or strong criticism for the procedure. Criticism of the procedure is because of the trauma that can occur to the rotator cuff and possible impingement syndrome, which can occur after antegrade nail insertion. The technique of retrograde nail insertion with the unreamed humeral nail is described in detail. In a series of 190 retrograde nailings performed in a prospective multicenter study, the most frequent intraoperative problems were fissure or avulsion at the entry portal (n = 8; 4.2%) and secondary radial nerve palsy (n = 8; 4.2%). All radial nerve palsies recovered spontaneously. Sixty-eight patients were followed up until the fractures healed. There were five (7.4%) bone healing problems. Four of five could be solved with use of the unreamed humeral nail in a second operative procedure, whereas the fifth bone healing problem required plate osteosynthesis. Function of the shoulder and elbow joint was excellent in 89.7% and 88.3% of the patients, respectively. Retrograde humeral nailing is a safe and reliable procedure if done properly. It is a valuable stabilization technique for acute and pathologic fractures and for pseudarthrosis. Bone healing problems after unreamed humeral nailing must be analyzed individually, but they can be treated with the same implant in combination with cancellous bone grafts, reaming, additional hardware, or intrafragmentary compression.

Adolescent↗

PubMed1997

[Magnetic resonance tomography examination of thoracolumbar spinal fractures after fixateur interne stabilization].

To analyse the possible injuries of vertebral segments, especially the disc, after unstable thoracolumbar fractures stabilised with AO internal fixator, we performed magnetic resonance imaging (MRI) of the traumatised region after implant removal. There were two aspects of disc degeneration (DD):(1) biochemical changes and (2) structural damage. MRI detects biochemical processes as one aspect of DD that is often small even in the presence of greater structural damage of the nucleus pulposus caused by fracture. None of the patients presented with structural failure of the anulus fibrosus, which is the essential structural component of the vertebral segments with regard to stability. We observed biochemical changes more often in the lower of the two fracture-adjacent discs and alterations of discal shape more often in the upper of the two, whereas loss of height concerned both discs to approximately the same degree. The supporters of upper-disc resection in thoracolumbar fractures justify their procedure among other things with the structural disc damage, such as alteration of shape and loss of height (altogether more frequent in the upper disc). Our observations that a disc with a structurally altered nucleus pulposus can be biochemically intact and can show an intact anulus fibrosus are arguments in favour of disc preservation. With regard to the upper disc, the widespread opinion that complete and regular disc damage requires a resection has to be revised. The question of whether the lower disc should be resected more often because of its greater biochemical changes cannot be answered by the present study alone. Besides the excellent static information in all anatomical structures of the vertebral column available by MRI, a repeat examination in a prone position yields dynamic information on the spinal cord in the case of suspected dorsal adhesions.

Adolescent↗

PubMed1997

The character of inhibition of the metabolism of 1,2-benzopyrone (coumarin) by grapefruit juice in human.

OBJECTIVE: Constituents of grapefruit juice are known to interfere with mammalian cytochrome P450 isozymes such as intestinal CYP3A4 and hepatic CYP2A6, lowering the biotransformation of drugs and increasing their bioavailability. The aim of this study was to investigate whether the presence of naringin is demanded for the inhibition of the coumarin 7-hydroxylase in man or other compounds are responsible for it. METHODS: In cross-over studies, doses of 10 mg coumarin, together with combinations of grapefruit juice, water and naringin, were given orally to one healthy male volunteer, We investigated increasing amounts of grapefruit juice, keeping the volume of liquid constant at 1 L; increasing doses of naringin given in water; increasing amounts of juice, keeping the dose of naringin constant; or increasing doses of naringin, keeping the amount of juice constant. Urine samples were collected up to 24 h after dosing and 7-hydroxycoumarin was quantified fluorimetrically in urine hydrolysates after HPLC separation to determine the excretion rates. RESULTS: While increasing amounts of grapefruit juice delay the excretion of 7-hydroxycoumarin by 2 h, increasing doses of naringin in water up to twofold (i.e. naringin content of 2 L grapefruit juice) do not cause any alteration in the time course of excretion. Experiments with increasing amounts of juice, keeping the dose of naringin constant, indicate that the inhibitory potency of small amounts of grapefruit juice can be amplified by naringin. The same is true when the ratio between juice constituents and naringin is enhanced up to threefold by adding naringin. CONCLUSION: As naringin alone is ineffective, the inhibitory effect of grapefruit juice on the metabolism of coumarin is caused by at least one compound other than naringin. The persistency of the primary inhibitor not identified yet can obviously be modulated by the naring(en)in-system.

