Effect of peripheral neuropathy on Achilles tendon: ultrasonographic study

Abstract Introduction Type 2 diabetes mellitus (T2DM) is frequently associated with diabetic peripheral neuropathy (DPN) and musculoskeletal complications, including Achilles tendon abnormalities. Limited evidence exists regarding if tendon abnormalities progress with increasing neuropathy severity or not. Therefore this study aimed to compare ultrasonographic Achilles tendon abnormalities between patients with T2DM with and without DPN, to investigate the relationship between neuropathy severity and tendon structural changes, and to determine whether diabetic peripheral neuropathy independently predicts tendon abnormalities after adjustment for potential confounding variables. Methodology This comparative cross-sectional study included 52 patients with T2DM recruited from the university Hospitals. Participants were classified into a DPN group ( n = 26) and a non-DPN group ( n = 26) based on clinical and electrophysiological assessment. All patients underwent clinical evaluation, laboratory investigations, nerve conduction studies, and musculoskeletal ultrasound examination of both Achilles tendons. Tendon thickness, cross-sectional area (CSA), fibrillar pattern, enthesophytes, bursitis, and Doppler activity were assessed. Statistical analyses included independent t-tests, chi-square tests, ANOVA, and multivariable regression models. Results Patients with DPN had significantly greater Achilles tendon thickness and CSA bilaterally compared with non-DPN patients (all p ≤ 0.001). Abnormal fibrillar patterns were more prevalent in the DPN group on both sides (right p = 0.006, left p = 0.001). Tendon thickness and CSA increased significantly with neuropathy severity, particularly between mild and severe DPN. Multivariable regression analysis demonstrated that DPN status was the strongest independent predictor of tendon thickness and CSA bilaterally (all p ≤ 0.002). Logistic regression demonstrated that DPN increased the odds of fibrillar pattern abnormalities by approximately fivefold on the right side and twenty-two-fold on the left side. Conclusion Diabetic peripheral neuropathy is associated with significant structural alterations of the Achilles tendon, including increased thickness, larger cross-sectional area, and disruption of the normal fibrillar architecture. These changes become more pronounced with increasing neuropathy severity. Musculoskeletal ultrasound is a valuable tool for the early detection of subclinical tendon involvement in patients with T2DM and DPN.