Multiple epiphyseal dysplasia (MED) is an autosomal dominantly inherited chondrodysplasia. It is clinically highly heterogeneous, partially because of its complex genetic background. Mutations in four genes, COL9A2, COL9A3, COMP, and MATR3, all coding for cartilage extracellular matrix components (i.e., the alpha2 and alpha 3 chains of collagen IX, cartilage oligomeric matrix protein, and matrilin-3), have been identified in this disease so far, but no mutations have yet been reported in the third collagen IX gene, COL9A1, which codes for the alpha1(IX) chain. MED with apparently recessive inheritance has been reported in some families. A homozygous R279W mutation was recently found in the diastrophic dysplasia sulfate transporter gene, DTDST, in a patient with MED who had a club foot and double-layered patella. The series consisted of 41 probands with MED, 16 of whom were familial and on 4 of whom linkage analyses were performed. Recombination was observed between COL9A1, COL9A2, COL9A3, and COMP and the MED phenotype in two of the families, and between COL9A2, COL9A3, and COMP and the phenotype in the other two families. Screening of COL9A1 for mutations in the two probands from the families in which this gene was not involved in the recombinations failed to identify any disease-causing mutations. The remaining 37 probands were screened for mutations in all three collagen IX genes and in the COMP gene. The probands with talipes deformities or multipartite patella were also screened for the R279W mutation in DTDST. The analysis resulted in identification of three mutations in COMP and one in COL9A1, but none in the other two collagen IX genes. Two of the probands with a multipartite patella had the homozygous DTDST mutation. The results show that mutations in COL9A1 can cause MED, but they also suggest that mutations in COL9A1, COL9A2, COL9A3, COMP, and DTDST are not the major causes of MED and that there exists at least one additional locus.

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Multiple epiphyseal dysplasia (MED) is characterized by pain and stiffness in joints and delayed and irregular ossification of epiphyses. Causative mutations have been recognized in six different genes. We have identified disease-causing mutations in the gene encoding matrilin-3, an extracellular matrix protein, in seven families with autosomal dominant MED. Review of the clinical and radiographic features in 12 of the affected family members shows a uniform pattern of skeletal anomalies in all patients with considerable degree of variability in severity, both between and within families. The characteristic clinical findings are onset of symptoms in early childhood with predominance of knee and hip related complaints, normal stature, and early-onset osteoarthritis. Radiographs show small and irregular epiphyses and mild metaphyseal irregularities and striations, especially at the knees and hips and mild spinal changes. Despite overlap, both clinically and radiographically, with other forms of MED, the described features may help to differentiate this particular form from other entities within the MED spectrum.

The aim of the study was to determine the content of particular elements Ca, Mg, P, Na, K, Zn, Cu, Fe, Mo, Cr, Ni, Ba, Sr, and Pb in the proximal femur bone tissue (cancellous and cortical bone) of 96 patients undergoing total hip replacement for osteoarthritis using ICP-AES and FAAS analytical techniques. The interdependencies among these elements and their correlations depended on factors including age, gender, place of residence, tobacco consumption, alcohol consumption, exposure to environmental pollution, physical activity, and type of degenerative change which were examined by statistical and chemometric methods. The factors that exerted the greatest influence on the elements in the femoral head and neck were tobacco smoking (higher Cr and Ni content in smokers), alcohol consumption (higher concentrations of Ni, Cu in people who consume alcohol), and gender (higher Cu, Zn, and Ni concentrations in men). The factors influencing Pb accumulation in bone tissue were tobacco, alcohol, gender, and age. In primary and secondary osteoarthritis of the hip, the content and interactions of elements are different (mainly those of Fe and Pb). There were no significant differences in the concentrations of elements in the femoral head and neck that could be attributed to residence or physical activity.

PurposeThe aim of this paper is to present the main results of a research project finished in 2008 which concerned the selective laser melted (SLM) prototype of a new kind of minimally invasive resurfacing hip arthroplasty (RHA) endoprosthesis with the original multi‐spiked connecting scaffold (MSC‐Scaffold). Previous attempts performed in pre‐Direct Metal Manufacturing (DMM) era demonstrated that it was impossible to manufacture suitable prototypes of this RHA endoprosthesis (especially of the MSC‐Scaffold) using traditional machining technologies. Owing to an extensive development of DMM technologies observed in recent years the manufacturing of such prototypes has become possible.Design/methodology/approachComputer aided design models of pre‐prototypes and the prototype of the RHA endoprosthesis with MSC‐Scaffold were designed and initially optimized within the claims and the general assumptions of international patents by Rogala. Prototyping in SLM technology was subcontracted to SLM Tech Center (Paderborn, Germany). Macroscopic and SEM microscopic evaluation of the MSC‐Scaffold was performed using SLM manufactured prototypes and paying special attention to the quality and precision of manufacturing.FindingsIt was found that SLM can be successfully applied to manufacturing of prototypes of the original minimally invasive RHA endoprosthesis. The manufacturing quality of the 3D spikes system of the MSC‐Scaffold, which mimics the interdigitations of articular subchondral bone, has been proved to be geometrically corresponding to the biological original. Nevertheless, some pores and non‐melted zones were found in SLM prototyped RHA endoprosthesis cross‐sections which need to be eliminated to minimize the potential risk of clinical failure.Research limitations/implicationsThe presented case study was performed with a limited number of samples. More research needs to be performed on the rapid prototyped samples including microstructural and mechanical tests. The results may enable the optimization of the SLM manufacturing process of the prototypes of the minimally invasive RHA endoprosthesis with MSC‐Scaffold.Practical implicationsThe SLM can be considered as potentially suitable for the fabrication of patient‐fitted minimally invasive RHA endoprostheses with MSC‐Scaffold.Originality/valueFor the first time, largely owing to SLM technology, it was possible to manufacture the prototype of the original minimally invasive RHA endoprosthesis with MSC‐Scaffold suitable for further research.