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Abstract Before patients begin out-of-bed exercises following internal fixation surgery for acetabular fractures, turning over in bed serves as a crucial intervention to mitigate complications associated with prolonged bed rest. However, data on the safety of this maneuver post-surgery are limited, and the biomechanical evidence remains unclear. This study aims to introduce a novel loading protocol designed to preliminarily simulate the action of turning over in bed and to compare the biomechanical properties of two fixation methods for acetabular fractures under this new protocol. A RNJ-500 microcomputer-controlled electronic torsion tester was utilized to simulate the action of turning over in bed and to conduct a dynamic torsion loading test. Initially, the torque values and torsional stiffness of six intact pelvis specimens (Group A) were measured. A double-column acetabular fracture model was then created and stabilized using two different fixation methods: the Dynamic Anterior Plate-Screw System for the Quadrilateral plate (DAPSQ, Group B) and the traditional anterior reconstruction titanium plate plus a 1/3 tubular buttress plate (Group C). All specimens underwent cyclic torsion loading ranging from 2° to 8°. The medial displacement and strain values of the quadrilateral plate were recorded and analyzed. As the torsion angles increased from 2° to 8°, Groups A and B exhibited significantly higher torque values compared to Group C (all P

Abstract Background The research on the biomechanical characteristics of individual implant placement for pilon fractures based on the different initial direction of fracture displacement is still insufficient. This study’s aim is to compare the stress distribution in bones and implants with various pilon fracture types. Methods Varus, valgus, dorsiflexion, and plantarflexion type fractures were categorized as type I, II, III, and IV, respectively. The buttress plate was placed medially in subtypes IA and IIB, whereas it was placed anterolaterally in subtypes IB and IIA; The anterior or posterior buttress plate was utilized in subtypes IIIA and IVA, the lag screws were applied in subtypes IIIB and IVB. The maximum equivalent stress of tibia (TI-Smax) and implants (IF-Smax), stress of fracture fragments (Sfe), and axial displacement values of the fracture fragments (ADfe) in each subtype were analyzed when the ankle was in a neutral position, 15° of varus and valgus in types I and II, 15° of dorsiflexion and plantarflexion in types III and IV. Results Under the same axial stress loading conditions, TI-Smax, Sfe, ADfe of subtypes IA and IIA were significantly lower than subtypes IB and IIB, while IF-Smax of subtypes IA and IIA were obviously larger than subtypes IB and IIB. Additionally, TI-Smax, Sfe, ADfe of subtypes IIIA and IVA were considerably lower as IF-Smax met expectations compared to subtypes IIIB and IVB. Conclusion Based on these results, when making decisions for open reduction and internal fixation in various pilon fractures, the choice and placement of the implant can be recommended as follows: the medial buttress plate for varus types; the anterolateral plate for valgus types; the anterior plate for dorsiflexion types; the posterior plate for plantarflexion types.

