Dynamic Microcirculation Characteristics of Plantar Skin Under Metatarsal Head of Human Foot in Response to Life-Like Pressure Stimulus.

OBJECTIVE: Diabetic foot ulcer (DFU) is a severe complication with high mortality. High plantar pressure and poor microcirculation are considered main causes of DFU. The specific aims were to provide a novel technique for real-time measurement of plantar skin blood flow (SBF) under walking-like pressure stimulus and delineate the first plantar metatarsal head dynamic microcirculation characteristics because of life-like loading conditions in healthy individuals. METHODS: Twenty young healthy participants (14 male and 6 female) were recruited. The baseline (i.e., unloaded) SBF of soft tissue under the first metatarsal head were measured using laser Doppler flowmetry (LDF). A custom-made machine was utilized to replicate daily walking pressure exertion for 5 min. The exerted plantar force was adjusted from 10 N (127.3 kPa) to 40 N (509.3 kPa) at an increase of 5 N (63.7 kPa). Real-time SBF was acquired using the LDF. After each pressure exertion, postload SBF was measured for comparative purposes. Statistical analysis was performed using the R software. RESULTS: All levels of immediate-load and postload SBF increased significantly compared with baseline values. As the exerted load increased, the postload and immediate-load SBF tended to increase until the exerted load reached 35 N (445.6 kPa). However, in immediate-load data, the increasing trend tended to level off as the exerted pressure increased from 15 N (191.0 kPa) to 25 N (318.3 kPa). For postload and immediate-load SBF, they both peaked at 35 N (445.6 kPa). However, when the exerted force exceeds 35 N (445.6 kPa), both the immediate-load and postload SBF values started to decrease. CONCLUSIONS: Our study offered a novel real-time plantar soft tissue microcirculation measurement technique under dynamic conditions. For the first metatarsal head of healthy people, 20 N (254.6 kPa)-plantar pressure has a fair microcirculation stimulus compared with higher pressure. There might be a pressure threshold at 35 N (445.6 kPa) for the first metatarsal head, and soft tissue microcirculation may decrease when local pressure exceeds it.

Combined vertical and external rotational force in plantarflexion position produces posterior pilon fracture: A preliminary cadaveric study.

BACKGROUND: Posterior pilon fracture is speculated to occur by a combination of rotation and axial load, which makes it different from rotational posterior malleolar fracture or pilon fracture, but is not validated in vitro. The aim of the current study is to investigate the injury mechanisms of posterior pilon fracture on cadaveric specimens. METHODS: Eighteen cadaveric specimens were mounted to a loading device to undergo solitary vertical loading, solitary external rotational loading, and combined vertical and external rotational loading until failure, in initial position of plantarflexion with or without varus. The fracture characteristics were documented for each specimen. RESULTS: Vertical loading force combined with external rotation force diversified the fracture types resulting in pilon fracture, tibial spiral fracture, rotational malleolar fracture, talar fracture or calcaneal fracture. Vertical violence combined with external rotational loading in position of 45° of plantarflexion and 0° of varus produced posterior pilon fracture in specimens No. 13 and 14. CONCLUSION: Combination of vertical and external rotational force in plantarflexion position on cadaveric specimens produce posterior pilon fracture.

The influence of local pain on balance control in patients with chronic ankle instability.

BACKGROUND: Local pain around the ankle joint is a common symptom in patients with chronic ankle instability (CAI). However, whether the local pain would impose any influence on the balance control performance of CAI patients is still unknown. METHODS: A total of twenty-six subjects were recruited and divided into the following two groups: pain-free CAI (group A) and pain-present CAI (group B). Subjects in both groups received two independent tests: the star excursion balance test and the single-leg stance test, in order to reflect their balance control ability more accurately. RESULTS: Compared with group A, the group B showed significantly more episodes of the history of sprains, decreased ankle maximum plantarflexion angle, and lower Cumberland scores (all p < 0.05). In the star excursion balance test, group B demonstrated a significantly reduced anterior reach distance than group A (p < 0.05). During the single leg stance test, group B showed a significant increase in the magnitude of electromyographic signals both in peroneus longus and soleus muscles than group A (each p < 0.05). Additionally, group B had a significantly more anterolaterally positioned plantar center of pressure than group A (p < 0.05). CONCLUSION: CAI patients with local pain around the ankle joint had more episodes of sprains and lower functional scores when compared to those without pain. The balance control performance was also worse in the pain-present CAI patients than those without pain.

