BACKGROUND: Mechanical complications affect the stability of implant restorations and are a key concern for clinicians, especially with the frequent introduction of new implant designs featuring various structures and materials. This study evaluated the effect of different prosthetic index structure types and implant materials on the stress distribution of implant restorations using both in silico and in vitro methods.
METHODS: Four finite element analysis (FEA) models of implant restorations were created, incorporating two prosthetic index structures (cross-fit (CF) and torc-fit (TF)) and two implant materials (titanium and titanium-zirconium). A static load was applied to each group. An in vitro study using digital image correlation (DIC) with a research scenario identical to that of the FEA was conducted for validation. The primary strain, sensitivity index, and equivalent von Mises stress were used to evaluate the outcomes.
RESULTS: Changing the implant material from titanium to titanium-zirconium did not significantly affect the stress distribution or maximum stress value of other components, except for the implant itself. In the CF group, implants with a lower elastic modulus increased the stress on the screw. The TF group showed better stress distribution on the abutment and a lower stress value on the screw. The TF group demonstrated similar sensitivity for all components. DIC analysis revealed significant differences between TF-TiZr and CF-Ti in terms of the maximum (P < 0.001) and minimum principal strains (P < 0.05) on the implants and the minimum principal strains on the investment materials in both groups (P < 0.001).
CONCLUSIONS: Changes in the implant material significantly affected the maximum stress of the implant. The TF group exhibited better structural integrity and reliability.

UNASSIGNED: This study aims to analyze the biomechanical characteristics of posterolateral plateau fractures fixed by a novel anatomical plate using finite element analysis.
UNASSIGNED: A three-dimensional digital model of the full length of right tibiofibula was obtained by CT scanning. A posterolateral tibial plateau fracture model was then created. The acquired fracture model was assembled with 4 groups of internal fixations: Group A, novel anatomical plate; Group B, straight buttress plate; Group C, oblique T-shaped locking plate; Group D, two lag screws. Axial loads of 500, 1,000 and 1,500 N perpendicular to the horizontal plane were used to simulate the stress on the lateral plateau of a 65 kg person standing, walking and fast running.
UNASSIGNED: Vertical displacements of the posterolateral fragments in each of the four groups gradually increased under loads from 500 N to 1,500 N. The maximum displacement of the fracture fragment in four groups were all located on the lateral side of the proximal part, and the displacement gradually decreased from the proximal part to the distal end. The maximum displacement values under the axial load of 1,500 N was in the following order: novel anatomical plate (1.2365 mm) < oblique T-shaped locking plate (1.314 mm) < two lag screws (1.3747 mm) < straight buttress plate (1.3932 mm). As the axial load increased, the stress value of the different internal fixation models gradually increased. The stress behavior of the same internal fixation model under different loads was similar. The maximum stress value under the axial load of 1,500 N was in the following order: novel anatomical plate (114.63 MPa) < oblique T-shaped locking plate (277.17 MPa) < two lag screws (236.75 MPa) < straight buttress plate (136.2 MPa).
UNASSIGNED: The patients with posterolateral plateau fractures fixed with a novel anatomical plate in standing, walking and fast running can achieve satisfactory biomechanical results, which lays the foundation for future applications. At the same time, clinical fracture types are often diverse and accompanied by damage to the soft tissue. Therefore, the ideal surgical approach and appropriate internal fixation must be selected based on the patient\'s injury condition.

OBJECTIVE: To investigate the clinical effect of orthopedic robot combined with Starr pelvic reduction frame in the treatment of Tile type C pelvic ring fracture.
METHODS: From October 2019 to May 2021, 14 patients with type C pelvic ring fracture were treated with robotic combined with Starr pelvic reduction frame, including 9 males and 5 females. The age ranged from 33 to 69 years. All the 14 patients had fresh closed fractures without femur, tibia and fibula fracture. Surgery was completed from 4 to 7 d after hospital admission. During the operation, the X-ray carbon bed was used, the pelvic ring was reduced by Starr pelvis reduction frame, and pelvic ring fracture was treated by orthopedic robot. Operation time, bleeding volume, fluoroscopy times of single screw placement, fracture reduction quality, affected limb function and complications were observed. Radiological reduction was evaluated using Matta scoring standard, and clinical efficacy was evaluated by Majeed pelvic function scoring system at the final follow-up.
RESULTS: All of 14 patients successfully completed the operation, the operation time was 84 to 141 min, the bleeding volume was 20 to 50 ml, and the fluoroscopy times of single screw insertion was 4 to 9 times. All of 14 patients were followed up for 12 to 24 months. The healing time was 3 to 7 months. No complications such as fracture of internal fixation, screw loosening, infection and nerve injury were found. According to the evaluation criteria of Matta imaging reduction, 9 cases were excellent, 4 cases were good, and 1 case was fair. At the final follow-up, Majeed pelvic function scoring system was used:10 cases were excellent, 4 cases were good.
CONCLUSIONS: The treatment of type C pelvic ring fracture with robotic combined Starr pelvis reduction frame is simple, time-saving, less trauma, less complications and effective.

