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Biomedical subjects

A Dávid

Publications and source records attributed to A Dávid.

At least 19 recordsLinked to original sources
PubMed2002

[Prosthesis implantation in the proximal ankle joint--a real therapeutic alternative in post-traumatic arthrosis?].

The results of total ankle arthroplasty were poor in the 1970s and 1980s compared to those of the arthrodeses. Because of the good long term results this technique has been accepted as the treatment of the choice for posttraumatic arthritis of the ankle. Recently the development of an unconstrained total ankle arthroplasty with an additional mobile polyethylene inlay between the fixed tibial and the talar component which enables a three dimensional range of motion seems to improve significantly the long term results of total ankle replacement. This technique, however, is an extremely demanding procedure. The range of motion after total ankle replacement following posttraumatic arthritis is poor compared to the results of total ankle replacement for rheumatoid arthritis. Furthermore, these data are obtained yet only by a few experienced surgeons in specialized centers. Further clinical trials have to be performed to answer the question whether the total ankle arthroplasty is a reliable alternative treatment of posttraumatic arthritis of the ankle. At present, the arthrodesis should be regarded as the treatment of choice for the posttraumatic arthritis of the ankle joint.

Ankle Injuries↗
PubMed2000

[Therapeutic possibilities in trochanteric fractures. Safe--fast--stable].

Trochanteric fractures frequently occur in elder patients with severe osteopenia. These fractures are highly unstable. Conservative treatment is not indicated because of the long period of immobilization until fracture healing is achieved. Simple fractures (A1) can be successfully fixed by either plate-hip screw systems like Dynamic Hip Screw (DHS) or nail-hip screw systems (Gamma-Nail, Proximal Femur Nail, Classic Nail). As a result of biomechanical and clinical trials the intramedullary implants should be preferred for fixation of more comminuted fractures (Type A2.2, A3.3) and subtrochanteric fractures. For ipsilateral femoral shaft and trochanteric fractures long nail-hip screw-systems are recommended like the long PFN or the long Gamma nail. In about 90% of the patients with trochanteric fractures postoperative weight bearing can be achieved by internal fixation if gliding systems are applied. Intraoperative and postoperative complications however occur more frequently after the implantation of Gamma-Nail than after application of a DHS. Other implants like Ender Nails, 130 degrees angled plate or twisted plate are not further recommended.

Aged↗
PubMed2000

Fixation of proximal tibia fractures by a retrograde nail: a biomechanical investigation.

Surgical treatment of proximal tibial fractures requires open reduction and internal fixation. The operative exposure causes additional soft-tissue injury and reduces the blood supply to the bone. A cephalograde tibial nail should offer comparable mechanical stability without these disadvantages. We compared the stability of both osteosyntheses in a fracture model with 12 fresh-frozen cadaver bones. While both implants exhibited comparable stiffness under sagittal loading, the plate had a higher rotational and varus stiffness. Despite this higher stiffness, rotational displacements at the fracture gap were nearly twice as large for this implant during loading. We conclude that the retrograde nail provides similar mechanical stability to plate fixation for proximal tibial fractures, while the closed reduction and soft-tissue preservation of this new technique are definite advantages.

Biomechanical Phenomena↗
PubMed2000

The theoretical basis for scaling-up by the use of the method of microwave granulation.

For the scaling-up achieved by the use of the method of wet microwave granulation based on calculations, there is a need for an exact mathematical description for the relationship between the dose of radiation and the resultant effect. By assessing the physical, physical-chemical, and chemical factors, we may conclude that, by the gross kinetic evaluation of the change in the enthalpy and the loss of humidity, there is a possible solution for the mathematical description of the single-step, single-pot granulation from the practical aspect of finding ways to scale-up. This paper overviews the experiments performed in a laboratory-size microwave vacuum granulator in testing two different granules with respect to composition and permittivity and presents the evaluation of the experimental data.

Calcium Citrate↗
PubMed1998

[Corrective arthrodesis in isolated post-traumatic malalignment of the subtalar joint].

