Treatment Patterns for Plantar Fibromatosis in the United States: A Retrospective Observational Study

Abstract

Category: Midfoot/Forefoot; Other Introduction/Purpose: Plantar fibromatosis (PF) is a rare disease affecting the plantar aponeurosis, characterized by disordered fibrous tissue and subsequent formation of subcutaneous nodules on the foot/feet. There are no established clinical guidelines for management of PF symptoms, and real-world evidence on treatment patterns among PF patients in the United States (US) is scarce. This retrospective observational study used a comprehensive approach to identify newly diagnosed PF patients and describe subsequent conservative (non-surgical) and surgical treatment patterns. Methods: Patients with evidence of PF from ICD-9/10 diagnosis codes in IQVIA’s PharMetrics ® Plus were identified between January 2015-March 2020 and linked to IQVIA’s Ambulatory Electronic Medical Records (AEMR) to confirm diagnosis, using PF- specific SNOMED diagnosis codes or problem name; the earliest evidence of PF was the diagnosis date. Further, eligible patients were required to have continuous enrollment (CE) in a health plan for 12 months before diagnosis (baseline), 24 months of CE after diagnosis (follow-up), evidence of PF ≥30 days after first diagnosis, and age ≥18 years on diagnosis date. Patients with prior diagnosis of PF (through 2014) or other select lower limb conditions during baseline were excluded. Baseline demographic/clinical characteristics and conservative treatment utilization prior to PF diagnosis were assessed. Proportion of patients receiving PF- related conservative and surgical treatment, frequency of use, and time from diagnosis to initiation of first treatment were reported during follow-up. Results: The incident PF cohort (N=620) had mean (SD) age of 52.2(9.9) years and 63.2% were women. Most common baseline comorbidities were thyroid diseases (14.2%), diabetes without complications (12.3%), and smoking (12.3%); 19.0% had evidence of foot or ankle pain/stiffness. During baseline, 53.5% of patients received prescribed analgesic medications (30.6% received opioids). Most patients (91.1%) received conservative treatment after PF diagnosis, including analgesics and physical/occupational therapy (Figure 1A). Among all treatment modalities, time to initiation (months) was shortest for orthotics (median:0.5; IQR:5.5), injectable corticosteroids (median:2.0; IQR:9.2) and prescribed NSAID (median:2.5; IQR:9.1; Figure 1B). Among 42 patients (6.8%) receiving PF-related surgery, conservative treatments were common both before surgery (83.3%; median time from diagnosis to surgery:6.0 months) and after surgery (92.9%). Conclusion: Most newly diagnosed PF patients received conservative treatments within the first 3 months after diagnosis. Analgesic use was high during baseline as well as follow-up. During the 24 months after diagnosis, few patients received surgery and conservative treatment modalities often continued after surgery. Overall, continued and widespread conservative management among PF patients indicates lack of treatment options for PF. Further studies on treatment patterns in US patients aged ≥65 years are needed.