Fluoroscopic System (fluoroscopic + system)

Distribution by Scientific Domains


Selected Abstracts


Investigation of in vivo 6DOF total knee arthoplasty kinematics using a dual orthogonal fluoroscopic system

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2006
George R. Hanson
Abstract Fluoroscopic techniques have been recently used to detect in vivo knee joint kinematics. This article presents a technique that uses two fluoroscopes to form a dual orthogonal fluoroscopic system for accurately measuring in vivo 6DOF total knee arthoplasty (TKA) kinematics. The system was rigorously validated and used to investigate in vivo kinematics of 12 patients after cruciate-retaining TKA. In a repeatability study, the pose of two different TKA components was reproduced with standard deviations (SD) of 0.17 mm and 0.57° about all three axes. In an accuracy study, the reproduced component positions were compared to the known component positions. Position and rotation mean errors were all within 0.11 mm and 0.24°, with SD within 0.11 mm and 0.48°, respectively. The results of this study show that the matching process of the imaging system is able to accurately reproduce the spatial positions and orientations of both the femoral and tibial components. For CR TKA patients, a consistent anterior femoral translation was observed with flexion through 45° of flexion, and thereafter, the femur translated posteriorly with further flexion. The medial,lateral translation was measured to be less than 2 mm throughout the entire flexion range. Internal tibial rotation steadily increased through maximum flexion by approximately 6°. Varus rotation was also measured with flexion but had a mean magnitude less than 2.0°. In conclusion, the dual orthogonal fluoroscopic system accurately detects TKA kinematics and is applicable towards other joints of the musculoskeletal system, including the wrist, elbow, shoulder, ankle, and spine. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source]


Trigger arrhythmia to confirm the position of totally implantable access ports (TIAP)

JOURNAL OF SURGICAL ONCOLOGY, Issue 5 2007
Huan-Fa Hsieh MD
Abstract Background Totally implantable access ports (TIAP) with cutdown method has few complications, but needs assessment of fluoroscopic system. Methods We present a method to confirm the position of TIAP catheter without fluoroscopic assessment. We use the cutdown method and trigger arrhythmia while introducing the TIAP catheter. Results This method was applied in 54 patients and no complications were found. Conclusions Checking the position by triggering arrhythmia while performing TIAP with cephalic vein cutdown in case of C-arm was not available is simple and safe. J. Surg. Oncol. 2007;96:436,437. © 2007 Wiley-Liss, Inc. [source]


Increased tibiofemoral cartilage contact deformation in patients with anterior cruciate ligament deficiency

ARTHRITIS & RHEUMATISM, Issue 12 2009
Samuel K. Van de Velde
Objective To investigate the in vivo cartilage contact biomechanics of the tibiofemoral joint following anterior cruciate ligament (ACL) injury. Methods Eight patients with an isolated ACL injury in 1 knee, with the contralateral side intact, participated in the study. Both knees were imaged using a specific magnetic resonance sequence to create 3-dimensional models of knee bone and cartilage. Next, each patient performed a lunge motion from 0° to 90° of flexion as images were recorded with a dual fluoroscopic system. The three-dimensional knee models and fluoroscopic images were used to reproduce the in vivo knee position at each flexion angle. With this series of knee models, the location of the tibiofemoral cartilage contact, size of the contact area, cartilage thickness at the contact area, and magnitude of the cartilage contact deformation were compared between intact and ACL-deficient knees. Results Rupture of the ACL changed the cartilage contact biomechanics between 0° and 60° of flexion in the medial compartment of the knee. Compared with the contralateral knee, the location of peak cartilage contact deformation on the tibial plateaus was more posterior and lateral, the contact area was smaller, the average cartilage thickness at the tibial cartilage contact area was thinner, and the resultant magnitude of cartilage contact deformation was increased. Similar changes were observed in the lateral compartment, with increased cartilage contact deformation from 0° to 30° of knee flexion in the presence of ACL deficiency. Conclusion ACL deficiency alters the in vivo cartilage contact biomechanics by shifting the contact location to smaller regions of thinner cartilage and by increasing the magnitude of the cartilage contact deformation. [source]