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Wang B.,Shanghai Institute of Traumatology and Orthopaedics | Wang B.,Shanghai JiaoTong University | Wang B.,University of Utah | Saltzman C.L.,University of Utah | And 2 more authors.
Clinical Orthopaedics and Related Research

Questions/purposes: In this study we sought to (1) compare ankle and hindfoot alignment of our study cohort with end-stage ankle arthritis with that of a control group; (2) explore the frequency of compensated malalignment between the tibiotalar and subtalar joints in our study cohort; and (3) assess the intraobserver and interobserver reliability of classification methods of hindfoot alignment used in this study.Background: Patients with ankle arthritis often present with concomitant hindfoot deformity, which may involve the tibiotalar and subtalar joints. However, the possible compensatory mechanisms of these two mechanically linked joints are not well known.Methods: Between March 2006 and September 2013, we performed 419 ankle arthrodesis and ankle replacements (380 patients). In this study, we evaluated radiographs for 233 (56%) ankles (226 patients) which met the following inclusion criteria: (1) no prior subtalar arthrodesis; (2) no previously failed total ankle replacement or ankle arthrodesis; (3) with complete conventional radiographs (all three ankle views were required: mortise, lateral, and hindfoot alignment view). Ankle and hindfoot alignment was assessed by measurement of the medial distal tibial angle, tibial talar surface angle, talar tilting angle, tibiocalcaneal axis angle, and moment arm of calcaneus. The obtained values were compared with those observed in the control group of 60 ankles from 60 people. Only those without obvious degenerative changes of the tibiotalar and subtalar joints and without previous surgeries of the ankle or hindfoot were included in the control group. Demographic data for the patients with arthritis and the control group were comparable (sex, p = 0.321; age, p = 0.087). The frequency of compensated malalignment between the tibiotalar and subtalar joints, defined as tibiocalcaneal angle or moment arm of the calcaneus being greater or smaller than the same 95% CI statistical cutoffs from the control group, was tallied. All ankle radiographs were independently measured by two observers to determine the interobserver reliability. One of the observers evaluated all images twice to determine the intraobserver reliability.Results: There were differences in medial distal tibial surface angle (86.6° ± 7.3° [95% CI, 66.3°–123.7°) versus 89.1° ± 2.9° [95% CI, 83.0°–96.3°], p < 0.001), tibiotalar surface angle (84.9° ± 14.4° [95% CI, 45.3°–122.7°] versus 89.1° ± 2.9° [95% CI, 83.0°–96.3°], p < 0.001), talar tilting angle (−1.7° ± 12.5° [95% CI, −41.3°–30.3°) versus 0.0° ± 0.0° [95% CI, 0.0°–0.0°], p = 0.003), and tibiocalcaneal axis angle (−7.2° ± 13.1° [95% CI, −57°–33°) versus −2.7° ± 5.2° [95% CI, −13.3°–9.0°], p < 0.001) between patients with ankle arthritis and the control group. Using the classification system based on the tibiocalcaneal angle, there were 62 (53%) and 22 (39%) compensated ankles in the varus and valgus groups, respectively. Using the classification system based on the moment arm of the calcaneus, there were 68 (58%) and 20 (35%) compensated ankles in the varus and valgus groups, respectively. For all conditions or methods of measurement, patients with no or mild degenerative change of the subtalar joint have a greater likelihood of compensating coronal plane deformity of the ankle with arthritis (p < 0.001–p = 0.032). The interobserver and intraobserver reliability for all radiographic measurements was good to excellent (the correlation coefficients range from 0.820 to 0.943).Conclusions: Substantial ankle malalignment, mostly varus deformity, is common in ankles with end-stage osteoarthritis. The subtalar joint often compensates for the malaligned ankle in static weightbearing.Level of Evidence: Level III, diagnostic study. © 2014, The Association of Bone and Joint Surgeons®. Source

Wang B.,Shanghai Institute of Traumatology and Orthopaedics | Wang B.,Shanghai JiaoTong University | Xu X.-Y.,Shanghai JiaoTong University
Foot and Ankle International

Background: Multiple techniques have been described for reconstruction of the lateral ligaments of the ankle. Most require extensive exposure and dissection, which may lead to potential problems with wound healing, higher risk of nerve injury, fibrosis, and stiffness. This study reports on the results of a minimally invasive method to reconstruct the ligaments using a semitendinosus tendon autograft and achieve a stable ankle while avoiding these problems. Materials and Methods: From September 2006 to May 2010, 25 patients (14 males, 11 females) with chronic ankle instability underwent lateral ligament reconstruction. The average age was 32.4 (range, 17 to 62) years old. A semitendinosus autograft was harvested through 2 small knee incisions. For the ankle reconstruction, 4 small incisions of 5 mm each were made at the medial and lateral side of the fibular tip, the talar neck, and the middle of the calcaneus. Anatomical reconstruction of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) was then performed through these small incisions. The mean final follow-up was 32.3 (range, 12 to 56) months. AOFAS questionnaires were used to measure clinical outcomes and donor site morbidity and patient satisfaction are also reported. Preoperative and postoperative stress tests were performed and radiographic parameters were measured. Results: The mean AOFAS score increased on average from 71.1 to 95.1 (P <.001). Tw o patients reported residual instability on uneven ground. No patient reported weakness or disability from the donor site. The satisfaction level was excellent in 20 patients and good in 5 patients. Significant improvement in stress radiographic parameters was noted for the talar tilt angle, with reduction from a mean of 14.0 to 3.8 degrees (P <.001); anterior talar displacement reduced from a mean of 12.3 to 4.6 mm (P <.001). Conclusion: Reconstruction of the lateral ankle ligaments using a semitendinosus tendon autograft and a minimally invasive approach can achieve a stable ankle while avoiding extensive exposure and risk of nerve injury. Level of Evidence: Level I V, retrospective case series. © The Author(s) 2013. Source

