Ultrasound study of the motion of the residual femur within a transfemoral socket during gait

Abstract

This study analyses the motion of the residual femur within a trans-femoral socket during gait using ultrasound data from two simultaneously transmitting transducers connected to two ultrasound scanners. Calibration tests accurately established the orientation of the two transducers mounted on the lateral wall of the socket. Relative positions of the ultrasound image of the femur were measured on video playback. Motion of the residual femur, relative to the lateral wall of the socket, at any instant during gait may be estimated, if the relative positions of the two transducers and the motion of the ultrasound image are known. A consistent pattern of femoral motion during 10 gait cycles is displayed graphically. The femoral motion in this paper is expressed as abduction/adduction or flexion/extension relative to the socket. However, without a full gait analysis study, the orientation of the socket relative to the ground or relative to the pelvis cannot be determined. Only one ultrasound scanner may be available for clinical use. Hence data collection may be restricted to only one transducer during gait. In order to simulate the single transducer mode, the ultrasound data recorded during the 10 previous gait cycles, was averaged at any instant of the gait cycle. The angular orientation of the femur was calculated based on the averaged data. Similar patterns of femoral motion were obtained irrespective of the technique adopted.

Transfemoral sockets with vacuum-assisted suspension comparison of hip kinematics, socket position, contact pressure, and preference: Ischial containment versus brimless

“…However, Xray is not dynamic and therefore may not be as accurate as other media, such as fluoroscope and ultrasound [3,[16][17]. These media also have limitations; therefore, a compromise may need to be recognized when evaluating dynamic skeletal kinematics.…”

“…While not as dynamically accurate [3,[16][17][18], X-ray images can be more clear and encompassing. X-ray was used in addition to fluoroscope to ensure accurate recording of the interface in the event the fluoroscope did not provide a discernable difference.…”

A noncontact sensor for measurement of distal residual-limb position during walking

“…These studies have shown that for transtibial amputee subjects, the vertical motion between the bones and the socket ranged to approximately 40 mm between the midstance and swing phases. Ultrasonic methods have also been used, in which ultrasound transducers are attached to the socket wall and their subsequent video recordings are analyzed [8][9].…”

Modern research and the forgotten prosthetic history of the Vietnam war

“…These images show a progressive narrowing of the ML aspect of the socket, which was the penultimate evolutionary step to the ischial tuberosity being captured inside the borders of the socket and providing the definition for a new limb/socket category. Recent studies using ultrasound imaging have found abduction occurring during ambulation, increasing to a maximum at midstance [44][45], but it is difficult to conceive of abduction occurring from lateral forces generated during walking in the last recorded evolution of this patient's socket as reduced to practice by Long. There are 46 limbs in the studies of Mayfield, Flandry et al, and Hachisuka et al that show significant improvement toward adduction in the prosthetic limb. It is interpreted that socket design and alignment were causal factors in the recorded improvement.…”

“…The total number of patients and cases far eclipses any other similar research study. Although research has been published that compares the quadrilateral and ischial containment sockets [42][43] and studies have imaged the femoral remnant in a prosthetic socket [15,[44][45], only two other research articles have been published that have measured the angular orientation of the femoral remnant in comparative socket designs using X-ray measurements with a sample size equal to or greater than five patients. The review of these two studies will be mostly limited to their X-ray analysis of alignment and reports on gait, but it should be noted that both studies exceed the research scope of Mayfield and Gottschalk et al, addressing such issues as metabolic efficiency and patient satisfaction with the respective designs.…”