Simultaneous measurements of knee motion using an optical tracking system and radiostereometric analysis (RSA)

Abstract

Background and purpose Invasive methods are more reproducible and accurate than non-invasive ones when it comes to recording knee kinematics, but they are usually less accessible and less safe, mainly due to risk of infection. For this reason, non-invasive methods with passive markers are widely used. With these methods, varying marker sets based on a number of single markers, or sets of markers, known as clusters, are used to track body segments. We compared one invasive method—radiostereometric analysis—with a non-invasive method, an optical tracking system with 15 skin-mounted markers.Methods 9 subjects (10 knees) were investigated simultaneously with a dynamic RSA system and a motion-capture system while performing an active knee extension.Results For flexion/extension, there was good agreement on an individual basis and at the group level. For internal/external rotation, the group mean was fairly similar, up to 25 degrees of flexion. Recordings of abductions and/or adductions revealed a systematic mean difference of 2–4 degrees during the range of flexion measured. The correlation between the 2 methods in the horizontal and frontal planes was poor.Interpretation Our skin-marker model provided reliable data for flexion/extension. Recordings of internal/external rotation and abduction/adduction were less accurate on an individual basis than at the group level, most probably due to soft-tissue motion and the presence of small true motion in these planes.

Subject-Specific Finite Element Modeling of the Tibiofemoral Joint Based on CT, Magnetic Resonance Imaging and Dynamic Stereo-Radiography Data in Vivo

“…Previous in vivo tibiofemoral (TF) FE modeling efforts have created models without sufficiently considering the functional joint kinematics involved in the joint loading process [4,5]. Studies have incorporated skeletal kinematics from either nonsubject-specific data [6][7][8] or skin surface marker measurements [9,10]-the latter are prone to soft-tissue artifacts [11] due to marker movement [12,13] and inaccurate marker positioning on the skin relative to the bone [14,15]. Two FEM studies have employed advanced imaging techniques to acquire skeletal kinematics: Beillas et al [7,8] used X-ray imaging that required surgical implantation of radio-opaque markers into the bone; Yao et al [16] utilized a loading device to exert a force on the knee as it was undergoing magnetic resonance imaging (MRI) in a supine position.…”

Validation of gait analysis with dynamic radiostereometric analysis (RSA) in patients operated with total hip arthroplasty

“…This method can also be used to measure joint motions, either by repeated static examinations or by the use of dynamic techniques based on film‐exchangers or high‐speed digital screens. RSA can be considered as “golden standard” in investigation of joint motions because of its high accuracy, high resolution, and detailed documentation …”

Comparative evaluation of densitometry values through osteotropic therapy for the knee arthroplasty

“…Исследования на основе метода рентгеноденсито-метрии показывают преобладание остеолиза в ранних периодах после эндопротезирования коленного сустава по сравнению с исходными показателями [4,9,14,15]. В условиях изначальной неполноценности костной ткани, при наличии сопутствующего остеопороза, про-блема нестабильности встает особенно остро в связи с возможным развитием перипротезных микроперело-мов [6,7].…”