[Biomechanical study of three-dimensional printed filler block design in open wedge high tibial osteotomy].

The use of a filling block can improve the initial stability of the fixation plate in the open wedge high tibial osteotomy (OWHTO), and promote bone healing. However, the biomechanical effects of filling block structures and materials on OWHTO remain unclear. OWHTO anatomical filling block model was designed and built. The finite element analysis method was adopted to study the influence of six filling block structure designs and four different materials on the stress of the fixed plate, tibia, screw, and filling block, and the micro-displacement at the wedge gap of the OWHTO fixation system. After the filling block was introduced in the OWHTO, the maximum von Mises stress of the fixation plate was reduced by more than 30%, the maximum von Mises stress of the tibia decreased by more than 15%, and the lateral hinge decreased by 81%. When the filling block was designed to be filled in the posterior position of the wedge gap, the maximum von Mises stress of the fixation system was 97.8 MPa, which was smaller than other filling methods. The minimum micro-displacement of osteotomy space was -2.9 µm, which was larger than that of other filling methods. Compared with titanium alloy and tantalum metal materials, porous hydroxyapatite material could obtain larger micro-displacement in the osteotomy cavity, which is conducive to stimulating bone healing. The results demonstrate that OWHTO with a filling block can better balance the stress distribution of the fixation system, and a better fixation effect can be obtained by using a filling block filled in the posterior position. Porous HA used as the material of the filling block can obtain a better bone healing effect.

A screw algorithm for congenital C2-3 fusion with high-riding vertebral arteries: feasibilities and clinical outcomes of five different fixation techniques.

OBJECTIVE: To propose a screw algorithm and investigate the anatomical feasibilities and clinical outcomes of five distinct fixation methods for C2-3 fused vertebra with high-ridding vertebral arteries (VA) (HRVA) when the C2 pedicle screw placement is unfeasible. METHODS: Thirty surgical patients with congenital C2-3 fusion, HRVA, and atlantoaxial dislocation (AAD) were included. We designed a algorithm for alternative screw implantation into C2-3 fused vertebrae, including C2 pedicle screw with in-out-in (passing VA groove) technique (in-out-in screw), subfacetal screw, translaminar screw, lateral mass screw, C3 pedicle screw. VA diameter and position, C2 and C3 pedicles, superior facets, fused lamina, and fused lateral mass dimensions were evaluated for screw implantation indication. Implant failure, reduction loss, implant placement accuracy were investigated by computed tomography. RESULTS: A total of 5 VAs were identified as distant VAs; a total of 2 VAs were categorized as occlusive VAs. Sufficient dimension of lateral mass and lamina provided the broadest indications for screw implantation, while the distant or occlusive VA provided the most limited indications for in-out-in screw. The indications of five alternative methods ranged from narrowest to widest as follows: in-out-in screw, C3 pedicle screw, subfacetal screw, translaminar screw, lateral mass screw. The translaminar screws and the lateral mass screws increased the probability of implant failure. All patients who received in-out-in screws, C3 pedicle screws, and subfacetal screws achieved fusion. The accuracy ranged from lowest to highest as follows: C3 pedicle screw, lateral mass screw, in-out-in screw, subfacetal screw, translaminar screw. No translaminar screws deviated. CONCLUSIONS: The algorithm proved to be a valuable tool for screw selection in cases of C2-3 fused vertebrae with HRVAs. The subfacetal screw, boasting broad indications, a high fusion rate, and exceptional accuracy, stood as the primary preferred alternative.

New Technique for Treatment of Spondylolysis and Contralateral Facet Fracture Using Navigation and Robotics: A Case Report.

CASE: A healthy 15-year-old male competitive hockey player presented with acute-on-chronic lower back pain was found to have a bilateral pars defect. After conservative treatment, subsequent computed tomography imaging demonstrated partial healing of the right-sided facet fracture but persistent left-sided pars fracture. A novel technique was performed, using robotic navigation to assist in laminar screw placement and to determine the optimal trajectory for subsequent microscopic surgery and bone grafting. CONCLUSION: Robotic navigation can be safely used to not only guide precise laminar screw placement for fixation and direct repair but also to provide guidance for microscopic tubular bone grafting of the pars defect.

MISMARPE protocol: minimally invasive surgical and miniscrew-assisted rapid palatal expansion.

