The motions and moments in the hip and knee in female patients on the waiting list for knee prosthesis surgery with medial (n ¼ 15) or lateral (n ¼ 15) osteoarthritis (OA) were compared with a control group (n ¼ 15). We hypothesized that not only the kinematics and kinetics of the knee but also of the hip would differ between patients the medial and lateral groups. At midstance, patients with lateral OA showed slightly (28) more maximal (peak) adduction ( p ¼ 0.015) of the hip joint and patients with medial OA had 78 more abduction (p < 0.001) than did controls. In patients with lateral OA, the femur was positioned in about 78 more maximum external rotation (p ¼ 0.001), but femur position did not differ between medial OA and controls ( p ! 0.8). There was a tendency to higher internal hip rotation moment in lateral OA compared to controls ( p ¼ 0.021). The maximum values of the internal knee abduction moments were 52% higher in medial OA ( p ¼ 0.005) and 63% lower in lateral OA ( p < 0.001) compared to controls. Cases with medial OA had 98 more, whereas those with lateral OA had 68 less external tibial rotation than controls (medial vs. lateral OA, p ¼ 0.001). We found an association between presence of lateral OA of the knee and the biomechanics of the hip joint. It remains to be evaluated if the changed biomechanics of the hip joint is a reason for development of lateral OA or an observation that is a result of this disease. ß
In patients with a similar degree of degenerative joint disease and within the limits of the constraints offered by the prostheses under study, the choice of joint area constraint has little influence on the gait pattern.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.