68 research outputs found

    Once-weekly oral medication with alendronate does not prevent migration of knee prostheses: A double-blind randomized RSA study

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    Background and purpose Early migration of joint replacements is an effect of poor fixation and can predict late loosening. By reducing the bone resorption after implantation of a joint replacement, it should be possible to enhance the initial fixation of the implant. We studied the effect of once-weekly treatment with alendronate after knee replacement

    In vivo evaluation of a vibration analysis technique for the per-operative monitoring of the fixation of hip prostheses

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    <p>Abstract</p> <p>Background</p> <p>The per-operative assessment of primary stem stability may help to improve the performance of total hip replacement. Vibration analysis methods have been successfully used to assess dental implant stability, to monitor fracture healing and to measure bone mechanical properties. The objective of the present study was to evaluate in vivo a vibration analysis-based endpoint criterion for the insertion of the stem by successive surgeon-controlled hammer blows.</p> <p>Methods</p> <p>A protocol using a vibration analysis technique for the characterisation of the primary bone-prosthesis stability was tested in 83 patients receiving a custom-made, intra-operatively manufactured stem prosthesis. Two groups were studied: one (n = 30) with non cemented and one (n = 53) with partially cemented stem fixation. Frequency response functions of the stem-femur system corresponding to successive insertion stages were compared.</p> <p>Results</p> <p>The correlation coefficient between the last two frequency response function curves was above 0.99 in 86.7% of the non cemented cases. Lower values of the final correlation coefficient and deviations in the frequency response pattern were associated with instability or impending bone fracture. In the cases with a partially cemented stem an important difference in frequency response function between the final stage of non cemented trial insertion and the final cemented stage was found in 84.9% of the cases. Furthermore, the frequency response function varied with the degree of cement curing.</p> <p>Conclusion</p> <p>The frequency response function change provides reliable information regarding the stability evolution of the stem-femur system during the insertion. The protocol described in this paper can be used to accurately detect the insertion end point and to reduce the risk for intra-operative fracture.</p

    No association between the aluminium content of trabecular bone and bone density, mass or size of the proximal femur in elderly men and women

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    BACKGROUND: Aluminium is considered a bone toxic metal since poisoning can lead to aluminium-induced bone disease in patients with chronic renal failure. Healthy subjects with normal renal function retain 4% of the aluminium consumed. They might thus also accumulate aluminium and eventually be at risk of long-term low-grade aluminium intoxication that can affect bone health. METHODS: We therefore examined 62 patients with femoral neck fractures or osteoarthritis of the hip (age range 38–93), with the aim of examining whether aluminium in bone is associated with bone-mineral density (BMD), content (BMC) or width of the femoral neck measured by dual-energy X-ray absorptiometry (DXA). During operations bone biopsies were taken from the trabecular bone of the proximal femur. The samples were measured for their content of aluminium using a mass spectrometer. RESULTS: No significant association between the aluminium content in bone and femoral neck BMD, BMC or width could be found after multivariate adjustment. CONCLUSION: Our results indicate that the accumulated aluminium content in bone during life does not substantially influence the extent of osteoporosis

    Is early migration enough to explain late clinical loosening of hip prostheses?

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    Porous titanium granules are better than autograft bone as a bone void filler in lateral tibial plateau fractures: A randomised trial.

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    A total of 20 patients with a depressed fracture of the lateral tibial plateau (Schatzker II or III) who would undergo open reduction and internal fixation were randomised to have the metaphyseal void in the bone filled with either porous titanium granules or autograft bone. Radiographs were undertaken within one week, after six weeks, three months, six months, and after 12 months. The primary outcome measure was recurrent depression of the joint surface: a secondary outcome was the duration of surgery. The risk of recurrent depression of the joint surface was lower (p < 0.001) and the operating time less (p < 0.002) when titanium granules were used. The indication is that it is therefore beneficial to use porous titanium granules than autograft bone to fill the void created by reducing a depressed fracture of the lateral tibial plateau. There is no donor site morbidity, the operating time is shorter and the risk of recurrent depression of the articular surface is less. Cite this article: Bone Joint J 2015; 97-B:836-41

    Early migrartion of acetabular components revised with cement.

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    Roentgen stereophotogrammetric analysis (RSA) was used to evaluate the migration in 17 cemented acetabular components after revision operations for mechanical loosening. All of the hips were examined four months and one year after surgery; ten of the hips were also examined after two years. In 15 of the 17 components, definite migration (0.5-2.7 mm) was identified, whereas two acetabular components showed no significant migration (< 0.25 mm). In 13 hips, the migration was seen within four months after surgery. There was a tendency for larger migration in revisions for severe bone destruction. These findings indicate that prosthetic fixation in revision operations is relatively poor. In cases with severe bone loss, cement fixations is extremely poor
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