| Abstract ID |
| 20260053 |
| Category |
| Foot & Ankle |
| Preferable Presentation |
| Oral Presentation |
| Title |
| IMPACT OF MIXED ULTRASONOGRAPHIC PATHOLOGY AND BASELINE SEVERITY ON PEMF EFFICACY IN ACHILLES TENDINOPATHY |
| Author |
|
| Presenter |
| Samuel Ka-Kin ling |
| Abstract |
| Background Pulsed electromagnetic field therapy has been shown to enhance outcomes when combined with eccentric exercise in midportion Achilles tendinopathy (MAT). However, baseline ultrasound findings revealed that some patients initially diagnosed with MAT also exhibited insertional pathology changes, forming a "Mixed" (MIX) pathology group. The clinical characteristics and treatment response of this MIX group remain unexplored, raising questions about the severity of MIX pathology and whether patients with isolated MAT respond better to PEMF. Objectives This post-hoc analysis aimed to evaluate: (1) whether baseline symptom severity differs among ultrasound-based IAT, MAT, and MIX classifications; (2) whether the MIX pathology group exhibits a differential response to PEMF therapy; and (3) whether baseline severity (VISA-A score) predicts PEMF efficacy. Study Design Data from 65 participants in a randomized, double-blind trial were analyzed. All participants underwent 12 weeks of eccentric exercise, combined with either active or sham PEMF for the initial 8 weeks. Based on ultrasound-identified pathological features (e.g., neovascularity, thickening, or calcification), participants were reclassified as: Insertional (IAT, n=32) if features were within 0–2 cm of the calcaneal insertion; Midportion (MAT, n=10) if features were 2–6 cm proximal to the insertion; or Mixed (MIX, n=23) if pathology spanned both regions. Participants were further stratified by baseline VISA-A score into Severe (≤70) and Mild (>70) subgroups. Outcomes were assessed at baseline, 4, 8, 12, 26, and 52 weeks. Data were analyzed using two-way mixed ANOVA and Mann-Whitney U tests with Bonferroni correction. Results (1) Ultrasound reclassification identified a significant proportion of MIX pathology, with 60% of MAT and 21% of IAT patients showing mixed features. Baseline symptom severity did not differ significantly across the three groups. (2) No significant differences in VISA-A scores were observed between PEMF and sham groups in the IAT or MAT subtypes. However, in the MIX group, the PEMF group showed significantly higher VISA-A scores at 26 weeks (80.10 ± 9.66) compared to Sham (62.16 ± 17.81, p=0.043). (3) Stratification by baseline severity revealed that in the Severe group (VISA-A ≤ 70), PEMF significantly improved VISA-A scores at 26 weeks (76.15 ± 10.99) compared to Sham (66.34 ± 19.14, p < 0.05). In the Mild group (VISA-A > 70), no significant differences were observed between PEMF and sham, and NPRS scores showed no significant differences across all groups. Conclusions This study highlights the clinical importance of ultrasonographic features in Achilles tendinopathy, identifying a previously underexplored MIX pathology group that may represent a distinct clinical entity. While baseline severity was similar across groups, the MIX pathology group responded more favorably to PEMF therapy, especially in patients with more severe baseline symptoms. These findings suggest that ultrasonographic classification could inform treatment strategies for Achilles tendinopathy. Due to the small sample size and uneven group distributions, these results should be interpreted cautiously and warrant validation in larger prospective studies. |