OBJECTIVE: To compare screw versus Kirschner wire fixation in the treatment of lateral humeral condyle fractures in children.
METHODS: A systematic search was conducted in PubMed, Embase, the Cochrane library, Web of Science, China National Knowledge Internet(CNKI), Wanfang Datebase from in ception to February 2022. Studies comparing screws and Kirschner wire fixation in the treatment of lateral humeral condyle fractures in children were included. Outcome measures included and excluded by a set of inclusion and exclusion criteria and evaluated for their quality, their excellent and good rate of fracture healing, malunion, delayed union or nonunion, infection, limitation of elbow flexion or extension(>10°) were extracted and analyzed using software Rev Man 5.3.
RESULTS: A total of 9 retrospective studies involving 647 patients were included, with 255 patients in the screw fixation group(including screw combined with Kirschner wire) and 392 patients in the Kirschner wire fixation group. Meta analysis showed the following:infection rate in the screw group was significantly lower than that in the Kirschner wire group[OR=0.22, 95%CI(0.09, 0.56), P=0.001]. There were no significant differences between the 2 groups in excellent and good rate of fracture healing, malunion rate(P>0.05). Subgroup analysis showed that infection rate in the screw-only group was significantly lower than that in the Kirschner wire group[OR=0.18, 95%CI(0.05, 0.65), P=0.009].
CONCLUSIONS: For lateral humeral condyle fractures, Screw fixation alone had a lower infection rate than kirschner wire fixation and screw combined with Kirschner wire fixation. There were no significant differences in the excellent and good rate of fracture healing, malunion. In terms of postoperative efficacy and safety of internal fixation, orthopaedic surgeons are more likely to recommend screws for fixation of lateral humeral condyle fractures in children.

BACKGROUND: This study aimed to investigate the positional consistency between the guidewire and the screw in spinal internal fixation surgery.
METHODS: This study involved 64 patients who underwent robot-assisted thoracic or lumbar pedicle screw fixation surgery. Guidewires were inserted with the assistance of the Tirobot. Either cannulated screws or solid screws were inserted. Guidewire and screw accuracy was measured using CT images based on the Gertzbein and Robbins scale. The positional consistency between guidewire and screw was evaluated based on the fused CT images, which could graphically and quantitatively demonstrate the consistency. The consistency was evaluated based on a grading system that considered the maximum distance and angulation between the centerline of the guidewire and the screw in the region of the pedicle.
RESULTS: A total of 322 screws were placed including 206 cannulated ones and 116 solid ones. Based on the Gertzbein and Robbins scale, 97.5% of the guidewires were grade A, and 94.1% of the screws were grade A. Based on our guidewire-screw consistency scale, 85% in cannulated group, and 69.8% in solid group, were grade A. Both solid and cannulated screws may alter trajectory compared to the guidewires. The positional accuracy and guidewire-screw consistency in the solid screw group is significantly worse than that in the cannulated screw group. The cortical bone of the pedicle has a positive guide effect on either solid or cannulated screws.
CONCLUSIONS: The pedicle screws may alter trajectory despite the guidance of the guidewires. Solid screws show worse positional accuracy and guidewire-screw consistency compared with cannulated screws. Trial registration The study was retrospectively registered and approved by our center\'s institutional review board.