Finite element stress analysis of the bearing component and bone resected surfaces for total ankle replacement with different implant material combinations.

BACKGROUND: A proper combination of implant materials for Total Ankle Replacement (TAR) may reduce stress at the bearing component and the resected surfaces of the tibia and talus, thus avoiding implant failure of the bearing component or aseptic loosening at the bone-implant interface. METHODS: A comprehensive finite element foot model implanted with the INBONE II implant system was created and the loading at the second peak of ground reaction force was simulated. Twelve material combinations including four materials for tibial and talar components (Ceramic, CoCrMo, Ti6Al4V, CFR-PEEK) and three materials for bearing components (CFR-PEEK, PEEK, and UHMWPE) were analyzed. Von Mises stress at the top and articular surfaces of the bearing component and the resected surfaces of the tibia and talus were recorded. RESULTS: The stress at both the top and articular surfaces of the bearing component could be greatly reduced with more compliant bearing materials (44.76 to 72.77% difference of peak stress value), and to a lesser extent with more compliant materials for the tibial and talar components (0.94 to 28.09% difference of peak stress value). Peak stresses at both the tibial and talar bone-implant interface could be reduced more strongly by using tibial and talar component materials with smaller material stiffness (7.31 to 66.95% difference of peak stress value) compared with bearing materials with smaller material stiffness (1.11 to 24.77% difference of peak stress value). CONCLUSIONS: Implant components with smaller material stiffness provided a stress reduction at the bearing component and resected surfaces of the tibia and talus. The selection of CFR-PEEK as the material of tibial and talar components and UHMWPE as the material of the bearing component seemed to be a promising material combination for TAR implants. Wear testing and long-term failure analysis of TAR implants with these materials should be included in future studies.

Effect of loading history on material properties of human heel pad: an in-vivo pilot investigation during gait.

BACKGROUND: This study was aimed to develop a novel dynamic measurement technique for testing the material properties and investigating the effect of continuous compression load on the structural and mechanical properties of human heel pad during actual gait. METHODS: The dual fluoroscopic imaging system (DFIS) and dynamic foot-ground contact pressure-test plate were used for measuring the material properties, including primary thickness, peak strain, peak stress, elastic modulus, viscous modulus and energy dissipation rate (EDR), both at time zero and following continuous loading. Ten healthy pilot subjects, aged from 23 to 72 (average: 46.5 ± 17.6), were enrolled. A "three-step gait cycle" is performed for all subjects, with the second step striking at a marked position on the force plate with the heel to maintain the location of the tested foot to be in the view of fluoroscopes. The subjects were measured at both relaxed (time-zero group) and fatigue (continuous-loading group) statuses, and the left and right heels were measured using the identical procedures. RESULTS: The peak strain, peak stress, elastic modulus, and EDR are similar before and after continuous load, while the viscous modulus was significantly decreased (median: 43.9 vs. 20.37 kPa•s; p < 0.001) as well as primary thicknesses (median: 15.99 vs. 15.72 mm; p < 0.001). Age is demonstrated to be moderately correlated with the primary thicknesses both at time zero (R = -0.507) and following continuous load (R = -0.607). The peak stress was significantly correlated with the elastic modulus before (R = 0.741) and after continuous load (R = 0.802). The peak strain was correlated with the elastic modulus before (R = -0.765) and after continuous load (R = -0.801). The correlations between the viscous modulus and peak stress/ peak strain are similar to above(R = 0.643, 0.577, - 0.586 and - 0.717 respectively). The viscous modulus is positively correlated with the elastic modulus before (R = 0.821) and after continuous load (R = 0.784). CONCLUSIONS: By using dynamic fluoroscopy combined with the plantar pressure plate, the in vivo viscoelastic properties and other data of the heel pad in the actual gait can be obtained. Age was negatively correlated with the primary thickness of heel pad and peak strain, and was positively correlated with viscous modulus. Repetitive loading could decrease the primary thickness of heel pad and viscous modulus.