OBJECTIVE: The purpose of this article is to present the MISMARPE technique, a new minimally invasive surgical procedure to treat maxillary transverse atresia in adult patients under local anesthesia and on an outpatient basis. TECHNIQUE DESCRIPTION: The technique consists of miniscrew-assisted rapid palatal expansion (MARPE) associated with a minimally invasive approach using maxillary osteotomies, latency and activation periods until the desired expansion is achieved. The present MISMARPE technique was performed in 25 consecutive cases with a success rate of 96%, yielding good skeletal outcomes with minimal trauma. The expander appliances, with their anchorage types, and a description of the surgical steps of the MISMARPE technique are presented. CONCLUSION: MISMARPE is a new and effective alternative for less invasive treatment of maxillary transverse deficiency in adults, compared to conventional surgery. Emphasis is placed on the importance of systematic and well-established protocols, for executing the procedures safely and predictably.

Miniscrew-assisted rapid palatal expansion (MARPE): Factors influencing planning.

OBJECTIVE: This cross-sectional study evaluated the bone thickness on mini-implants insertion site, the factors that influence the digital planning of MARPE appliance (miniscrew-assisted rapid palatal expansion), and its different designs. METHODS: A total of 135 plannings were assessed regarding the size of the expander screw used, the positioning and the type of the mini-implant rings, and their location in relation to the teeth. Bone thickness measurements were assessed in the region of the mini-implants' trajectory. Differences between the sexes was verified using the ANOVA test (5% significance). RESULTS: 73 cases were planned with 4 mini-implants and 62 cases, with 6 mini-implants. In 90% of cases, teeth #16 and #26 were used as supports, and the most used expander screw was 13mm (64.1% of cases). The anterior mini-implants of conventional MARPE showed more pronounced insertion in bone in males (5.9 ± 2mm; p= 0.025). The extra mini-implants (anterior region) were inserted with greater bone thickness in males (11.1 ± 2.3mm) compared to females (9.9 ± 1.8mm; p=0.041). A greater bone thickness was observed in males (10.1 ± 2.1 mm) when using mini-implants in the paramedian region. CONCLUSION: Additional rings allow more pronounced bone insertion. Male patients had greater bone thickness, which may be related to greater difficulty in opening the sutures. The alveolar process region seems to be a satisfactory site for mini-implants to those patients with reduced bone thickness in the paramedian posterior region. MARPE appliance must be customized for each patient, due to bone thickness and anatomical variations.

Association between cup fixation screw and iliopsoas impingement after total hip arthroplasty.

BACKGROUND: Iliopsoas impingement after total hip arthroplasty can result not only from acetabular cup but also from cup fixation screw. However, research addressing this screw impingement is scarce, leaving the details undetermined. This study aimed to elucidate the incidence and threshold of symptomatic iliopsoas impingement attributable to protrusion of the cup fixation screw into the iliopsoas muscle and to evaluate its impact on postoperative radiographic imaging findings and patient-reported outcome measures. METHODS: A total of 152 hips were included in this study. The symptomatic threshold of screw protrusion was determined using a receiver operating characteristic curve, and patients were divided into low-protrusion and high-protrusion groups using this threshold. The area and Hounsfield Unit values of the iliopsoas muscle on CT and the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire postoperatively were investigated. FINDINGS: 10 hips (6.5%) were exhibited symptoms of IPI in this series. The threshold for screw protrusion length was identified as 6.4 mm. Patients in the high protrusion group exhibited significantly larger area and lower Hounsfield Unit values of the iliopsoas muscle. In addition, the high protrusion group revealed significantly lower scores (total, pain, movement, mental). Furthermore, subscales scores (pain, movement) in the high protrusion group didn't improve from 3 months to 12 months postoperatively with significance. INTERPRETATION: This study underscores the imperative for surgeons to consider the length of the cup fixation screw. This careful consideration is crucial for mitigating the incidence of postoperative iliopsoas impingement and enhancing total hip arthroplasty outcomes.

Two-screw osteosynthesis is biomechanically superior to single-screw osteosynthesis for type II odontoid fractures.

