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Biomedical subjects

G Muhr

Publications and source records attributed to G Muhr.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Experiences with the pulse oximeter during preclinical cardiopulmonary resuscitation].

The use of pulse oximetry during pre-hospital cardiopulmonary resuscitation was prospectively investigated in 23 cases. The question was whether the measurement of oxygen saturation during pre-clinical resuscitation is useful and what conclusions are possible. We were able to obtain confidential data for oxygen saturation in 82.6% (n = 19) of cases. Our results show that pulse oximetry could be used as a means of quality control during resuscitation. It is a useful part of pre-hospital monitoring and should be used during resuscitation as early as possible.

Adult↗
PubMed1997

[Traumatic axial dislocation injury of the carpus and metacarpus with triquetrum fracture. Rare entity or typical injury].

Although there are only 39 reports of compression injuries with axial dislocation of the carpus and metacarpus, there are similar patterns of injury. In all cases the dislocation is located either between the first and second or the third and fourth metacarpals and the corresponding carpal bones so that weak points of the carpal arch can be assumed in these regions. Clinical and radiological findings in a 22-year-old patient with dislocation of the third and fourth metacarpals and a fracture of the os triquetrum of the right hand after compression injury of both forearms with severe soft tissue injuries are described. Wound débridement and subsequent skin grafting were performed. The osseous lesions were reduced and held by two Kirschner wires and an external fixator. Results at follow-up were satisfactory.

Accidents, Occupational↗
PubMed1997

[Pediatric forearm fractures. Diagnosis, therapy and possible complications].

Nonoperative management of forearm fractures in children has a good outcome in over 90% of all cases. In our own series (n = 102) there were only six children (6.1%) with significant limitation (> 25 degrees) of forearm rotation. In these cases two out of four (50%) were located in the proximal third but only two out of 68 in the distal third. Indications for operative stabilization are the following: compound fractures, fractures associated with vessel and nerve injuries, joint fractures, dislocated fractures of the middle and proximal third, and Monteggia/Galeazzi injuries. As implants intramedullary devices are preferred. Twenty children were managed with elastic IM rods between 1994 and 1995 at our institution. At final follow-up all had a free ROM and a maximal axial malalignment of less than 5 degrees. In the region of the distal forearm K-wires are useful. Plates play a dominant role for corrections and nonunions; external skeletal stabilization is indicated for temporary fixation in compound fractures.

Bone Plates↗
PubMed1997

[Ossovenography as a diagnostic criterion of post-traumatic femoral head necrosis in internal fixation devices].

Despite advances in the field of orthopedic surgery, necrosis of the femoral head still remains a serious problem. Under normal conditions magnetic resonance tomography (MRT) is the gold standard for early diagnosis. Because of magnetic interference, this technique is not applicable in the diagnosis of posttraumatic necrosis with internal fixation, however. This seems to be an ideal indication for ossovenography: contrast medium is injected into the femoral head under X-ray control and the venous flow is documented. Furthermore, it is possible to get histological samples from suspicious areas. Ossovenography was performed in 12 patients and the results were compared with histological samples. In every patient in whom necrosis of the femoral head was diagnosed by ossovenography (91.6%), we also found necrosis on histological examination. In one patient in whom physiological flow was found, there was a corresponding absence of necrosis in the histological sample. There were no complications during ossovenography. The results suggest that ossovenography is a promising and reliable method for early diagnosis of necrosis of the femoral head in the presence of internal fixation devices.

Adult↗
PubMed1997

Arachidonic acid induces DNA-fragmentation in human polymorphonuclear neutrophil granulocytes.