Anticoagulants↗

PubMed1997

[Use of information systems for direct surgical patient management].

The aim of this prospective study was to evaluate the use of a modern computer-based hospital information system for the management of patients in our surgical department. The results showed that the information system was well accepted by the medical staff and found to be useful throughout daily work. In addition, they justify the effort to install and maintain such a system.

Attitude to Computers↗

PubMed1996

[Results of primary unreamed tibial nailing of tibial fractures with severe open or closed soft tissue injuries].

Primary stabilization was performed in 72 tibial fractures with sever open (n = 37) or closed (n = 35) soft tissue injury using unreamed interlocking nails. In 60 (83%) cases the fractures healed without additional procedures. There were 2 cases of osteitis, but both these fractures healed after removal of the nail or after reamed nailing. In 9 patients with delayed union reamed nailing (n = 8) or bone grafting (n = 1) led to healing. In 1 patient with hypertrophic pseudarthrosis, union was achieved after substitution of a reamed nail for the anreamed nail. The infection rate was similar to that observed with external fixation. More secondary procedures, such as bone grafting or a change of the osteosynthesis technique, are necessary with external fixation than with unreamed nailing. Further advantages of unreamed nailing are the internal treatment of the fracture and the patient's greater comfort. Therefore, unreamed nailing can be recommended for the primary treatment of tibial fractures with severe open or closed soft tissue trauma.

Adolescent↗

PubMed1996

Metabolic and analytical interactions of grapefruit juice and 1,2-benzopyrone (coumarin) in man.

OBJECTIVE: Grapefruit juice is known to inhibit mammalian cytochrome P450 isozymes such as CYP3A4. The aim of this study was to investigate the influence of the juice on the fate of coumarin (1,2-benzopyrone) metabolized by CYP2A6 in man. Its potentially inhibitory effect was examined when low and high amounts of grapefruit juice were taken. METHODS: In crossover studies, doses of 10 mg coumarin (Venalot) were given orally to an healthy male volunteer. The drug was taken either with water or with grapefruit juice, at different volumes (300 ml or 4 x 250 ml at intervals of 30 min). Urine samples were collected up to 24 h after dosing. After in vitro hydrolysis they were analysed fluorimetrically for umbelliferone, the metabolite of coumarin, and cumulative excretion curves were established. HPLC and TLC served to identify fluorescent metabolites from the juice. RESULTS: If coumarin is given in water its excretion is complete after 6 h and 70% of the dose is recovered. Grapefruit juice (300 ml) given simultaneously slightly retards the appearance of the fluorescent metabolite in the urine within the first few hours. The recovery of coumarin remains unaffected. One litre of juice enhances the delay and increases the recovery of coumarin to nearly 100%. Respective controls with grapefruit juice alone lead to remarkable excretions of a fluorescent material identified as conjugated scopoletin, which strongly interferes with the analysis of the coumarin experiment. The precursor of scopoletin is widely present at different concentrations in commercially available grapefruit juices. However, the autoinhibition of the juice is correlated neither to the concentration of naringin nor to that of scopoletin. CONCLUSION: Only grapefruit juice given at high doses (1 L) retards the appearance of the main metabolite of coumarin administered orally but increases its recovery. Due to scopoletin formed from the grapefruit juice, experiments especially with coumarin are strongly affected.

