Microvascular Impairment Association With Achilles Tendon Degeneration In Patients With Peripheral Vascular Disease: A Cross-Sectional Observational Study

Abstract

Background: Peripheral vascular disease (PVD) leads to progressive impairment of both macrovascular and microvascular circulation in the lower limbs. Chronic ischemia compromises tissue oxygenation and directly affects collagen turnover within tendons, particularly the Achilles tendon, which contains a vulnerable watershed zone. Understanding the relationship between microvascular dysfunction and tendon degeneration may help identify early musculoskeletal complications in PVD patients.

Objective: To evaluate the association between microvascular impairment and Achilles tendon degenerative changes in patients with PVD.

Materials and Methods: The cross-sectional observational study was conducted at a tertiary care centre and included 40 adult patients with clinically and Doppler-confirmed PVD. Microvascular assessment included ankle–brachial index (ABI) and transcutaneous oxygen pressure (TcPO₂). Achilles tendon evaluation was performed using high-frequency ultrasonography and Power Doppler to assess tendon thickness, echotexture, fibrillar pattern, calcifications, and neovascularity. Patients with diabetes, prior tendon ruptures, systemic inflammatory diseases, or steroid/fluoroquinolone exposure were excluded. Correlation between microvascular parameters (ABI, TcPO₂) and tendon degeneration was analysed.

Results: The total of 40 participants (mean age 62.8 ± 8.5 years), 72.5% (n = 29) showed ultrasound-confirmed Achilles tendon degeneration. Patients with ABI <0.7 exhibited significantly greater tendon thickening (mean 6.9 ± 1.1 mm vs 5.3 ± 0.8 mm, p < 0.001). Severe microvascular impairment (TcPO₂ <30 mmHg) was strongly associated with hypoechoic degeneration (77% vs 42%, p = 0.02), higher Doppler neovascularity scores (2.1 ± 0.8 vs 1.1 ± 0.5, p < 0.01), and reduced fibrillar pattern integrity. Overall, microvascular parameters showed moderate to strong correlation with degenerative tendon changes, indicating that worse perfusion was associated with more severe structural alterations.

Conclusion: Microvascular dysfunction shows a significant association with Achilles tendon degeneration in patients with PVD. Low ABI and reduced TcPO₂ values are linked to greater tendon thickening, altered echotexture, and increased neovascularity. Screening for Achilles tendon changes using ultrasound in patients with chronic limb ischemia may aid in early detection, functional preservation, and prevention of potential tendon complications.