Highly precise thickness measurement of multilayer films based on the cross-correlation algorithm using a widely tunable MG-Y laser.

Inspired by the demodulation algorithm of Fabry-Perot composite sensors in the field of fiber-optic sensing, this paper proposes a method based on a widely tunable modulated grating Y-branch (MG-Y) laser combined with the cross-correlation algorithm to achieve a highly precise measurement of the optical thickness of each layer of a multilayer optical sample. A sample consisting of a double glass stack was selected, and the interference spectrum of the stacked sample was acquired using a widely tunable MG-Y laser. A fast Fourier transform (FFT) algorithm combined with a finite impulse response (FIR) bandpass filter was utilized to separate the different frequency components of the multilayer optical sample. The normalized spectra of each layer were reconstructed using the Hilbert transform. Subsequently, a cross-correlation algorithm was employed to process the normalized spectrum and determine the optical thickness of each layer with high precision. The samples were measured at predetermined locations, with 150 consecutive measurements performed to assess the repetition of the thickness. The standard deviation of these measurements was found to be lower than 1.5 nm. The results show that the cross-correlation algorithm is advantageous in the optical thickness measurement of multilayer films.

[Treatment of open fracture bone defect of distal femur with antibiotic cement column and bone graft].

OBJECTIVE: To investigate the efficacy of antibiotic cement column combined with iliac bone graft in the treatment of open fracture with bone defect of distal femur. METHODS: From October 2014 to March 2021, 16 patients of open fracture bone defect of distal femur were treated with antibiotic bone cement column and iliac bone graft, including 12 males and 4 females. The age ranged from 28 to 68 years old. There were 11 cases of traffic accident injury, 5 cases of falling injury, 3 cases as Gustilo type Ⅰ, 5 cases as type Ⅱ and 8 cases as type ⅢA. AO classification was used:9 cases of C2 type and 7 cases of C3 type. The time from injury to final bone grafting ranged from 4 to 119 days. The length of bone defect ranged from 2 to10 cm. Fractures healing time, complications and knee function Merchan score were recorded. RESULTS: All the 16 patients were followed up from 9 to 29 months. The incisions of 16 patients healed in one stage without postoperative infection, plate fracture, limb shortening and valgus and varus deformity. The healing time randed from 4 to 10 months . Knee joint function according to the Merchant scoring standard, showed that 8 cases were excellent, 4 cases were good, 3 cases were fair, and 1 case was poor. CONCLUSION: The use of antibiotic bone cement column combined with iliac bone graft in the treatment of open and complex bone defects of distal femur is an effective surgical method to prevent infection, assist fracture reduction, increase fixation strength and significantly reduce the amount of bone grafting.

Spatiotemporal drivers of urban water pollution: Assessment of 102 cities across the Yangtze River Basin.

Effective management of large basins necessitates pinpointing the spatial and temporal drivers of primary index exceedances and urban risk factors, offering crucial insights for basin administrators. Yet, comprehensive examinations of multiple pollutants within the Yangtze River Basin remain scarce. Here we introduce a pollution inventory for urban clusters surrounding the Yangtze River Basin, analyzing water quality data from 102 cities during 2018-2019. We assessed the exceedance rates for six pivotal indicators: dissolved oxygen (DO), ammonia nitrogen (NH3-N), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total phosphorus (TP), and the permanganate index (CODMn) for each city. Employing random forest regression and SHapley Additive exPlanations (SHAP) analyses, we identified the spatiotemporal factors influencing these key indicators. Our results highlight agricultural activities as the primary contributors to the exceedance of all six indicators, thus pinpointing them as the leading pollution source in the basin. Additionally, forest coverage, livestock farming, chemical and pharmaceutical sectors, along with meteorological elements like precipitation and temperature, significantly impacted various indicators' exceedances. Furthermore, we delineate five core urban risk components through principal component analysis, which are (1) anthropogenic and industrial activities, (2) agricultural practices and forest extent, (3) climatic variables, (4) livestock rearing, and (5) principal polluting sectors. The cities were subsequently evaluated and categorized based on these risk components, incorporating policy interventions and administrative performance within each region. The comprehensive analysis advocates for a customized strategy in addressing the discerned risk factors, especially for cities presenting elevated risk levels.

