APPLICATION OF WEIGHTBEARING CT IN PROGRESSIVE COLLAPSING FOOT DEFORMITY

Progressive collapsing foot deformity (PCFD), a complex and common condition, remains challenging among the treatment of foot and ankle disorders. Despite today's era of modernized personalized medicine, there is still a lack of knowledge about the underlying multifactorial etiology as well as for an accurate assessment of PCFD. One of the key challenges is to identify those patients at risk for progressive collapse. As the planning of surgical interventions depends on the amount and location of deformity, the precise differentiation facilitated by the imaging diagnostics is paramount. PCFD is generally characterized by hindfoot valgus, loss of the longitudinal arch, forefoot abduction as well as by the involvement of soft tissue disorders such as the insufficiency of the posterior tibial tendon and dysfunction of the spring ligament. Additional critical characteristics include the peritalar subluxation and subtalar osseus impingement, which involve the lateral and dorsal subluxation of the foot under the talus. The ability to recognize this significant osseous impingement at the level of the subtalar joint, while assessing the hindfoot deformity associated with symptomatic PCFD, holds significant relevance in assisting foot and ankle surgeons to decide on the suitable management approach such as choosing between realignment fusion procedures and osteotomies. This presentation aims to demonstrate how weightbearing computed tomography (WBCT) revolutionized the understanding of this complex foot deformity and how it impacts the treatment.