Operative Intervention Does Not Change Pain Perception in Diabetic Foot Ulcer Patients

CATEGORY: Diabetes, Midfoot/Forefoot INTRODUCTION/PURPOSE: Most diabetic foot ulcer (DFU) patients have peripheral neuropathy (PN), which presents with numbness, pain and weakness. DFU patient’s perceived pain and other clinical factors affecting their pain level have not been reported. Although high prevalence of depression among diabetes patients have been reported, its correlation with perception of pain has not been investigated in patients with ulcers. PROMIS (Patient-Reported Outcomes Measurement Information System) allows accurate quantification of patient’s physical function (PF), pain interference (PI) and Depression. We aimed to investigate 1) if DFU patient’s pre- and postoperative pain level correlate with demographic data/ laboratory values/surgical procedure and 2) if depression level and/or surgical intervention impacts pain. METHODS: Prospectively collected PROMIS (PF, PI, D) assessments were obtained for patients who underwent surgical intervention for infected DFU between February 2015 and November 2018 (n=240). Patients who had at least 3 consecutive visits with a minimum follow up of 3 months and had completed all assessments for each visit were included (n=92). Demographic data, BMI, medical comorbidities, Hemoglobin A1C (A1C), procedure performed, wound healing status, PN, depression, and amputation level were collected. The mean follow-up duration was 4.7 (3-12) months. T-score distribution of initial PROMIS scores were calculated and compared to the US population. Chi-Square test and Minimum clinically important differences (MCID) were calculated to assess the co-occurrence of different PROMIS domains. We also analyzed other clinical factors and their influences on MCID changes in PROMIS domains. RESULTS: The 92 patients were 80.4% male (n=74) and had an average age of 60.5 (33-96) and BMI of 34.1 (22.0-57.5). Irrigation and debridement (n=39), forefoot amputations (n=46), mid/hindfoot amputations (n=14) and Syme or above amputations (n=12) were performed. Mean pre-operative PF, PI, and depression PROMIS scores were 34.4, 58.7, and 51.4, respectively. Average scores at final follow up increased 1.7, decreased 0.1, and increased 0.2, respectively. Depression and PI were the most strongly associated co-occurrences (p=0.03) pre-operatively and remained significant (p<0.01) with respect to post-operative MCID. PF and PI also strongly co-occurred pre-operatively (p=0.04) and with post-operative MCID assessment (p=0.02). PF was affected by initial A1C (p=0.03) and wound healing status (p=0.03). PN was the only clinical factor found to affect PI (p=0.03). CONCLUSION: DFU patients with PN experience a significant amount of pain. Contrary to previous studies, we did not find a higher prevalence of depression in our DFU cohort compared to the average United States population. The study results do not indicate the origin of pain, which can be further investigated using other measures, such as PROMIS Neuropathic Pain Quality Scale. Surgical intervention did not significantly relieve pain in DFU patients. These findings may be referenced for pre-operative patient education and setting expectation for surgery.