Comparison of Locking Plate Alone and Locking Plate Combined with 3D Printed Polymethylmethacrylate Augmentation in Treating Proximal Humerus Fractures in the Elderly.

BACKGROUND: Locking plates are widely used in open reduction internal fixation (ORIF) for proximal humeral fracture (PHF). However, the optimal surgical treatment of unstable, displaced PHF in elderly patients remains controversial. This study aimed to compare the radiological and clinical outcomes of surgical treatment of PHF in the elderly with locking plate (LP) alone and locking plate combined with 3D printed polymethylmethacrylate (PMMA) prosthesis augmentation (LP-PA). METHODS: From May 2015 to April 2021, a total of 97 patients aged ≥ 60 years with acute unstable PHF who underwent osteosynthesis with either LP (46 patients) or LP-PA (51 patients) were retrospectively analyzed. For the LP-PA group, a customized proximal humeral prosthesis made of PMMA cement was intra-operatively fabricated by a three-dimensional (3D) printed prototype mold for the humeral medial support. Radiological outcomes were analyzed by measuring the value of neck-shaft angle (NSA) and humeral head height (HHH). The clinical outcomes were evaluated using Constant-Murley Score (CMS), Disabilities of the Arm Shoulder and Hand (DASH) score, American Shoulder and Elbow Surgeons (ASES) score, and the shoulder range of motion (ROM). Pain was measured using a visual analogue scale (VAS). RESULTS: At the one-year follow-up, all fractures healed radiologically and clinically. The mean changes of NSA and HHH over the follow-up period were markedly smaller in the LP-PA group (3.8 ± 0.9° and 1.7 ± 0.3 mm) than those in the LP group (9.7 ± 2.1° and 3.2 ± 0.6 mm, both P < 0.0001). The LP-PA group also presented lower DASH score (17.1 ± 3.6), higher ASES score (89.5 ± 11.2) and better ROM in forward elevation (142 ± 26°) and external rotation (59 ± 11°) compared to the LP group (28.9 ± 4.8 for DASH score, P < 0.0001; 82.3 ± 9.0 for ASES score, P < 0.001; 129 ± 21° for forward elevation, P = 0.008; and 52 ± 9° for external rotation, P = 0.001). There was no significant difference in overall complication rate between the two groups, although the complication rate of screw perforation was higher in the LP-PA group (P = 0.172). CONCLUSIONS: For PHF in elderly patients, the combination of LP fixation and PMMA prosthesis augmentation effectively improved humeral head support and reduction maintenance, providing satisfactory outcomes both radiologically and clinically. This technique also reduced the incidence of screw perforation associated with plate fixation alone, making it a reasonable option to ensure satisfactory clinical outcomes.

Management of segmental defects post open distal femur fracture using a titanium cage combined with the Masquelet technique A single-centre report of 23 cases.

INTRODUCTION: The segmental bone defects post open distal femur fracture presents a reconstructive challenge, which often requires extreme solutions. The present study reviewed a new treatment strategy which used a cylindrical titanium mesh cage as an adjunct to the Masquelet technique. METHODS: We retrospectively reviewed a consecutive series of 23 patients treated for segmental bone defects post open distal femur fracture using a titanium mesh cage combined with the Masquelet technique under a 2-staged protocol in our institution from 2017 to 2021. The study group consisted of 13 men and 10 women with an average age of 44.1 years. The surgical debridement was performed with antibiotic polymethylmethacrylate (PMMA) cement spacer implanted into the bone defect combined with cement-wrapped plate stabilization, or antibiotic beads with vacuum sealing drainage (VSD) to cover the wound. The second stage of the Masquelet technique for bone defect repair began at least 4-6 weeks after the first stage, once all signs of possible infection were eliminated. After the cement spacer was removed, the definitive reconstruction was completed with exchange to a cylindrical titanium mesh cage filled with cancellous autograft within the induced membrane. The bone defect with cage was stabilized with a distal femoral Less Invasive Stabilization System (LISS). The radiological and clinical records of the enrolled patients were retrospectively analyzed. RESULTS: The mean follow-up was 38.6 months. The average number of operations before the second stage was 1.3. The mean interval between the two stages was 12.7 weeks. The average length of the defect measured 8.3 cm (ranging from 6.1 to 12.4 cm). All the defects filled with autograft within the cage achieved bony union, with a mean healing time of 8.4 months. At the latest follow-up, the mean knee extension measured 6.2° (ranging from 0° to 20°), and the mean flexion measured 101.8° (ranging from 60° to 120°). Complications included two instances of superficial stitch abscess, which eventually healed. CONCLUSIONS: The use of a titanium cage implanted into an induced membrane in a 2-staged Masquelet protocol could achieve satisfactory clinical outcomes in cases of segmental defects following open distal femur fractures.

