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Biomedical subjects

C Bünger

Publications and source records attributed to C Bünger.

At least 91 records · Page 5Linked to original sources
PubMed1986

99mTc-DPD uptake in juvenile arthritis. Scintimetry and autoradiography of the knee in dogs.

Unilateral arthritis of the knee was induced in mongrel puppies by intraarticular injections of 1% Carragheenan. Bone metabolism was studied by a scintimetric technique on static 99mTc-diphosphonate bone scans every 2nd week during the induction of arthritis for 3 months and monthly in a postarthritic phase of another 3 months. Changes in uptake of radionuclide were present after 2 weeks. The induction phase was characterized by a decreased uptake in the calcification layer of the juxta-articular growth plates and a moderately increased epiphyseal uptake. The postarthritic phase was characterized by normalization of growth plate uptake and a marked increase in epiphyseal uptake. Using contact autoradiography, the epiphyseal uptake was seen mainly in a narrow subchondral and subsynovial bone layer, around bone cysts and osteophytes, whereas central epiphyseal bone was osteopenic with decreased uptake of tracer. The study suggests that the early scintigraphic appearance of juvenile non-suppurative arthritis may be an overall decrease in uptake of 99mTc-diphosphonate due to a depression of growth plate metabolism.

Animals↗
PubMed1986

Microcirculation of the juvenile knee in chronic arthritis.

In order to investigate pathogenetic factors in growth abnormalities of the knee in hemophilic arthropathy and juvenile rheumatoid arthritis, the hemodynamic changes of the knee following chronic synovial inflammation and elevated joint pressure were studied in puppies. Unilateral arthritis was induced by intraarticular injections of carrageenan solution. Regional blood flow (RBF) was measured by tracer microsphere technique. Microvascular volume (VV) was estimated from the distribution volumes of Cr51-labelled erythrocytes and I125 fibrinogen. Mean transit times (TT) of blood components were calculated from volume/flow ratios. The arthritic joint capsules were characterized by high RBF rates, increased VV, low tissue hematocrit (HCT) and short TT of blood. In the juxtaarticular epiphyses and the patella, RBF was largely unchanged, whereas VV was significantly elevated and TT of blood prolonged. The growth plates formed borders for the extension of these changes. The increased permeability and surface area between blood and bone in arthritis may accelerate the resorption and subsequent destruction of subchondral bone in chronic arthropathies of the juvenile knee.

Animals↗
PubMed1985

Patellofemoral function in total condylar knee arthroplasty.

A series of 100 total condylar knee arthroplasties was studied to determine radiographic and clinical patellofemoral function. Before operation there was lateral patellar tilt in 31 cases and lateral displacement in 52. After operation tilt was present in 8 and displacement in 14. Only a few patients had medial patellar displacement. Dislocation or fracture of the patella was not encountered. Six patients had postoperative patellar pain. In one case there was a radiolucent zone at the bone-cement interface in the patella, without pain. Patellofemoral function before operation was good in 3, fair in 54, and poor in 43 cases. After operation it was good in 88 and fair in 12. Both tilt and displacement slightly reduced postoperative patellofemoral function. Patellar reconstruction with the total condylar prosthesis shows reasonably good tolerance of moderate malpositioning of the patellar prosthesis, affords sufficient stability and usually painless patellofemoral function.

Adult↗
PubMed1985

A histomorphometric analysis of subchondral bone in juvenile arthropathy of the dog knee.

Subchondral bone changes in arthropathy were investigated in an animal model using mongrel dog knees. Unilateral arthritis of the knee was induced by repeated intra-articular instillations of Carrageenin solution in 14 mongrel puppies. Histomorphometric analysis of cartilage and bone was performed blindly in both knees of each dog. Arthritis resulted in a significant increase in the joint cartilage thickness and a significant decrease in subchondral epiphyseal trabecular bone volume (VTB%) and trabecular thickness (TRTH), suggesting negative bone balance. No significant changes in osteoid surfaces (OS%) and resorptive surfaces (RS%) were found. The dynamic parameters suggest an increased bone turnover in the arthritic subchondral bone.

Animals↗
PubMed1984

Early results after Colles' fracture: functional bracing in supination vs dorsal plaster immobilization.