We analyzed DNA-fragmentation in human polymorphonuclear neutrophil granulocytes (PMNs) from healthy donors after addition of exogenous arachidonic acid (AA) and eicosapentaenoic acid (EPA) by flow cytometry (propidium iodide staining of DNA and DNA strand break detection). The PMNs were incubated from 30 min up to 48 hours in RPMI 1640 which was supplemented with different concentrations of AA or EPA (5-40 microM). In contrast to EPA the addition of AA led to a significant increase in apoptosis up to 67.8% compared to the RPMI-control whereas the addition of EPA led to an inhibition of DNA-fragmentation. When the cells were incubated with MK 886 (1 microM, inhibitor of leukotriene biosynthesis) an increase in DNA-fragmentation (up to 63.3%) was observed. Conversely, in the presence of indomethacin (1 microM, inhibitor of prostanoid synthesis) an inhibition in DNA-fragmentation (up to 60.9%) occurred. Furthermore, preincubation of PMNs with pentoxifylline (1mM, phosphodiesterase inhibitor) reduced AA-stimulated DNA-fragmentation up to 43.4%. These data provide evidence for the involvement of AA and distinct AA metabolites in the regulation of apoptosis in human PMNs.

Apoptosis↗
PubMed1997

[Treatment of open fractures exemplified by tibial shaft fracture].

Main goals in open fracture treatment is to avoid deep infections and achieve uneventful bone healing. Because post-traumatic soft tissue trauma and risk for contamination is underestimated in most cases, the therapeutical protocol must be followed consequently to avoid problems. Strategy includes decontamination by radical debridement, wound lavage, revision surgery, early antibiotics, fasciotomy to secure soft tissue perfusion, no primary skin suture and fracture management by biologic fixation methods. In special cases, temporary shortening and callotaxis after soft tissue healing is indicated. After solid soft tissue healing, fracture treatment is unproblematic in most cases. Following this concept, complication rates in open tibial shaft fractures are extremely low.

External Fixators↗
PubMed1997

[Changes in therapeutic principles in fractures of the extremities with severe soft tissue injuries exemplified by tibial fracture].

Functional results after open fractures have been improved during the last decades. Especially the rates of amputation and chronic osteitis after open tibial fractures have been reduced from 30% to less than 5%. The initial management of this type of fracture includes reconstruction of the perfusion of the involved vessels, subsequent debridement with resection of avascular tissues, decompression of compartments by fasciotomy and initial shortening of the tibia by osteotomy and followed by callus distraction in order to achieve the physiological length of the leg. Cortical bone with periostal stripping has to be covered by local muscle transfer or by free vascularized tissue transfer within 3-7 days. Bone defects are either reconstructed by cancellous bone graft or, if the defect is longer than 2 cm, by continuous segmental transfer, according to the technique described by Ilizarov.

Amputation, Surgical↗
PubMed1997

[Callotaxis--osteogenesis by stretching--a conservative possibility for restoring leg length after post-traumatic primary tibial shortening?].

From 1993 to the beginning of 1996 28 patients (20 male/8 female) with open fractures of the lower leg (classification of Gustilo Type II, Type III) were treated by a primary shortening with a maximum of 5.7 cm (+/- 0.6 cm) after first debridement. After this management 23 patients showed a good soft-tissue cover; 5 patients needed a supplementary musculus latissimus dorsi-transfer to cover the bone. After an average of 22 days (+/- 4.2 days) and the radiologic sign of new callus 8 patients were treated by callotaxis in the fracture gap; 20 patients underwent lengthening by callotaxis of a separate osteotomy after an average of 24 days (+/- 3.6 days). After the mean of 52 weeks (+/- 1 weeks) all patients demonstrated good healing of the fracture and osteotomy. No one showed clinical or radiological signs of osteitis.

Adult↗
PubMed1997

[Distal tibial fracture--an indication for osteosynthesis with the unreamed intramedullary nail?].

In a prospective study, 50 fractures of the distal fifth of the tibia with additional involvement of the ankle joint in 18 patients were stabilized by unreamed nailing. In all, 90% of all fractures healed uneventfully without further surgical intervention after unreamed nailing, the highest ratio of complications (22%) being seen in all patients with distal fractures of the fibula without additional plating (of the fibula). Tibial fractures close to the ankle joint can be managed by unreamed nailing; distal fractures of the fibula should be additionally stabilized by fibular plating.

