The advantages to using a 50/50 mixture of lidocaine and bupivacaine with respect to onset and duration of local anesthesia instead of using the solutions independently were evaluated. In a double-blind randomized experiment, 12 subjects, each volunteering both feet, were studied. One foot was injected with 1 ml of one of the following three solutions: 1% plain lidocaine, 0.25% plain bupivacaine (Marcaine), or a 50/50 mixture of 1% lidocaine and 0.25% bupivacaine; and in the other foot, a 1-ml injection of normal saline as a blinded control. A 5.07 (10 g) Semmes-Weinstein monofilament wire was used for testing for sensory blockade, and the onset and duration of anesthesia was recorded for each subject. It was determined that there was no significant difference in the mean onset times for the three solutions, and no significant difference between the durations of anesthesia of plain lidocaine and the 50/50 mixture. Additionally, it was determined that bupivacaine had a prolonged duration of anesthesia compared with the other two solutions. The results of this preliminary study suggest that there is no clinical advantage, with respect to onset and duration of local blockade, to using a 50/50 mixture of plain lidocaine and plain bupivacaine in place of their independent use.
Two emollients, ammonium lactate 12% lotion and a liposome-based moisturizing lotion, were compared in a double-blind test for efficacy in the treatment of plantar xerosis. A total of 43 out of 57 participants (75%) with bilateral plantar xerosis followed instructions completely and applied the lotions (one to each foot) twice daily for 4 weeks. Each participant was evaluated once a week for 6 weeks (the final 2 weeks for evaluation of post-treatment regression) to determine xerotic grade (degree of dryness) and treatment effectiveness. With both lotions, significant improvement began during the second week of treatment and continued into the fourth week. There were no significant differences between the two lotions in the 6-week patterns of either xerotic grade or treatment effectiveness.
To test the null hypothesis that limb dominance (laterality) and side of complaint are not associated in a diverse population, nearly 400 patients (40% male, 60% female) of varying age and body size from three South Florida podiatric medical teaching facilities were surveyed in 1995-1996. Radiographs of feet were available for 15% of the patients, and the metatarsus adductus angle was measured on each x-ray. The typical patient was a women (median age, 49 years) of average body weight and average body-mass index. No statistical association was found between laterality and side of complaint in the broader sample, although a significant association did appear in the subsample of patients with bilateral x-rays. The prevalence of metatarsus adductus deformity (metatarsus adductus angle > 15 degrees) among patients with x-rays was 62%. No sex-specific, age-specific, or body size-specific associations were found between handedness and metatarsus adductus deformity.