Between 1990 and 1995, 27 patients with posttraumatic disorders of the subtalar joint were treated by correcting fusion. Preoperatively 24 patients (88.89%) suffered from pain; 15 (55.56%) had a walking range below 100 m. Seven patients were unable to work in their original profession. After an average period of 13.85 months postoperatively the patients were examined again. At this time 18 (66.67%) had no or minimal pain; 19 (70.37%) had no claudication. According to the score of Angus and Skuginna, in 81.48% of patients the result of the correcting arthrodesis was successful; according to Kitaoka's clinical rating system for ankle-hindfoot, midfoot, hallux and lesser toes, the average postoperative score was 75.8 points.

Adult↗
PubMed1998

[Intramedullary boring in infected intramedullary nail osteosyntheses of the tibia and femur].

UNLABELLED: The infection after intramedullary nailing is a severe complication, which is hard to eradicate. The results of reaming the intramedullary canal after removal of the infected nail were evaluated in our investigation. From 1984 to 1991 fifty-five patients with infected intramedullary nails of the lower extremity were included in this trial. Twenty-one patients had an infection of the femur. Thirty-four patients had a primary infection of the nail, twenty-one patients had multiple operations with periods of infection prior to nailing. All patients had signs of a chronic osteitis and sinus formation. At the time of the follow-up the success of the procedure was evaluated regarding recurrence of infection, range of motion of the extremity and patient comfort. The mean time of observation was 10.1 +/- 4.9 years. All patients with initially infected intramedullary nails had no recurrence of the infection, compared to 62% of those with multiple operations prior to nailing. At the time of the follow up all fractures had healed. 85% of the patients performed full weight bearing. 32 patients (91%) had good or excellent ROM of the adjacent joints. CONCLUSION: Intramedullary reaming after infected nails is a successful procedure and results in infect healing in the majority of patients.

Adult↗
PubMed1998

[Loosening of Schanz screws in external fixator montage of the lower extremity].

We analyzed the failure of Schanz pins in 234 patients with fractures of the lower extremity. All patients had the AO external fixator and stainless steel pins (ISO 58/32-1). The mean duration of treatment was 14 weeks. During this time 88 of a total of 1147 pins became loose. The first failures occurred 2 weeks after insertion. Most pins failed after 5-6 weeks. Early loosening was not accompanied signs of local infection, while late failures regularly developed pintract infections. Pins next to the fracture gap exhibited the highest rate of loosening. Intermediate pins had the lowest one. We could not detect an effect of the configuration of the external fixation. Eighty-one percent of the failed pins were exchanged consequently. We conclude that the early occurrence of pin loosening is due to mechanical reasons. Significant factors for this complications were the location close to the fracture gap and the number of pins in that segment.

Adolescent↗
PubMed1998

[Liberation of interleukin 12 (IL12) after trauma and polytrauma].

We determined concentrations of IL-12 (p70), IL-12 (p40) and concomitantly of IL-10 in plasma and partly in culture supernatants stimulated peripheral blood mononuclear cells (PBMC) of 30 traumatized patients (ISS: 17-57; APACHE II: 7-45; during their course on the intensive care unit. Our results showed that individually systemic IL-12 could be extremely increased post trauma (p70 > 1000 pg/ml and p40 > 2500 pg/ml). Patients who succumbed to sepsis/multi organ failure, partly exhibited subnormal systemic IL-12-values. The capacity to synthesize IL-12-p40 from SAC-stimulated PBMC in vitro was individually increased in non-septic patients and correlated to respective plasma values.

APACHE↗
PubMed1997

[Possibilities and limits of functional conservative therapy of acute Achilles tendon ruptures].

According to sonographic criteria, 55 patients underwent surgical treatment with mobilisation in a lower leg plaster or conservative treatment with early mobilisation in heel pad (3 cm) shoes when an acute Achilles tendon rupture (ATR) was diagnosed. The follow-up period in 51 patients was 2.4 years (operated group = 28 patients, conservative group = 23 patients) with clinical examination and testing of isokinetic muscle strength in knee joint flexion. After surgical treatment, minor wound infections occurred in 10.6%. Reruptures occurred in 13% of the conservative group. Following conservative treatment, the rate of stress-related achillodynia was significantly higher (P = 0.019). In the operated group mean isokinetic muscle strength was 13.7% lower than in the uninvolved leg and decreased significantly with non-operative treatment to 75.3% (P = 0.012). We recommend surgical treatment of acute ATR. The indications for conservative treatment depend on the extent of the rupture (measured by ultrasound in the equinus position), the desired level of daily activity and the patient's degree of compliance.