Adult↗
PubMed1996

Arthroscopic diagnosis of posttraumatic disorders of the wrist.

Arthroscopy of the wrist is a helpful diagnostic procedure in cases of painful problems that cannot be diagnosed by clinical and radiological examination. Arthroscopy of the wrist was done in 32 patients, who could not be diagnosed by clinical and radiological examination. During arthroscopy, lesions of the fibrocartilaginous disc and of the cartilage, synovitis of the joint capsule, scaphoid-lunate dissociations and a loose body were detected. As a result of arthroscopic findings, 10 operative procedures were necessary. Resection of a torn disc, local synovectomy, reconstruction of the torn scaphoid-lunate ligament and removal of a loose body were done by open arthrotomy (8 patients). In 2 patients shaving of chondral ulcers on the radial joint surface was performed, which obviated the need for an explorative arthrotomy. Arthroscopy is a simple method that enables new diagnostic possibilities in rare but difficult cases of posttraumatic pain of the wrist.

Adult↗
PubMed1996

[Retrograde interlocking nailing of distal femoral fractures with the intramedullary supracondylar nail].

Between June 1993 and September 1995, 18 distal femoral fractures were treated using the supracondylar intramedullary nail. There were 8 type A fractures and 10 type C fractures (AO classification). The operative technique involved retrograde insertion of an unreamed supracondylar nail through the intercondylar notch. Follow-up was available on all patients and averaged 18.3 months (range 6-32 months). All fractures healed with an average time to union of 12.4 weeks (range 8-16 weeks). Bone grafting was not necessary in any case. Sixteen patients achieved almost the same ROM as they had had before the injury. One patient developed a varus malignant and underwent correction with a supracondylar osteotomy 20 months post trauma. There were no infections or nonunions. The retrograde supracondylar nail is an excellent alternative to plate osteosynthesis in the management of dia- and supracondylar femoral fractures.

Adult↗
PubMed1996

[Ultrasound follow-up of callus distraction of the tibia. Technique, possibilities and limits].

In a prospective study 20 patients were monitored with serial sonograms and radiographs during distraction osteogenesis at the lower limb. All sonograms were obtained in four planes using a 7.5 MHz transducer. The distraction gap was seen as a sonolucent area in all patients after corticotomy. At an average of 20.7 (14-28) days after the beginning of the distraction, echogenic foci occurred and showed increasing longitudinal alignment with further distraction. Radiographical signs of beginning mineralization were seen an average of 48.3 days after the start of the distraction. Exact measurement of the distraction gap was possible in all patients during lengthening. Bone healing complications and hematoma could be detected by ultrasound. A rapid increase of bone mineralization was seen after the distraction was stopped. With increasing cortication of the regenerate bone, sonograms showed a hyper-reflecting solid line so that further mineralization and the time of removal of the fixator could not be assessed by ultrasound. Ultrasound is more sensitive than radiography in identifying new bone formation during distraction, measuring the length of the distraction gap, and detecting early bone-healing complications and can therefore reduce the need for radiographs.

Adult↗
PubMed1996

[The dynamic hip screw with support plate--a reliable osteosynthesis for highly unstable "reverse" trochanteric fractures?].

ORIF management of unstable trochanteric fractures of type A3 of the A0 classification is difficult because of lateral dislocation of the proximal fractured segments, particularly when only the sliding hip-screw is used for fixation. A connectable butt-press plate was recently developed in order to prevent this type of dislocation. We review the results with this fixation technique in 22 elderly patients with an average age of 76 years who presented with highly unstable trochanteric fracture of the A3 type. Three patients died of diseases unrelated to the trauma or operation before the fractures had healed. The other 19 were followed prospectively until fracture healing had occurred. Complaints, leg shortening and changes in the CCD angle were recorded. Furthermore, the mobility score was determined. Although the patients were able to bear full weight after the operation, no lateral dislocation of fragments was observed. Only 1 patient had a varus dislocation of 5 degrees until the fracture had consolidated. This was due to severe osteopenia and subsequent dislocation of the screw within the femoral head. No pseudarthrosis, osteitis or rotational malalignment was noted. Five of the surviving patients had a lower mobility score after fracture healing as compared to the status before the fracture was sustained. On the basis of this review, we recommend the use of this new connectable buttress plate with sliding hip screws because it provides sufficient fixation of highly unstable fractures of type A3.