[The analysis of the therapeutic effect for 10 cases of type C extreme distal radial fracture in micro needle plate internal fixation].

OBJECTIVE: To analyze the clinical outcomes of mini-plate combined with wireforms in the treatment of Type C distal radial fractures with marginal articular fragments. METHODS: This retrospective study included a total of 10 cases, including 5 males and 5 females, with 6 cases involving the left side and 4 cases involving the right side, of Type C distal radial fractures with marginal articular fragments. The age of the patients ranged from 35 to 67 years old. All patients underwent surgical treatment utilizing mini-plate combined with wireforms for internal fixation. RESULTS: The follow-up period ranged from 6 to 18 months. Complete fracture healing was observed in all cases, with healing times ranging from 10 to 16 weeks. During the entire follow-up period, patients reported high levels of satisfaction with the treatment outcomes, and there were no incidences of incision infection, chronic wrist pain, or wrist traumatic arthritis. At the final follow-up assessment, the Mayo score for the wrist joint ranged from 85 to 95, with 7 cases rated as excellent and 3 cases as good. CONCLUSION: Mini-plate combined with wireforms proves to be an effective fixation method for Type C distal radial fractures with marginal articular fragments. The early initiation of wrist joint exercises, strong fixation, maintenance of proper reduction, minimal complications, and high rates of excellent and good outcomes demonstrate the reliability and efficacy of this treatment approach.

Treating Inferior Pole Fracture of Patella with Hand Plating System: First Clinical Results.

OBJECTIVE: Inferior pole fractures of patella are notorious fractures where it is difficult to obtain rigid internal fixation by conventional methods. The objective of the study was to introduce the Hand Plating System (HPS), which was a novel surgical technique for inferior pole fractures of patella, and to report the radiological and clinical outcomes following the application of the surgical technique. METHODS: The study was designed as a retrospective cohort study. Between July 2017 and December 2018, 30 patients who were diagnosed with inferior pole fracture of the patella without additional orthopaedic injuries were enrolled in this case series. After X-ray and 3D-CT examinations, all patients underwent open reduction and internal fixation by HPS with or without supplementary cannulated screw and lag screw stabilization. The bony union time, final range of motion (ROM), Bostman score, visual analog scale (VAS), and complications were measured as the clinical outcomes under a minimum of 12 months of follow-up. RESULTS: All of the operations went well with the mean operative time of 76.2 ± 15.3 min. Bony union achieved in all the cases at an average of 9.5 ± 1.4 weeks after surgery. There was no loss of reduction, fixative failure, or surgical implant removal during follow-up. The average range of motion 1 year postoperatively was 0°-123.3°. The mean Bostman Score at the last follow-up was 26.8 ± 2.1 with the satisfactory rate of 100%. The pain feeling during walking as measured by VAS averaged at 0.9 ± 1.3. No complications developed except for one case of poor incision healing, which healed eventually after surgical debridement. CONCLUSIONS: HPS was demonstrated as a secure fixation and as a kind of tension band for inferior pole fractures of the patella. Satisfactory recovery of knee function and low complication rate, including no need for hardware removal, could be expected.

Perioperative Protocol of Ankle Fracture and Distal Radius Fracture Based on Enhanced Recovery after Surgery Program: A Multicenter Prospective Clinical Controlled study.