Plasma membrane-resident receptor kinases (RKs) are crucial for plants to sense endogenous and exogenous signals in regulating growth, development, and stress response. Upon perception of ligands by the extracellular domain, RKs are usually activated by auto- and/or trans-phosphorylation of the cytoplasmic kinase domain, which in turn phosphorylates downstream substrates to relay the signaling. Therefore, monitoring ligand-induced in vivo phosphorylation dynamics of RKs and their associated proteins provides mechanistic insight into RK activation and downstream signal transduction. Phos-tag specifically binds phosphomonoester dianions of phosphorylated serine, threonine, and tyrosine residues, which enables Phos-tag-containing SDS-PAGE gels to separate phosphorylated proteins from non-phosphorylated form. Here, we describe a detailed method of Mn2+-Phos-tag SDS-PAGE analysis to detect the ligand-induced in vivo phosphorylation of RKs and associated proteins.

UNASSIGNED: To explore the effectiveness of arthroscopic treatment of scaphoid fracture nonunion with bone graft and Kirschner wire combined with screw fixation.
UNASSIGNED: The clinical data of 14 patients with scaphoid fracture nonunion who met the selection criteria between February 2021 and September 2022 were retrospectively analyzed. There were 13 males and 1 female with an average age of 32 years ranging from 17 to 54 years. The time from injury to operation ranged from 6 to 15 months, with an average of 9.6 months. According to the Slade-Geissler classification of scaphoid fracture nonunion, there were 3 cases of grade Ⅲ, 8 cases of grade Ⅳ, and 3 cases of grade Ⅴ. The preoperative visual analogue scale (VAS) score was 5.9±1.0, and the modified Mayo wrist score was 53.2±9.1. There were 2 cases of scaphoid nonunion advanced collapse, both of which were stage Ⅰ. All patients were treated with arthroscopic bone graft and Kirschner wire combined with screw fixation, and the fracture healing was observed by X-ray film monthly after operation, and the effectiveness was evaluated by VAS score and modified Mayo wrist score before and after operation.
UNASSIGNED: All patients were followed up 6-14 months, with an average of 8.4 months. All fractures healed in 4-8 months, with an average of 6.3 months. The postoperative pain symptoms and wrist function of the patients significantly improved when compared with those before operation, and the VAS score at last follow-up was 2.4±1.3, and the modified Mayo wrist score was 87.1±6.7, which were significantly different from those before operation ( t=12.851, P<0.001; t=-14.410, P<0.001). According to the modified Mayo wrist evaluation, 9 cases were excellent, 3 cases were good, and 2 cases were fair.
UNASSIGNED: Arthroscopic bone graft and Kirschner wire combined with screw fixation is an effective surgical method for the treatment of scaphoid fracture nonunion.
UNASSIGNED: 探讨腕关节镜下克氏针联合螺钉植骨内固定治疗腕舟骨骨折不愈合的疗效。.
UNASSIGNED: 回顾分析2021年2月—2022年9月收治且符合选择标准的14例腕舟骨骨折不愈合患者临床资料。其中男13例，女1例；年龄17～54岁，平均32岁。受伤至手术时间6～15个月，平均9.6个月。术前舟骨骨折不愈合Slade-Geissler分级：Ⅲ级3例、Ⅳ级8例、Ⅴ级3例。术前疼痛视觉模拟评分（VAS）为（5.9±1.0）分，改良Mayo腕关节评分为（53.2±9.1）分。其中舟骨骨折不愈合进行性塌陷2例，均为Ⅰ期。均采用腕关节镜下克氏针联合螺钉植骨内固定治疗。术后每月复查X线片观察骨折愈合情况；手术前后采用VAS评分和改良Mayo腕关节评分评价疗效。.
UNASSIGNED: 14例患者术后均获随访，随访时间6～14个月，平均8.4个月。患者骨折均愈合，愈合时间4～8个月，平均6.3个月。患者术后疼痛症状及腕关节功能较术前明显改善，末次随访时VAS评分为（2.4±1.3）分，改良Mayo腕关节评分为（87.1±6.7）分，与术前比较差异均有统计学意义（ t=12.851， P<0.001； t=−14.410， P<0.001）。根据改良Mayo腕关节评分评价，获优9例、良3例、一般2例。.
UNASSIGNED: 腕关节镜下克氏针联合螺钉植骨内固定是治疗腕舟骨骨折不愈合的有效手术方式。.

