Objectives: To investigate the association between calcaneal bump height and hindfoot radiographic parameters on weight-bearing lateral radiographs in adult males with Progressive Collapsing Foot Deformity (PCFD), and to determine whether posterior calcaneal morphology differs between feet with and without PCFD-related flatfoot alignment. Materials: We retrospectively reviewed 583 men (1166 feet), aged 17–46 years, who underwent standing weight-bearing lateral foot radiographs between 1 January 2024 and 31 August 2025. Radiographic measurements included calcaneal pitch, Meary’s angle, navicular height, tibiocalcaneal angle, Böhler’s angle, Fowler–Philip angle, calcaneal bump height, and additional calcaneal morphological indices. A flatfoot alignment consistent with PCFD was defined as a calcaneal pitch 64.6°, Böhler’s angle ≤ 32.9°, Meary’s angle > 4.9°, calcaneal bump height ≤ 3.9 mm, and Fowler–Philip angle > 61.1° were independently associated with flatfoot alignment (Nagelkerke R2 = 0.293, p < 0.001). Conclusions: Calcaneal bump height is reduced in PCFD and reflects posterior calcaneal remodelling associated with hindfoot malalignment and medial arch collapse. Although not a primary diagnostic parameter, calcaneal bump height provides complementary morphological information that may inform surgical planning and osteotomy strategy aimed at restoring physiologic hindfoot biomechanics and Achilles tendon loading in patients with PCFD.
Tuncez et al. (Mon,) studied this question.