Surgical management of concurrent lateral ankle instability and osteochondral lesions of the talus increases dynamic sagittal ankle range of motion.

PURPOSE: A biomechanical study, in which imaging modalities are used to strictly include patients with concurrent lateral ankle instability (LAI) and osteochondral lesions of the talus (OLT), is needed to demonstrate the static and dynamic ankle range of motion (ROM) restriction in these patients, and determine whether ankle ROM restriction can be corrected postoperatively. METHODS: Eight patients with concurrent LAI and OLT treated with the arthroscopic modified Broström procedure and microfracture were recruited from June 2019 to January 2020. Patients were assessed using outcome scales, static ankle ROM, and a stair descent gait analysis for dynamic ankle ROM, a day prior to surgery and one year postoperatively. Eight healthy subjects were assessed using the same modalities upon recruitment. Operative outcomes and variables during stair descent were documented and compared among the preoperative, postoperative, and healthy groups. A curve analysis, one-dimensional statistical parametric mapping, was performed to compare the dynamic ankle kinematics and muscle activation curves over the entire normalised time series. RESULTS: The functional outcomes of patients with concurrent LAI and OLT were significantly worse than those of healthy subjects preoperatively, but were partially improved postoperatively. Patients had decreased static and dynamic ROM preoperatively, and static ROM did not significantly increase postoperatively (preoperative, 39.6 ± 11.3; postoperative, 44.9 ± 7.1; healthy, 52.0 ± 4.6; p = 0.021). Patients showed increased dynamic ankle flexion ROM (preoperative, 41.2 ± 11.6; postoperative, 53.6 ± 9.0; healthy, 53.9 ± 3.4; p = 0.012) postoperatively, as well as increased peroneus longus activation (preoperative, 35.8 ± 12.0; postoperative, 55.4 ± 25.1; healthy, 71.9 ± 13.4; p = 0.002) and muscle co-contraction of the tibialis anterior and peroneus longus (preoperative, 69.4 ± 23.4; postoperative, 88.4 ± 9.3; healthy, 66.2 ± 18.1; p = 0.045). CONCLUSIONS: Patients with concurrent LAI and OLT had decreased static and dynamic sagittal ankle ROM and altered neuromuscular activation patterns. The arthroscopic modified Broström procedure and microfracture did not significantly increase the static sagittal ankle ROM. However, the dynamic sagittal ankle ROM, peroneus longus activation and muscle co-contraction of the tibialis anterior and peroneus longus increased postoperatively. LEVEL OF EVIDENCE: IV.

The effect of partial deltoid ligament injuries on the external rotation stability: A cadaveric study.

BACKGROUND: The anterior and posterior part of the deltoid ligament have different functions during ankle flexion motion. Partial ligament injuries have been demonstrated in previous clinical reports. However, the efficacy of external rotation stress test in partial injured cases is unavailable till now. METHODS: Thirty-two fresh cadaveric specimens were included and allocated into two destabilization groups. In the first group, the anterior portion of deltoid ligament (DL) and syndesmotic ligament were sequentially severed, while in the second group, the posterior portion of DL and syndesmotic ligament were sequentially severed. Mortise view radiographs were taken after each destabilization stage when the ankles were placed at plantarflexion and dorsiflexion positions and stressed in standard external rotation force. The medial clear space (MCS) and talar tilt (TT) angle were measured and compared among different destabilization stages. RESULTS: When the ankles were placed at neutral position, the TT significantly increased in all destabilization stages. The MCS significantly increased after the partial deltoid ligament ruptures only with presence of syndesmotic ligament injuries. There was no significant difference of MCS at plantarflexion for all stages of destabilization if the anterior portion of DL is preserved. Similarly, no significant increase of MCS was detected at dorsiflexion if the posterior portion of DL and posterior inferior tibiofibular ligament are intact. CONCLUSION: Partial DL rupture causes ankle rotational instability at different ankle joint positions, especially when combined with syndesmotic injuries. The neutral position is recommended for diagnosis of partial DL ruptures under external rotation stress.