The data on the use of a one- or two-screw technique (1S, 2S) for ventral osteosynthesis of type II dens fractures are contradictory. The aim was to design an apparatus to mimic the physiological conditions and test stability with 1S, 2S, and a headless compression screw (HCS) for osteosynthesis of artificially created type II odontoid fractures. The apparatus was mounted on a Zwick materials testing machine. A total of 18 C1-2 specimens were stratified into three groups (1S, 2S, HCS). Odontoid fractures were artificially created, and osteosynthesis was performed. Each specimen was tested at loads increasing from 1 to 40 N. Screw loosening was observed visually, by fatigue data, and by a camera tracking system. Analysis of the Zwick data and the camera data revealed a significant higher stability after 2S compared to 1S and HCS treatment (Zwick data: p = 0.021, camera data: p < 0.001), while visible screw loosening showed a superiority of the 2S only over HCS (p = 0.038). The developed apparatus allowed the dynamic study of the atlantoaxial joint with a high approximation to physiological conditions. The results demonstrated superiority of the 2S over the 1S and HCS in biomechanical stability in the treatment of type II odontoid fractures.

Arthroscopic reduction and hollow screw internal fixation for Eyres Type IIIA scapular coracoid fracture: a case report.

BACKGROUND: A coracoid process fracture combined with an acromioclavicular (AC) joint dislocation is an uncommon injury that typically causes significant pain and limits shoulder movement. Open reduction and internal fixation have been the traditional treatment approach. However, arthroscopic techniques are emerging as a promising alternative for managing these injuries. CASE REPRESENTATION: A 35-year-old woman presented with right shoulder pain following an accidental fall. Imaging studies revealed a coracoid process fracture along with an AC joint dislocation. The fracture was classified as an Eyres Type IIIA, which warranted surgical intervention. Our team performed arthroscopic coracoid fracture reduction and internal fixation surgery, as well as AC joint dislocation repair using Kirschner wires. Six months after surgery, the patient demonstrated a satisfactory functional outcome with complete bone healing. CONCLUSION: This case report highlights the potential of arthroscopic reduction and fixation as a novel treatment option for fractures of the coracoid base.

Clinical and functional outcome of traumatic osteochondral fracture in adolescent patella.

The objective of this descriptive cross-sectional study was to assess the functional outcomes of adolescents who had undergone internal fixation for patellar post-traumatic OCD fracture from 2019-2021. The injury mechanism was divided into two categories: a) torsional mechanism and b) direct contact injury. All candidates underwent X-ray and MRI/CT scan prior to the surgery to confirm the diagnosis. Operative treatment was open reduction and internal fixation (ORIF) of osteochondral fragment using headless screws. All patients were assessed pre-operatively with knee-ROM/IKDC (International Knee Documentation committee) score and satisfaction score, and postoperatively at one year follow-up. Fourteen patients were selected, with the mean age of 16.1±3.2 years. On one-year follow-up, no difference was noted in ROM when compared to the unaffected limb. The mean satisfaction score was 86±6.3 %. The mean pre-operative-IKDC score was 47.6±5.8 out of 100, whereas on one-year follow-up it was 88.6±2.2 which was statistically significant (p<0.05). Excellent outcomes can be achieved with headless screws for urgent ORIF (next elective list) of the osteochondral fragment.

Biomechanical evaluation of Gamma 3 nail with anti-rotation screw fixation for unstable femoral neck fractures: a biomechanical study.

This study aims to evaluate the biomechanical performance of the Gamma 3 nail with an anti-rotation screw (GNS) and compare it to two established gold-standard methods for treating unstable femoral neck fractures (UFNFs). Synthetic bone models were prepared with Pauwels' type III osteotomy and an additional posterior wedge. Three different implant configurations were tested: three cannulated crews (3CS) in an inverted triangle configuration, a dynamic hip screw with an anti-rotation screw (DHSS), and GNS. Non-destructive cyclic axial loading was applied at 7° adduction, with 1000 cycles ranging from 100 to 1000 N. Subsequently, a construct failure test was conducted using progressive axial compression, and fracture reduction loss was recorded. The average axial stiffness was 321 ± 52 N/mm for 3CS, 430 ± 71 N/mm for DHSS, and 519 ± 104 N/mm for GNS. The average ultimate failure loads were 2699.3 N for 3CS, 3427.1 N for DHSS, and 3758.9 N for GNS. GNS demonstrated significantly greater axial stiffness compared to the other two groups (P < 0.05). Both DHSS and GNS exhibited similar failure loading, which were greater than those of 3CS (P < 0.05). GNS offers the advantages of a minimally invasive and intramedullary implant with comparable stability to the DHSS system. Moreover, GNS demonstrated superior biomechanical performance compared to 3 CS configuration.