Achilles Tendon↗
PubMed1997

[Corrective soft tissue interventions for equinovarus deformity. Foot deformities after tibial compartment syndrome].

Sixty-three patients with rigid equinovarus contractures of the foot following ischemic episodes in the lower leg were treated at our institute from 1983 to 1994 by lengthening the Achilles tendon and the tendon of the m.tibialis posterior, release of the tendons of the m.flexor digitorum longus and the m.flexor hallucis longus and release of the dorsal capsule of the ankle joint. Patients with an equinus deformity greater than 20 degrees, with an additional hind foot varus deformity of more than 5 degrees and/or malrotation of the midfoot were not eligible for this procedure. The initial equinus deformity ranged from 7 degrees to 20 degrees (mean 14 degrees). The clinical and radiological results of 41 patients were evaluated retrospectively with a minimum follow-up of 1 year (mean 3.4 years). The overall results were evaluated according to a modified score of Angus and Cowell. Results were good in 60.9%, fair in 29.3% and poor in 9.8%. The range of motion of the ankle joint and the subtalar and midtarsal joints could not be improved. Postoperative complications were observed in 8 patients, one intraoperative lesion of the posterior tibial artery occurred, one avulsion fracture of the anterior tibial metaphysis and one compression syndrome of the tibial nerve. One patient had an initially incomplete correction with a remaining equinus deformity of 10 degrees, and two recurrences of the foot deformity after initially correct position were observed. Furthermore, two hematomas and two soft-tissue infections required surgical revision. These complications may have been due to the preoperatively scarred soft tissue at the medial aspect of the hind foot and a residual postoperative soft-tissue defect after the correction of the foot deformity had been achieved. In conclusion, the technique described is effective in correcting mild pes equinovarus deformities after ischemic episodes in the lower leg. If the pes equinus deformity is greater than 20 degrees, corrective osteotomies of the hind foot should be performed instead.

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

[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↗
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

[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

Surgical correction of talipes equinovarus following foot and leg compartment syndrome.

Between 1984 and 1994, 40 patients with a posttraumatic compartment syndrome of the lower leg and foot were treated for talipes equinovarus adductus foot deformity, which subsequently developed. Twenty patients had a wedge osteotomy followed by arthrodesis of the midtarsal joint (Chopart joint). Another 17 patients had an arthrodesis of the midtarasal and subtalar joints. In the remaining three patients, in addition to arthrodesis, lengthening of the tendons of the long flexors and the Achilles tendon was performed. Complications included wound infections (six cases), drill hole infections (three cases), chronic osteomyelitis (one case), and an ankle joint infection (one case). The clinical result was assessed as good in 37.5%, fair in 52.5%, and poor in 10% of the patients. Before the operation, 37 patients required modified footwear. After the operation, only eight patients needed them. Wedge osteotomy of the midtarsal and subtalar joints followed by an arthrodesis is an advantageous treatment modality for the correction of severe postischemic equinovarus adductus foot deformities. In our study, patient satisfaction was high. While complications frequently occur, it is not extraordinary considering the salvage nature of the procedure.

Achilles Tendon↗
PubMed1996

Classification of articular cartilage lesions of the knee at arthroscopy.

Classification systems for articular cartilage lesions in the knee have been based primarily on the appearance and severity of damage to the articular cartilage. Each of these systems has deficiencies in the documentation of articular cartilage abnormalities. This article proposes a new classification system for articular cartilage lesions in the knee. This system incorporates multiple parameters such as appearance, depth of involvement, area, clinical stage, and location of the lesion. A four-sector-mapping system allowing precise documentation of the location of articular cartilage lesions in the femorotibial joint is proposed. One numerical category is used to assess severity of a chondral defect. The use of these categories allows the surgeon to accurately grade and locate damage to the articular cartilage and its relationship to other concomitant intra-articular abnormalities. The proposed classification system has proven advantageous in communicating complex findings.

Arthroscopy↗