The surgical correction of insertional Achilles tendinopathy (IAT) repair typically involves tendon debridement, osteophyte removal, lengthening of the gastroc-soleus complex, and resection of the posterior superior calcaneal eminence. Limited evidence has supported decompression of the superior calcaneal prominence, because this step has had a pronounced association with the surgical treatment of Haglund's syndrome. To appreciate the posterior calcaneal abnormality, 20 lateral weightbearing radiographs of asymptomatic patients were compared with 20 lateral weightbearing radiographs of patients with symptomatic IAT. The radiographs were evaluated for the calcaneal inclination angle, Fowler-Philip angle, total angle, parallel pitch lines, Chauveaux-Liet angle, and the presence or absence of retrocalcaneal enthesiophytes. Patients with IAT were also examined clinically and using magnetic resonance imaging to determine the incidence of Haglund's syndrome within the symptomatic population. A comparison of the radiographs revealed minimal differences in calcaneal morphology between the 2 populations. Of the analyzed variables, only an elevated Chauveaux-Liet angle and the presence of a retrocalcaneal enthesiophytes were characteristic of patients with IAT. The results of the present study have confirmed the absence of morphologic calcaneal variation and the presence of altered calcaneal angulations in symptomatic patients. Both the clinical examination and magnetic resonance imaging revealed a 25% frequency of Haglund's syndrome within the IAT population. Because these 2 diagnosis are clinically and radiographically divergent, their surgical interventions warrant distinct goals using separate methods. By understanding the abnormality, the surgeon can taper the correction precisely and specifically toward patients with IAT.