UNASSIGNED: To compare the biomechanical differences among the five internal fixation modes in treatment of Day type Ⅱ crescent fracture dislocation of pelvis (CFDP), and find an internal fixation mode which was the most consistent with mechanical principles.
UNASSIGNED: Based on the pelvic CT data of a healthy adult male volunteer, a Day type Ⅱ CFDP finite element model was established by using Mimics 17.0, ANSYS 12.0-ICEM, Abaqus 2020, and SolidWorks 2012 softwares. After verifying the validity of the finite element model by comparing the anatomical parameters with the three-dimensional reconstruction model and the mechanical validity verification, the fracture and dislocated joint of models were fixed with S 1 sacroiliac screw combined with 1 LC-Ⅱ screw (S 1+LC-Ⅱ group), S 1 sacroiliac screw combined with 2 LC-Ⅱ screws (S 1+2LC-Ⅱ group), S 1 sacroiliac screw combined with 2 posterior iliac screws (S 1+2PIS group), S 1 and S 2 sacroiliac screws combined with 1 LC-Ⅱ screw (S 1+S 2+LC-Ⅱ group), S 2-alar-iliac (S 2AI) screw combined with 1 LC-Ⅱ screw (S 2AI+LC-Ⅱ group), respectively. After each internal fixation model was loaded with a force of 600 N in the standing position, the maximum displacement of the crescent fracture fragments, the maximum stress of the internal fixation (the maximum stress of the screw at the ilium fracture and the maximum stress of the screw at the sacroiliac joint), sacroiliac joint displacement, and bone stress distribution around internal fixation were observed in 5 groups.
UNASSIGNED: The finite element model in this study has been verified to be effective. After loading 600 N stress, there was a certain displacement of the crescent fracture of pelvis in each internal fixation model, among which the S 1+LC-Ⅱ group was the largest, the S 1+2LC-Ⅱ group and the S 1+2PIS group were the smallest. The maximum stress of the internal fixation mainly concentrated at the sacroiliac joint and the fracture line of crescent fracture. The maximum stress of the screw at the sacroiliac joint was the largest in the S 1+LC-Ⅱ group and the smallest in the S 2AI+LC-Ⅱ group. The maximum stress of the screw at the ilium fracture was the largest in the S 1+2PIS group and the smallest in the S 1+2LC-Ⅱ group. The displacement of the sacroiliac joint was the largest in the S 1+LC-Ⅱ group and the smallest in the S 1+S 2+LC-Ⅱ group. In each internal fixation model, the maximum stress around the sacroiliac screws concentrated on the contact surface between the screw and the cortical bone, the maximum stress around the screws at the iliac bone concentrated on the cancellous bone of the fracture line, and the maximum stress around the S 2AI screw concentrated on the cancellous bone on the iliac side. The maximum bone stress around the screws at the sacroiliac joint was the largest in the S 1+LC-Ⅱ group and the smallest in the S 2AI+LC-Ⅱ group. The maximum bone stress around the screws at the ilium was the largest in the S 1+2PIS group and the smallest in the S 1+LC-Ⅱ group.
UNASSIGNED: For the treatment of Day type Ⅱ CFDP, it is recommended to choose S 1 sacroiliac screw combined with 1 LC-Ⅱ screw for internal fixation, which can achieve a firm fixation effect without increasing the number of screws.
UNASSIGNED: 采用有限元分析比较5种内固定方式治疗Day Ⅱ型骨盆新月形骨折脱位（crescent fracture dislocation of pelvis，CFDP）的生物力学差异，探讨最符合力学原理的内固定方式。.
UNASSIGNED: 取1名健康成年男性志愿者骨盆CT数据，利用Mimics17.0、ANSYS 12.0-ICEM、Abaqus 2020、SolidWorks 2012软件建立Day Ⅱ型CFDP有限元模型，通过与三维重建模型解剖参数比较以及力学有效性验证来评估模型有效性后，分别采用S 1骶髂螺钉+1枚LC-Ⅱ螺钉（S 1+LC-Ⅱ组）、S 1骶髂螺钉+2枚LC-Ⅱ螺钉（S 1+2LC-Ⅱ组）、S 1骶髂螺钉+2枚髂骨后螺钉（posterior iliac screw，PIS）（S 1+2PIS组）、S 1骶髂螺钉+S 2骶髂螺钉+1枚LC-Ⅱ螺钉（S 1+S 2+LC-Ⅱ组）、经第2骶椎髂骨翼（S 2-alar-iliac，S 2AI）螺钉+1枚LC-Ⅱ螺钉（S 2AI+LC-Ⅱ组）固定骨折及脱位关节。对各内固定模型站立位下加载600 N应力后，观测5组内固定模型中新月形骨折块最大位移、内固定最大应力（髂骨骨折处螺钉最大应力及骶髂关节处螺钉最大应力）、骶髂关节位移、内固定周围骨应力分布。.
UNASSIGNED: 经验证构建的有限元模型有效。加载600 N应力后，各内固定模型新月形骨折块均存在一定位移，其中S 1+LC-Ⅱ组最大，S 1+2LC-Ⅱ组及S 1+2PIS组最小；内固定最大应力主要集中在骶髂关节和新月形骨折线处，其中骶髂关节处螺钉最大应力S 1+LC-Ⅱ组最大、S 2AI+LC-Ⅱ组最小，髂骨骨折处螺钉最大应力S 1+2PIS组最大、S 1+2LC-Ⅱ组最小。骶髂关节位移 S 1+LC-Ⅱ组最大、S 1+S 2-LC-Ⅱ组最小。各内固定模型中骶髂螺钉周围最大应力集中在螺钉与皮质骨的接触面，髂骨处螺钉集中于骨折线松质骨处，S 2AI螺钉集中在髂骨侧松质骨内。骶髂关节处螺钉周围骨最大应力S 1+LC-Ⅱ组最大、S 2AI+LC-Ⅱ组最小，髂骨处螺钉周围骨最大应力S 1+2PIS组最大、S 1+LC-Ⅱ组最小。.
UNASSIGNED: Day Ⅱ型CFDP治疗宜选择S 1骶髂螺钉联合1枚LC-Ⅱ螺钉内固定，在不增加螺钉数量情况下即可达牢固固定效果。.

