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Biomedical subjects

B Albrektsson

Publications and source records attributed to B Albrektsson.

17 recordsLinked to original sources
PubMed1989

Morphometrical studies of human femoral condyles.

Thirty-six cadaver knees were examined by various morphometrical methods in order to obtain mathematical and graphical data concerning the geometry of the lower end of the femora. It was found that the paramedian sagittal curves represented magnifications of a certain curvature pattern specific to the medial and the lateral femoral condyle. These curves could be expressed mathematically for each condyle. Furthermore, we found dimensional as well as geometrical intervariations between the different size groups in the knee sample. This could serve as an argument for preferring a different design for medial and lateral condyle components in knee prostheses.

Femur↗
PubMed1989

Wear of ion-implanted pure titanium against UHMWPE.

Six specimens were manufactured from commercially pure titanium (grade IV) to resemble femoral head prostheses, and five of them ion implanted to increase the wear properties. Together with three cobalt-chrome controls they were run for one million cycles on a 10-station joint simulator. For the first time both the polymer and metallic wear were quantified in the same study. The purpose of the investigation was to estimate the potential for using commercially pure titanium as a bearing surface against ultrahigh-molecular-weight polyethylene for total joint application. It was concluded that the wear properties of titanium were improved by ion implantation, and that these positive effects could probably be enhanced with development of a better polishing technique, and by finding methods of extending the penetration depth of the nitrogen ions.

Biocompatible Materials↗
PubMed1989

Osseointegrated knee prostheses. An experimental study in rabbits.

Osseointegration, defined as direct bone-to-implant contact, has been suggested as an approach for improving the results of arthroplasties of the major joints. An experimental investigation in femoral-patellar joint of the rabbit was performed to evaluate whether osseointegration could be achieved in a one-stage surgical procedure. After three months, it was found that the screws used for anchorage of the prosthesis showed an average direct bone-to-implant contact of 60% in three selected consecutive threads on each side. The range was 40-90%. These figures correspond well with previously reported ones from bone anchored titanium fixtures. It was therefore concluded that osseointegration of dynamically loaded screws used for anchorage of a femoral-patellar joint prosthesis may be achieved in spite of the fact that no controlled healing period for the screws was observed.

Animals↗
PubMed1988

Implant fixation improved by close fit. Cylindrical implant-bone interface studied in rabbits.

Cylindric titanium implants of three different diameters were inserted and stabilized in a 3.7-mm burr hole in the rabbit tibia. The purpose of the study was to investigate the interfacial reaction to screw- and cylinder-shaped implants, and to determine if there is a critical gap at the insertion between bone and implant that prevents direct cortical bone apposition on the implant. The study indicated that this critical gap approached zero.

Animals↗
PubMed1987

Acute tissue reactions to potassium alginate with and without colour/flavour additives.

The acute tissue reactions to potassium alginate, locally applied to a microvascular bed, were studied with the use of the vital microscopic hamster cheek pouch model combined with correlative histology. This experimental model permitted us to study microvascular permeability, blood flow, vessel diameters and leucocyte adhesion to vessel walls intravitally, and leucocyte migration and mastcell degranulation histologically. Deionized water alone and potassium alginate with flavour and colour mixed in saline was found to cause severe microvascular alterations, while potassium alginate, without flavour and colour, but mixed in saline and applied to the microvasculature resulted in a minor inflammatory reaction.

Alginates↗
PubMed1986

Osseointegration of titanium implants.

Forty-eight screws, six double cylindrical implants and six T-plates were inserted into the tibia or femur of 6 dogs. Two titanium screws were inserted into the proximal tibia of 5 patients to anchor a titanium mould. The implants were removed en bloc with adjacent bone tissue after 3 to 14 months. They were sectioned using a technique that allowed analysis of the intact tissue-to-metal specimens. Osseointegration, defined as a direct bone-to-implant contact without interposed soft tissue, was confirmed in all screw-shaped implants while the cylindres had only partial bone contact as did the T-plates. We conclude that osseointegrated implants may be applicable in joint reconstruction for arthrosis or rheumatoid arthritis.

Adult↗
PubMed1984

Heat caused by drilling cortical bone. Temperature measured in vivo in patients and animals.

