ABSTRACT
We compared the effects of capsule resection versus capsule suturing in patients treated with a dual-mobility trapeziometacarpal joint prosthesis. We included 131 patients with capsular resection and 57 patients with repair. The mean scores for pain and the brief Michigan Hand Outcomes Questionnaire were similar between the groups preoperatively and at 6 weeks and 1 year postoperatively. Mean key pinch strength was also similar in both groups before surgery and at 1 year, but higher in the capsular resection than in the suture group at 6 weeks. The incidence of complications reported throughout the 1-year postoperative period was not significantly different between the groups. One implant in the capsular resection group was revised for reasons most likely unrelated to capsule management. We conclude that the capsule can be safely resected during trapeziometacarpal joint implant arthroplasty.Level of evidence: III.
ABSTRACT
The brain's arousal state is controlled by several neuromodulatory nuclei known to substantially influence cognition and mental well-being. Here we investigate whether human participants can gain volitional control of their arousal state using a pupil-based biofeedback approach. Our approach inverts a mechanism suggested by previous literature that links activity of the locus coeruleus, one of the key regulators of central arousal and pupil dynamics. We show that pupil-based biofeedback enables participants to acquire volitional control of pupil size. Applying pupil self-regulation systematically modulates activity of the locus coeruleus and other brainstem structures involved in arousal control. Furthermore, it modulates cardiovascular measures such as heart rate, and behavioural and psychophysiological responses during an oddball task. We provide evidence that pupil-based biofeedback makes the brain's arousal system accessible to volitional control, a finding that has tremendous potential for translation to behavioural and clinical applications across various domains, including stress-related and anxiety disorders.
