Biomedical subjects

Wouter J A Dhert

Publications and source records attributed to Wouter J A Dhert.

21 records · Page 2Linked to original sources

PubMed2004

Bone tissue engineering in a critical size defect compared to ectopic implantations in the goat.

Since the application of the autologous bone graft, the need for an alternative has been recognized. Tissue engineering (TE) of bone by combining bone marrow stromal cells (BMSCs) with a porous scaffold, is considered a promising technique. In this study we investigated the potential of tissue engineered bone to heal a critical sized defect in the goat. Orthotopic bone formation was compared to ectopic bone formation in comparable constructs. TE constructs were prepared from goat BMSCs and porous biphasic calcium phosphate ceramic scaffolds. These constructs and scaffolds without cells were implanted paired in critical sized iliac wing defects. Comparable samples were implanted intramuscularly. After 9 (n=7) and 12 (n=8) weeks implantation, the samples were analyzed histomorphometrically. After 9-weeks implantation in the iliac wing defect, significantly more bone apposition was found in the TE condition. After 12 weeks, the defects were almost completely filled with bone, but no significant advantage of TE was determined anymore. This contrasted with the intramuscular samples where TE implants showed significantly more bone at both time points. In conclusion, bone TE is feasible in critical sized defects. However, when appropriate osteoconductive/inductive materials are applied the effect of cell seeding may be temporary.

Animals↗

PubMed2003

Temperature elevation after vertebroplasty with polymethyl-methacrylate in the goat spine.

Although the general complication rate for vertebroplasty is low, neural compression and thermal damage have been related to the use of polymethyl-methacrylate cement. This study focuses on the risk of thermal tissue damage after vertebroplasty. In this study, cavities were created by a transpedicular approach in the vertebral bodies (L3, L4, and L5) of four milk goats, and polymethyl-methacrylate cement was injected. In three locations (the bone-cement interface, the epidural space, and the disc space) the temperature was measured in regular intervals after injection of the cement. The mean injected volume was 0.8 ml, which accounted for a 22% volume fraction. The mean peak temperature of the bone-cement interface was 44.6 degrees C, while the maximum temperature at the epidural space and disc space was 37.0 and 37.5 degrees C, respectively. The local temperature measured after in vivo vertebroplasty did not reach values that are known to cause tissue necrosis.

Animals↗

PubMed2002

The epidemiology of total hip replacement in The Netherlands and Sweden: present status and future needs.

By combining data from the Discharge registers and the census bureaus in The Netherlands and Sweden, we calculated the age-specific incidences of primary total hip replacement (THR), studied the demographic profile of the population receiving THR and predicted demands. In the period 1986-1997, the number of THRs increased by 20% in Sweden to 10,000 operations (113/100,000 inhabitants) and by 68% to 17,400 operations (112/100,000 inhabitants) in The Netherlands. Of this increase 3% and 15% could be explained by changes in the age-profile and size of the population, respectively. Although the overall incidence of THR was similar in both countries in 1997, we found that, after correction for differences in population structure, the incidence of THR was 20% higher in The Netherlands. In Sweden, relatively more men were operated on than in The Netherlands. We also found that in Sweden, but not in the Netherlands, relatively more older people were operated on in 1997 than in 1987. Assuming no further change in the age- and sex-specific arthroplasty rates, the predicted annual number of total hip replacements by the year 2020 will increase by at least one fourth in Sweden and almost one half in The Netherlands.

Adult↗