In vivo temperature measurements were performed at drilling in the femoral cortex of the rabbit, dog and man. In the clinical study the bone temperature was measured at fixation of a Richards plate to stabilize a pertrochanteric fracture. With a drill speed of around 20 000 rpm and saline cooling, temperatures of 40 degrees C in rabbits, 56 degrees C in dogs and 89 degrees C in patients were recorded at a distance of 0.5 mm from the periphery of the drill hole. The difference in temperature between the animal and clinical studies was mainly attributed to the difference in cortical thickness between the species. When drilling straight through the canine femur from the lateral to the medial side, a 9 degrees C higher temperature was measured in the remote, medial cortex compared to that recorded in the lateral cortex. This difference arose because it is difficult for the cooling agent to reach the medial cortex. The results of the present study indicate that temperatures measured in animal experiments are not applicable to the clinical situation where very high temperatures may arise on drilling in cortical bone, even if saline cooling is used.

Aged↗
PubMed1983

Bristow-Latarjet procedure for recurrent anterior dislocation of the shoulder. A 2-5 year follow-up study on the results of 112 cases.

A follow-up study of 111 out of 112 patients operated on for shoulder joint dislocation according to the Bristow-Latarjet procedure during the years 1975 through 1979 in four Swedish hospitals is presented. The average follow-up time was 30 months (range 24-60 months). There were seven cases of significant recurrences (6 per cent). During follow-up, further surgery had been performed on four of these. Another eight patients (7 per cent) had experienced occasional insignificant subluxations. In one case neurolysis of the musculocutaneous nerve was undertaken because of postoperative paresis of elbow flexors. The average limitation of outward rotation as compared with the nonoperated side was 19 degrees in adduction and 21 degrees in abduction. There was a measurable difference in strength between the operated and nonoperated shoulders. The results were considered excellent or good by 101 of the patients (90 per cent), fair by eight and bad by three. Of 12 cases with failed surgery before the Bristow-Latarjet procedure 10 regarded the result as good or excellent.

Adolescent↗
PubMed1982

The tarsal tunnel syndrome in children.

There are few reports on the tarsal tunnel syndrome in children. This paper concerns 10 such children. In adults the syndrome is equally distributed among the sexes but all these children were girls. Trauma preceded the symptoms in only two cases. The symptoms differed in some aspects from those usually seen in adults. Six of the children walked with the affected foot in supination. Three of the six, and one other, used crutches at intervals. All were operated on and at follow-up nine were symptom-free and the tenth had improved.

Adolescent↗
PubMed1981

Sacral rhizotomy in cases of ano-coccygeal pain. A follow-up of 24 cases.

The long-term effect of sacral rhizotomy in 24 patients with coccygodynia was evaluated. Prior to section of both the S-4 and S-5 roots all patients had coccygeal pain and tenderness which had not responded to severe conservative and surgical therapeutic measures. In 8 patients the coccalgia (S-4 S-5 pain) was associated with unilateral pain in the S-3 area, in another 8 patients it was associated with disabling lumbago and in the remaining group of 8 patients coccalgia occurred without pain in neighbouring areas. Only 6 patients responded well to sacral rhizotomy. All these patients belonged to the final group of 8 patients with pain distribution limited to the S-4 S-5 area. Serious complications occurred after 6 of the 24 rhizotomies. Five of these patients belonged to the two groups who besides coccalgia also had disabling lumbago or signs of rhizopathy about the S-4 level. A restrictive attitude to sacral rhizotomy in coccalgia is recommended especially when it is associated with pain in neighbouring areas and also if there is any reason to believe that there are factors present predisposing to the development of arachnoiditis.

Coccyx↗
PubMed1978

Microcirculation in grafted bone. A chamber technique for vital microscopy of rabbit bone transplants.

A method enabling in vivo observations of the microcirculation in orthotopically transplated bone in the rabbit is presented. The technique permits repeated study of a well-defined bone tissue compartment both before and after grafting to an autogenous or allogenous recipient site, respectively. It yields information about the reorganization of the microvascular system and the resorptive and formative processes of bone remodelling during incorporation of grafted bone. In the autologous experimental series, new capillaries were seen in the bone grafts 4 to 5 days after transplantation. No re-utilization of pre-existing graft vessels was observed.

Animals↗