Biomedical subjects

S Toksvig-Larsen

Publications and source records attributed to S Toksvig-Larsen.

59 records · Page 4Linked to original sources

PubMed1991

Surface flatness after bone cutting. A cadaver study of tibial condyles.

A methodologic study with which the cut surface could be quantified was performed on cadaveric tibial bone prepared for endoprosthetic components. Using sterilized, dental-imprint material and measuring with a Zeiss UMC 850, the characteristics of the cut surface were defined. A clinically flat surface was found to be uneven, with a maximum roughness between the uppermost and lowermost points of 1.0 and 2.4 mm for the bone surface and between 1.2 and 2.3 mm for the imprint. The flatness, defined as the standard deviation of the measuring points, was between 0.15 and 0.40 mm for the bone and 0.20 and 0.42 mm for the imprint. This lack of flatness creates gaps between the prosthesis and the bone.

Bone and Bones↗

PubMed1991

Cement interface temperature in hip arthroplasty.

The temperature was measured using thermocouples in the bone-cement interface during cement curing in 30 total hip replacement operations. A modern technique was used, including lavage and precooled vacuum-mixed cement. The mean maximum temperature in the acetabulum was 43 (38-52) degrees C and in the femur 40 (29-56) degrees C. The use of a precooled femoral prosthesis did not affect the peak temperature.

Bone Cements↗

PubMed1990

An internally cooled saw blade for bone cuts. Lower temperatures in 30 knee arthroplasties.

A saline-cooled saw, which has been shown to give good control of the heat generation during bone cutting under laboratory conditions, was tested in in vivo. With a saline flow of 80 mL/min, the maximum cutting temperature in 30 knee prosthetic operations was 32 (25-37) degrees C in the saw blade and respectively 30 (26-35) degrees C and 29 (26-34) degrees C 2 and 3 mm underneath the cut surface. Because the temperature generated by conventional osteotomy equipment may exceed 70 degrees C, the use of our cooled double saw blade during joint replacement prevents heat osteonecrosis.

Arthroplasty↗

PubMedDate not supplied

Improving accuracy of bone resections using robotics tool holder and a high speed milling cutting tool.

The use of non-cemented prosthetic components in implant surgery is demanding a high quality of bone beds in order to allow for a good level of osseointegration. Two parameters are significant in the evaluation of the quality of the host bone: roughness, which reports on the presence of gaps and peeks, and flatness, which reports on the total percentage of bone which lies in a given interval from the prosthesis. Robot assisted cutting of 32 pig femours and tibiae was performed using various techniques and options. This paper demonstrates roughness and flatness can be taken of the order of the limits necessary for osseointegration, by using a milling cutting tool mounted on a strong support, in this case a robot arm, improving on the results obtained by similar studies referred to hand sawed bones by 10 times.

Analysis of Variance↗

PubMedDate not supplied

Frequent complications in distal femoral osteotomy: a retrospective 8 year multicenter follow-up.

A total of 32 distal femoral osteotomies performed between 1971 and 1993 were evaluated, with a follow-up of 8 (2-23) years. Indications were lateral gonarthrosis in 23 cases (group I), and there were a variety of other indications in 9 cases (group 2). Twenty-six of the patients were submitted to revision surgery. Eleven operations were performed as a result of complications, such as pseudarthrosis (5), deep infection (3), and stiff knee (3). The remaining 16 were removals of fixation devices and they were not considered complications. Clinical results were evaluated based on different clinical scores (HSS, Lysholm, and Tegner) and NHP (Nottingham Health Profile), and there were 10 cases with good or excellent results. Results were better if the postoperative HKA angle (Hip-Knee-Ankle) was within 0-8 degrees of varus. As accuracy of correction is of importance, and serious complications frequent, it is important to entrust cases such as these to the care of surgeons with a good knowledge of the surgical technique.

Adult↗