Gait analysis in patients with a preformed articulated knee spacer.

Two-stage revision is one of the most widely accepted procedures to eradicate infection and restore function in infected knee prosthesis; while the use of an articulated spacers is advocated by many as a means to preserve function between stages, no data are available regarding gait parameters after spacer implant. The aim of present study was to assess and compare the gait parameters of patients with articulated knee spacers with a normal reference population and with the sound limb. Computerised gait analysis, was performed 8 to 14 weeks after the infected knee prosthesis had been removed and a preformed, articulated, knee spacer had been implanted, in 10 consecutive patients. Kinematic data show a mean gait velocity reduction of 70% and a decrease of the range of motion of the operated knee of 59%, compared with controls. While ground reaction forces were only slightly reduced, frontal and sagittal moments and calculated powers around the affected knees were near zero or zero. Our findings point out the ability of a preformed articulated spacer to preserve, although reduced, the normal gait parameters and joint range of motion and the capacity of the human body to provide useful postural modifications, even in the absence of the proprioceptive input from a normal knee or from a traditional total knee replacement.

Semi-automated analysis of coronary flow Doppler images: validation with manual tracings.

Coronary flow velocity reserve (CFVR) is conventionally obtained by manual tracings of Doppler profiles, as ratio of stress vs baseline diastolic peak velocity. When <1.9, this parameter evidences reduced coronary flow and possible microcirculatory disease. Our goals were: 1) to develop a novel technique for semi-automated detection of Doppler flow velocity profile, allowing the automated computation of CFVR and other parameters; 2) to validate this technique in comparison with conventional measurements obtained by manual tracing; 3) to test for differences between normal (N) subjects and patients with rheumatoid arthritis (RA). Linear correlation and Bland-Altman analyses showed that the proposed method was highly accurate and repeatable compared to the manual measurements. Comparison between N and RA groups evidenced significant differences in some of the automated parameters.

Quantification of coronary flow velocity reserve by means of semiautomated analysis of coronary flow Doppler images.

Coronary flow reserve (CFVR) is conventionally obtained by manual tracings of Doppler profiles, as ratio of control vs stress diastolic peak velocity. This parameter could help in discriminating between normal (N) and microcirculatory pathologic (P) subjects, even the clinical meaning of 1.93) and 15 P (CFVR<1.8) subjects, to assess whose of the new parameters could be able to discriminate between these groups. Results indicated that many of the new parameters were able to evidence significant differences between N and P, thus representing new clinical indices useful for the diagnosis.