BackgroundManaging complicated acetabular fractures involving the quadrilateral plate (QLP) can be challenging for surgeons, especially when complicated by comminution and osteoporosis. Traditional implants do not provide sufficient fixed strength or a proper match. The new-type pre-contoured infrapectineal buttress plates may have drawbacks, such as inaccurate fitting on the medial surface of QLP and an inability to apply reversed compression force to resist medial displacement of femoral head. Therefore, the primary purpose of this study is to introduce a novel technique that utilizes a special contoured pelvic brim reconstruction titanium plate combined with quadrilateral screws to reduce and stabilize acetabular fractures involving the QLP through the ilioinguinal approach. Additionally, the secondary purpose is to evaluate both clinical effectiveness and radiological outcomes of this technique for QLP fractures.MethodsWe conducted a retrospective analysis of prospectively collected data from 48 patients (31 males and 17 females) who suffered from acute displaced fractures of the QLP and were treated between January 2012 and December 2019 using a special contoured plate combined with quadrilateral screws. The patients' mean age was 47.56 ± 11.31 years (range: 19–73 years). Fracture patterns included 20 both-column fractures, 12 anterior column and posterior hemitransverse fractures, eight T-type fractures, five transverse fractures and three anterior column fractures with the QLP affected, all of which had femoral head protrusion. Immediate postoperative reduction quality was evaluated according to Matta's criteria. Final clinical functions were assessed during follow-up using the modified Merle d’Aubigné and Harris Hip scores (HHS).ResultsThe patients were followed up for an average of 48.36 ± 12.94 months (ranging from 24 to 84 months). The mean operative time was 246.08 ± 54.30 min (ranging from 178 to 397 min), and the average blood loss was 715.16 ± 263.84 ml (ranging from 400 to 2000ml). The radiological grading at postoperative stage showed anatomical reduction in 30 patients (62.50%), satisfactory reduction in 14 patients (29.17%), and poor reduction in four patients (8.33%). At the final follow-up, no re-protrusion of the femoral head was observed. In terms of functional outcome, the mean modified Merle d’Aubigné-Postel score was excellent in 26 patients (54.17%), good in 17 patients (35.42%), fair in four patients (8.33%), and poor in one patient (2.08%). The HHS was excellent in 23 patients (47.92%), good in 20 patients (41.67%), fair in four patients (8.33%), and poor in one patient (2.08%). The average HHS was 87.38 ± 7.86 (ranging from 52 to 98). Postoperative complications included lateral femoral cutaneous nerve injury in two patients, delayed wound healing and subsequent development of an inguinal hernia in one patient. Late complications were observed in two patients, with one case of heterotopic ossification and another case of post-traumatic osteoarthritis underwent hip arthroplasty within two years after surgery.ConclusionOur results indicate that employing the contoured plate specifically designed for QLP injuries, in conjunction with quadrilateral screws through the ilioinguinal approach, can lead to positive outcomes in the treatment of displaced acetabular fractures involving the QLP. This straightforward and efficient technique offers a viable option for surgeons who are managing complex acetabular fractures.

Abstract This study aims to investigate the feasibility and efficacy of anterior atlantoaxial motion preservation fixation (AMPF) in treating axis complex fractures involving the odontoid process fracture and Hangman’s fractures with C2/3 instability. A retrospective study was conducted on eight patients who underwent AMPF for axis complex fractures at the General Hospital of Central Theater Command from February 2004 to October 2021. The types of axis injuries, reasons for injuries, surgery time, intraoperative blood loss, spinal cord injury classification (American Spinal Injury Association, ASIA), as well as complications and technical notes, were documented. This study included eight cases of type II Hangman’s fracture, five cases of type II and three cases of type III odontoid process fracture. Five patients experienced traffic accidents, while three patients experienced falling injuries. All patients underwent AMPF surgery with an average intraoperative blood loss of 288.75 mL and a duration of 174.5 min. Two patients experienced dysphagia 1 month after surgery. The patients were followed up for an average of 15.63 months. One case improved from C to E in terms of neurological condition, three cases improved from D to E, and four cases remained at E. Bony fusion and Atlantoaxial Motion Preservation were successfully achieved for all eight patients. AMPF is a feasible and effective way for simultaneous odontoid process fracture and Hangman’s fractures with C2/3 instability, while preserving atlantoaxial movement.

