Radiological association between Haglund's deformity and plantar calcaneal spur: A retrospective case-control study

ObjectivesPlantar calcaneal spur (PCS) is a bony outgrowth of the calcaneal tuberosity frequently associated with chronic heel pain. Although its precise etiology remains uncertain, mechanical stress and repetitive traction forces are frequently implicated. Haglund's deformity, defined as a bony enlargement on the posterosuperior calcaneus, results in retrocalcaneal impingement of the Achilles tendon. While both conditions involve stress-related alterations of the calcaneus, their potential association has not been clearly established. This study aimed to evaluate the relationship between PCS and Haglund's deformity by determining the incidence of Haglund's deformity in symptomatic PCS patients and investigating associated factors.MethodsIn this retrospective case-control study, 377 patients aged ≥18 years who underwent weight-bearing lateral foot radiographs between March 2023 and March 2024 were included. The case group (n = 94) consisted of patients with symptomatic PCS, and the control group (n = 283) comprised patients without PCS. Haglund's deformity was assessed radiographically using the BRINK angle, with values >20° considered diagnostic. Demographic characteristics and comorbidities were analyzed.ResultsHaglund's deformity was significantly more prevalent in the PCS group (62/94; 66.0%) compared with controls (53/283; 18.7%) (p = 0.001). Diabetes mellitus showed a significant association with Haglund's deformity (p = 0.01). No significant differences were observed in age, sex, body mass index, or other comorbidities.ConclusionOur findings demonstrate a strong radiological association between PCS and Haglund's deformity, suggesting shared biomechanical stress pathways involving the plantar fascia and Achilles tendon. Prospective studies incorporating biomechanical evaluation are warranted to clarify underlying mechanisms and clinical implications.