Length change pattern of the ankle deltoid ligament during physiological ankle motion.

BACKGROUND: Length change pattern of the ankle deltoid ligament during physiological ankle motion is still confused currently and had not been studied in vivo. METHODS: The deltoid ligaments from 7 cadaveric specimens were dissected. Lengths of each band during 30° plantarflexion to 20° dorsiflexion were measured. A dual fluoroscopy imaging system was utilized to capture the images of hindfoot joint of 7 healthy subjects during the stance phase of walking. 3D bone models were reconstructed from CT images. Lengths of each band were calculated after model-image registration utilizing a solid modeling software. Percentage of length variation and poses when the bands were in maximum extension were documented among each band. RESULTS: The anterior border of tibiocalcaneal ligament (TCL) had only 1.7% length variation in vitro and 5.7% length variation in vivo. The tibionavicular ligament, tibiospring ligament, and deep anterior tibiotalar ligament were in maximum extension at 30° plantarflexion, however, superficial posterior tibiotalar ligament, deep posterior tibiotalar ligament, and the posterior border of TCL were in maximum extension at 20° dorsiflexion. The tibionavicular ligament, tibiospring ligament, and deep anterior tibiotalar ligament were in maximum extension during foot flat. The TCL was in maximum extension during midstance. The superficial posterior tibiotalar ligament and deep posterior tibiotalar ligament were in maximum extension during heel off and toe off. CONCLUSION: The length of TCL did not change during ankle dorsiflexion and plantarflexion. The bands anterior to and posterior to the TCL showed different length change pattern during physiological ankle dorsiflexion and plantarflexion.

Outcome Comparison Between Functional Ankle Instability Cases With and Without Anterior Ankle Impingement: A Retrospective Cohort Study.

Functional ankle instability (FAI) and anterior ankle impingement (AAI) are likely to occur simultaneously. Nevertheless, how AAI affects ankle instability remains largely unknown. This study aimed to assess patients with FAI + AAI and those having FAI without AAI after arthroscopic synovectomy combined with the modified Broström procedure. Patients with chronic ankle instability who underwent surgery at the Huashan Hospital of Fudan University (China) from January 2010 to December 2015 were reviewed. Propensity score matching was performed (FAI + AAI: n = 86; FAI without AAI: n = 43). Ankle function was assessed by the American Orthopedic Foot and Ankle Society (AOFAS) and the Meislin criteria at 3 months, 1 year, and final follow-up. In the FAI + AAI group, AOFAS scores increased from 52.6 ± 7.2 to 78.6 ± 8.2, 84.2 ± 6.4, and 83.6 ± 11.3 at 3 months, 1 year, and last follow-up, respectively (p < .001). In the FAI without AAI group, AOFAS scores increased from 64.3 ± 10.5 to 85.2 ± 8.6, 91.4 ± 7.9, and 90.2 ± 9.8 at 3 months, 1 year, and last follow-up, respectively (p < .001; all p < .05 for differences between the 2 groups at each time point). The 2 groups showed similar scores based on the Meislin criteria (p = .38). Hypertrophic distal fascicle of the anteroinferior tibiofibular ligament showed lower AOFAS scores (all p < .05). Patients with FAI with or without AAI had improved outcomes with arthroscopic synovectomy combined with the modified Broström procedure; however, patients with combined FAI and AAI showed a relatively poorer outcome in comparison with those suffering from FAI alone, probably because of hypertrophic distal fascicle of the anteroinferior tibiofibular ligament.

Arthrodesis for Treatment of Intra-Articular Synovial Cysts of the Hallux Interphalangeal Joint.

