The three-dimensional anatomy of the ostrich (Struthio camelus) knee (femorotibial, femorofibular, and femoropatellar) joint has scarcely been studied, and could elucidate certain mechanobiological properties of sesamoid bones. The adult ostrich is unique in that it has double patellae, while another similar ratite bird, the emu, has none. Understanding why these patellae form and what purpose ...

Complications of patellofemoral arthroplasty often occur soon after implantation and, as well as other factors, can be due to the design of the implant or its surgical positioning. A number of studies have previously considered the wear of ultra-high-molecular-weight polyethylene patellae following suboptimal implantation; however, studies have primarily been carried out under a limited number ...

The knee has two joints, the tibio-femoral and the -patello-femoral, but until recent years the second has received relatively little attention. This neglect is surprising, because the importance of lesions of the extensor mechanism, and the need for a powerful quadriceps muscle, have long been appreciated. This article surveys first the methods of examination of the patello-femoral joint, then...

UNLABELLED Although the presence of patellar tilt usually implies a tight lateral retinaculum and unhealthy pressure distributions within the patellar cartilage, it is possible for the bony portion of the patella to appear tilted while the articular cartilage is in fact fully congruous in a medial-lateral direction. We call this "congruous tilt." In such cases, a patient may not suffer from an ...

Nail-patella syndrome is a rare disorder characterized classically by the tetrad of nail hypoplasia or aplasia, aplastic or hypoplastic patellae, elbow dysplasia, and the presence of iliac horns. Iliac horns are considered pathognomonic, and the presence of hypoplastic or aplastic patellae in conjunction with nail abnormalities is a cardinal feature of diagnosis. Elbow dysplasia is present in m...

There are multiple etiologies for recurrent patellar instability. While patella alta, an elevated tibial tubercle trochlear groove distance, and prior lateral patellar dislocations with medial patellofemoral ligament (MPFL) insufficiency have been shown to be risk factors for recurrent patellar instability, trochlear dysplasia can result in a significant impediment to normal patellar tracking. ...

REASONS FOR PERFORMING STUDY Lateral heel wedges are used to treat horses and ponies with patella fixation or bone spavin. However, these therapies are purely empirically based and lack scientific evidence. OBJECTIVES Lateral heel wedges would change joint motion in the sagittal, but mainly in the transversal planes, in healthy horses. This effect would be increased by restricted feeding and ...