Abstract
BACKGROUND: The relationship between insertional Achilles tendinopathy (IAT) and Haglund's deformity has not been fully elucidated. This study aimed to determine the optimal cutoff value of MRI-based Achilles thickness and intratendinous degeneration for IAT and further explored the correlations of IAT and Haglund's deformity. MATERIALS AND METHODS: Thirty heels with symptomatic IAT (IAT group) underwent surgeries and 38 healthy participants without heel pain (control group) were enrolled. Five different radiographic parameters for diagnosing Haglund's deformity were measured. The IAT changes including tendon thickness and intratendinous degenerative ratio (ITD ratio) were obtained on MRI. The correlations of IAT and different radiographic parameters of Haglund's deformity were evaluated. RESULTS: A total of 68 feet were enrolled. The optimal thresholds of Achilles tendon thickness and ITD ratio were 6.1 mm and 48.8%, respectively. Both tendon thickness and ITD ratio were positively correlated with bump height and bump-calcaneus ratio (p < 0.001), but Fowler-Phillip angle, Heneghan-Pavlov parallel pitch lines and X-Y ratio were not. CONCLUSION: Achilles tendon thickness of more than 6.1 mm and intratendinous abnormality of over 48.8% were confirmed to be diagnostic cutoff values for IAT. Haglund's deformity was determined as a risk factor of IAT requiring surgery. Both radiographic parameters of Haglund's deformity using the bump height and the bump-calcaneus ratio were useful in predicting the presence of IAT on MRI. LEVEL OF CLINICAL EVIDENCE: Level III, Retrospective cohort study.