Our results support the superiority of 3D templating over 2D templating in predicting implant size.

The present investigation aims to evaluate periprosthetic bone remodelling after total knee arthroplasty by the use of dual-energy X-ray absorptiometry (DXA). Twelve patients affected by osteoarthrosis of the knee joint underwent primary total knee arthroplasty at an average age of 70.5 years. None of them had received a knee prosthesis before on the contralateral side. Anteroposterior and lateral DXA measurements of the femur, tibia and total knee (both sides) were taken 2 weeks, 3 and 9 months postoperatively. The 2-week measurement was used as an individual reference value to be compared with the 3- and 9-month findings. In addition, the contralateral knee was investigated also in order to estimate how far bone mineral loss was due to implantation or to an individual decline in bone mineral density (BMD). The comparison of BMD values after knee arthroplasty revealed a conspicuous decrease of bone density within 9 months. Bone mineral loss amounted to an average of 9.2% in anteroposterior and 17.8% in lateral DXA measurements. Lateral femur shots showed an average decrease of density of even 21.5%. In contrast, the BMD values of the contralateral knees remained almost unchanged. DXA, especially lateral shots of the femur, promises to be a suitable method for early assessment of periprosthetic bone remodelling after total knee arthroplasty.

No abstract

The mRNA fingerprinting technique, differential display reverse transcription polymerase chain (DDRT-PCR), was used to detect changes in the overall pattern of gene expression in human articular knee chondrocytes-induced by interleukin-1 beta (IL-1 beta), the prototypical inducer of catabolic responses in degenerate joint diseases. One hundred different primer combinations generated approximately 10,000 different PCR fragments for IL-1 beta treated, as well as for untreated human chondrocytes, cultivated in alginate beads. This represented 53% of all expressed chondrocyte genes as based on statistical considerations. Side by side comparisons of differential display patterns originating from two different donor tissues yielded 44 reproducibly, differentially-displayed cDNA fragments, which were subcloned and sequenced. Sequence homology searches revealed sequence identities to the human necrosis factor alpha (TNF-alpha) and IL-1 regulated gene TSG-6, fibronectin, osteopontin, calnexin, and the DNA repair enzyme ERCC5. The differential expression was confirmed with Northern and quantitative PCR analyses. The known function of these genes and their known IL-1 responsiveness indicate that the employed model system reflects the pleiotropic effects of IL-1 on the overall gene expression in human articular chondrocytes and identifies genes involved in very different biochemical pathways. Twenty-seven cDNAs lacked sequence homologies to known genes and may represent novel genes.

We concluded that the use of Bailey-Dubow rods in early childhood can be recommended for the femur, whereas insertion into the tibia or humerus is associated with a considerable complication rate.