With the increasing success of hip joint replacements, the average age of patients has decreased, patients have become more active and their expectations of the implant durability have risen. Thus, pre-clinical endurance tests on hip implants require defining realistic in vivo loads from younger and more active patients. These loads require simplifications to be applicable for simulator tests a...

Major advances in total hip replacement have occurred since the prosthesis was first developed by Charnley in the 1960s. Yet substantial concerns currently exist over newer hip implants as a result of rising revision rates and increased risk of cancer. By the 1980s revision rates of total hip replacements were as low as 20% after 15 years of follow-up. Throughout this era, the main focus was re...

Forty years have elapsed since the first total hip arthroplasty in Croatia, a procedure that has revolutionized treatment of a whole range of states resulting in hip dysfunction and has brought about significant improvements in restoring functional ability and quality of life of the affected patients. Modern progress in the development of the hip joint endoprosthetics is closely connected to a ...

Wear is an important issue in hip implants. Excessive wear can lead to toxicity and other implant associated medical issues such as patient discomfort and decreased mobility. Since implant wear is result of contact between surfaces of femoral head and acetabulum implant, it is important to establish a model that can address implant surface roughness interaction. A statistical contact model is d...

We prospectively analysed hospital stay, discharge policy, hospital cost and postoperative recovery of 102 consecutive total hip arthroplasties performed in a Belgian university hospital during a one-year period starting in October 2001. Of the independent patients, 87.4% regained independence after 6 weeks and 19.6% used rehabilitation units. Preoperative residence, hip function and mental sco...

The assessment of the primary stability of cementless implants still remains a subjective factor in total hip replacement (THR) and, as a consequence, the excessive press-fitting of a THR component can be the cause of intra-operative fractures. Objective information about the stability of implant-bone structures can be obtained using methods based on vibration analysis. After extensive in vitro...

The occurrence of audible squeaking in some patients with ceramic-on-ceramic (CoC) hip prostheses is a cause for concern. Great effort has been dedicated to understand the mechanics of the hip squeaking to gain a deeper insight into factors contributing to sound emission from CoC hip articulation. Disruption of fluid-film lubrication and friction were reported as the main potential cause, while...

An unpublished trial of a metal-on-metal total hip replacement, funded by the USmedical device company Stryker, was stopped early more than a year before the UK regulator told surgeons not to use the implant, the BMJ has learnt. Earlier this month the Medicines and Healthcare Products Regulatory Agency (MHRA) told surgeons to stop using the MITCH TRH cup/heads, made by Finsbury Orthopaedics (no...

Define tribology and discuss its effect on total hip arthroplasty (THA). Tribology is defined as the science of interacting surfaces in relative motion and includes the principles of friction, lubrication, and wear of implant materials. Tribology of the articulating materials in THA is the most important issue for long-term survival of the implants because the fixation of implants either with o...

Despite total hip replacement (THR) gives generally satisfactory results, the quality of outcome in young patients is markedly decreased compared to the average THR outcome. For this population, pharmacological treatment with bisphosphonate would be beneficial to decrease the peri-implant osteolysis. However, as this population does not necessarily suffer from osteoporosis, a nonsystemic treatm...