We report an extremely rare case of both recurrent lateral patella dislocation and medial patellofemoral instability, following prior operations to correct patella maltracking. Manual translation of the patella revealed medial and lateral instability with a positive apprehension sign. 3-D computer modelling of kinematics based on MRI data demonstrated that the patella deviated laterally at full...

BACKGROUND Patellar abnormalities are a common cause of pain and lameness in dogs; however, in vivo the relative motion between the femur and patella in dogs is not well described. The objective of this study was to define normal in vivo sagittal plane patellofemoral kinematics in three axes of motion using non-invasive methods. We hypothesized patellofemoral alignment in the sagittal plane wou...

Objective. To use a musculoskeletal model and simulation of running to examine: (1) the in ̄uence of two commonly prescribed treatments for patellofemoral pain (vastus medialis oblique strengthening and orthoses) and (2) the functional signi®cance of timing di€erences between vastus medialis oblique and vastus lateralis on lateral patellofemoral joint loads. Design. A three-dimensional musculosk...

OBJECTIVE To use a musculoskeletal model and simulation of running to examine: (1) the influence of two commonly prescribed treatments for patellofemoral pain (vastus medialis oblique strengthening and orthoses) and (2) the functional significance of timing differences between vastus medialis oblique and vastus lateralis on lateral patellofemoral joint loads. DESIGN A three-dimensional muscul...

Recurrent dislocation of the patella is a common orthopaedic problem which occurs in about 44% of cases after first-time dislocation. In most cases of first-time patellar dislocation, the medial patellofemoral ligament (MPFL) becomes damaged. Between 2010 and 2012, 33 children and adolescents (39 knees) with recurrent patellar dislocation were treated with MPFL reconstruction using the adductor...

[Purpose] The purpose of this study was to evaluate the correlation between intrinsic patellofemoral pain syndrome (PFPS) in young adults and lower extremity biomechanics. [Subjects] This experiment was carried out with sixty (24 men and 32 women), who are normal university students as subjects. [Methods] All subjects underwent 3 clinical evaluations. For distinguishing the intrinsic PFPS from ...

STUDY DESIGN Single-group repeated measures design. OBJECTIVE To quantify patellofemoral joint reaction forces and stress while squatting with and without an external load. BACKGROUND Although squatting exercises in the rehabilitation setting are often executed to a relatively shallow depth in order to avoid the higher joint forces associated with increased knee flexion, objective criteria ...

The intimate relation which the patella has with the knee joint and quadriceps muscle suggests that patellofemoral joint osteoarthritis is likely to be an important cause of knee pain and disability. Two hundred and seventy three subjects who reported knee pain in a postal questionnaire survey and 240 control subjects consented to have anteroposterior weightbearing and lateral knee radiographs....

BACKGROUND Significant correlation has been previously demonstrated between radiographic and clinical diagnoses of knee osteoarthritis (OA); however, the specific findings on clinical examination that relate best to a radiographic diagnosis have not been fully elicited. AIMS We aimed to explore the relationship between clinical symptoms and physical findings with radiographic diagnoses of tib...

Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. The short and mid-term outcomes are related to malposition and unexplained pain. Whether external rotation of the femoral component in isolated patellofemoral joint replacement is required is unclear. The primary aim of this study is to determine the CT-measured femoral component rotati...