Talus

The musculoskeletal model was implemented in the AnyBody Modeling System (v. 7.0.1, AnyBody Technology A/S, Aalborg, Denmark) based on the detailed muscular geometry of the cadaveric dataset TLEM 2.0 [27 (link)].
The model consists of a simplified upper body (lumbar region, rigid trunk, neck, and head) and 11 segments representing the lower limbs: pelvis, right and left femurs, patellas, shanks, tali, and feet. Each lower limb comprises four joints: the hip joint is modelled as a 3 degrees of freedom (DOF) ball-and-socket, while knee, talocrural and subtalar joints are modelled as 1-DOF hinges. Additionally, the position of the patella is defined as a function of the knee flexion angle, therefore not introducing additional DOFs.
The model contains 55 muscle actuators in each leg, divided into 169 elements in accordance with the original TLEM dataset [27 (link),28 (link)]. Coordinates of insertion and origin points of the single elements were extracted from the contours of measured attachment areas. The muscle elements were modelled with a simple muscle model represented by constant strength actuators.

We added scorings for Yonghesuchus sangbiensis, based upon our original observations of the holotype of this taxon (IVPP V 12378), to the morphological cladistic data set of Nesbitt [2 ]. We also added a new character to the data set, resulting in a modified data matrix composed of 413 characters and 78 taxa (following the a priori pruning of the following operational taxonomic units [OTUs] that were also excluded by Nesbitt [2 ]: Archosaurus rossicus, Prestosuchus chiniquensis, UFRGS 0156 T, UFRGS 0152 T, Lewisuchus admixtus and Pseudolagosuchus major). In addition, several scorings for Gracilisuchus stipanicicorum and Turfanosuchus dabanensis were modified based upon new direct observations and interpretations of the relevant specimens. Additional file 1 provides details of and justifications for all rescorings and Additional file 2 is the data matrix. This data matrix is also available at TreeBASE (http://purl.org/phylo/treebase/phylows/study/TB2:S15917).
The data matrix was analysed under equally weighted parsimony using TNT 1.1 [21 (link)]. A heuristic search with 100 replicates of Wagner trees (with random addition sequence) followed by TBR branch-swapping (holding 10 trees per replicate) was performed. The best trees obtained from the replicates were subjected to a final round of TBR branch swapping. Zero length branches in any of the recovered MPTs were collapsed (rule 1 of Coddington & Scharff [22 (link)]). Characters 32, 52, 75, 121, 137, 139, 156, 168, 188, 223, 247, 258, 269, 271, 291, 297, 328, 356 and 399 were treated as additive (ordered) following Nesbitt [2 ], as was the new character 413. Decay indices (=Bremer support values) were calculated and a bootstrap resampling analysis, using 10,000 pseudoreplicates, was performed reporting both absolute and GC (i.e. difference between the frequencies of recovery in pseudoreplicates of the original group and the most frequently recovered contradictory group) frequencies. Templeton tests (T-t) were conducted using PAUP* 4.0 [23 ] to determine the significance of alternative phylogenetic topologies, with a 5% threshold for significance (p-value ≤ 0.05 = significantly less parsimonious [S]; p-value > 0.05 = non-significant [NS]).
Nesbitt & Butler [20 (link)] included the enigmatic archosaurs Erpetosuchus granti and Parringtonia gracilis within the data matrix of Nesbitt [2 ]. They recovered E. granti and P. gracilis within a monophyletic Erpetosuchidae; however, this clade acted as a wildcard taxon that substantially reduced phylogenetic consensus within Archosauria. Erpetosuchidae was recovered by Nesbitt & Butler [20 (link)] within a major polytomy that also included Avemetatarsalia, Ornithosuchidae, Aetosauria + Revueltosaurus, Ticinosuchus + Paracrocodylomorpha, G. stipanicicorum and T. dabanensis. It is noteworthy that Erpetosuchidae was found as the sister taxon of T. dabanensis in some of the most parsimonious trees recovered by Nesbitt & Butler [20 (link)]. As a result, we conducted a second analysis where we added E. granti and P. gracilis to the data matrix. Character scorings for the two erpetosuchids follow Nesbitt & Butler [20 (link)], with the exception of the scorings for the new character added here. This data matrix was therefore composed of 413 characters and 80 taxa, and was analysed under the same search criteria described above. This modified data matrix is supplied as Additional file 3, and is also available at TreeBASE as submission S15917 (http://iczn.org/code).
There is some disagreement over the identification and interpretation of the element described as the astragalus of T. dabanensis by Wu & Russell [12 (link)], with Nesbitt [2 ] scoring all astragalus characters as uncertain for T. dabanensis. To reflect this uncertainty, we reran both of the analyses described above, but rescored all astragalus characters (characters 354–370) as uncertain for T. dabanensis.