Background: The enhanced recovery after surgery (ERAS) program is aimed to shorten patients' recovery process and improve clinical outcomes. This study aimed to compare the outcomes between the ERAS program and the traditional pathway among patients with ankle fracture and distal radius fracture. Methods: This is a multicenter prospective clinical controlled study consisting of 323 consecutive adults with ankle fracture from 12 centers and 323 consecutive adults with distal radial fracture from 13 centers scheduled for open reduction and internal fixation between January 2017 and December 2018. According to the perioperative protocol, patients were divided into two groups: the ERAS group and the traditional group. The primary outcome was the patients' satisfaction of the whole treatment on discharge and at 6 months postoperatively. The secondary outcomes include delapsed time between admission and surgery, length of hospital stay, postoperative complications, functional score, and the MOS item short form health survey-36. Results: Data describing 772 patients with ankle fracture and 658 patients with distal radius fracture were collected, of which 323 patients with ankle fracture and 323 patients with distal radial fracture were included for analysis. The patients in the ERAS group showed higher satisfaction levels on discharge and at 6 months postoperatively than in the traditional group (P < 0.001). In the subgroup analysis, patients with distal radial fracture in the ERAS group were more satisfied with the treatment (P=0.001). Furthermore, patients with ankle fracture had less time in bed (P < 0.001) and shorter hospital stay (P < 0.001) and patients with distal radial fracture received surgery quickly after being admitted into the ward in the ERAS group than in the traditional group (P=0.001). Conclusions: Perioperative protocol based on the ERAS program was associated with high satisfaction levels, less time in bed, and short hospital stay without increased complication rate and decreased functional outcomes.

Silk Fibroin/Hydroxyapatite Coating Improved Osseointegration of Porous Titanium Implants under Diabetic Conditions via Activation of the PI3K/Akt Signaling Pathway.

The application of three-dimensional printed porous titanium implants (TIs) is compromised in patients suffering from diabetes mellitus (DM), which disturbs the normal process of implant osseointegration, resulting in fixation failure. It was possibly because of reactive oxygen species (ROS) overproduction at the bone-implant interface. A silk fibroin-based hydroxyapatite (SF/HA) hybrid material emerged as a novel biological material for accelerating new bone formation. We proposed that the SF/HA hybrid coated titanium implant (SHT) could mitigate DM-mediated impaired osseointegration, which had never been reported previously. To test this assumption and further elucidate the mechanisms, primary rabbit osteoblasts were seeded on TIs or SHTs and cultured with normal serum, diabetic serum (DS), DS + N-acetyl-L-cysteine (NAC) (a potent ROS inhibitor), and DS + LY294002 (a specific PI3K/Akt inhibitor) for osteoblast behavior examinations. An animal study was performed on diabetic rabbits implanted with the two kinds of implants for osseointegration tests. DM-mediated ROS overproduction caused osteoblastic biological dysfunctions and apoptotic injury, associated with suppression of PI3K/Akt signaling in osteoblasts cultured on a TI substrate. Of note, the SHT substrate significantly suppressed ROS overproduction under diabetic conditions, improved osteoblast functional recovery including ameliorative osteoblast adhesion and morphology, improved cellular proliferation and differentiation, and abrogated apoptosis, which exhibited the same effect as NAC administration on the TI. The in vitro results were further corroborated in vivo by enhanced osteogenesis and osseointegration of SHTs in diabetic rabbits. Moreover, the aforesaid promotive effects afforded by the SF/HA coating were totally abolished with administration of LY294002 for blocking PI3K/Akt signaling. The above results collectively demonstrated that the SF/HA hybrid coating significantly ameliorated DM-mediated impaired osseointegration of the TI via reactivation of the ROS-mediated PI3K/Akt signaling pathway. The hybrid coating elicited a novel surface biofunctionalization strategy to attain favorable clinical performance of TI in diabetics.

Spectral analysis of Brillouin dynamic gratings in polarization-maintaining fibers.

Experiment observations show that the spectra of Brillouin dynamic gratings in polarization-maintaining fibers based on a polarization decoupled scheme are quite broad and usually have multiple peaks. In this paper, we measure the birefringence distribution along polarization-maintaining fibers with high spatial resolution using optical frequency-domain reflectometry. Based on birefringence measurements, both the simulation and experiment are carried out to determine the spectra of Brillouin dynamic gratings generated within the same polarization-maintaining fibers, indicating quantitatively that spectral broadening and irregularity are mainly due to phase mismatch caused by the non-uniformity of birefringence along polarization-maintaining fibers.