Synovial cysts are benign tissue masses that develop near joints and tendons as a result of fluid leakage. They can be difficult to eradicate, and adjacent tendon and joint surfaces can complicate their treatment. We retrospectively analyzed the data from 4 consecutive patients who had undergone hallux interphalangeal fusion from January 2009 to December 2010. Of the 4 patients, 3 were male and 1 was female, with a mean age of 55 ± 22 (range 26 to 79) years. These 4 patients had developed painful interphalangeal arthritis with radiographic cystic changes of 1 to 4 years' duration. All patients were treated at a single facility, with surgical fixation of the joint performed by insertion of a single 4.3-mm headless lag screw across the interphalangeal joint. A final postoperative follow-up examination was performed at 22 ± 7 (range 14 to 30) months postoperatively. The mean American Orthopaedic Foot and Ankle Society hallux functional scores increased significantly from 70.8 ± 6.1 preoperatively to 90.5 ± 5.2 postoperatively (p < .01). No complications were observed, and complete interphalangeal joint fusion was observed at a mean of 9.2 ± 1.2 weeks. In conclusion, these preliminary data suggest that arthrodesis is an alternative effective treatment of symptomatic synovial cyst formation localized to the hallux interphalangeal joint.

Comparison of Four Methods for Percutaneous Achilles Tendon Lengthening: A Cadaveric Study.

Percutaneous Achilles tendon lengthening can result in Achilles tendon rupture. This complication has been controversially linked to torsion effects in the Achilles tendon. Routine percutaneous triple-hemisection techniques (group A), rotary triple-hemisection (group B), distal double-hemisection (group C), and proximal double-hemisection (group D) were compared in cadaveric specimens to provide insights into the mechanism of uneven incision lengthening and inadvertent Achilles tendon rupture. The degree of Achilles tendon torsion on various planes was measured in 20 lower limb pairs from fresh cadavers. The increase in postoperative maximum ankle joint dorsiflexion degree and the length of the lengthened Achilles tendon were greater in group B (p < .05) and group C (p < .05) compared with the routine percutaneous triple-hemisection technique (group A). The width of the tensile gap of the distal incision was significantly greater in group B (p < .05) and group C (p < .05) compared with that in group A. Rotary triple-hemisection was shown to eliminate the effect of Achilles tendon torsion on percutaneous Achilles tendon lengthening. Because proximal double-hemisection is performed away from the distal Achilles tendon where the fibers rotate sharply, the technique results in more even extension of the incisions and achieves a greater increase in the maximum degree of ankle joint dorsiflexion. Uneven incision lengthening was observed with the routine percutaneous triple-hemisection and distal double-hemisection techniques. Achilles tendon torsion affected the surgical outcomes. Rotary triple-hemisection and proximal double-hemisection techniques resulted in more even extension of the incisions and achieved a greater increase in the degree of maximum ankle joint dorsiflexion.

Lateral Sesamoid Position Relative to the Second Metatarsal in Feet With and Without Hallux Valgus: A Prospective Study.

We sought to determine whether hallux valgus displaces the sesamoid bones laterally away from a stationary first metatarsal or whether the first metatarsal head is displaced medially from the stationary sesamoids, which remain in position relative to the rest of the forefoot. We reviewed weightbearing radiographs in the dorsal plantar view of 128 consecutive patients (149 feet) seen over 2 months in 2014. Of these, 82 feet (55%) had a hallux valgus angle of >15° (hallux valgus group) and 67 feet (45%) had an angle of no more than 15° (control group). We measured the absolute distances from the center of the lateral sesamoid and the first metatarsal head to the long axis of the second metatarsal. Next, the relative distances, defined as the ratio of these 2 absolute distances to the length of the second metatarsal, were calculated to adjust for foot size. Both the absolute and the relative distances from the center of the first metatarsal head to the second metatarsal differed significantly between the 2 groups and correlated positively with the hallux valgus angle and first intermetatarsal angle. However, neither the absolute nor the relative distance to the lateral sesamoid bone differed significantly between the groups, nor did they correlate with either of the 2 angles. Thus, despite medial shifting of the first metatarsal in hallux valgus, the lateral sesamoid retains its relationship to the second metatarsal in transverse plane. Its apparent lateral movement is a radiographic misinterpretation. Awareness of this misinterpretation should improve the success of corrective surgery.

Osteochondroma of the Talar Neck: A Case Report and Literature Review.

