INTRODUCTION Medial patellar subluxation is usually seen after lateral retinacular release. Spontaneous medial subluxation of the patella is a very rare condition. There are few reports in the literature on the pathophysiology of iatrogenic medial patellar subluxation. To our knowledge, there are no reports of the pathophysiology of non-iatrogenic medial patellar subluxation in the English lite...

Case Description-A 4.6-month-old pot-bellied pig was evaluated because of non-weight-bearing lameness (grade 5/5) in the right forelimb of 4 days' duration. Clinical Findings-Clinical and radiographic examination revealed a closed, lateral luxation of the right shoulder joint. Treatment and Outcome-Initial attempts at closed reduction failed to provide adequate stability of the shoulder joint. ...

OBJECTIVE To make a comparative analysis on three femoropatellar radiographic parameters, between knees with chronic failure of the anterior cruciate ligament (ACL) and normal knees. METHODS Thirty volunteer patients with a diagnosis of unilateral isolated chronic ACL injury for more than one year and a normal contralateral knee were selected. Digital radiographs were produced for all the pat...

Osteochondral fracture (OCF) in the weight-bearing surface of the lateral femoral condyle, associated with patellar dislocation, is an uncommon lesion. We report three cases of acute lateral patellar dislocation with large OCF in the weight-bearing portion of the lateral femoral condyle. In patients with lateral patella dislocation or lateral femoral condyle OCF, careful physical examination, r...

BACKGROUND AND PURPOSE Reduced motor unit activity of the vastus medialis muscle relative to the vastus lateralis muscle has been implicated as a cause of lateral patellar subluxation. The purpose of this study was to assess the influence of vastus muscle motor unit activity on patellar kinematics. SUBJECTS Twenty-three women (mean age=26.8 years, SD=8.5, range=14-46) with a diagnosis of pate...

Thirty patients with 49 snapping hips and patellar malalignment underwent surgical release of the iliotibial tract contracture over the trochanteric area. Minimal follow-up was 2 years (average 4.6 years, range: 2-9 years). Eight patients underwent computed tomography (CT) preoperatively and 1 month postoperatively to investigate the patellar location in the patellofemoral articulation with kne...

The aim of our study was to evaluate the association between patellar alignment by using magnetic resonance imaging images and radiographic manifestations of patello-femoral osteoarthritis (OA). Subjects were recruited to participate in a natural history study of symptomatic knee OA. We examined the relation of patellar alignment in the sagittal plane (patellar length ratio (PLR)) and the trans...

Optimal patellar tracking and component alignment are important in achieving a well-functioning total knee arthroplasty (TKA). The patella is constrained partly by design of the prosthetic trochlear groove, and patellar tracking is governed by a combination of static and dynamic factors. Maltracking may result from excessive or unbalanced tension in the surrounding soft tissues. This article de...