Treatment for transverse patella fractures with minimally invasive techniques (Review).

The transverse fracture pattern is the most common pattern among patellar fractures. Although open reduction with internal fixation using tension band wiring is the common method for treating the majority of transverse patellar fractures with displacement, this approach has distinct disadvantages, including damage to the blood supply and general post-operative complications. Therefore, minimally invasive techniques have been introduced to overcome these problems. In the present review, the advanced surgical procedures using Kirschner wires with cerclage, cannulated screw optioning of supplementary cerclage tension banding, external fixation and combined tension-band braided polyester with a suture button, as well as post-operative rehabilitation, were described in detail. To improve any malreduction due to poor control of the patellar articular surfaces, the utility of arthroscopically assisted techniques was also presented. The advantages and disadvantages of the above-mentioned techniques were also discussed. Minimally invasive techniques were demonstrated to achieve improved knee joint mobility, shorter hospitalization and more favorable outcomes. Such techniques decrease the risk of complications compared to conventional open reduction and fixation. Although specific problems associated with each technique still require to be resolved to reduce late complications, such as the onset of patella-femoral arthritis, minimally invasive techniques remain an alternative option for treating transverse patellar fractures.

Induced Membrane Technique for the Treatment of Infected Forearm Nonunion: A Retrospective Study.

PURPOSE: Infected forearm nonunion remains a challenge for the hand surgeon. Autologous bone grafting within an induced membrane following implantation of a cement spacer, also known as the Masquelet technique, is a procedure used for addressing segmental bone defects. This report summarized our experience using this technique to treat the infected forearm nonunion. METHODS: We retrospectively reviewed a series of 32 patients treated for infected forearm nonunion by the 2-stage Masquelet technique between 2009 and 2018. There was an infected nonunion of the ulna in 28 patients and an infected nonunion of the radius in 4 patients. All patients had undergone an average of 2.7 procedures before presenting at our institution. Treatment involved a staged procedure in which an antibiotic-impregnated cement spacer was implanted into the bone defect following debridement without internal fixation. It was left in place for 4-6 weeks, during which time a membrane formed around the cement spacer. In the second stage, the induced membrane was incised, and the cement spacer was removed. The defect was then filled with cancellous autograft with the addition of internal fixation. Postoperative radiographs were taken for the evaluation of bone healing. The functional results of the affected forearm were evaluated for motion loss of elbow or wrist and rotation loss of forearm. RESULTS: All nonunions healed without recurrent infection or loosening of internal fixation at the time of final follow-up. All the patients showed substantial functional improvement, with excellent results in 14 patients, satisfactory results in 13, and unsatisfactory results in 5. CONCLUSIONS: The induced membrane technique is an effective solution for infected forearm nonunion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Compressed-sensing fiber-optic white light interferometry.

In this Letter, we propose a dynamic fiber-optic white light interferometry (WLI) based on the compressed-sensing (CS) principle. The time-varying interference spectra of a Fabry-Perot cavity under vibration are considered as a two-dimensional (2D) signal with respect to both laser wavelength and time, which can be compressively sampled using a programmable semiconductor laser source during the measurement process. After CS reconstruction, the spectrum acquisition rate is equal to the random wavelength modulation rate, up to 10 MHz in this Letter, providing an attractive alternative to laser-based dynamic interferometry. Numerical simulations and nanometer-scale vibration experiments verify the effectiveness of the scheme.

Rhombic optical path difference bias white light interferometric fiber-optic gyroscope.

We present a novel, to the best of our knowledge, white light interferometric fiber-optic gyroscope (IFOG) scheme using a fiber-optic rhombic optical path difference (OPD) bias structure to interrogate with a sensing coil to realize rotation rate measurement without a phase modulator. The OPD bias structure composed of four (2×1) 3 dB single-mode fiber couplers was constructed to implement non-reciprocal OPD bias. White light interferometric demodulation was utilized to acquire the change in OPD due to the Sagnac-phase shift. Absolute linear output can be obtained. We produced the principle prototype of rhombic OPD bias white light IFOG without utilizing a phase modulator. An experimental demonstration of the IFOG prototype system achieves linear output with respect to the OPD difference in detecting rotation rate.