Anticoagulants↗

PubMed1996

Knowledge retrieval as one type of knowledge-based decision support in medicine: results of an evaluation study.

We report on a prospective, prolective observational study, supplying information on how physicians and other health care professionals retrieve medical knowledge on-line within the Heidelberg University Hospital information system. Within this hospital information system, on-line access to medical knowledge has been realised by installing a medical knowledge server in the range of about 24 GB and by providing access to it by health care professional workstations in wards, physicians' rooms, etc. During the study, we observed about 96 accesses per working day. The main group of health care professionals retrieving medical knowledge were physicians and medical students. Primary reasons for its utilisation were identified as support for the users' scientific work (50%), own clinical cases (19%), general medical problems (14%) and current clinical problems (13%). Health care professionals had accesses to medical knowledge bases such as MEDLINE (79%), drug bases ('Rote Liste', 6%), and to electronic text books and knowledge base systems as well. Sixty-five percent of accesses to medical knowledge were judged to be successful. In our opinion, medical knowledge retrieval can serve as a first step towards knowledge processing in medicine. We point out the consequences for the management of hospital information systems in order to provide the prerequisites for such a type of knowledge retrieval.

Computer Systems↗

PubMed1996

[Systemic complications in intramedullary nailing].

Today intramedullary nailing is the treatment of choice in stabilizing femoral and tibial diaphysial fractures because of its superior bone healing compared to other forms of osteosyntheses. By interlocking, the indication can be extended to all fractures in which interlocking bolts can be fixed in the proximal and distal main fragment. Küntscher's principle of elastic clamp has changed to intramedullary splinting. With that method reaming is limited to a few reaming processes, and unreamed nailing has become possible. Today implants start at a diameter of 9 mm. The diameter of implants of all manufacturers is less than a few years ago. Since the importance of embolization by increasing the intramedullary pressure as a result of reaming is accepted, the question arises concerning the clinical relevance of embolization if reaming is restricted and unreamed nails are applied. In our own investigations, relevant intravasation of bone marrow content appeared only in reamed femoral nailing. The bone marrow cavity of the tibia is smaller, the configuration of the tibia allows more back-streaming of the content, and the venous drainage system in the distal tibia is much less extensive than in the supracondylar area. All pulmonary complications in the literature are reported after nailing of femoral fractures. Therefore, systemic complications in intramedullary nailing are only a problem in femoral fractures. The pathophysiological connection between intramedullary pressure increases and pulmonary impairment is not clarified in detail. Relevant content of the bone marrow cavity is not only bone marrow, but also the blood with which the marrow cavity is refilled after each reaming process and which passes into the circulation during the following reaming. This blood is activated concerning coagulation. By reaming, the pathogenic content of the bone marrow cavity is embolized, which can become clinically relevant if cofactors are present. Cofactors are volume deficit, shock, lung contusion and pre-existing pulmonary impairment. These conditions can never be excluded before primary stabilization after trauma. Today the importance of systemic complications during unreamed nailing is controversial. Our experimental and echocardiographic investigations clearly show that the velocity of the nail into the bone marrow cavity and the gap between the nail and cortical bone at the entrance in the distal fragment determine the amount of embolized material. By carefully inserting the nail and choosing thin nails with a correct length, which can gain stability by fixation in the condylar area and not by clamping in the distal fragment, echocardiography reveals only minimal embolization. Therefore unreamed nailing is the treatment of choice, if the situation of the patient allows the procedure of nailing in itself. Multitrauma patients in shock or with unstable circulation should be stabilized primarily with external fixation. After consolidation, early change to an intramedullary nail should be performed.

Embolism, Fat↗

PubMed1995

Parosteal osteosarcoma of the talus.

A case of parosteal osteosarcoma in the very rare location of the talus is presented. The radiological, pathological, and clinical characteristics of parosteal osteosarcoma are described and the differential diagnosis discussed.

Adult↗

PubMed1995

[The "inserted" condylar plate].