Osteochondroma occurs most frequently in the long bones such as the proximal humerus, tibia, and distal femur. It is rare for it to originate in the talar neck. In the present case report, we describe a case of osteochondroma arising from the talar neck. Furthermore, a review of the published studies of talar osteochondroma was performed to obtain a better understanding of the symptoms, diagnosis, and treatment of this unusual entity.

In vivo three-dimensional analysis of hindfoot kinematics in stage II PTTD flatfoot.

BACKGROUND: This study aims to evaluate the rotation and translation of each joint in the hindfoot and compare the differences in healthy foot with that in stage II PTTD flatfoot by analyzing the reconstructive three-dimensional (3D) computed tomography (CT) image data during several extreme positions. METHODS: CT scans of 20 healthy feet and 20 feet with stage II PTTD flatfoot were taken in maximal positions of plantarflexion, dorsiflexion, inversion, eversion, external rotation and internal rotation conditions. The images of the hindfoot bones were reconstructed into 3D models. The "twice registration" method was used to calculate the spatial changes of the talus relative to the calcaneus in the talocalcaneal joint, the navicular relative to the talus in talonavicular joint, and the cuboid relative to the calcaneus in the calcaneocuboid joint. RESULTS: Compared with normal participants, with the calcaneus relative to the talus, participants with stage II PTTD flatfoot presented more dorsiflexion (p < 0.05), adduction (p < 0.05), and eversion (p < 0.05) in rotation, and more anterior (p < 0.05) and distal translation (p < 0.05) from maximal plantarflexion to maximal dorsiflexion; more dorsiflexion (p < 0.05), eversion (p < 0.05), and abduction (p < 0.05) in rotation and more lateral translation (p < 0.05) from maximal inversion to maximal eversion; and a greater degree of adduction (p < 0.05) in rotation, and more lateral (p < 0.05) and posterior translation (p < 0.05) from maximal internal rotation to maximal external rotation condition. For navicular relative to the talus, they demonstrated more eversion (p < 0.05) and adduction (p < 0.05) in rotation, and more lateral (p < 0.05), anterior (p < 0.05), and distal translation (p < 0.05) from maximal plantarflexion to maximal dorsiflexion; more eversion (p < 0.05) and adduction (p < 0.05) in rotation, and more lateral (p < 0.05) and proximal (p < 0.05) translation from maximal inversion to maximal eversion; more eversion (p < 0.05) and abduction (p < 0.05) in rotation and more lateral (p < 0.05) translation from maximal internal to maximal external rotation condition. The cuboid position relative to the calcaneus in the calcaneocuboid joint did not change significantly in rotation and translation in different positions (p > 0.05). CONCLUSIONS: As previous studies shown, regarding both of the cadaveric foot and the live foot, hindfoot joint instability occurred in patients with stage II PTTD flatfoot.

Comparison of wedge resection (Winograd procedure) and wedge resection plus complete nail plate avulsion in the treatment of ingrown toenails.

The present retrospective study compared the efficacy of wedge resection (Winograd procedure) and wedge resection plus complete nail plate avulsion for the treatment of ingrown toenails (onychocryptosis). Two surgical methods were performed in 95 patients with a stage 2 or 3 ingrown toenail. Each patient was examined weekly until healing and then at 1, 6, and 12 months of follow-up. The outcomes measured were surgical duration, healing time, recurrence rate, the incidence of postoperative infection, and cosmetic appearance after surgery. Of the 95 patients (115 ingrown toenails) included in the present study, 39 (41.1%) underwent wedge resection (Winograd procedure) and 56 (59%), wedge resection plus complete nail plate avulsion. The mean surgical duration for wedge resection (Winograd procedure) and wedge resection plus complete nail plate avulsion was 14.9 ± 2.4 minutes and 15.1 ± 3.2 minutes, respectively (p = .73). The corresponding healing times were 2.8 ± 1.2 weeks and 2.7 ± 1.3 weeks (p = .70). Recurrence developed in 3 (3.2%) patients after wedge resection (Winograd procedure) and in 4 (4.2%) after wedge resection plus complete nail plate avulsion. In addition, postoperative infection occurred in 3 (3.2%) patients after wedge resection (Winograd procedure) and 2 (2.1%) after wedge resection plus complete nail plate avulsion. Both of the surgical procedures were practical and appropriate for the treatment of ingrown toenails, being simple and associated with low morbidity and a high success rate. However, cosmetically, wedge resection (Winograd procedure) would be the better choice because the nail plate remains intact.