Promotion of osteointegration under diabetic conditions by a silk fibroin coating on 3D-printed porous titanium implants via a ROS-mediated NF-κB pathway.

Clinical evidence indicates the compromised application of titanium implants (TIs) in diabetics, associated with reactive oxygen species (ROS) overproduction at the bone-implant interface. Silk fibroin (SF) has displayed impressive biocompatibility in the application of biomedical material and optimal anti-diabetic effects in oriental medicine. We proposed that SF-coated titanium implants (STIs) could alleviate diabetes-induced compromised osteointegration, which has rarely been reported before. To confirm this hypothesis and explore the underlying mechanisms, rat osteoblasts cultured on 3-dimensional (3D) -printed titanium implants (TIs) and STIs were subjected to normal serum (NS), diabetic serum (DS), DS with N-acetyl-L-cysteine (a ROS inhibitor) or SN50 (an NF-κB inhibitor). Anin vivostudy was performed on diabetic sheep with TIs or STIs implanted into bone defects on thecrista iliaca. The results demonstrated that ROS overproduction induced by diabetes lead to osteoblast dysfunctions and cellular apoptosis on the TI substrate, associated with the activation of an NF-κB signaling pathway in osteoblasts. Importantly, the STI substrate significantly attenuated ROS production and NF-κBp65 phosphorylation, thereby ameliorating the osteoblast biological dysfunctions. These results were further confirmedin vivoby the improved osteointegration of the STIs, as evidenced by Micro-CT and histological examinations compared with those of TIs. These results demonstrated that the ROS-mediated NF-κB signaling pathway played a crucial role in diabetes-induced implant destabilization. Importantly, the SF coating, as a promising material for biomaterial-engineering, markedly improved the clinical treatment effect of TIs under diabetic conditions, possibly associated with the suppression of the NF-κB pathway.

Signal-to-noise ratio analysis of computational distributed fiber-optic sensing.

In this work, we analyze the signal-to-noise ratio of the computational distributed fiber-optic sensing technique via differential ghost imaging in the time domain using the illumination pattern of Walsh-Hadamard sequences instead of random sequences. When only the white Gaussian noise is considered in the detection, both the theoretical and experimental results show that the computational method requires twice more number of averages compared to the conventional time-domain method in order to achieve the same level of signal-to-noise ratio. Since the computational approach is focusing on stationary measurement, doubling the measurement time can normally be acceptable in practice, but it can reduce the sampling rate requirement significantly compared to the conventional method, offering great advantage to simplify the data acquisition design in the distributed fiber-optic sensing system.

Computational distributed fiber-optic sensing.

Ghost imaging allows image reconstruction by correlation measurements between a light beam that interacts with the object without spatially resolved detection and a spatially resolved light beam that never interacts with the object. The two light beams are copies of each other. Its computational version removes the requirement of a spatially resolved detector when the light intensity pattern is pre-known. Here, we exploit the temporal analogue of computational ghost imaging, and demonstrate a computational distributed fiber-optic sensing technique. Temporal images containing spatially distributed scattering information used for sensing purposes are retrieved through correlating the "integrated" backscattered light and the pre-known binary patterns. The sampling rate required for our technique is inversely proportional to the total time duration of a binary sequence, so that it can be significantly reduced compared to that of the traditional methods. Our experiments demonstrate a 3 orders of magnitude reduction in the sampling rate, offering great simplification and cost reduction in the distributed fiber-optic sensors.

Brillouin optical time-domain analysis via compressed sensing.

