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Biomedical subjects

B E Albrektsson

Publications and source records attributed to B E Albrektsson.

8 recordsLinked to original sources

Roentgen stereophotogrammetric analysis as a predictor of mechanical loosening of knee prostheses.

The tibial components in 143 patients with total knee replacements performed before 1988 were assessed for micromotion using roentgen stereophotogrammetric analysis (RSA) over a period of 13 years. The fixation of the prostheses remained clinically sound in all cases, although revision had been required for other reasons in seven. In a second group taken from all cases with RSA available on our full database to 1990, 15 tibial components had been followed by RSA from the insertion until, 1 to 11 years after the initial arthroplasty, they were revised for mechanical loosening of the tibial component; 12 of these comprised all the loosenings in the base group, thus making a total of 155 consecutive cases, while an additional three were inserted after the base material had been compiled. The mean migration in the first group was about 1 mm at one year, but subsequent migration was slower, reaching a mean of about 1.5 mm after ten years. About one-third migrated continuously throughout follow-up, while two-thirds ceased to migrate after one to two years. In the revision group, 14 components had migrated continuously and at one year significantly more than those in the first group. One revision case lacked the crucial one-year follow-up and could not be classified. These findings suggest that mechanical loosening begins early in the postoperative period. Clinical symptoms which necessitate revision, seen at this stage in 20% of abnormally migrating tibial components, may not appear until up to ten years after the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

A new radiographic method for detection of tibial component migration in total knee arthroplasty.

In a prospective study the accuracy of a new radiographic method, Matched Indicators for Radiographic Assessment (MIRA), used to assess tibial component migration in total knee arthroplasty was evaluated. Radiopaque markers were placed in the tibial component and the tibial metaphysis in a standardized way so that four vertical distances could be measured on standard radiographs. Subsidence during the first postoperative year was measured both with this new method and with roentgen stereophotogrammetric analysis in 27 Freeman-Samuelson total knee arthroplasties. The error of measurement of MIRA was determined using the known error of roentgen stereophotogrammetric analysis. The new method was found to be promising with an accuracy of 1 mm, and the correlation between MIRA and roentgen stereophotogrammetric analysis was high when subsidence exceeded this value. Therefore, subsidence of clinical importance should be detected with MIRA. The method is simple and well suited for routine follow-up examination of large patient materials.

Aged↗

Proximally cemented versus uncemented Freeman-Samuelson knee arthroplasty. A prospective randomised study.

We studied the effect of a layer of cement placed under the tibial component of Freeman-Samuelson total knee prostheses with a metal back and an 80 mm intramedullary stem, using roentgen stereophotogrammetry to measure the migration of the tibial component during one year in 13 uncemented and 16 cemented knees. The addition of cement produced a significant reduction in migration at one year, from a mean of 1.5 mm to one of 0.5 mm (p less than 0.01), including a significant reduction in pure subsidence. One year postoperatively the clinical results were similar between the groups, but, at three years, one uncemented knee had required revision.

Adult↗

The effect of a stem on the tibial component of knee arthroplasty. A roentgen stereophotogrammetric study of uncemented tibial components in the Freeman-Samuelson knee arthroplasty.

We studied the effect of a metal tray with an intramedullary stem on the micromotion of the tibial component in total knee arthroplasty. Of 32 uncemented Freeman-Samuelson knee arthroplasties performed in London and Gothenburg, nine had a metal backing and stem added to the tibial component. Micromotion of the tibial components, expressed as migration and inducible displacement, was analysed using roentgen stereophotogrammetric analysis up to two years follow-up. The addition of a metal back and a 110 mm stem to the standard polyethylene component significantly reduced both migration over two years and inducible displacement.

Adult↗

ICLH knee arthroplasty. A consecutive study of 108 knees with uncemented tibial component fixation.

One hundred eight ICLH knee arthroplasties with cementless tibial component fixation were performed from 1978 through 1982 in Gothenburg, Sweden. The patients were followed for 2-8 years (mean, 4 years) with clinical and radiographic examinations at regular intervals, and the data were computer-analyzed. Patellar subluxation-dislocation, often accompanied by pain, occurred in 50% of the knees. Eleven arthroplasties failed due to aseptic loosening. Survival rate analysis performed using three different definitions of failure resulted in cumulative success rates after 8 years of 86%, 78%, and 72%. Most failures occurred between 2 and 5 years after surgery. Patients with bilateral arthritis were overrepresented among the failures. There was a significant correlation between failure and poor bone sclerosis around the polyethylene pegs. Most patients can be treated with cementless fixation, but other types of fixation should be considered for elderly patients and patients with severe bilateral disease.

Aged↗

Micromotion of noncemented Freeman-Samuelson knee prostheses in gonarthrosis. A roentgen-stereophotogrammetric analysis of eight successful cases.

Micromotion of the tibial component of eight Freeman-Samuelson arthroplasties without cement for gonarthrosis were followed for two years and studied by roentgen-stereophotogrammetric analysis (RSA). In five cases, displacement over time was studied, and in all cases migration was found to range from 0.7 to 4.8 mm after two years. One tibial component migrated continuously during the period studied, while the remaining prostheses migrated mostly during the first six months. The direction of the migration was erratic. Inducible displacement ranging from 0.8 to 5.0 mm was found in all cases. Clinically, all of the patients were scored as successful although one with continuous migration had the lowest score. This degree of micromotion is compatible with good results after two years, and appears to be a characteristic of the immediate interlocking fixation used in the Freeman-Samuelson prosthesis.

Aged↗

Total prosthetic replacement of ankylosed knees.

Total knee arthroplasty is reliable for achieving pain relief, increasing range of motion, maintaining stability, and improving walking ability. In this study, the results in knees with a preoperative range of motion of 0 were reviewed to determine whether an ankylosed knee can be replaced successfully. In eight of nine knees, the results with regard to pain, stability, and walking ability were good at follow-up evaluations greater than 2 years after operation. Range of motion was also improved in all knees but was still limited. Motion achieved was in a physiologic arc with all knees having full, or nearly full, extension.

Ankylosis↗