PURPOSE Risk factors associated with a clinical presentation of patellar tendinopathy are patellar tendon ultrasonographic abnormality (PTA) and excessive loading. It remains unknown whether characteristics of an athlete's landing technique contribute to this excessive patellar tendon loading. This study investigated whether asymptomatic athletes with and without PTA had different landing strat...

OBJECTIVES Malrotation of the femoral component can result in post-operative complications in total knee arthroplasty (TKA), including patellar maltracking. Therefore, we used computational simulation to investigate the influence of femoral malrotation on contact stresses on the polyethylene (PE) insert and on the patellar button as well as on the forces on the collateral ligaments. MATERIALS...

Only 20 years ago reconstruction of the anterior cruciate ligament (ACL) involved an open intra-articular operation in which the graft was placed in a position where it was not anatomical and which involved opening both the medial and lateral capsules. There was a long scar and considerable analgesia was required after the operation. The patient remained in hospital for ten days and in a cast f...

Internal and external rotation of the femur plays an important role in defining the orientation of the patellofemoral joint, influencing contact areas, pressures, and cartilage stress distributions. The purpose of this study was to determine the influence of femoral internal and external rotation on stresses in the patellofemoral cartilage. We constructed finite element models of the patellofem...

PURPOSE To assess the Insall-Salvati ratio in normal Indian adults to determine its applicability and the incidence of patella alta and baja in Indian populations. METHODS 800 knees in 200 men and 200 women aged 18 to 50 (mean, 30) years were evaluated using lateral radiographs. The knee was set in semi-flexion (30º) to enable good visualisation of the patellar tendon and its insertion into t...

CONTEXT Patellar instability is a common clinical problem, affecting between 7 and 49 people per 100,000. However, not all patellar instabilities are equal, the etiology of the disorder is multifactorial, and a clear understanding of the cause of instability is crucial for appropriate surgical treatment. The goal of this article is to identify how to best treat patellar instability to provide g...

A low-contact stress, high-congruity, mobile-bearing patellofemoral joint arthroplasty decreases the contact force in the patellofemoral joint, theoretically reducing patellar polyethylene wear and increasing implant longevity. This article describes the case of a 47-year-old obese woman who presented with pain and loss of extension after a low-contact stress, high-congruity, mobile-bearing pat...