Affiliation: University of Eastern Finland
Location: Kuopio, Finland
microscopy, electron microscopy, spectroscopy, mechanical testing, coatings
Väänänen P, Koistinen A, Nurmi J, Lappalainen R. Biomechanical in vitro evaluation of the effect of cyclic loading on the postoperative fixation stability and degradation of a biodegradable ankle plate. J Orthop Res. 2008;26:1485-8 pubmed publisher
..Cyclic loading, applied either during or after 12 weeks of hydrolytic degradation, does not seem to have any clinically relevant effect on the fixation stability or the degradation properties. ..
Isaksson H, Harjula T, Koistinen A, Iivarinen J, Seppänen K, Arokoski J, et al
. Collagen and mineral deposition in rabbit cortical bone during maturation and growth: effects on tissue properties. J Orthop Res. 2010;28:1626-33 pubmed publisher
..In cortical bone, the collagen network reaches its mature composition and mechanical strength prior to the mineralized matrix. ..
Koistinen A, Korhonen H, Kiviranta I, Kroger H, Lappalainen R. Analysis of plastic deformation in cortical bone after insertion of coated and non-coated self-tapping orthopaedic screws. Proc Inst Mech Eng H. 2011;225:629-39 pubmed
..This can be explained by natural variability in bone tissue, which also made automated image analysis difficult. ..
Koistinen A, Santavirta S, Lappalainen R. Apparatus to test insertion and removal torque of bone screws. Proc Inst Mech Eng H. 2003;217:503-8 pubmed
..The equipment can be used to measure insertion and removal torques as described in the standard. Furthermore, it also allows testing of normal screws and bolts. ..
Koistinen A, Santavirta S, Kroger H, Lappalainen R. Effect of bone mineral density and amorphous diamond coatings on insertion torque of bone screws. Biomaterials. 2005;26:5687-94 pubmed
..By using a polished AD coating, insertion torque was decreased even up to 50% in comparison with the screws without coating. The results suggest that AD coating provides a stable, smooth surface and reduces the risk of screw failures. ..
Korhonen R, Koistinen A, Konttinen Y, Santavirta S, Lappalainen R. The effect of geometry and abduction angle on the stresses in cemented UHMWPE acetabular cups--finite element simulations and experimental tests. Biomed Eng Online. 2005;4:32 pubmed
..These factors should be taken into account in future development of THR prostheses. FE technique is a useful tool with which to address these issues. ..
Rengaraj S, Venkataraj S, Jee S, Kim Y, Tai C, Repo E, et al
. Cauliflower-like CdS microspheres composed of nanocrystals and their physicochemical properties. Langmuir. 2011;27:352-8 pubmed publisher
..99 to 2.06 eV. The cauliflower-like CdS microspheres could be applied to photocatalytic degradation studies. ..
Rengaraj S, Jee S, Venkataraj S, Kim Y, Vijayalakshmi S, Repo E, et al
. CdS microspheres composed of nanocrystals and their photocatalytic activity. J Nanosci Nanotechnol. 2011;11:2090-9 pubmed
..These results suggest that CdS microspheres will be an interesting candidate for photocatalytic detoxification studies under visible light radiation. ..
Turunen S, Lammi M, Saarakkala S, Koistinen A, Korhonen R. Hypotonic challenge modulates cell volumes differently in the superficial zone of intact articular cartilage and cartilage explant. Biomech Model Mechanobiol. 2012;11:665-75 pubmed publisher
..This indicates that the mechanobiological responses of cartilage and cell signalling may be significantly dependent on the integrity of the mechanical environment of chondrocytes. ..