Objective The application of three‐dimensional (3D) printing technology in the management of posterior wall acetabular fractures can greatly reduce surgical invasiveness and operative time and simplify the procedure of reconstruction plate contouring, but the cost and time of patient‐specific plate preparation on the basis of traditional 3D‐printed pelvis model should not be neglected. We described a new method for patient‐specific plate preparation by using 3D‐printed plate template. The study aimed to assess the effectiveness and feasibility of the 3D‐printed plate template in patient‐specific plate preparation for posterior wall acetabular fractures. Methods A total of 65 cases of posterior wall acetabular fractures with surgical treatment from December 2012 to December 2020 were chosen. According to the different plate contouring methods, the 65 cases were divided into three groups, which were group A (21 cases), group B (20 cases), and group C (24 cases). In group A, the 3D‐printed plate template was used to contour the patient‐specific reconstruction plate before surgery, whereas the 3D‐printed hemipelvis model was adopted for group B. In group C, the reconstruction plate was contoured intraoperatively. Among the three groups, the instrumentation time, surgical time, blood loss, patient‐specific plate preparation time, complications, reduction quality, and hip function were compared. The Kruskal–Wallis test was used to analyze the reduction quality and hip function among three groups. Results In comparison with group C, patients in groups A and B were featured by obviously shorter instrumentation time (−22, −23 min), shorter surgical time (−46, −44 min), and less intraoperative blood loss (−110, −122 mL). Compared to the hemipelvis model in group B (2.29 ± 0.56 vs. 12.70 ± 3.79 days), the 3D printing time for plate templates in group A was significantly shorter. The reduction quality and hip function had no obvious statistical difference among the three groups. The complication rate within group A (3/21) and group B (3/20) were both slightly lower than group C (5/24), with no obvious difference. Conclusions Both the patient‐specific pre‐contoured plate fixation methods based on the 3D‐printed hemipelvis model and plate template can achieve satisfactory clinical efficacy, with the advantage of shorter instrumentation and surgical time, and less intraoperative blood loss. However, 3D printing of plate template is easier and less time‐consuming, considering the shorter time and less cost for 3D printing of physical model.

Abstract Purpose Matta scoring standard is one of the most frequently used postoperative imaging evaluations for acetabular fracture reduction, but has obvious shortcomings. This study, for the first time, proposed the concept of inclined angles of acetabular quadrilateral plate. The purpose of this study was to investigate the normal range of the inclined angles in adults by digital measurement and explore the feasibility of using them to evaluate the reduction quality of acetabular quadrilateral fractures after surgery. Methods Firstly, the pelvic CT three-dimensional reconstruction data of 40 healthy adults including 20 males and 20 females were collected. The normal range of the anterior, middle, and posterior inclined angles were measured via Mimics software. Secondly, a modified Matta criteria that combined the classic Matta criteria and evaluation criteria of the inclined angles was proposed. And we classified modified Matta criteria into three grades including excellent, good and poor. Finally, a total of 125 cases with quadrilateral plate fractures was included and the postoperative CT data were analyzed by using both the classic Matta criteria and our modified Matta criteria. Then, the accuracy and consistency of both criteria to evaluate postoperative hip function was investigated. Results The average anterior inclined angle: male (97.11° ± 2.59°), female (90.63° ± 2.09°); middle inclined angle: male (105.57° ± 1.93°), female (100.64° ± 2.46°); and posterior inclined angle: male (112.62° ± 2.54), female (106.37° ± 2.53°). Whether in males or in females, the anterior, middle, and posterior inclined angles showed a progressively increasing trend. All the three inclined angles in males were all significantly larger than those in females (p

Failure to adequately reconstruct the tendon-to-bone interface constitutes the primary etiology underlying rotator cuff retear after surgery. The purpose of this study is to construct a dynamic chondroitin sulfate and chitosan hydrogel scaffold (CHS) with bone morphogenetic protein 2 (BMP2), then seed tendon stem cells (TSCs) on BMP2-CHS for the rotator cuff reconstruction of tendon-to-bone interface. In this dynamic hydrogel system, the scaffold could not only have good biocompatibility and degradability but also significantly promote the proliferation and differentiation of TSCs. The ability of BMP2-CHS combined with TSCs to promote regeneration of tendon-to-bone interface was further verified in the rabbit rotator cuff tear model. The results showed that BMP2-CHS combined with TSCs could induce considerable collagen, fibrocartilage, and bone arrangement and growth at the tendon-to-bone interface and promote the biomechanical properties. Overall, TSCs seeded on CHS with BMP2 can enhance tendon-to-bone healing and provide a new possibility for improving the poor prognosis of rotator cuff surgery.