Chen J.,Tongji University | Wang L.,Tongji University | Chen B.,Shanghai Institute of Traumatology and Orthopaedics | Yan S.,Tongji University
Proceedings of the 12th International Symposium on Structural Engineering, ISSE 2012

The load curves of 100 test subjects jumping at five different rates have been measured using three-dimensional motion capture technique in conjunction with fixed force plates. The variation ranges and statistical properties of the three key load parameters: jumping frequency, impact factor and contact ratio are investigated based on the test results. A modified half-sine-power load model is proposed to simulate the jumping load, in which the jumping frequency and contact ratio are independent parameters whilst the impact factor needs to be determined by frequency and contact ratio. The applicability and feasibility of the proposed model has been validated by comparison of the simulated load curve with measured curve and by comparison of the acceleration response of single degree of freedom system subjected to the simulated and measured jumping load. The results prove that the suggested model can be adopted for vibration serviceability assessment of large span structures. Source

Fan Y.,Shanghai JiaoTong University | Wang J.,Shanghai Institute of Traumatology and Orthopaedics | Wei L.,Shanghai Institute of Traumatology and Orthopaedics | He B.,Shanghai JiaoTong University | And 2 more authors.
International Journal of Cardiology

Background/objectives: Major bleeding in patients with acute coronary syndrome (ACS) increases the risk of recurrent ACS and mortality. However, the mechanism involved is poorly understood. Bleeding induces iron deficiency. Iron deficiency enhances inflammation in other diseases. Thus, in this paper, the particular effect of iron deficiency on atherosclerotic plaque destabilization, especially the pro-inflammatory role of iron deficiency in atheroma and the mechanism involved were investigated. Methods: Extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase-9 (MMP-9) mRNA levels were investigated by RT-PCR. EMMPRIN and MMP-9 protein levels, nuclear factor (NF)-κB-p65 protein levels, peroxisome proliferator-activated receptor γ (PPARγ) protein levels, and mitogen-activated protein kinase (MAPK) phosphorylation were determined by western blotting. MMP-9 enzymatic activity was assayed by gelatin zymography. Results: Iron deficiency enhanced EMMPRIN, MMP-9 production, and MMP-9 enzymatic activity in THP-1 derived macrophages and foam cells. Iron deficiency elicited the activation of NF-κB and p38 MAPK. By using the p38 inhibitor and NF-κB inhibitor, the study established that EMMPRIN and MMP-9 inductions by iron deficiency required the consecutive upstream activation of p38 MAPK and NF-κB. This pro-inflammatory action was not prevented by PPARγ agonist. Meanwhile, iron deficiency did not modulate PPARγ expression. Retinoid X receptor agonist suppressed the effects of iron deficiency on EMMPRIN, MMP-9, and NF-κB, but not on MAPK activation. Conclusions: Iron deficiency enhances atheroma inflammation through p38 MAPK-NF-κB-EMMPRIN/MMP-9 pathway. Our findings provide a potential mechanism for the association of major bleeding with recurrent ACS and mortality in patients with ACS. © 2010 Elsevier Ireland Ltd. All rights reserved. Source

Zhang W.,Shanghai JiaoTong University | Zhang W.,Shanghai Institute of Traumatology and Orthopaedics | Pan W.,Xian Physical Education University | Zhang M.,Xian Physical Education University | And 3 more authors.
Biotechnology Letters

Fibrin glue combined with bone morphogenetic protein (BMP) and recombined bone xenograft (RBX), were compared to evaluate their effect on the tendon-bone interface healing. The interface of fibrin glue-BMP developed new cartilage but the new bone was thinner whereas the interface of RBX had large areas of chondrocyte-like cells, bone formation and an immature neo-enthesis structure. At 12 weeks, bone mineral density of RBX group (152 ± 52 cm3) and fibrin glue-BMP group (109 ± 13 cm3) was calculated by micro-computed tomography. The ultimate load of fibrin glue-BMP group (60 ± 18 and 51 ± 14 N) and RBX group (65 ± 21 and 57 ± 15 N) was shown by biomechanics at 6 and 12 weeks. RBX thus has an advantage on accelerating tendon-bone interface healing. © 2010 Springer Science+Business Media B.V. Source

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