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Biomedical subjects

M Kramhøft

Publications and source records attributed to M Kramhøft.

At least 19 recordsLinked to original sources
PubMed1996

Inter- and intraobserver study of radiographic assessment of cemented total hip arthroplasties.

Radiographs are commonly used to identify loosened total hip prostheses. Interobserver and intraobserver variation was studied in an attempt to interpret 60 random pairs of radiographs with a time interval of 6 months to 12 years between the radiographs. Each of the four observers evaluated all pairs of radiographs independently, and the evaluations were repeated after 2 to 4 weeks. Each observer classified the femoral stem and the acetabular cup separately as stable or loose. Radiolucent lines of more than 2 mm were recorded. For the acetabular components, any change in inclination or migration was noted, and for the femoral components, subsidence or any change in varus or valgus of the stem was noted. There was considerable disagreement in observations of the acetabular component; agreement by all four observers was obtained in only 34 of 60 cases (57%). For the femoral component, agreement was obtained in 37 cases (62%). The observers agreed two and two (pairwise) on the acetabular component in 70 to 83% of cases and on the femoral component, in 72 to 82% of cases. Intraobserver variation was great with regard to the acetabular component, with kappa values ranging from 0.489 to 0.633. As to the femoral component, kappa values ranged from 0.737 to 0.800. Interpretation of radiographs of artificial hip arthroplasty is difficult, and comparisons between different series of implants should be made by the same person.

Cementation↗
PubMed1994

Outcome of infected total knee arthroplasty.

The results of 44 cases of deep infection after total knee arthroplasty were reviewed. The average age of the patients was 62 years (range, 31-81 years), and all had positive bacterial cultures from deep aspiration or tissue biopsy. Osteitis was revealed in 22 cases. One case was initially treated with antibiotics only, 27 cases were treated with surgical debridement and antibiotics, and 16 cases had immediate removal of the prosthesis. In 21 cases, failed debridement was followed by removal of the prosthesis. Revision arthroplasty was attempted in 15 of the 37 cases in which the prosthesis was removed; the infection was cured in 11 cases. A total of 25 cases that underwent removal of the prosthesis had an arthrodesis performed, and 4 ultimately underwent amputation. In no case of osteitis was the infection cured merely by debridement and antibiotics, and the index prostheses were retained mainly in cases in which osteitis did not develop.

Adult↗
PubMed1994

Effects of polymerization heat and monomers from acrylic cement on canine bone.

We investigated the effects of polymerization heat and toxicity of polymethylmetacrylate bone cement in the canine tibial diaphysis. Heat was studied by filling the tibias with either bone cement or bone wax contained in a monomer tight membrane pouch. Toxicity was studied by filling both tibias with cement, with the control side contained in the membrane pouch. Bone blood perfusion was measured by microsphere technic, and bone remodeling by 99mTc-methylene diphosphonate uptake and by histologic technique. In bone exposed to the combination of polymerization heat and monomer, both perfusion and remodeling were impaired. We did not find any effects of polymerization heat alone. We conclude that hot toxic chemicals from bone cement during polymerization may inhibit bone blood perfusion and remodeling, whereas heat alone seems to be of minor importance for the regenerative processes in cemented diaphyseal bone.

Animals↗
PubMed1993

Variation of cortical hypertrophy depending on the medullary filling material. An experimental study of canine tibial diaphysis.

In order to evaluate the mineralization of bone after polymethyl methacrylate cementation, measurements of the periosteal apposition were made histologically and measurements of the bone-mineral content were made by dual-photon absorptiometry of the tibial diaphysis in 15 adult mongrel dogs in paired studies. Six dogs were investigated 4 weeks after intramedullary reaming of both sides and obturation of the medullary cavity with bone-wax on one side. Nine dogs were reamed on both sides. The medullary cavities were filled with polymethyl methacrylate bone-cement and bone-wax, respectively. The authors found (1) an increased bone-mineral content and an increased periosteal apposition after filling with bone-wax in comparison with the reamed side and (2) a decreased bone-mineral content and a decreased periosteal apposition on the cemented side in comparison with bone-wax. These findings are interpreted as consequential upon repair processes with a high remodeling and mineralization rate after reaming or filling with bone-wax, whereas remodeling in inhibited after filling with acrylic bone-cement.

Absorptiometry, Photon↗
PubMed1993

Ulna non-union leading to Monteggia fracture deformity. Two cases of slowly developing radial head luxation.

The author presents two cases in which pseudoarthrosis of the ulnar diaphysis resulted in dislocation of the head of the radius. The pathogenesis of this secondary dislocation is discussed. The cause of anterior Monteggia fractures is not yet clear. Various explanations have been put forward: direct action of a force (Speed and Boyd, 1940), forced pronation (Evans, 1949) and hyperextension with strong contraction of the biceps (Wright, 1963). This work presents two cases of Monteggia fracture characterized by a "slow" fracture mechanism. The biomechanical aspects are discussed.

Adult↗
PubMed1991

Histological evaluation of cortical bone reaction to PMMA cement.