Abstract Background Posterior wall acetabular fractures remain one of the most difficult fracture injuries to treat. Accurate assessment of fracture characteristics and appropriate preoperative surgical strategies are essential for excellent reduction. This paper evaluates the feasibility and effectiveness of a one-stop computerized virtual planning system for the surgical management of posterior wall acetabular fractures. Methods 52 cases of posterior wall acetabular fractures treated surgically were selected in our department between January 2015 and December 2020 for retrospective analysis. 52 cases were classified into group A (25 patients) and group B (27 patients) according to whether computerized virtual planning procedures were performed preoperatively. In group A, virtual surgical simulation was conducted using a one-stop computerized planning system preoperatively. In group B, traditional surgery was employed. Reduction quality, surgical time, blood loss, hip function, complications, and instrumentation time were compared between the two groups. Results The actual surgery for all patients in group A was essentially the same as the virtual surgery before the operation. Compared to group B, patients in group A had markedly shorter surgical time (−43 min), shorter instrumentation time (−20 min), and less intraoperative blood loss (−130 ml). However, no significant statistical difference was observed in reduction quality and hip function. The complication rate was slightly lower in group A (4/25) than in group B (7/27), without a significant difference. Conclusion The one-stop computerized virtual planning system is a highly effective, user-friendly and educational tool for allowing the cost-efficient surgical simulation of posterior wall acetabular fractures and providing a more individualized therapeutic schedule. The one-stop computerized planning system is feasible to treat posterior wall acetabular fractures, which is an effective method than the conventional treatment of posterior wall acetabular fractures. Trial registration: retrospective registration.

Abstract Background There is still some controversy about the augmentation of the inferior extensor retinaculum after arthroscopic anterior talofibular ligament repair. The aim of this study was to evaluate the novel arthro-Broström procedure with endoscopic retinaculum augmentation using all-inside lasso-loop stitch techniques for chronic lateral ankle instability. Methods Thirty-four cases with grade-2 or grade-3 chronic anterior talofibular ligament lesions who underwent the novel arthro-Broström procedure with endoscopic retinaculum augmentation using all-inside lasso-loop stitch techniques were assessed retrospectively. A total of 30 cases (30 ankles) were followed up for a mean of 26.67 ± 4.19 months (range, 24—36 months). four cases were excluded due to insufficient medical records or loss of follow-up reports. The Cumberland Ankle Instability Tool scores, The Karlsson-Peterson scores and Visual Analogue Scale scores were evaluated before surgery and at the final follow-up time. Also, the results of stress fluoroscopic tests and complications were recorded. Results At the final follow-up, the average of the Cumberland Ankle Instability Tool scores, The Karlsson-Peterson scores and Visual Analogue Scale scores were 86.63 ± 6.69 (range, 77—100), 90.17 ± 4.64 (range, 85—100) and 0.53 ± 0.63 (range, 0—2), respectively. Moreover, the results of stress fluoroscopic tests were improved significantly after surgery. Mild keloid formation and/or knot irritation were observed in four cases. No wound infections, nerve injuries and recurrent instability were recorded. Also, no stiffness or arthritis of the subtalar joint was encountered. Conclusions The arthro-Broström procedure combined with endoscopic retinaculum augmentation using all-inside lasso-loop techniques is reliable and safe due to the advantage of direct endoscopic visualization.

Abstract Objective To evaluate the morphological asymmetry of pelvic rings existing in healthy individuals in terms of three‐dimensional (3D) geometric shapes. Methods This study was a retrospective self‐control study. CT images of healthy pelvises, scanned from Jan 2014 to Jan 2019, were taken from 159 subjects (88 males and 71 females) aged 20 to 59 years (39.1 ± 8.7 years). Digital pelvic ring models were reconstructed from CT images and then flipped over the corresponding sagittal planes to obtain their mirrored models. A 3D deviation analysis of a pelvic ring was conducted between the original model and its mirrored model via model registration and quantification of the geometric differences. Next, the pelvic rings were split to the left and right hipbones. The same flipping procedures as done by pelvic rings were performed for left hipbones to obtain their mirrored models. A 3D deviation analysis was also performed between the left and right hip bones. Quantitative variables representing deviation mainly included the average deviation (AD) and the maximum deviation (MD). MDs over 4 mm and 10 mm were deemed as critical levels for evaluating the severity of asymmetry as per Matta's scoring system. The quantitative assessments of the asymmetry covered pelvic rings, bilateral hip bones and the specific anatomic regions of a hip bone. Results 157 out of 159 pelvic rings (98.74%) had more than 4 mm of the MD and 27 (16.98%) of them exceeded 10 mm of the MD. The MD of pelvic rings was 1.23 times as high as that for the bilateral hip bones (7.46 mm vs. 6.08 mm, P

