The Corrective Power of Subtalar Arthrodesis With Mini/Medial Bone Block (SAMBB) in Patients Affected by Progressive Collapsing Foot Deformity (PCFD): Analysis Using Weight-bearing Cone Beam CT.

Progressive Collapsing Foot Deformity (PCFD) is a complex, multiplanar condition characterized by hindfoot valgus, peritalar subluxation, midfoot abduction, and collapse of the medial arch, which may progress to rigid deformity with pain and functional impairment. In advanced stages, subtalar arthrodesis is a well-established surgical option to restore hindfoot alignment and stability. Subtalar Arthrodesis with Mini/Medial Bone Block (SAMBB) is an evolution of the Grice-Green technique, using an autologous bone graft to achieve stable correction of talocalcaneal alignment and improve joint congruency, with favorable clinical and radiographic outcomes. This study aims to evaluate the three-dimensional corrective effect of SAMBB using weight-bearing CT (WBCT), focusing on hindfoot alignment and talocalcaneal and talonavicular relationships.

Inclusion Criteria: * Patients of both sexes, aged between 18 and 80 years * Patients affected by grade A2 Progressive Collapsing Foot Deformity (PCFD) * Patients who have provided informed consent to participate in the study Exclusion Criteria: * Patients who have previously undergone corrective surgery on the deformity under study. * Patients with prior lower limb fractures resulting in altered biomechanics. * Patients affected by PCFD of grade A1, B2, C2, E1, or E2 according to the PCFD classification \[2\]. * Patients with active acute or chronic infections. * Patients with chronic inflammatory joint diseases. * Patients with significant lower limb trauma occurring after the surgical intervention. * Patients with pre-existing gait abnormalities (e.g., amputations, neuromuscular diseases, poliomyelitis, hip dysplasia). * Patients with cognitive deficits. * Patients with concomitant neurological disorders. * Patients affected by cancer. * Pregnant patients.