INTRODUCTION Acute patellar dislocation is a common injury usually associated with a significant traumatic mechanism resulting in lateral displacement. Vertical axis rotation following dislocation is a rare variant of this type of injury and can prevent closed reduction in the acute setting. CASE PRESENTATION A 32-year old gentleman presented with an irreducible patella dislocation following ...

Acute patellar dislocation or subluxation is a common cause for knee injuries in the United States and accounts for 2% to 3% of all injuries. Up to 49% of patients will have recurrent subluxations or dislocations. Importance of both soft tissue (predominantly, the medial patellofemoral ligament, MPFL, which is responsible for 60% of the resistance to lateral dislocation) and bony constraint of ...

[Purpose] The aim of this study was to determine the intrarater reliability of using ultrasonography as a measurement tool to assess the patella position in a weight-bearing condition. [Subjects and Methods] Ten healthy adults participated in this study. Ultrasonography was used to assess the patella position during step down with the loading knee in flexion (0° and 20°). The distance between t...

BACKGROUND Patellar tendinopathy (jumper's knee) is characterized by localized tenderness of the patellar tendon at its origin on the inferior pole of the patella and a characteristic increase in signal intensity on magnetic resonance imaging at this location. However, it is unclear why the lesion typically occurs in this area of the patellar tendon as surface strain gauge studies of the patell...

Natural dynamics can be exploited in the control of bipedal walking robots: the swing leg can swing freely once started; a kneecap can be used to prevent the leg from inverting; and a compliant ankle can be used to naturally transfer the center of pressure along the foot and help in toe off. Each of these mechanisms helps make control easier to achieve and results in motion that is smooth and n...

In this case report, the surgical treatment of a calf with congenital, unilateral lateral patellar luxation clinical, radiography, and computed tomography findings is presented. A 5-day-old was referred due to an extremely flexed knee joint hindlimb weakness. Radiographic, tomographic, orthopedic examination demonstrated grade 3 normal stifle bone anatomy. Surgery includes release medial imbric...

Chondromalacia of the patella is frequently encountered in patients with anterior knee pain. Arthroscopic chondroplasty with perforation of subchondral bone remains a popular treatment alternative in spite of the inferior mechanical properties of the fibrocartilaginous tissue that this procedure is designed to promote. We report a case of cystic degeneration of the patella as a previously unrec...

Congenital patellar dislocation is a rare condition in which the patella is permanently dislocated and cannot be reduced manually. The patella develops normally as a sesamoid bone of the femur. This congenital dislocation results from failure of the internal rotation of the myotome that forms the femur, quadriceps muscle and extensor apparatus. It usually manifests immediately after birth, alth...

DISCUSSION In cases where the surgeon would prefer to resurface a defi cient patella because the option of retaining the host would lead to maltracking, we have found this technique to be reliable, versatile and cheap to overcome the otherwise complicated scenario of patella defi ciency. It avoids the risk of fracture by reducing the amount of bone that would otherwise be resected for a traditi...

BACKGROUND Medial opening wedge high tibial osteotomy (HTO) is a well-described treatment in early medial compartmental osteoarthritis of the knee. However, two undesirable sequelae may follow -patella baja and changes in the posterior tibial slope (TS). MATERIALS AND METHODS We conducted a retrospective study in patients who underwent HTO in our center between September 2009 and February 201...