Comparing the Utility of Custom Foot Orthoses vs Prescription-grade Prefabricated Foot Orthoses

Abstract

Category: Hindfoot; Ankle Introduction/Purpose: Both prefabricated and custom-made foot orthoses have long been effective treatment foot and ankle conditions and deformities. Foot orthoses function by replacing the insole of a shoe to redistribute forces during weightbearing activities and can be a cost-effective and noninvasive treatment modality. Custom foot orthoses are created using a 3D scan or weightbearing impression of the patient’s foot and are intended to accommodate a patient’s foot anatomy, whereas prefabricated (off the shelf) orthoses are often prescribed unaltered or minimally modified. Custom orthoses have a much higher cost and are variably covered by insurance. The aim of this study is to compare the effectiveness of custom versus prefabricated foot orthoses for foot and ankle conditions using validated patient-reported outcome scales. Methods: Consecutive patients prescribed custom or prefabricated orthoses at a single institution were retrospectively reviewed. Following IRB approval, a follow-up research survey was distributed to patients to collect patient-reported outcomes. Collected outcome measures included the Foot and Ankle Single Assessment Numeric Evaluation (FA SANE), PROMIS Mobility, PROMIS Pain Interference (PI), and PROMIS Physical Function (PF). All patients with a baseline and minimum three-month follow-up score were included in the final sample. Statistical analysis was conducted using the ANOVA statistical test. In all cases, a p-value of less than 0.05 was considered significant. Results: A total of 238 patient records were included. 152 patients received a custom orthosis, while 86 patients received a prefabricated orthosis. Both groups reported significant improvement from baseline to follow-up in the FA SANE, PROMIS PI and PROMIS PF (p < 0.001). However, assessing PROMIS Mobility, we did not observe a significant difference in improvement from baseline to follow-up in either group. Comparing outcomes between groups, patients receiving custom orthoses reported significantly greater PF at follow-up compared to the prefabricated group (p < 0.05). However, at follow-up there was no significant difference between the custom and prefabricated groups in PI, Mobility, or FA SANE. Mean satisfaction scores were significantly higher for patients with custom orthotics compared to prefabricated orthotics (8.1 vs. 7.5, p < 0.01). Conclusion: Both custom and prefabricated foot orthoses result in improvement in pain and physical function over time. Although the results found in this study lacked definitive evidence in favor of the custom orthoses over prefabricated orthoses, overall patient-reported outcomes were higher for patients receiving custom orthoses. Further research, including longer term follow up, differentiation based on specific clinical diagnoses and deformities, and subsequent need for surgery may ultimately lead to definitive guidelines for custom versus prefabricated orthoses.