Adult flatfoot is a common foot deformity, mainly manifested as medial arch collapsing, hindfoot valgus and forefoot abduction. People have a more thorough understanding of the pathological changes and pathogenesis of flatfoot with further research. There is a new expert consensus for adult flatfoot published in Foot & Ankle Inter. in 2020. The expert panel reviewed the latest literature to develop consensus recommendations for flatfoot, including its nomenclature, diagnosis, classification and operative treatment. The consensus represents a new understanding of the disease and a new concept because of the authority of its authors and the comprehensiveness of its content, and it is also a phased summary of the theoretical and clinical progress of adult flatfoot. This article gives a detailed interpretation of the content in the consensus.
成人平足症是常见的足部畸形，主要表现为内侧足弓塌陷、跟骨外翻、前足外展。随着对平足研究的深入，人们对该疾病的病理变化及发病机制理解更加透彻。2020年10月在Foot & Ankle International杂志上发表了有关平足的最新共识。该共识结合该领域内的最新进展，对平足的命名、诊断、分级及手术治疗等进行了更新。该共识因其制定者的权威性以及内容的全面性代表了对疾病的新认识和新理念，同时也是对成人平足症理论和临床进展的阶段性总结，本文对该共识中内容进行了解读。.

UNASSIGNED: Forefoot varus is a physical and radiographic examination finding associated with the Progressive Collapsing Foot Deformity (PCFD). Varus position of the forefoot relative to the hindfoot is caused by medial midfoot collapse with apex plantar angulation of the medial column. Some surgeons use the term forefoot supination to describe this same deformity (see Introduction section with nomenclature). Correction of this deformity is important to restore the weightbearing tripod of the foot and help resist a recurrence of foot collapse. When the forefoot varus deformity is isolated to the medial metatarsal and medial cuneiform, correction is indicated with an opening wedge medial cuneiform (Cotton) osteotomy, typically with interposition of an allograft bone wedge from 5 to 11 mm in width at the base. When the forefoot varus is global, involving varus angulation of the entire forefoot and midfoot relative to the hindfoot, other procedures are needed to adequately correct the deformity.
UNASSIGNED: Level V, consensus, expert opinion.

UNASSIGNED: Progressive collapsing foot deformity (PCFD) is a complex 3D deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot supination. Although a medial displacement calcaneal osteotomy can correct heel valgus, it has far less ability to correct forefoot abduction. More severe forefoot abduction, most frequently measured preoperatively by assessing talonavicular coverage on an anteroposterior (AP) weightbearing conventional radiographic view of the foot, can be more effectively corrected with a lateral column lengthening procedure than by other osteotomies in the foot. Care must be taken intraoperatively to not overcorrect the deformity by restricting passive eversion of the subtalar joint or causing adduction at the talonavicular joint on simulated AP weightbearing fluoroscopic imaging. Overcorrection can lead to lateral column overload with persistent lateral midfoot pain. The typical amount of lengthening of the lateral column is between 5 and 10 mm.
UNASSIGNED: Level V, consensus, expert opinion.
UNASSIGNED: Lateral column lengthening (LCL) procedure is recommended when the amount of talonavicular joint uncoverage is above 40%. The amount of lengthening needed in the lateral column should be judged intraoperatively by the amount of correction of the uncoverage and by adequate residual passive eversion range of motion of the subtalar joint.Delegate vote: agree, 78% (7/9); disagree, 11% (1/9); abstain, 11% (1/9).(Strong consensus).
UNASSIGNED: When titrating the amount of correction of abduction deformity intraoperatively, the presence of adduction at the talonavicular joint on simulated weightbearing fluoroscopic imaging is an important sign of hypercorrection and higher risk for lateral column overload.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus).
UNASSIGNED: The typical range for performing a lateral column lengthening is between 5 and 10 mm to achieve an adequate amount of talonavicular coverage.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus).

UNASSIGNED: Peritalar subluxation represents an important hindfoot component of progressive collapsing foot deformity, which can be associated with a breakdown of the medial longitudinal arch. It results in a complex 3-dimensional deformity with varying degrees of hindfoot valgus, forefoot abduction, and pronation. Loss of peritalar stability allows the talus to rotate and translate on the calcaneal and navicular bone surfaces, typically moving medially and anteriorly, which may result in sinus tarsi and subfibular impingement. The onset of degenerative disease can manifest with stiffening of the subtalar (ST) joint and subsequent fixed and possibly arthritic deformity. While ST joint fusion may permit repositioning and stabilization of the talus on top of the calcaneus, it may not fully correct forefoot abduction and it does not correct forefoot varus. Such varus may be addressed by a talonavicular (TN) fusion or a plantar flexion osteotomy of the first ray, but, if too pronounced, it may be more effectively corrected with a naviculocuneiform (NC) fusion. The NC joint has a curvature in the sagittal plane. Thus, preserving the shape of the joint is the key to permitting plantarflexion correction by rotating the midfoot along the debrided surfaces and to fix it. Intraoperatively, care must be also taken to not overcorrect the talocalcaneal angle in the horizontal plane during the ST fusion (eg, to exceed the external rotation of the talus and inadvertently put the midfoot in a supinated position). Such overcorrection can lead to lateral column overload with persistent lateral midfoot pain and discomfort. A contraindication for an isolated ST fusion may be a rupture of posterior tibial tendon because of the resultant loss of the internal rotation force at the TN joint. In these cases, a flexor digitorum longus tendon transfer is added to the procedure.
UNASSIGNED: Level V, consensus, expert opinion.

UNASSIGNED: In the treatment of progressive collapsing foot deformity (PCFD), the combination of bone shape, soft tissue failure, and host factors create a complex algorithm that may confound choices for operative treatment. Realignment and balancing are primary goals. There was consensus that preservation of joint motion is preferred when possible. This choice needs to be balanced with the need for performing joint-sacrificing procedures such as fusions to obtain and maintain correction. In addition, a patient\'s age and health status such as body mass index is important to consider. Although preservation of motion is important, it is secondary to a stable and properly aligned foot.
UNASSIGNED: Level V, consensus, expert opinion.

De novo mutations that contribute to rare Mendelian diseases, including neurological disorders, have been recently identified. Whole-exome sequencing (WES) has become a powerful tool for the identification of inherited and de novo mutations in Mendelian diseases. Two important guidelines were recently published regarding the investigation of causality of sequence variant in human disease and the interpretation of novel variants identified in human genome sequences. In this study, a family with supposed movement disorders was sequenced via WES (including the proband and her unaffected parents), and a standard investigation and interpretation of the identified variants was performed according to the published guidelines. We identified a novel de novo mutation (c.2327C > T, p.P776L) in DYNC1H1 gene and confirmed that it was the causal variant. The phenotype of the affected twins included delayed motor milestones, pes cavus, lower limb weakness and atrophy, and a waddling gait. Electromyographic (EMG) recordings revealed typical signs of chronic denervation. Our study demonstrates the power of WES to discover the de novo mutations associated with a neurological disease on the whole exome scale, and guidelines to conduct WES studies and interpret of identified variants are a preferable option for the exploration of the pathogenesis of rare neurological disorders.

Practice guidelines for five of the most common podopediatric deformities are presented. In establishing these diagnosis and management guidelines, the authors have reviewed an extensive body of literature and considered their experience as clinicians in one of the busiest settings for the evaluation and treatment of disorders of children\'s feet. No attempt has been made to be encyclopedic; rather, the authors emphasize practical visual descriptors and the rationale for treatment to demonstrate the value of early intervention in moderate-to-severe orthopedic pathology of the foot and leg.