Psychosocial factors associated with poor outcomes after amputation for complex regional pain syndrome type-I

BACKGROUND: Amputation for longstanding therapy resistant complex regional pain syndrome type-I (CRPS-I) is controversial. Reported results are inconsistent. It is assumed that psychological factors play a role in CRPS-I. OBJECTIVE: To explore which psychological factors prior to amputation are associated with poor outcomes after amputation in the case of longstanding therapy resistant CRPS-I. METHODS: Between May 2008 and August 2015, 31 patients with longstanding therapy resistant CRPS-I were amputated. Before the amputation 11 psychological factors were assessed. In 2016, participants had a structured interview by telephone and filled out questionnaires to assess their outcome. In case of a perceived recurrence of CRPS-I a physician visited the patient to examine the symptoms. Associations between psychological factors and poor outcomes were analysed. RESULTS: Four of the 11 psychological factors were associated with poor outcomes. Regression analyses showed that change in the worst pain in the past week was associated with poor social support (B = 0.3, 95% confidence interval: 0.1;0.6) and intensity of pain before amputation (B = 2.0, 95% confidence interval 0.9;3.0). Patients who reported important improvements in mobility (n = 23) had significantly higher baseline resilience (median 79) compared to those (n = 8) who did not report it (median 69)(Mann-Whitney U, Z = -2.398, p = 0.015). Being involved in a lawsuit prior to amputation was associated with a recurrence in the residual limb (Bruehl criteria). A psychiatric history was associated with recurrence somewhere else (Bruehl criteria). CONCLUSION: Poor outcomes of amputation in longstanding therapy resistant CPRS-1 are associated with psychological factors. Outstanding life events are not associated with poor outcome although half of the participants had experienced outstanding life events.