A randomized clinical study of functional bracing in supination (FUSU) versus dorsal plaster immobilization (DPI) was conducted in 145 patients with Colles' fracture. A dynamic wrist unit was developed and used in 68 patients allocated for FUSU. The anatomical end result after FUSU was excellent or good in 80% of the patients versus 64% after DPI (P less than 0.05), in particular due to less dorsal angulation (P less than 0.001) and less radial shortening. The functional recovery was equal after 7 weeks and 3 months. At 6 months, 92% satisfactory results were achieved after FUSU versus 86% after DPI (P less than 0.05). Both anatomical and functional benefits were recorded in Frykman type V, VI, and VIII fractures and in the group of displaced intra-articular fractures. The functional benefit from FUSU is suggested primarily to be secondary to decreased fracture redislocation.

Adult↗
PubMed1984

Haemodynamics in acute arthritis of the knee in puppies.

In order to study the haemodynamic changes of the juvenile knee in acute arthritis, an experimental model was developed in puppies by unilateral intra-articular injections of Carragheenin solution into the knee. Tissue blood flow was studied by the tracer microsphere technique in eight dogs and simultaneous intra-articular and intraosseous pressure recordings were performed in seven other dogs. The intra-articular pressure was elevated in all arthritic knees. Hyperaemia was found in the knee-joint capsule and distal femoral metaphysis, whereas juxta-articular epiphyseal blood flow rates were not significantly changed. A decrease of femoral muscle blood flow was encountered. Intraosseous pressure recordings during venous tamponade of the knee-joint capsules suggested a qualitative change of bone vasculature in acute arthritis. The juxta-articular bone blood flow in arthritis appears to be influenced by synovial hyperaemia, synovial effusion pressure, an "inflammatory resistance factor" and the anatomical relationship of the epiphyseal vessels to the knee-joint capsule.

Acute Disease↗
PubMed1983

Hemodynamics of the juvenile dog knee in relation to increased venous outlet resistance.

Tissue blood flow was measured by the tracer microsphere technique in the juxta-articular bones of the immature knee, knee joint capsule and skeletal muscles of the hind limbs after unilateral bone cannulation of the distal femoral epiphysis, surgical exploration of the popliteal vessels and unilateral isolated increase of venous outlet resistance in the distal femoral epiphysis during Halothane anaesthesia. Pressure registration was performed in a liquid-filled electromanometric pressure recording system. Significant regional differences in bone blood flow was found within the different bone compartments of both control and test limb. Bone cannulation resulted in insignificant hyperaemia in the distal femoral epiphysis. No changes of distribution pattern of bone blood flow followed the surgical procedure. Ligation of the medial genicular vein caused a three fold increase of venous outlet resistance measured after 5 min, while an insignificant decrease of arterial inlet resistance was calculated. After one hour a significant decrease of both arterial inlet resistance and venous outlet resistance was found. In addition evidence of a veno-arterial reflex mechanism causing a significant unilateral decrease of distal skeletal muscle blood flow was found. The results demonstrate the presence of both venous and arterial regulation, predominantly metabolic, of bone blood flow in the knee.

Animals↗
PubMed1983

Hemodynamics of the juvenile knee in relation to increasing intra-articular pressure. An experimental study in dogs.

The relationships between intraosseous pressure and regional blood flow in the juxta-articular epiphyses were determined in the knees of immature dogs. Intraosseous pressures were continuously registered in one knee. Regional blood flow rates were simultaneously determined by the microsphere technique before and after venous tamponade of both knee joint capsules. During complete venous tamponade the intraosseous pressure of the distal femoral epiphyses rose 268%, while flow increased 122%. A concurrent 20-fold flow increase of the knee capsule and 3-4-fold flow increase of the proximal femoral bone was observed. Evacuation of the knee joints resulted in an immediate drop of the intraosseous pressure of the distal femoral epiphyses, whereas hyperaemia prevailed for at least half an hour and was most pronounced in the distal femoral epiphyses and knee joint capsule. Intraosseous pressure registration did not significantly influence regional blood flow. It is suggested that the changes of intraosseous pressures during knee joint tamponade reflect changes in the venous outlet resistance. The results demonstrate the significance of intra-articular pressure increase on the hemodynamics of the juxta-articular tissues of the knee and proximal femoral bone. These findings may be of importance in the pathogenesis of growth disturbances observed in juvenile degenerative arthritis.

Animals↗
PubMed1983

Blood flow in the juvenile hip in relation to changes of the intraarticular pressure. An experimental investigation in dogs.

