A 6 Year Analysis of Diagnosis and Demographic Factors in Custom and Prefabricated Foot Orthosis Prescriptions at a Large Institution

Research Type: Level 4 – Case series Introduction/Purpose: Foot orthoses (FOs) are a commonly used treatment modality for a variety of foot and ankle pathologies. Due to their simple and non-invasive nature, FOs are often a first-line treatment. While FOs are a very commonly prescribed treatment, there is limited large-scale demographic and diagnostic data on their utilization. Furthermore, the distinction between which types of patients and pathologies should get which type of orthosis has not been well described. This study aims to analyze the demographics and diagnoses associated with FO prescriptions at a large institution, providing insight into usage patterns across different patient populations. Methods: A retrospective review of all patient encounters where an FO was prescribed at a single large institution from January 1st, 2018, to July 1st, 2024, was completed. Data collection included basic demographic characteristics, including sex, age, and BMI, diagnosis information from ICD-10 codes, and orthosis type (custom or prefabricated). Encounters that involved individual diagnosis codes that did not occur in at least one other encounter were excluded from the analysis. Diagnosis data was then consolidated into 27 categories by a fellowship-trained foot and ankle surgeon. Any diagnoses that did not fit into these categories were subsequently grouped and included as “other.” Demographic characteristics and orthosis type were then compared across the ten most common prescription diagnoses. Results: In total, 10,082 encounters for FO prescription were included in the analysis. The five most common diagnosis categories were “Unspecified Pain Foot/Ankle” (13.9%), Heel Pain/Plantar Fascia Pathology (11.4%), “Flatfoot Deformity/Posterior Tibial Tendinitis (10.7%), “Hallux Valgus/Hallux Rigidus” (10.7%), and “Metatarsalgia” (7.4%). When combining the 10 most common diagnosis categories (n=7,555) and analyzing demographic characteristics, we found an average overall age of 53 (SD 18) years, and BMI of 27.6 (SD 6.4). The population had more female representation (4,502, 60%), and there were slightly fewer custom FOs (3,648, 48%) than prefabricated FOs (3,907 52%) (Table 1). While the overall distribution of custom-to-prefabricated FOs is approximately equal, large discrepancies were found between diagnosis categories, with Unspecified Pain Foot/Ankle favoring prefabricated (82%), while Cavo(varus) Foot/Ankle Deformity favors custom (81%). Conclusion: Custom FOs were more commonly prescribed for structural deformities (e.g., Cavo(varus) foot, Flatfoot), while prefabricated FOs were more frequently used for general pain conditions (e.g., unspecified pain, plantar fasciitis). While this finding aligns with the conceptual benefits of a custom FO, there is a lack of robust literature comparing orthosis types in specific conditions. Future studies focusing on the comparison of different FO types in specific populations and diagnoses are paramount in the pursuit of a cost-effective, patient-oriented, and evidence-based treatment algorithm for FOs.