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The total hip arthroplasty is one of the most common artificial joint replacement procedures. Several different surface coatings have been shown to improve implant fixation by facilitating bone ingrowth and consequently enhancing the longevity of uncemented orthopaedic hip prostheses. In the present study, two different layered double hydroxides (LDHs), Mg-Fe- and Mg-Al-LDH, were investigated as potential magnesium (Mg)-containing coating materials for orthopaedic applications in comparison to Mg hydroxide (Mg(OH)2). In vitro direct cell compatibility tests were carried out using the murine fibroblast cell line NIH 3T3 and the mouse osteosarcoma cell line MG 63. The host response of bone tissue was evaluated in in vivo experiments with nine rabbits. Two cylindrical pellets (3 × 3 mm) were implanted into each femoral condyle of the left hind leg. The samples were analyzed histologically and with μ-computed tomography (μ-CT) 6 weeks after surgery. An in vitro cytotoxicity test determined that more cells grew on the LDH pellets than on the Mg(OH)2-pellets. The pH value and the Mg2+ content of the cell culture media were increased after incubation of the cells on the degradable samples. The in vivo tests demonstrated the formation of fibrous capsules around Mg(OH)2 and Mg-Fe-LDH. In contrast, the host response of the Mg-Al-LDH samples indicated that this Mg-containing biomaterial is a potential candidate for implant coating. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 525–531, 2016.

Background: The early detection of osteonecrosis of the femoral head (ONFH) is difficult, but important for prevention of destruction of the femoral head. The objective of this study was to determine whether the occurrence of osteonecrosis of the femoral head (ONFH) correlates with changes in bone turnover markers. Methods: In 40 patients undergoing primary total hip arthroplasty (THA), different bone turnover markers and hormones (bone specific alkaline phosphatase, osteocalcin, beta cross-laps, 25-hydroxy-cholecalciferol, and parathormone) gained from blood were determined on the morning of the surgery. Twenty-two patients needed a THA due to progressed ONFH. In 18 cases blood was gained from patients with the indication for a THA given due to advanced osteoarthritis (AO) of the hip. Results: Bone specific alkaline phosphatase, osteocalcin, beta cross-laps, and parathormone did not show any deviation from standard values, neither for the group of osteonecrosis nor for the osteoarthritis group. 25-Hydroxy-cholecalciferol revealed on average decreased values without significant differences between both groups (P < 0.05). The tested bone turnover markers and hormones failed to predict the occurrence of ONFH. Thus, the focus has to be put on different parameters to find a specific parameter that possibly predicts the risk of ostenecrosis and that is suited to follow up ONFH.