The blood flow in the hip joint of puppies was studied by means of the microsphere technique. The flow was determined before, during and after intraarticular pressure increase. A venous tamponade of 50 mmHg resulted in a significantly reduced flow in the femoral head and after an arterial tamponade of 150 mmHg the flow almost ceased. The proximal femoral metaphysis, the acetabulum and the hip joint capsule, on the contrary, showed varying degrees of flow increase. It is suggested that the significantly increased blood flow in the hip joint capsule during the intraarticular pressure increase of 50 mmHg and 150 mmHg is caused by an autoregulatory mechanism tending to restore the blood flow in the suffering femoral head. The demonstrated disturbance of the circulation in the juvenile femoral head after venous tamponade supports the theory that synovitis may be the basic mechanism in the production of Calvé-Legg-Perthes' disease.

Acetabulum↗
PubMed1983

Relationship between intraosseous pressures and intra-articular pressure in arthritis of the knee. An experimental study in immature dogs.

The influence of chronic synovial inflammation and effusion on the juxta-articular bone haemodynamics in the juvenile knee was studied in 12 immature dogs with Carragheenin-induced unilateral arthritis. Using a fluid filled electromanometric pressure recording system simultaneous pressure measurements were taken from the distal femoral metaphysis, juxta-articular epiphyses and knee joint cavity in general anaesthesia followed by intraosseous phlebographies. During resting conditions the intraosseous pressure of the distal femoral epiphysis and the intra-articular pressure was significantly elevated. The phlebographies showed increased accumulation of contrast in arthritic femoral epiphyses with decreased contrast clearance rate. During increasing intra-articular pressure an augmented vulnerability of the blood supply of the arthritic femoral epiphyses was demonstrated. The results suggests that joint effusion may play an important role in the bone changes in juvenile degenerative arthritis of the knee.

Animals↗
PubMed1982

Intraosseous pressure in the patella in relation to simulated joint effusion and knee position: an experimental study in puppies.

Simultaneous pressure measurements were carried out in the patella, juxtaarticular epiphyses and the knee joint cavity of six mongrel puppies. The mean intraosseous pressure in the patella was 12.2 mmHg, range 8-15 mmHg. An increase in intraarticular pressure in turn caused an increase in the intraosseous pressure of the patella and juxtaarticular epiphyses. The pressure increase in the patella was the most pronounced. During extension of the knee joint, a significant rise in intraosseous pressure of the tibial epiphysis and patella was observed, whereas during flexion femoral epiphyseal pressure and patellar pressure increased significantly. The introduction of moderate intraarticular effusion amplified intraosseous pressure responses during flexion of the knee joint. The intraosseous pressure changes during knee movement could not be explained solely by the corresponding changes in intraarticular pressure. Intraosseous phlebography revealed a venous drainage system largely parallel to the arterial blood supply. The contrast clearance time was decreased during moderate elevation of the intraarticular pressure, suggesting increased bone blood flow of the patella.

Animals↗
PubMed1981

Intraosseous pressures in the knee in relation to simulated joint effusion, joint position, and venous obstruction. An experimental study in growing dogs.

The present study was performed in 9 mongrel puppies, 8-10 weeks old. Under anaesthesia simultaneous pressure registrations were taken from the distal femoral metaphysis, the distal femoral epiphysis, the proximal tibial epiphysis together with the arterial pressure. An intra-articular pressure increase resulted in a significant increase in the intraosseous pressure in the distal femoral epiphysis, while the pressures in the femoral metaphysis and tibial epiphysis remained unchanged. During maximal flexion of the empty joint a significant increase in femoral epiphyseal pressure was observed, while maximal extension resulted in a significant increase in tibial epiphyseal pressure. The presence of a moderate intra-articular effusion augmented these findings. By selective ligation of the venous drainage from the juxta-articular bones in the popliteal fossa and on the femur, different levels of epiphyseal hypertension could be produced. These pressure increases never reached the level of the arterial pressure. Thus they revealed only a partial impairment of the vascular circulation in the juxta-articular bones.

Animals↗
PubMed1981

The relationship between increasing intraarticular pressures and intraosseous pressures in the juxtaarticular bones. An experimental investigation in dogs.

The present experiment investigation of the relationship between intraarticular and intraosseous pressures was carried out in mongrel dogs. Under general anaesthesia simultaneous pressure measurements were performed in the femoral artery, the knee joint and the tibia and femur adjacent to the knee joint. The intraarticular pressure was increased by infusion of saline. Increase in the knee joint pressure caused an increase in the femoral intraosseous pressure, while the tibial intraosseous pressure remained unchanged. The pressure increase in the femur was most pronounced in dogs with intact epiphyseal plates. It is suggested that the rise in the femoral pressure was caused by compression of the venous drainage from the bone. Further evidence to support this suggestion was obtained from anatomical studies, intraosseous phlebography and experiments with selective venous compression.

Age Factors↗