Plantar forefoot pain: ultrasound findings before and after treatment with custom-made foot orthoses

Abstract

Abstract Purpose No prior studies investigated the role of ultrasound in the assessment of response of patients undergoing treatment of metatarsalgia with custom-made orthoses. Our aim was to describe ultrasound findings of patients with plantar forefoot pain treated with custom-made foot orthoses. Methods Twenty patients (15 females; mean age: 62.6 ± 11 years) affected by metatarsalgia in 27/40 feet underwent clinical evaluation before, three months and six months after treatment with custom-made full foot insole with a support proximal and an excavation below the painful metatarsals. Ultrasound was performed before and three months after the use of orthoses to examine the presence of intermetatarsal/submetatarsal bursitis, metatarsophalangeal joints effusion, anterior plantar fat pad oedema, flexor tendinitis/tenosynovitis, and Morton’s neuroma. Outcome measures were clinical response with Foot Function Index (FFI)/Visual Analogue Scale (VAS) and ultrasound features changes. Results Median VAS and FFI before treatment were 8[5–8.5] and 45.85[32.4–59.4], respectively. After 3 and 6 months of insoles use, both median VAS (2.5 [0–5] and 0 [0–2.75], respectively) and median FFI (7.9 [3.95–20] and 0 [0–3.95], respectively) showed a significant reduction in pain and disability (p < .001). Before treatment, ultrasound revealed 22 intermetatarsal bursitis, 16 submetatarsal bursitis, 10 joint effusions, 20 fat pad oedema, 3 flexor tendinitis/tenosynovitis and 3 Morton’s neuromas. After 3 months of treatment, a significant decrease of intermetatarsal bursitis (7, p < .001) was observed. No significant changes were observed in any other ultrasound parameters. Conclusion Ultrasound might be able to detect some imaging features associated with the response of forefoot pain to custom-made foot orthoses, especially intermetatarsal bursitis.