As determined by the individual situation, an autogenous tricortical bone graft of appropriate size was harvested from the ipsilateral iliac crest. Cancellous bone was harvested with the smallest osteotome possible. A longitudinal dorsal incision was made lateral to the extensor hallucis longus tendon with an interface between the extensor hallucis longus tendon and the dorsalis pedis artery, both of which were retracted correspondingly. The soft tissue was distracted by a lamina spreader to expose the talonavicular and navicular-cuneiform joints. The talonavicular and navicular-cuneiform joints were distracted using a Hintermann distractor over separate K-wires. The articular surfaces were debrided in situ with cartilage shovels to the subchondral bone. A K-wire was used to drill the subchondral sclerotic bone plate into a favaginous condition for fusion. Then bite off the excess osteophyte from the lateral 4-corners. The plantar ligament and plantar soft tissue of the navicular are loosened with a sharp knife, leaving only the insertion point of the posterior tibial tendon. The whole debridement process created a relative space around the navicular bone. Subsequently, a periosteal detacher was pressed against the lateral bony protrusion of the navicular bone to rotate the bone outwards to the original top location. Once the reduction was deemed satisfactory by direct visualization, two to three crossing K-wires were used for temporary fixation. After the demonstration of the corrected medial longitudinal arch on the C-arm, the lateral half of the navicular bone (including the talonavicular and navicular-cuneiform joints involved in the necrotic lesion) was excised using an osteotome to form a broad dorsal trapezoid laterally and a rectangular longitudinal bone bed. And the modified tricortical iliac bone block was inserted into the space between the talus and the cuneiforms. Finally, two hollow lag screws and a dorsal LCP were used to arthrodese the talonavicular-cuneiform joints. A transverse Herbert screw was used (where needed) to fix the bone block and medial navicular bone. The wound was closed after packing the previously acquired cancellous bone to smooth the defect gaps.
Postoperatively, a protective non-weight bearing short-leg plaster cast was applied for 6 weeks, after which weight-bearing was gradually allowed as tolerated.

The general characteristics of the enrolled subjects included age, sex, and flexible flatfoot conditions. Both lateral foot radiographs of the children at the time of diagnosis and at the end of treatment were taken to evaluate the effects of foot insole application in a barefoot standing position. Foot lateral radiography was used for radiographic measurement. The bilateral calcaneal pitch angle (CPA) and Meary’s angle, known as the talo first metatarsal angle (TMA), were measured in both feet. CPA is defined as the angle between the calcaneus and inferior aspect of the foot. TMA is defined as the angle between the line of the longitudinally bisected talus and the longitudinal axis of the 1^st metatarsal bone (Fig. 2). Both radiologic indices calculated through foot lateral radiography in a standing position are usually used clinically as criteria for flexible flatfoot: CPA < 15’; TMA > 3’.^{[14 (link)]} Both indices were periodically followed up within 3 to 4 months after the beginning of the foot insole prescription. The process of radiologic evaluation with adjustment of the foot insole was terminated at the point of loss of the associated symptoms, as mentioned above. All the radiographic parameters were measured by a trained physiatrist.
The foot insole was also adjusted periodically for 3 to 4 months after confirmation of the follow up radiograph. The device was custom-made using ethylene vinyl acetate with foam materials. This supported the medial longitudinal arch (Fig. 3). During the intervention, the foot insole was revised according to the height of the pad.