Anatomy of the sural nerve with an emphasis on the incision for medial displacement calcaneal osteotomy.

An inappropriately positioned skin incision for medial displacement calcaneal osteotomy can put the sural nerve at risk; however, unanimous agreement has not been reached about the optimal strategy for making this incision. In the present cadaveric study, 20 cadaveric specimens were dissected to describe the anatomic course of the sural nerve within the operative area and to provide a more practical reference for surgeons to make a safe incision. The following points were used in the analyses: point A, the tip of the lateral malleolus; point B, the inferior margin of the calcaneus on the plumb line through point A; point C, the posteroinferior margin of the calcaneus; and point D, the lateral border of the Achilles tendon on the same level (collinear) with point A. With careful dissection, the distances of the sural nerve to points A and B in the vertical direction (lines D1 and D2, respectively), to points A and C in the diagonal direction (lines D3 and D4, respectively), and to points A and D in the horizontal direction (lines D5 and D6, respectively) were measured. The landmarks were identified and the distances measured by 3 independent researchers. The median ratio of D1 to D1+D2, D3 to D3+D4, and D5 to D5+D6 was 0.36 (range 0.20 to 0.47), 0.26 (range 0.19 to 0.32), and 0.43 (range 0.34 to 0.52), respectively. Accordingly, we believe it is relatively safe to make an oblique incision that runs through the point that is no less than one third of the distance from the tip of the lateral malleolus to the posteroinferior margin of the calcaneus.

Accessory navicular bone incidence in Chinese patients: a retrospective analysis of X-rays following trauma or progressive pain onset.

BACKGROUND: Optimal treatment of symptomatic accessory navicular bones, generally asymptomatic 'extra' ossicles in the front interior ankle, remains debated. OBJECTIVE: Incidence and type of accessory navicular bones in Chinese patients were examined as a basis for improving diagnostic and treatment standards. METHODS: Accessory navicular bones were retrospectively examined in 1,625 (790 men and 835 women) patients with trauma-induced or progressive symptomatic ankle pain grouped by gender and age from August 2011 to May 2012. Anterior-posterior/oblique X-ray images; presence; type; affected side; modified Coughlin's classification types 1, 2A, 2B, and 3; and subgroups a-c were recorded. RESULTS: Accessory navicular bones were found in 329 (20.2%) patients (143 men and 186 women; mean age, 47.24 ± 18.34, ranging 14-96 years). Patients aged 51-60 exhibited most accessory navicular bones (29.7%), with risk slightly higher in women and generally increasing from minimal 10.9% at ages 11-20 to age 51 and thereafter declining to 0.4% by age 90. The incidence was 41.6% for Type 1 (Type 1a: 9.1%, Type 1b: 15.5%, and Type 1c: 19.4%), 36.8% for Type 2 (Type 2Aa: 2.1%, Type 2Ab: 13.7%, Type 2Ac: 5.1%, Type 2Ba: 2.1%, 2Bb: 2.1%, and 2Bc: 11.6%), and 21.6% for Type 3 (Type 3a: 4.5%, Type 3b: 14%, and Type 3c: 3.0%). CONCLUSIONS: Approximately one-fifth (20.3%) of ankle pain patients exhibited accessory navicular bones, with Type 2 most common and middle-aged patients most commonly affected. Thus, accessory navicular bones may be less rare than previously thought, underlying treatable symptomatic conditions of foot pain and deformity.

A novel 9-region systematic assessment tool for separated ossicle at the fibular tip effects on lateral ankle ligament complex integrity: a cadaveric study.

