BACKGROUND The posterior cruciate ligament (PCL) plays an important role in maintaining physiological kinematics and function of the knee joint. To date mainly in-vitro models or combined magnetic resonance and fluoroscopic systems have been used for quantifying the importance of the PCL. We hypothesized, that both tibiofemoral and patellofemoral kinematic patterns are changed in PCL-deficient ...

BACKGROUND Rice farming activities involve prolonged manual work and human-machine interaction. Prolonged farming risk-exposure may result in lower limb malalignment. This malalignment may increase the risk of lower extremity injury and physical disabilities. However, the prevalence and factors associated with lower extremity malalignment have not yet been reported. This study aimed to investig...

An accurate method to locate of the flexion-extension (F-E) axis and longitudinal rotation (LR) axis of the tibiofemoral joint is required to accurately characterize tibiofemoral kinematics. A method was recently developed to locate these axes using an instrumented spatial linkage (ISL) (2012, "On the Estimate of the Two Dominant Axes of the Knee Using an Instrumented Spatial Linkage," J. Appl....

The purpose of this study was to expand and validate the cartilage damage index (CDI) to detect cartilage damage in the lateral tibiofemoral compartment. We used an iterative 3-step process to develop and validate the lateral CDI: development (100 knees), testing (80 knees), and validation (100 knees). The validation set included 100 knees from the Osteoarthritis Initiative that was enriched to...

Achieving deep flexion after total knee replacement remains a challenge. In this study we compared the soft-tissue tension and tibiofemoral force in a mobile-bearing posterior cruciate ligament-sacrificing total knee replacement, using equal flexion and extension gaps, and with the gaps increased by 2 mm each. The tests were conducted during passive movement in five cadaver knees, and measureme...

OBJECTIVE Knee osteoarthritis (OA) has a significant genetic component. The authors have assessed the role of three variants reported to influence risk of knee OA with p<5×10-8 in determining patellofemoral and tibiofemoral Kellgren Lawrence (K/L) grade in knee OA cases. METHODS 3474 knee OA cases with sky-line and weight-bearing antero-posterior x-rays of the knee were selected based on the ...

BACKGROUND The range of motion after a total knee arthroplasty is an important clinical outcome affecting the life of the patient. The aim of this study was to determine the most important factors influencing the postoperative knee flexion in Tehran, Iran. METHODS Between July 2007 and January 2009, on 95 cases of total knee joint replacement (89 patients), who were followed for 1 year postop...

Background After total knee arthroplasty (TKA), most patients have an improvement; however, a few continue to have residual pain. We reported a case series of painful knee after TKA with unreported reason. Material and Methods Forty-six arthroscopic surgeries were performed for painful knee after TKA. Of these, 16 were excluded due to infection, patellar clunk syndrome, patellofemoral synovia...

This study assessed the accuracy of surface-measured OpenSim-derived tibiofemoral kinematics in functional activities. Ten subjects with unilateral, isolated grade II PCL deficiency performed level running and stair ascent. A dynamic stereo radiography (DSX) system and a Vicon motion capture system simultaneously measured their knee or lower extremity movement. Surface marker motion data from t...

OBJECTIVES Cartilage defects are present in subjects with knee osteoarthritis (OA). Although they are often present in healthy subjects, there is little data on the natural history of cartilage defects. The aim of this study was to examine the change in cartilage defects over 2 yr and to identify factors associated with this change. METHODS One hundred and twenty-four healthy subjects underwe...