Abstract Background The treatment of comminuted posterior wall acetabular fractures remains challenging due to the difficulty in understanding of fracture patterns and lack of appropriate preoperative planning process. Virtual preoperative planning procedures are now being commonly used in orthopedic surgery to aid in management of such complex problems. Our aim was to evaluate the feasibility and clinical value of a new method by applying computerized virtual preoperative planning procedures in the treatment of comminuted posterior wall acetabular fractures. Methods A total of 45 patients with comminuted posterior wall acetabular fractures from June 2014 to December 2018 were retrospectively analyzed. Based on the usage of computerized virtual preoperative planning procedures, they were assigned to group A and group B. In group A (24 patients), the new method was applied before surgery. In group B (21 patients), the conventional surgery was performed without assistance of computerized virtual preoperative planning procedures. The two groups were assessed in terms of blood loss, surgical time, reduction quality, fracture healing time, postoperative complications, and hip function. Results There were no significant differences in demographic data between the two groups. Patients in group A had significantly less intraoperative blood loss (429.58 vs 570.24 ml, P 0.05). The general postoperative complication rate in group A and group B was 12.5% and 28.6%, respectively, but the difference between the two groups was not statistically significant. Conclusion The application of computerized virtual preoperative planning procedures is feasible in comminuted posterior wall acetabular fractures. It helps orthopedic surgeons better understand the fracture characteristics, enables simulation of the reduction process and preoperative planning of internal fixation methods. This new preoperative planning method using a 3D virtual model is a more effective method than conventional method in surgical treatment of comminuted posterior wall acetabular fractures. Trial registration retrospectively registered.

Fungal polyketides (PKs) are one of the largest families of structurally diverse bioactive natural products biosynthesized by multidomain megasynthases, in which thioesterase (TE) domains act as nonequivalent decision gates determining both the shape and the yield of the polyketide intermediate. The endophytic fungus Preussia isomera XL-1326 was discovered to have an excellent capacity for secreting diverse bioactive PKs, i.e., the hot enantiomers (±)-preuisolactone A with antibacterial activity, the single-spiro minimoidione B with α-glucosidase inhibition activity, and the uncommon heptaketide setosol with antifungal activity, which drive us to illustrate how the unique PKs are biosynthesized. In this study, we first reported the genome sequence information of P. isomera. Based on genome mining, we discovered nine transcriptionally active genes encoding polyketide synthases (PKSs), Preu1–Preu9, of which those of Preu3, Preu4, and Preu6 were cloned and functionally characterized due to possessing complete sets of synthetic and release domains. Through heterologous expression in Saccharomyces cerevisiae, Preu3 and Preu6 could release high yields of orsellinic acid (OA) derivatives [3-methylorsellinic acid (3-MOA) and lecanoric acid, respectively]. Correspondingly, we found that Preu3 and Preu6 were clustered into OA derivative synthase groups by phylogenetic analysis. Next, with TE domain swapping, we constructed a novel “non-native” PKS, Preu6-TEPreu3, which shared a very low identity with OA synthase, OrsA, from Aspergillus nidulans but could produce a large amount of OA. In addition, with the use of Preu6-TEPreu3, we synthesized methyl 3-methylorsellinate (synthetic oak moss of great economic value) from 3-MOA as the substrate, and interestingly, 3-MOA exhibited remarkable antibacterial activities, while methyl 3-methylorsellinate displayed broad-spectrum antifungal activity. Taken together, we identified two novel PKSs to biosynthesize 3-MOA and lecanoric acid, respectively, with information on such kinds of PKSs rarely reported, and constructed one novel “non-native” PKS to largely biosynthesize OA. This work is our first step to explore the biosynthesis of the PKs in P. isomera, and it also provides a new platform for high-level environment-friendly production of OA derivatives and the development of new antimicrobial agents.

