One of the most important factors that causes the failure of a knee prosthesis is the infection that can arise in the tissues after implantation due to an incorrect surgical procedure, to a difficult repairing process or to other patient’s pathological conditions. The infection can arise soon after implantation as well as in one or two years after the operation. In order to let the infection he...

In surgical knee replacement, the damaged knee joint is replaced with artificial prostheses. An accurate clinical evaluation must be carried out before applying knee prostheses to ensure optimal outcome from surgical operations and to reduce the probability of having long-term problems. Useful information can be inferred from estimates of the stress acting onto the bone-prosthesis system of the...

Introduction: Modern transfemoral knee prostheses are designed to offer comfort and self-confidence to amputees. These prostheses are mainly based upon either a passive concept, with a damping system, or an active computational intelligent design to control knee motion during the swing phase. In Brazil, most lower extremity amputees are unable to afford modern prostheses due to their high cost....

The purpose of this prospective randomized study was to compare the postoperative recovery and early results of 2 groups of patients undergoing total knee arthroplasty: 107 patients received an established fixed-bearing posterior-stabilized prosthesis (Legacy Posterior Stabilized [LPS]), and 103 patients the meniscal-bearing prosthesis (Meniscal Bearing Knee [MBK]). Surgical procedures were the...

A patient with multiple sclerosis (MS) and severe osteoarthritis of the right knee with valgus deformity developed early in the postoperative period a posterior dislocation of the knee after total knee arthroplasty (TKA), due to severe spasm of her hamstring muscles. At revision surgery the posterior cruciate retaining prosthesis was exchanged for a non-linked constrained knee prosthesis. Techn...

Four-bar linkage mechanisms produced by many designers of knee joints for trans-femoral prostheses can provide knee rotation to permit walking only. In Afro-Asian countries people are accustomed to a squatting posture in their daily activities. A six-bar linkage knee-ankle mechanism trans-femoral prosthesis is described which was developed and fitted to an amputee. The motion patterns of the an...

The aim of this biomechanical study was to investigate knee joint kinematics following total knee arthroplasty. We compared eight congruent posterior cruciate ligament retaining and four ultracongruent cruciate sacrificing Natural Knee prostheses to the untreated human cadaveric knee joint. A six-degree-of-freedom testing device was used to evaluate knee joint kinematics with a load of 300 Newt...

INTRODUCTION: The range of motion (ROM) after total knee arthroplasty (TKA) is one of the most important factors for patient satisfaction, especially in Asian countries. To enhance the knee flexion angle, “highflexion” designs have been introduced in total knee prostheses. One of such design was a new design of femoral prosthesis, which increased the posterior cut on the bone by 2 mm and thicke...

A passive forward kinematics knee model was used to predict knee motion of a total joint replacement. Given ajoint angle, maps of articular surfaces, and patient-specific ligament properties, this model predicted femorotibial contact locations based on the principle of ligament-strain minimization. The model was validated by physical experiments on a commonly implanted knee prosthesis, showing ...