This study was designed to investigate histological changes in the tibia of adult mongrel dogs receiving PMMA bone cement in one tibial shaft and an inert filler, Bone wax, in the other. Sixteen dogs were used, 2 dogs were investigated at one week, 6 dogs at four weeks and 8 dogs at twelve weeks. It was shown in this study, that intramedullary implantation of PMMA bone cement leads to considerable impairment of bone remodelling. At each period of observation the index periosteal apposition/cortex thickness was lower on the cemented side; at 4 weeks an index of 0.42 (0.17-0.64) compared to 0.72 (0.42-0.91), and a 60-70 microns concentric fibrillar fibrous membrane was seen between cement and bone. On the Bone wax side few or no areas of fibrous tissue were detected at both 4 and 12 weeks; and when such tissue was present, islands of bone developing directly onto the wax was seen. The bone remodelling was impaired on the cemented side and limited to the outer half after 4 weeks.

Animals↗
PubMed1991

The influence of smoking on complications after primary amputations of the lower extremity.

A total of 165 primary above-the-knee (AK) and below-the-knee (BK) amputations in 137 patients were reviewed retrospectively. Of the 77 patients who smoked, 44 smoked cigarettes, 30 cheroots, and three a pipe. There were 88 nonsmokers. At the time of surgery, the smokers were on average 6.4 years younger than the nonsmokers. The review revealed no discrepancy between smokers and nonsmokers with regard to amputation level, the BK to AK ratio being 2:1. In cigarette smokers the risk of infection and reamputation was 2:5 times higher than in cheroot smokers or nonsmokers. The poor results obtained in cigarette smokers may be ascribed to the fact that this group of patients smoked during the phase of healing and that only cigarette smokers tend to inhale. Inhalation of smoke leads to high concentrations of nicotine, which compromise the cutaneous blood-flow velocity and increase the risk of the formation of microthrombi. Consequently, amputees should abstain from cigarette smoking during the phase of healing. Preferably, the habit should be broken one week before surgery, which is the requisite period for the process of coagulation and the fibrinogen level to normalize and for free radicals to be eliminated.

Aged↗
PubMed1990

[Injured cyclists and bicycle passengers. A prospective study of the causes of accidents, accident patterns and consequences].

In a one-year prospective investigation in 1985, all bicycle accidents in Denmark were registered. The circumstances of the accident were recorded. All injuries were classified in the AIS and the ISS scales. After one year, the patients were contacted and sick leave and sequelae were registered. A total of 576 patients (320 men and 256 women), were treated after bicycle accidents. Bicycle accidents were seen most frequently in the ages from 5 to 19 years. The accidents were distributed uniformly over the week and occurred most frequently in the summer. 392 of the accidents were single-accidents, and the majority had used a bicycle-track if possible. Collision with other road users and bad road conditions were responsible for 41%, and defects in the bicycle for 9%, mainly on handlebars, front fork, front wheel, gear and chain. Two were admitted dead, and 114 were admitted to hospital (20%) for median four days. Eleven per cent had sustained serious lesions (fractures or lesions of the head). 556 had an AIS-score less or equal to three and un 387 the AIS-score was one. 561 had an ISS-score less than ten, five between ten and 75 and two had 75. Eight patients could not be classified. The patients AIS score is determined as the highest score of an injured region. AIS score of 6 is fatal. The ISS score is the addition of the square of the 3 highest AIS values. ISS of 75 is fatal. AIS is thus a value of the most serious lesion and ISS is a value of how traumatized the patient is.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Traffic↗
PubMed1989

[Moped accidents. A prospective study on the causes of accidents, injury patterns and sequelae].

In a one year prospective investigation, the circumstances and sequelae of 75 moped accidents were registered. The patients were aged mainly between 14 and 18 years and the accidents happened mainly in the afternoon hours. The majority of the injuries were on the head and the extremities. Twenty-one of the patients were admitted to hospital for median 4.8 days, 50 were treated as outpatients and four were dead on admission. The patients were contacted one year after the accident and one had severe sequelae and five had minor sequelae.

Accidents, Traffic↗
PubMed1988

Epidemiology of distal forearm fractures in Danish children.

We recorded all the distal forearm fractures in inhabitants under 20 years of age in Frederiksborg County, Denmark, throughout 1985. The population at risk was 97,791 persons, and fractures occurred in 269 boys and 205 girls. The peak incidence in girls occurred at ages 10-12 (105 per 10,000) and in boys at ages 12-14 (100 per 10,000). Fractures occurred more often in the autumn than in the spring.

Adolescent↗
PubMed1987

Displaced supracondylar fractures of the humerus in children.

From 1972 to 1981, 60 children with severely displaced supracondylar fractures were treated with closed reduction and vertical osseous traction with a screw in the olecranon. None of the patients had complications (infection or neurovascular damage) due to the treatment, but eight patients had loss of reduction and required second reduction. The average hospitalization time was 2.6 weeks, and all fractures had united within four weeks. A follow-up study of 56 patients was performed an average of 78 months after the injury. All patients had an excellent (75%) or good (25%) end result. Vertical osseous traction is easy to apply and carries few risks of complications. The method is recommended, provided longer hospitalization time is acceptable or permissible.

Child↗