Type D Personality, Back Pain, and Vagus Nerve Stimulation in Orthopaedic Rehabilitation: A Systematic Narrative Review with Clinical Case

Abstract Background: Type D personality (negative affectivity and social inhibition) is associated with poor outcomes in cardiovascular and orthopaedic populations. Recent studies show significant associations with chronic back pain. Vagus nerve stimulation (VNS), particularly in its non-invasive form of transcutaneous auricular stimulation (taVNS), has emerged as a promising neuromodulatory approach to restore autonomic balance and attenuate inflammatory signaling. Methods: A systematic narrative review (2005–2025) was conducted in PubMed, Scopus, PsycINFO, and Web of Science. Inclusion criteria: validated DS14 assessment, pain outcomes, and autonomic/inflammatory measures. Studies were screened according to PRISMA guidelines. Results: Eight studies showed that Type D personality is associated with higher pain, disability, and increased risk of pain chronification. Mechanisms include maladaptive stress processing, movement avoidance, and inflammatory activation (IL-6, TNF-α). Nine taVNS studies demonstrated reductions in cytokines, improved HRV, postoperative analgesia, and enhanced wound healing. A clinical case illustrates successful taVNS application in delayed recovery after knee arthroplasty. No studies have directly tested taVNS in Type D patients; however, mechanistic overlaps suggest that taVNS may counteract pathophysiological features of Type D personality. Conclusion: Type D personality represents a biopsychosocial risk factor with biological underpinnings in autonomic and inflammatory dysregulation. VNS and taVNS provide a biologically plausible, safe, and scalable intervention with potential relevance for this population. Future randomized controlled trials are required to establish efficacy of taVNS in Type D patients within cardiovascular and orthopedic rehabilitation.