Sex-specific Differences in Multisite Pain Presentation among Adults with Lower-Limb Loss

Objectives: Multisite pain remains significantly understudied following lower-limb loss (LLL), especially among females. This study aimed to explore sex-specific differences in the presentation of multisite pain post LLL. Hypotheses were multisite pain would be more prevalent among females post LLL as compared with males, and female sex would be significantly associated with multisite pain prevalence.

Methods: In this cross-sectional study, participants answered standardized questions regarding the presence of amputation-specific (ie, phantom-limb, residual-limb) and secondary (ie, contralateral-limb, low-back) pain. Multisite pain was defined as pain in ≥ 2 locations. Sex-specific differences in pain prevalence were evaluated using chi-square tests (P ≤ 0.050). Using logistic regression, the association between sex and multisite pain was examined after controlling for covariates (age, body mass index, time since amputation, amputation etiology and level).

Results: The sample included 303 adults (33% females) ≥ 1 year post unilateral LLL. More females than males reported pain in the residual limb (53.0% vs. 38.4%), low back (56.0% vs. 39.9%), contralateral knee (37.0% vs. 24.1%), and contralateral hip (25.0% vs. 12.3%; P < 0.050). More females than males were classified as having multisite pain (72.0% vs. 54.7%; P = 0.004). While patterns of multisite pain were similar (ie, pain affected both amputation-specific and secondary sites) between sexes, being female was independently associated with higher odds of having multisite pain (odds ratio: 2.40, 95% confidence interval: 1.40 to 4.12).

Discussion: Female sex appears to be associated with multisite pain ≥ 1 year after LLL. Future work is needed to identify mechanisms underlying sex-specific differences in pain presentation and evaluate the impact of sex on pain-related outcomes post amputation.