Criterion and construct validity of prosthesis-integrated measurement of joint moment data in persons with transtibial amputation.

Prosthesis-integrated sensors are appealing for use in clinical settings where gait analysis equipment is unavailable, but accurate knowledge of patients' performance is desired. Data obtained from load cells (inferring joint moments) may aid clinicians in the prescription, alignment, and gait rehabilitation of persons with limb loss. The purpose of this study was to assess the accuracy of prosthesis-integrated load cells for routine use in clinical practice. Level ground walking of persons with transtibial amputation was concurrently measured with a commercially available prosthesis-integrated load cell, a 10-camera motion analysis system, and piezoelectric force plates. Ankle and knee flexion/extension moments were derived and measurement methods were compared via correlation analysis. Pearson correlation coefficients ranged from 0.661 for ankle pronation/supination moments to 0.915 for ankle flexion/extension moments (P < .001). Root mean squared errors between measurement methods were in the magnitude of 10% of the measured range and were explainable. Differences in results depicted differences between systems in definition and computation of measurement variables. They may not limit clinical use of the load cell, but should be considered when data are compared directly to conventional gait analysis data. Construct validity of the load cell (ie, ability to measure joint moments in-situ) is supported by the study results.

Effects of immediate switch from cyclosporine microemulsion to tacrolimus at first acute rejection in renal allograft recipients.

BACKGROUND: A number of institutions have reported favorable results in renal transplant patients after conversion from cyclosporine (CsA) to tacrolimus at the time of acute rejection, but no prospective, controlled study has been performed to date. Here, we report the first randomized study comparing patients whose therapy was changed at a first episode of acute rejection to tacrolimus with those who were maintained on CsA microemulsion (ME). METHODS: This 3-month, prospective, open, multicenter, parallel-group study was conducted at 15 centers in seven European countries. In total, 119 renal graft recipients experiencing a first biopsy-proven acute rejection episode while receiving CsA-ME were randomized (1:1) to start tacrolimus-based therapy (n=61) or to continue CsA-ME-based therapy (n=58). RESULTS: Baseline characteristics were comparable for both groups. The initial rejection episode responded to steroid treatment in 93.4% (tacrolimus) and 63.8% (CsA-ME) (P=0.001), respectively. In patients at risk, the incidence of recurrent rejection events within 3 months was significantly lower with tacrolimus therapy (5/57, 8.8%) compared with CsA-ME therapy (15/44, 34.1%) (P=0.002). Patient and graft survival were similar in both study groups 3 months after randomization. The most frequently reported adverse events were increased serum creatinine (29.5% vs. 22.4%), hypertension (24.6% vs. 22.4%), and urinary tract infection (18.0% vs. 20.7%) for tacrolimus versus CsA-ME. Tremor was more common in tacrolimus treated-patients (17.4% vs. 2.1%, P=0.011). CONCLUSIONS: Early conversion to tacrolimus therapy benefited the resolution of acute rejection episodes and significantly reduced the risk of recurrent rejection compared with continuation of CsA-ME.