Aged↗
PubMed1996

[Is functional conservative treatment of stable lateral ankle fractures justified?].

For Weber type B ankle fractures, operative treatment is generally recommended. Yet, there is no general agreement about the role of functional treatment. In a prospective follow-up study from December 1990 to May 1994, 146 patients were reviewed. The mean follow-up time was 17.3 months for clinical examinations and 19.6 months for X-rays. There were no failures. In all, 85 patients (58%) were treated conservatively (group K). A below-the-knee plaster was applied to 23 patients for 6 weeks, and 62 patients had functional treatment with an ankle brace. According to the Olerud Score, the first subgroup (K-plaster) achieved 89.4 points and the last (K-func.) reached 95.7 points. There were no signs of post-traumatic arthritis. 61 patients (42%) had open reduction and internal osteosynthesis (group OP). In 19 patients a plaster immobilization was necessary, and in 42 patients early mobilization was possible. The first subgroup (OP-plaster) achieved 85.0 points in the Olerud Score; the last (OP-func.) achieved 92.4 points. According to the degree of instability following ankle injuries, a new algorithm for treatment of type B ankle fractures is described, emphasizing early mobilization and functional after treatment.

Adult↗
PubMed1996

[Infected pseudarthrosis].

Sequestrectomy, fragment fixation, wound treatment and bone grafting are the old principles of infected non union surgery. Today these principles are the frame, which contents a more aggressive treatment. Sequestrectomy is a radical excision of the complete infected bone-soft-tissue-scar, the resulting defects are covered by one of the various techniques (skin-traction, flap surgery, bone shifting, etc.). Out of 71 infected non unions, treated by radical resection and bone segment transport, healing rate without recurrence of infection was 94%, in 3 additional patients (4%) amputation was performed. For bone fragment fixation, a non devastating implant, like external fixateur, is preferred. To close the wound, the law of avoiding a dead space is used. Defects are closed by muscle flaps, by fragment shortening or by a antibiotic spacer temporarily. The skin is closed by skin-traction techniques or with flap surgery. After soft tissue healing, small bone defects are filled by autografts, defects of more than 3-4 cm with transported segments. Previous limb shortening to close bone defects, with a lengthening later in a "healthy" region, is also possible. Local antibiotic wound treatment cases a significant reduction of the contamination rate, improved dressing techniques support wound healing free of infection. This therapeutic techniques are comparable to open fracture treatment, where by similar surgery a very low infection rate can be achieved.

Amputation, Surgical↗
PubMed1996

[Ilizarov procedure in pseudarthrosis].

The treatment of nonunions has made an important development through the work of Ilizarov describing the principles of compression and distraction by using the ring-fixator. While local compression is sufficient in hypertrophic nonunions, the treatment of choice for atrophic infected nonunions with bony defects is a corticotomy followed by a segmental transport, especially in case of an osseous defect larger than 3 cm. Primary shortening poses a better starting point both for soft-tissue reconstruction and for early docking. External fixation systems are the ring-fixator, the unilateral fixator and hybrid systems combining both fixation methods. The use of a ring-fixator makes a shorter time of osseous consolidation possible when compared to a unilateral system (25,8 d/cm - 35,8 d/cm). Soft-tissue reconstruction before initiation of transport also shortens the time of osseous consolidation compared to later soft-tissue coverage. A docking-region in the metaphyseal area is supported by minimal internal fixation and cancellous bone graft. Segmental transport is complicated by local infection, regenerate failure (4.3% and regenerate fracture (2.9%).

Adult↗