Cementing technique in femoral resurfacing.

INTRODUCTION: The cementing technique is one of the various speculated factors that might contribute to the failures of resurfacing arthroplasty of the hip. The influence of bony preparation by jet lavage or lavage only in combination with different cementing techniques and cements of different viscosity in a study on fresh human femoral heads has not been evaluated so far. MATERIALS AND METHODS: Sixty fresh human femoral heads were prepared for resurfacing following manufacturers' instructions and divided into 12 groups. The different groups received either syringe lavage or jet lavage and either a low-, medium- or high-viscosity cement with either packing or quarter filling of the implant with recess of the femoral stem in each case. Application of the implant was standardized. After polymerization, the femoral heads were cut into quarters and polished. Cement penetration was assessed using a square millimeter grid under optical zoom. RESULTS: Manual packing with high viscosity cement is a reproducible method in resurfacing arthroplasty. Syringe lavage and jet lavage mainly showed comparable cement penetration patterns when applied same cementing techniques. The penetration depth ranged from a mean of 0.6 to 3.2 mm with 0.4 being the lowest and 4.0 being the deepest. The mantle thickness ranged from 0.8 to 2.4 mm with statistically significant thicker mantles with filling, compared to packing. CONCLUSION: Our results showed distinct less penetration depth than previously reported and that just medium viscosity cement reached reliable results in the supposed range of penetration depth and cement mantle thickness. Jet lavage should be recommended for the low-viscosity cement but avoided in combination with a cement filling technique of lower viscosity cements. Filling of the implant caused the greatest penetration depth and a higher number of incomplete seatings and should therefore be avoided.

Single nucleotide polymorphisms of the aromatase gene (CYP19A1), HER2/neu status, and prognosis in breast cancer patients.

PURPOSE: Estrogen exposure is involved in both breast cancer susceptibility and the prognosis in patients with breast cancer. Aromatase is involved in the production of estrogens, and altered expression of it might be associated with the prognosis. The aim of this study was to examine the effect of single nucleotide polymorphisms (SNPs) in the aromatase gene, CYP19A1, on the prognosis, and in relation to tumor and patient characteristics in a cohort of breast cancer patients. PATIENTS AND METHODS: The cohort analyzed in this study consisted of 1,257 patients with invasive primary breast cancer. Polymorphisms rs10046, rs4646 and rs700519 were genotyped within this group. RESULTS: The variant genotypes of rs10046 and rs4646 were associated with a lower percentage of HER2-positive tumors. There was no association of rs700519 and rs4646 with disease-free survival (DFS) or overall survival (OS). The variant genotype of rs10046 was significantly associated with a better 5-year DFS (hazards ratio 0.51; 95% CI, 0.32 to 0.81; P=0.004) adjusted for age, nodal status, tumor size grading, and hormone receptor status. This effect appeared to be determined in the subgroup of premenopausal patients. CONCLUSION: SNPs rs10046 and rs4646 may influence the HER2 status of breast cancer tumors, and rs10046 genotypes are associated with an altered DFS. Genotypes of aromatase polymorphisms may influence the prognosis for breast cancer patients not only by affecting the extent of estrogen exposure but also through an alteration in tumor characteristics.