Twelve extensive segmental and comminuted fractures of the femur affecting the metaphyseal areas (7 times proximal, 5 times distal) and the diaphysis were treated with extremely long condylar plates (16 to 20 holes). The condylar plates were inserted via a proximal and a distal incision leaving the Musculus vastus lateralis intact at the fracture site in all cases. Following standard preparation of the blade position using the seating chisel, the condylar plate was inserted behind the musculus vastus lateralis with the blade pointing towards the surgeon. The condyles or the trochanteric area were tilted slightly and the plate was turned 180 degrees and driven home. No screws were inserted in the area of the fracture, in particular, lag screws were not used. Ten out of 12 fractures healed without problems, in 2 cases bone grafting was necessary. Three main observations resulted from analysis of the operations and subsequent clinical and radiographical assessments. In the presence of relatively intact soft tissue covering, an astonishingly good reduction of the fragments was achieved after restoration of leg length and extension. In the healing process, callus formed rapidly and provided medial support. The bone structure was found to be more homogeneous than in the case for plate fixation involving several screws at the fracture site around which considerable fluctuations in bone density frequently occur. The application of condylar plates behind the musculus vastus lateralis by only proximal and distal incision for osteosyntheses of extensive multifragmental fractures is a further development of bridge-plating and can be recommended for long fractures.

Bone Plates↗

PubMed1995

[The value of MR tomography in traumatic patella dislocations].

PURPOSE: To describe the MR imaging findings in patients with lateral patellar dislocation. MATERIAL AND METHODS: The MRIs of 31 patients with patellar dislocation were evaluated retrospectively. Arthroscopic surgery was performed in 23 cases. RESULTS: Hemarthrosis was found in 30/31, contusions of the lateral femoral condyle in 30/31 and of the medial patellar facet in 26/31 cases. Injury of the medial patellar retinaculum was seen in 28/31 cases. Osteochondral fractures were found in 18 patients; compared to arthroscopy there were one false-positive and 5 false-negative findings concerning loose cartilage bodies. In 7 cases, patellar dislocation was not suspected before MR imaging. CONCLUSION: Hemarthrosis, lateral femoral and medial patellar contusion, and retinacular disruption are typical findings after lateral patellar dislocation. A careful search for free osteochondral fragments is mandatory as it influences the indication and performance of arthroscopic surgery.

Adolescent↗

PubMed1995

[MRI studies on the distensibility of cruciate ligaments of healthy knee joint].

AIM: Examination of the distensibility of the cruciate ligaments to evaluate the tense plasty of the cruciate ligaments. MATERIAL AND METHOD: A functional MR study was performed using a Magnetom Open (0.2 Tesla, Fa. Siemens). We measured the length and width of the anterior and posterior cruciate ligament in volunteers (n = 12), age 20-40. We examined in 4 knee positions between maximal extension and maximal flexion. RESULTS: Using the Wilcoxon test, the statistics do not show any significant difference between the length and width of the cruciate ligaments in the monoxial movement. CONCLUSION: Our results may support the operative tense plasty of the cruciate ligaments although the entire complex mechanical system has not been examined.

Adult↗

PubMed1995

[Rupture of lateral ligaments of the ankle joint: MR imaging before and after functional therapy].

PURPOSE: Documentation via MRI of the healing of ruptured lateral collateral ankle ligaments after functional therapy. PATIENTS AND METHODS: 35 patients with ankle sprain were examined by MRI and stress radiographs, 13 were operated afterwards, 22 patients underwent a functional conservative therapy and were examined by MRI and stress radiographs and second time after three months. RESULTS: MRI reports were correct in 12 of 13 operated cases. After conservative therapy we did not find any disrupted ankle ligament. MRI showed intact ligaments thickened by scar. CONCLUSION: MRI is able to show injuries of the lateral collateral ankle ligaments and demonstrates the healing by scar after conservative therapy.

Adolescent↗

PubMed1995

[Is there a connection between intramedullary pressure increase, bone marrow intravasation and deep venous thrombosis of the leg in endoprosthetics?].