A compressed-sensing-technique-based Brillouin optical time-domain analysis is proposed. The Brillouin spectrum has a sparse representation in its discrete cosine transform domain, which can be successfully recovered from far fewer measurements with high probability through an orthogonal matching-pursuit algorithm. This work shows both empirically and experimentally that the amount of frequency acquisitions needed is only 30% of those required by a conventional distributed Brillouin fiber-optic sensing system with 1 MHz frequency increment in the acquisition process to obtain Brillouin spectra along an optical fiber; therefore, the number of acquisitions and the amount of data storage/transfer are greatly reduced. Moreover, the proposed method does not need any hardware modification in an existing sensing system and can also be adopted by Brillouin optical time-domain reflectometry.

[Clinical outcomes of buttress plating in treating posterior Pilon fractures through modified posteromedial approach].

OBJECTIVE: To explore clinical outcomes of buttress plating in treating posterior Pilon fracture by amodified posteromedial approach. METHODS: From July 2014 to January 2015, 10 patients with posterior Pilon fracture were respectively analyzed, including 7 females and 3 males, aged from 31 to 54 years old. One patient were type , 3 patients were type IIand 6 patients were type III according to classification of Pilon fracture by YU Guang-rong. All patients were treated by buttress plating through amodified posteromedial approach. Postoperative complications, fracture healing and reduction were observed, AOFAS score were used to evaluate function recovery at 1 year after operation. RESULTS: All patients were followed up for 12 to 18 months with an average of(14.1±3.2) months. All incisions were primarily healed at stage I without wound complication, neurovascular injuries or musculus flexor contracture. According to Burwell-Charnley imaging scoring, 8 patients got anatomical reduction and 2 patients got moderate reduction. All fracture got healing from 12 to 16 weeks with an average of(13.2±1.8) weeks. According to AOFAS score at 1 year after operation, 8 got excellent results and 2 moderate. All patients returned to work at about(4.7±1.4) months (ranged from 3 to 6 months) after operation. CONCLUSIONS: Buttress plating using a modified posteromedial approach in treating posterior Pilon fractures is an effective method, has less complications, and could recovery early weight-bearing functional exercise.

Ophiopogonin D improves osteointegration of titanium alloy implants under diabetic conditions by inhibition of ROS overproduction via Wnt/ß-catenin signaling pathway.

A high failure rate of titanium implants in diabetic patients has been indicated in clinical evidences. Excessive oxidative stress at the bone-implant interface plays an important role in the impaired osteointegration under diabetic conditions. While the underlying mechanisms remain unknown and the targeted treatments are urgently needed. Ophiopogonin D (OP-D), isolated from Chinese herbal Radix Ophiopogon japonicus, is generally reported to be a potent antioxidant agent. In the present study, we hypothesized that OP-D exerted promotive effects on osteointegration against oxidative stress, and investigated the underlying mechanisms associated with alteration of Wnt/ß-catenin signaling pathway. Rabbit osteoblasts incubated on titanium alloy implant were co-cultured with normal serum (NS), diabetic serum (DS), DS + OP-D, DS + NAC (a potent ROS inhibitor) and DS + OP-D + Dkk1 (a Wnt inhibitor) for examinations of osteoblast behaviors. For in vivo study, titanium alloy implants were implanted into the femoral condyle defects on diabetic rabbits. Results demonstrated that diabetes-induced oxidative stress resulted in osteoblast dysfunctions and apoptotic injury at the bone-implant interface, concomitant with the inactivation of Wnt/ß-catenin signaling. Importantly, OP-D administration attenuated oxidative stress, directly reactivating Wnt/ß-catenin signaling. Osteoblast dysfunctions were thus reversed as evidenced by improved osteoblast adhesion, proliferation and differentiation, and ameliorated apoptotic injury, exerting similar effects to NAC treatment. In addition, the positive effects afforded by OP-D were confirmed by improved osteointegration and oetogenesis within the titanium alloy implants in vivo by Micro-CT and histological analyses. Furthermore, the pro-osteogenic effects of OP-D were almost completely abolished by the Wnt inhibitor Dkk1. These results demonstrated, for the first time, OP-D administration alleviated the damaged osteointegration of titanium alloy implants under diabetic conditions by means of inhibiting oxidative stress via a Wnt/ß-catenin-dependent mechanism. The OP-D administration would become a reliable treatment strategy for implant failure therapy in diabetics due to the optimal anti-oxidative and pro-osteogenic properties.