Coverage maps demonstrate 3D Chopart joint subluxation in weightbearing CT of progressive collapsing foot deformity

Abstract

A key element of the peritalar subluxation (PTS) seen in progressive collapsing foot deformity (PCFD) occurs through the transverse tarsal joint complex. However, the normal and pathological relations of these joints are not well understood. The objective of this study to compare Chopart articular coverages between PCFD patients and controls using weight-bearing computed tomography (WBCT). In this retrospective case control study, 20 patients with PCFD and 20 matched controls were evaluated. Distance and coverage mapping techniques were used to evaluate the talonavicular and calcaneocuboid interfaces. Principal axes were used to divide the talar head into 6 regions (medial/central/lateral and plantar/dorsal) and the calcaneocuboid interface into 4 regions. Repeated selections were performed to evaluate reliability of joint interface identification. Surface selections had high reliability with an ICC > 0.99. Talar head coverage decreases in plantarmedial and dorsalmedial (− 79%, p = 0.003 and − 77%, p = 0.00004) regions were seen with corresponding increases in plantarlateral and dorsolateral regions (30%, p = 0.0003 and 21%, p = 0.002) in PCFD. Calcaneocuboid coverage decreased in plantar and medial regions (− 12%, p = 0.006 and − 9%, p = 0.037) and increased in the lateral region (13%, p = 0.002). Significant subluxation occurs across the medial regions of the talar head and the plantar medial regions of the calcaneocuboid joint. Coverage and distance mapping provide a baseline for understanding Chopart joint changes in PCFD under full weightbearing conditions.

Novel wireless laser doppler flowmeter-based investigation of earlobe vascular dynamics in cardiopulmonary exercise testing

“…TNCA assessed using radiography is the gold standard method for evaluating the talonavicular joint under loading conditions; it may be associated with 3D coverage of the talonavicular joint and evaluation using weightbearing CT 10 , 21 ) . In addition, talonavicular joint assessment methods, other than CT-based approaches, that significantly correlate with TNCA, have rarely been reported.…”

Distance mapping and volumetric assessment of the ankle and syndesmotic joints in progressive collapsing foot deformity

“…As the foot moves in external rotation under and distal to the talus, the talar bone assumes a internal rotation and plantarflexed position 30,32,33 . The talar head becomes uncovered and some of the collapse is established 25 .…”

“…For more detailed coverage analysis, the tibiotalar joint was divided into nine zones in a 3 × 3 grid using the principal axes of the joint surface while the medial and lateral gutters were divided anterior and posterior regions (Fig. 2) 25 . Measurements performed in articular areas were defined as the distance along the normal direction of vectors projected from the tibial subchondral surface to the opposed surfaces of the talus or distal fibula, as described previously 24,28 .…”

“…Colored CMs were also created using the measured DMs and following previously published methodology 24 , aiming to better depict and highlight areas of adequate joint interaction, joint subluxation, and extra-articular impingement 25 . Pink was chosen to highlight uncoverage of articular regions that were either completely uncovered or had distances greater than 5 mm (Fig.…”

Ankle Joint Bone Density Distribution Correlates with Overall 3-Dimensional Foot and Ankle Alignment

“…The articulation of the fibula with the lateral talus could explain increased lateral constraints, which concurs with physiological valgus 33 . In studies of valgus abnormalities such as progressive collapsing foot deformity (PCFD), WBCT and tools such as distance and coverage maps 40,41 have recently provided new insights into advanced disease patterns such as sinus tarsi and subfibular impingement 42,43 . It is likely that such impingement leads to denser bone in the lateral aspect of the hindfoot.…”