Screw Configuration Does Not Significantly Alter Neck Shortening After Valgus-Impacted Femoral Neck Fracture (OTA Type 31B1.1).

OBJECTIVES: To compare 3 different cancellous screw configurations used for Garden 1 femoral neck fractures (FNFs). DESIGN: Retrospective review. SETTING: A large urban academic medical center. PATIENT SELECTION CRITERIA: All patients with Orthopaedic Trauma Association 31B1.1 FNF who underwent in situ fixation with cancellous screws between 2012 and 2021 were included. Patients were divided into 3 groups: 2 screws placed in a parallel fashion, 3 screws placed in an inverted triangle configuration, and 3-screw fixation with placement of 1 "out-of-plane" screw perpendicular to the long axis of the femur. OUTCOME MEASURES AND COMPARISONS: Postoperative femoral neck shortening (mm) was the primary outcome, which was compared among the 3 groups of different screw configurations. RESULTS: Sixty-one patients with a median follow-up of 1 year (interquartile range 0.6-1.8 years) and an average age of 72 years (interquartile range 65.0-83.0 years) were included. All fractures demonstrated bony healing. Overall, 68.9% of the cohort had ≤2 mm of femoral neck shortening. There was no difference between groups in the proportion of patients who experienced greater than 2 mm of shortening (P = 0.839) or in the amount (mm) of femoral neck shortening (Kruskal-Wallis χ2 = 0.517, P = 0.772). CONCLUSIONS: Although most patients with valgus-impacted FNF treated with screw fixation do not experience further femoral neck shortening, some patients demonstrated continued radiographic shortening during the healing process. The development of further femoral neck shortening and the amount of shortening that occurs do not differ based on implant configuration. Multiple different screw configurations seem to be acceptable for achieving healing and minimizing further femoral neck impaction. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effect of a Percutaneous Screw Guide on Screw Placement for Posterior Talar Fractures.

AIM: This study aimed to evaluate the hypothesis that the utilization of percutaneous screw guides enhances the precision of screw placement in the surgical fixation of talar fractures. METHODS: Computed tomography (CT) scans of ankle joints were obtained from 40 healthy adults and 10 cadaveric specimens between April 2019 and August 2020 at Ningbo No. 6 Hospital. The acquired CT data were imported into Materialise Interactive Medical Image Control System (MIMICS) software for processing. Three-dimensional (3D) digital models of the ankle joints were reconstructed, and relevant anatomical parameters were measured. A percutaneous screw guide (PSG) was designed and fabricated to facilitate accurate screw placement in the posterior talar process. Ten eligible cadaveric ankle joints were selected for further analysis and their 3D models were reconstructed using the MIMICS software. Screw trajectory parameters were then measured and analyzed based on these cadaveric models, forming the model group for comparative analyses. Ten cadaveric specimens were utilized in this study, equally divided into two groups: a guider group (n = 5) and a free-hand group (n = 5). In the guider group, talar posterior process screws were inserted using percutaneous screw guidance. In the free-hand group, screws were inserted into the talar posterior process without guidance. Post-operative CT scans were performed on all specimens. The following parameters were quantitatively compared between the two groups: screw trajectories, entry point distances in specimens with preselected screws, entry point distance trajectories in the 3D model, operation time, frequency of fluoroscopic imaging, and number of drilling attempts. RESULTS: Following the generation of the 3D models from 10 cadavers, a virtual screw was digitally inserted into each model. In the model group, the preselected screw trajectory was oriented towards the medial aspect of the talar neck base, with a cephalad inclination angle (CIA) of 3.1° ± 1.5° in the transverse~plane and a medial diverge angle (MDA) of 12.0° ± 1.4° in the coronal plane. The CIA and MDA of the screw trajectory in the guider group were 2.1° ± 1.7° and 11.2° ± 1.6°, respectively, whereas the CIA and MDA in the free-hand group were 6.0° ± 2.2° and 18.8° ± 1.6°, respectively. Statistical analysis revealed significant differences in both CIA and MDA between the two groups (p < 0.05). Furthermore, the guider group yielded superior outcomes in terms of entry point distance, operation time, fluoroscopic exposure time, and number of drilling attempts compared to the free-hand group (p < 0.05). CONCLUSIONS: Percutaneous screw guidance can improve the accuracy and safety of the posterior process of the talar screws, which can be feasible for percutaneous fixation. Further studies are required to confirm the efficacy and clinical outcomes of percutaneous screw guidance.