OBJECTIVE: The purpose of this study was to introduce the surgical method of K-wire combined with screw in the treatment of Arbeitsgemeinschaftfür Osteosynthesefragen (AO) type B3.1 phalangeal fractures and to compare its clinical, radiological and functional outcomes with K-wire fixation.
METHODS: This was a retrospective comparative study. From January 2015 to February 2022, we treated 86 patients with AO type B3.1 phalangeal fractures. A total of 71 patients were finally included in the statistical analysis. Thirty-nine patients received K-wires combined with screw, and 32 patients received simple K-wires. The follow-up time was at least 6 months. Outcome measures included general information, operative time, total active motion (TAM), pinch strength, radiological union time, pain assessed by visual analog scale (VAS), Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score, cost, and complications.
RESULTS: The follow-up time was 6-12 months, with an average of 7.9 months. All patients achieved clinical and radiological union. Compared with the K-wire fixation group, the TAM, radiological union time and VAS score of the K-wire combined with screw group had obvious advantages. Compared with the opposite healthy hand, the grip strength of the two groups was similar, and there was no significant difference in the QuickDASH score. The incidence rate of complications in the K-wire combined with screw group (2/39) was lower than that in the K-wire fixation group (7/32).
CONCLUSIONS: Compared with simple K-wire fixation, K-wire combined with screw in the treatment of AO type B3.1 phalangeal fractures is a safer and reliable surgical method. K-wire controls the rotation and plays a role similar to a \"lock\". The screw can exert pressure and fix it more firmly. It shortens the time of fracture healing and has a higher TAM and fewer postoperative complications.

Background: The effects of cannulated screws made of polyetheretherketone (PEEK) on the biomechanical properties of the vertebral body during vertebra-pediculoplasty remain unclear. This study aimed to investigate whether PEEK screws have the potential to replace titanium alloy screws. Methods: The surgical model of two different materials of screws was constructed using the finite element method. The biomechanical effects of the two models on the vertebral body under different working conditions were compared. Results: ① The peak von Mises stress of PEEK screws was significantly lower than that of titanium screws, with a reduction ranging from 52% to 80%. ② The von Mises stress values for the injured T12 spine were similar for both materials. Additionally, the segmental range of motion and intervertebral disc pressure showed no significant difference between the two materials. Conclusion: PEEK screws demonstrated advantages over titanium screws and may serve as a viable alternative for screw materials in vertebra-pediculoplasty.