X-reality for phantom limb management for amputees: A systematic review and meta-analysis

Phantom limb is a disabling neuropsychiatric condition among amputees resulting in pain and disturbance that impact their functions, quality of life, and autonomy. While pharmacological approaches appeared to be ineffective, the emergence and integration of X-reality, including virtual reality, augmented reality, and mixed reality, might elevate the effectiveness of mirror therapy in managing phantom limb. The objective of this study is to review X-reality for managing phantom pain. A systematic search was conducted on PubMed, Scopus, Web of Science, PsycINFO, Embase, and CINAHL. Sixteen (n = 16) studies containing 66 lower-limb and 53 upper-limb amputees were included for the review over the thematic framework of amputee characteristics and intervention designs, while thirteen (n = 13) studies were further proceeded for the meta-analysis. We found eleven studies on virtual reality (n = 11), four studies on marker-based augmented reality (n = 4) and one study on mixed reality (n = 1) with a total of 40 game/task themes involving, motor skills, motor control, and stimulus-sensing. Regardless, all these interventions adopted the movement representation strategies with different techniques. Overall, the X-reality interventions reduced the pain level of the amputees (mean difference: -2.30, 95% CI, -3.38 to -1.22), especially the virtual reality subgroup (mean difference: -2.83, 95% CI, -4.43 to -1.22). However, there were substantial heterogeneity and partially explained by the subgroup analysis on publication year. The strength of evidence was limited by case reports and case series in this review.