Robot-assisted internal fixation of calcaneal fractures versus conventional open reduction internal fixation: a systematic review and meta-analysis.

The aim of the study was to compare the efficacy and safety of robot-assisted (RA) percutaneous hollow screw fixation with traditional open reduction internal fixation (ORIF) for the treatment of calcaneal fractures through a systematic review and meta-analysis. An extensive search was conducted in the following databases-PubMed, CNKI, Embase, and the Cochrane Library-to gather research on patients with calcaneal fractures published up to July 2024. This search focuses on studies comparing the effectiveness of robot-assisted percutaneous cannulated screw fixation versus ORIF. We will include studies published in both English and Chinese. Our screening process adhered strictly to predefined inclusion and exclusion criteria, emphasizing randomized controlled trials (RCTs) and cohort studies. The ROBINS-I tool was utilized to evaluate the risk of bias in non-randomized studies. Meta-analysis was conducted using Review Manager 5.4.1. The final analysis incorporated six retrospective cohort studies comprising 247 patients-122 treated with robotic-assisted percutaneous cannulated screw fixation and 125 with conventional open reduction and internal fixation. The findings indicated that patients undergoing robotic-assisted percutaneous cannulated screw fixation experienced advantages over those receiving conventional treatment in terms of reduced hospital stay, lower estimated blood loss, and higher AOFAS scores at both 3 and 6 months. No statistically significant differences were observed between the two methods concerning operative time, fracture healing duration, or the frequency of intraoperative fluoroscopies. Robotic-assisted percutaneous cannulated screw fixation is a safe and viable treatment approach for patients with calcaneal fractures. When compared to ORIF methods, this robotic-assisted technique demonstrated significant benefits, including reduced hospital stay, lower estimated blood loss, and improved AOFAS scores at both 3 and 6 months.

Comparative effectiveness of oblique lumbar interbody fusion with anterior screw fixation versus percutaneous pedicle screw fixation for treating lumbar degenerative diseases: A systematic review and meta-analysis.

PURPOSE: Lumbar degenerative diseases impose a substantial health burden, prompting the exploration of advanced surgical approaches such as Oblique Lumbar Interbody Fusion (OLIF). This meta-analysis aims to evaluate the comparative efficacy of OLIF with anterior screw fixation (OLIF-AF) against OLIF with posterior pedicle fixation (OLIF-PF) in addressing these conditions. METHODS: A systematic search across multiple databases identified five studies meeting inclusion criteria, incorporating a total of 271 patients. Comparative analysis encompasses primary and secondary outcomes related to fusion rates, intraoperative parameters, patient-reported measures, and radiographic assessments. RESULTS: Primary outcome analysis demonstrated no statistically significant difference in total fusion rates between OLIF-AF and OLIF-PF. However, secondary outcomes revealed distinct advantages in OLIF-AF, showcasing lower intraoperative blood loss and reduced operative times compared to OLIF-PF. Nonetheless, patient-reported outcomes, encompassing measures such as pain scores and functional assessments, as well as radiographic parameters, exhibited no significant variations between the two techniques. CONCLUSION: While OLIF-AF displayed favorable results in intraoperative parameters, such as reduced blood loss and shorter operative times, it did not significantly differ in patient-reported outcomes and radiographic assessments compared to OLIF-PF. Interpretation of findings must consider limitations in sample sizes and study heterogeneity. Future investigations with larger, more diverse cohorts and extended follow-ups are imperative to confirm these preliminary findings and comprehend the actual clinical impact of these OLIF techniques in managing lumbar degenerative diseas.

A biomechanical study comparing the compression force and osseous area of contact of two screws fixation techniques used in ankle joint arthrodesis model.