PURPOSE: Fibular tip ossicle separation can cause ligament injury leading to chronic lateral ankle instability. A cadaveric study was conducted to preliminarily assess the effects of fibular tip separated ossicle location and size on lateral ankle ligament complex integrity. METHODS: X-ray examinations and dissection of the anterior talofibular and calcaneofibular ligaments were conducted in ten radiographically confirmed normal below-knee cadaveric specimens extracted from donated fresh cadavers. Ossicle and bone fragment location and size were recorded, and distal fibula, articular surface, and adjacent ligament effects were determined by a novel 9-region matrix. RESULTS: Ligament risk varied by region. Anterior talofibular ligament width, perpendicular distance to fibular tip, sagittal width of distal fibula, and coronal width of distal fibula at attachment were 7.45 ± 0.22, 11.75 ± 1.03, 20.56 ± 1.54, and 8.68 ± 0.12 mm, respectively. Sagittal distal fibula and calcaneofibular ligament maximum widths at fibular attachment articular surfaces were 16.81 ± 0.96 and 3.50 ± 0.44 mm, respectively. Anterior talofibular to calcaneofibular ligament distance was 2.35 ± 0.14 mm. Separated ossicles >10 mm in regions 1-3 affected anterior talofibular ligaments, calcaneofibular ligaments, and fibular ankle joints; while those in regions 4, 8, and 7 or 9 affected anterior talofibular or calcaneofibular ligaments or were without impact. CONCLUSIONS: At the fibular tip, separated ossicles sized >10 mm impact collateral ligaments and articular surfaces, while those 5-10 and <5 mm impact anterior talofibular or calcaneofibular ligaments, potentially impairing the lateral ankle ligament complex. Thus, systematic matric-based assessment of ossicle size and location can potentially improve and standardize ankle fracture care.

Chinese consumers' psychology and behavior of the foods with nutrition claims based on AISAS model.

Objective: We analyzed the impact of nutrition claims on Chinese consumer psychology and behavior process based on the theoretical framework of AISAS (Attention-Interest-Search-Action-Share) model. Design: To adopt questionnaires to collect gender, age, income and other basic information of adult residents and a 5-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree) to collect data on residents' attention to nutrition claims, interest in nutrition claims, search on nutrition claim information, purchasing behavior on food with nutrition claims, sharing information on food with nutrition claims. Then to study the relationship between the basic situation of residents and their attention, interest, search, food purchase behavior and sharing of nutrition claims by using exploratory factor analysis, reliability and validity test, structural equation modeling estimation and hypothesis testing. Participants: Chinese adults. Setting: Multi-stage stratified random sampling method was used to collect the valid online questionnaire of 630 Chinese adults from Central, North, East, South, Northwest, Southwest, and Northeast China. Results: Younger adults and those with higher household incomes exhibited heightened attention to nutrition claims. Furthermore, consumers' attention to nutrition claims could be transformed into food information sharing through interest, information search, and food purchase. Consumers' interest in food with nutrition claims could be transformed directly into food purchase. Consumers' search for related information could be directly transformed into food information sharing. Conclusion: Chinese consumers' age and household income could be included in the AISAS model for the foods with nutrition claims, and the consumers' action and share could transform from their interest and search.

Consumer Preferences and Willingness to Pay for High-Quality Vegetable Oils: A Cross-Sectional Analysis of Chinese Residents.

The consumption of edible vegetable oil is an important source of essential fatty acids and vitamin E for the human body. Guiding residents to consume scientifically and reasonably control the intake of edible oils is an important part of promoting the construction of a healthy China. Currently, Chinese residents have an insufficient understanding of the scientific consumption of edible oils, leading to an intake exceeding the dietary recommendations, resulting in excessive fat intake and increasing the risk of chronic diseases such as obesity and cardiovascular diseases. Based on the Theory of Planned Behavior (TPB) and using Structural Equation Modeling (SEM), this study analyzed the cognitive preferences and willingness to pay a premium for edible vegetable oils among urban consumers in China. The survey included 1098 Chinese urban consumers of vegetable oils. The research found that attitudes, health value, monetary value, and environmental endowment of urban residents are the main predicting factors of the intention to purchase high-quality vegetable oils. This study confirms the applicability of the Theory of Planned Behavior in the consumption of high-quality vegetable oils and provides theoretical contributions and insights for Chinese enterprises and policymakers in formulating marketing strategies for vegetable oils.