Deep vein thrombosis still is a severe problem in hip replacement. Based on pathophysiological considerations, it is postulated that there is a connection between intramedullary pressure peaks, resulting intravasation of bone marrow, and the induction of deep vein thrombosis. The content of the bone marrow cavity can be considered active where coagulation is concerned. Intravasation may contribute to the development of deep vein thrombosis. In addition to medicamentous prophylaxis and early mobilization, a surgical technique also helps in the prophylaxis thrombosis. In this technique, intramedullary pressure increases are avoided as far as possible, which consequently minimizes intravasation of the content of the bone marrow cavity.

Aged↗

PubMed1995

[The effect of bone marrow embolization on the choice of procedure in the stabilization of femoral fractures].

Because of an extended venous drainage system, especially in the supracondylar area, a pressure increase in the femoral cavity results in embolization of the contents of the bone marrow cavity. Bone marrow embolization alone is mostly not apparent clinically but together with cofactors it may result in severe pulmonary damage and occasionally even in death. Cofactors are volume deficit, shock, thoracic and polytrauma and preexisting pulmonary disease. In the field of traumatology a pressure increase in the femoral cavity regularly occurs during unavoidable movement of femoral fragments in traction, during reduction, intraoperatively during intramedullary nailing, and in hip replacement. A hematoma acts as a hydraulic transmitter. Early osteosynthesis within 24 h avoids permanent intravasation of moderate amounts of the contents of the bone marrow cavity. Concerning intramedullary nailing, there are considerable differences between reamed and unreamed nailing. Reaming always leads to high-pressure increases in the femoral cavity, resulting in embolization. Therefore, reaming should not be performed if cofactors of manifestation of pulmonary impairment are present. Unreamed nailing results in less intravasation, but is not entirely harmless, as considerable pressure increases occur in unreamed nailing as well. The gap between the nail and the entrance of the distal fragment is the decisive parameter. Not just the smaller intravasation of bone marrow during unreamed nailing is important. After each reaming process, the bone marrow cavity rapidly refills with blood, which is activated concerning coagulation and pressed into the circulation during the following reaming process. Because of superior bone healing, interlocking nailing is the treatment of choice in diaphysial femoral fractures. As far as the differential indications of reaming are concerned, the discussion is not yet closed. However, reaming should undoubtedly be restricted to a few reaming processes. Before unreamed femoral nailing, the width of the bone marrow cavity must be examined exactly. If the width of the bone marrow cavity, the patient's condition and experience of the surgeon allow unreamed nailing, this procedure can be recommended. As the venous drainage system of the tibia is not important compared to the femur, the question of reaming or not in tibial fractures is not influenced by the danger of embolization, but by soft tissue damage and the stability of interlocking bolts. In patients with femoral fractures and co-factors for the manifestation of pulmonary impairment, the choice of osteosynthesis type should take plating in its improved form into consideration, as this preserves the vascularity of the fragments.(ABSTRACT TRUNCATED AT 400 WORDS)

Bone Marrow↗

PubMed1994

[Results of implantation of uncemented porous metal hip prostheses].

72 patients having cementless spongy-metal hip prosthesis were reexamined by clinical and radiological check up two to seven years after implantation (average 43 months). In case of five patients hip prosthesis had to be changed due to loosening (no bony ingrowth n = 2, loosening of acetabular component due to technical faults n = 3). In correlation to clinical results 88% could be considered as excellent or good, 9% acceptable and 3% as inadequate. 10% of the patients complained about thigh pain. The typical radiological bony reactions of the surrounding bone are described. An evaluation of the radiological results can only be done under consideration of the clinical problems involved. In view of the positive results obtained in the recent time the use of spongy-metal hip prosthesis can be recommended for cementless hip joint replacement in case of younger patients. Especially in case of cemented hip joints which have become loose it will be an advantage to use spongy-metal hip prosthesis.

Adult↗