Background and Objectives: To investigate the digital measurement method for the plate trajectory of dynamic anterior plate-screw system for quadrilateral plate (DAPSQ), and then design a third-generation DAPSQ plate that conforms to the needs of the Chinese population through collating a large sample anatomical data. Materials and Methods: Firstly, the length of the pubic region, quadrilateral region, iliac region, and the total length of the DAPSQ trajectory were measured by a digital measurement approach in 22 complete pelvic specimens. Then, the results were compared with the direct measurement of pelvic specimens to verify the reliability of the digital measurement method. Secondly, 504 cases (834 hemilateral pelvis) of adult pelvic CT images were collected from four medical centers in China. The four DAPSQ trajectory parameters were obtained with the digital measurement method. Finally, the third-generation DAPSQ plate was designed, and its applicability was verified. Results: There was no statistically significant difference in the four trajectory parameters when comparing the direct measurement method with the digital measurement method (p > 0.05). The average lengths of the pubic region, quadrilateral region, iliac region, and the total length in Chinese population were (60.96 ± 5.39) mm, (69.11 ± 5.28) mm, (84.40 ± 6.41) mm, and (214.46 ± 10.15) mm, respectively. Based on the measurement results, six models of the DAPSQ plate including small size (A1,A2), medium size (B1,B2), and the large size (C1,C2) were designed. The verification experiment showed that all these six type plates could meet the requirement of 94.36% cases. Conclusions: A reliable computerized method for measuring irregular pelvic structure was proposed, which not only provided an anatomical basis for the design of the third-generation DAPSQ plate, but also provided a reference for the design of other pelvic fixation devices.

To observe the lesion characteristics of vertebral subchondral bone by establishing a rat model of intervertebral disc degeneration. Thirty-two Sprague--Dawley rats were randomly divided into four groups of eight rats each, and one group served as the control group without any treatment. The rats in the experimental group were injected with 30 μl of anhydrous alcohol under the endplate (sub-endplate) above the Co6 vertebrae and 30 μl of phosphate buffered saline buffer under the endplate above the Co8 vertebrae. Eight rats were randomly taken for follow-up testing at 2, 4, and 8 w after establishment of models. The rats underwent imaging X-rays and magnetic resonance imaging to assess vertebral subchondral bone and intervertebral disc degeneration grades; then serum enzyme-linked immunosorbent assay was performed to measure tumor necrosis factoralpha, interleukin-1 beta, type I procollagen amino-terminal peptide, type I collagen carboxy-terminal peptide, vascular endothelial growth factor A and endostatin. The Co5/Co6 and Co7/Co8 motion segments (including the adjacent vertebrae and intervertebral disc) were used to perform micro-computed tomography, histological staining with hematoxylin and eosin, sapphire green, and toluidine blue, as well as for detecting the expression of collagen type II, and vascular endothelial growth factor A expression. Collagen type II, aggregated proteoglycan (aggrecan), sox-9, vascular endothelial growth factor A by immunohistochemical tests. Imaging, histologic staining and immunohistochemistry confirmed the successful establishment of intervertebral disc degeneration model. Histological observations and immunohistochemical analysis showed progressive degeneration of major intervertebral disc structures. Blocking the intervertebral disc trophic pathway in the vertebral subchondral bone region can successfully establish intervertebral disc degeneration rat model, and the possible main lesion characteristics of the vertebral subchondral bone during this process include abnormal bone remodeling, destruction of blood vessels and enhanced inflammatory response. [ABSTRACT FROM AUTHOR]