U.P.B. Sci. Bull., Series D, Vol. 73, Iss. 2, 2011 ISSN 1454-2358 ASPECTS OF CONTACT REGION BETWEEN BONE AND IMPLANT FOR DIFFERENT ENDOPROSTHESIS TYPES Carmen STICLARU 1 , Arjana DAVIDESCU 2 , Mircea DREUCEAN 3 Lucrarea prezintǎ un studiu comparativ al implanturilor de old utilizate în cadrul artroplastiei total, evidenţiind importanţa utilizǎrii unor proteze personalizare în cazul persoanelor cu dizabilitǎţi. Analiza cu element finit permite studiul diferitelor aspecte ale zonei de contact între os si protezǎ. Se evidenţiazǎ, comparativ cu protezele clasice existente pe piaţǎ, avantajele utilizǎrii unei proteze personalizate. Studiul se face pentru opt pacienţi care prezintǎ aspecte particulare ale articulaţiei de old. Informaţiile ce se obţin cu ajutorul acestui studiu se pot folosi de medicii ortopezi în momentul alegerii unui anume tip de implant de old. The paper presents some interesting aspects of the contact between the bone and the implant in case of different types of endoprosthesis. This comparative study is made for different types of stems. Mechanical adaptation influences the success of many orthopaedic treatments, especially total joint replacements. A good contact between the bone and the stem indicates a long life solution for an endoprosthesis. A personalized stem is very useful for persons with disabilities. The contact results from Ansys illustrate the aspects from the bone – stem interface. With this information the orthopaedist can made a good decision for a proper hip joint endoprosthesis used for a named patient. Keywords: Total hip arthroplasty, Computational model, Hip prosthesis, Finite element, Modelling, Stem. 1. Introduction Arthroplasty is the reconstruction or reshaping of a damaged or diseased joint. This elective surgery most often involves joint replacement, the implantation of an artificial joint (prosthesis). In addition to osteoarthritis, arthroplasty can be a treatment for conditions including hip fractures, other source of acute trauma and rheumatoid arthritis. Arthroplasty may be used to: replace all or part of a joint with prosthesis, resurface a joint with the patient’s own tissue, reshape the bone and cartilage that make up the joint. 1 Asist Prof., Mechatronics Dept., University POLITEHNICA of Timisoara, Romania, e-mail: carmen.sticlaru@mec.upt.ro 2 Prof., Mechatronics Dept., University POLITEHNICA of Timisoara, Romania 3 Prof., Mechatronics Dept., University POLITEHNICA of Timisoara, Romania