INTRODUCTION: Arthrodesis of a (diseased) ankle joint is usually performed to achieve pain relief and stability. One basic principle of arthrodesis techniques includes rigid fixation of the surfaces until union. It seems plausible that stable anchoring and homogeneous pressure distribution should be advantageous, however, it has not been investigated yet. The aim is to achieve uniform compression, as this is expected to produce favorable results for the bony fusion of the intended arthrodesis. Numerous implants with different biomechanical concepts can be used for ankle fusion. In this study, headless compression screws (HCS, DePuy Synthes, Zuchwil, Switzerland) were compared biomechanically to an alternative fixation System, the IOFix device (Extremity Medical, Parsippany, NJ, USA) in regard to the distribution of the compression force (area of contact) and peak compression in a sawbone arthrodesis-model (Sawbones® Pacific Research Laboratories, Vashon, WA, USA). This study aims to quantify the area of contact between the bone interface that can be obtained using headless compression screws compared to the IOFix. In current literature, it is assumed, that a large contact surface with sufficient pressure between the bones brings good clinical results. However, there are no clinical or biomechanical studies, that describe the optimal compression pressure for an arthrodesis. MATERIAL AND METHODS: Two standardized sawbone blocks were placed above each other in a custom-made jig. IOFix and headless compression screws were inserted pairwise parallel to each other using a template for a uniform drilling pattern. All screws were inserted with a predefined torque of 0.5 Nm. Pressure transducers positioned between the two sawbone blocks were compressed for the measurement of peak compression force, compression distribution, and area of contact. RESULTS: With the IOFix, the compression force was distributed over significantly larger areas compared to the contact area of the HCS screws, resulting in a more homogenous contact area over the entire arthrodesis surface. Maximum compression force showed no significant difference. CONCLUSION: The IOFix system distributes the compression pressure over a much larger area, resulting in more evenly spread compression at the surface. Clinical studies must show whether this leads to a lower pseudarthrosis rate.

[Robot-assisted versus traditional fluoroscopy-assisted posterior fixation in treatment of thoracolumbar fractures with ankylosing spondylitis: a retrospective study].

Objective: To compare the effectiveness of robot-assisted (RA) minimally invasive surgery versus traditional fluoroscopy-assisted (FA) open posterior fixation surgery in treating thoracolumbar fractures with ankylosing spondylitis (AS). Methods: A clinical data of 21 cases of thoracolumbar fractures with AS who met the selection criteria between December 2016 and December 2023 was retrospectively analyzed. Ten cases underwent RA minimally invasive surgery group (RA group) and 11 cases underwent FA open posterior fixation surgery (FA group). There was no significant difference in gender, age, fracture segment distribution, fracture type, time from injury to surgery, visual analogue scale (VAS) score, and American Spinal Injury Association (ASIA) grading between RA group and FA group ( P>0.05). The operation time, intraoperative blood loss, radiation exposure time, radiation dose, hospital stay, and complications of the two groups were recorded. According to Gertzbein-Robbins criteria, the accuracy of screw implantation was evaluated by CT within 1 week after surgery. During follow-up, pain and nerve function were evaluated by VAS score and ASIA grading. Results: All patients underwent surgery successfully, and there was no significant difference in operation time ( P>0.05). The intraoperative blood loss and hospital stay in the RA group were significantly less than those in the FA group ( P<0.05), and the radiation exposure time and radiation dose were significantly more than those in the FA group ( P<0.05). A total of 249 pedicle screws were implanted in the two groups, including 118 in the RA group and 131 in the FA group. According to the Gertzbein-Robbins criteria, the proportion of clinically acceptable screws (grades A and B) in the RA group was significantly higher than that in the FA group ( P<0.05). Patients in both groups were followed up 3-12 months, with an average of 6.8 months. The VAS scores of the two groups after surgery were significantly lower than those before surgery, and the differences were significant ( P<0.05). The RA group had lower scores than the fluoroscopy group at 1 week and 3 months after surgery ( P<0.05). There was no significant difference in neurological function grading between groups at 1 week and 3 months after surgery ( P>0.05). In the FA group, 1 case of deep infection and 1 case of deep vein thrombosis of lower extremity occurred, while no complication occurred in the RA group, and there was no significant difference in the incidence of complications between groups ( P>0.05). Conclusion: Both RA minimally invasive surgery and FA open posterior fixation surgery can achieve good effectiveness. Compared with the latter, the former has more advantages in terms of intraoperative blood loss, hospital stay, and accuracy of pedicle screw insertion.

[Effectiveness of reduction robot combined with navigation robot-assisted minimally invasive treatment for Tile type B pelvic fractures].

Objective: To explore the effectiveness of reduction robot combined with navigation robot-assisted minimally invasive treatment for Tile type B pelvic fractures. Methods: Between January 2022 and February 2023, 10 patients with Tile type B pelvic fractures were admitted. There were 6 males and 4 females with an average age of 45.5 years (range, 30-71 years). The fractures were caused by traffic accident in 5 cases, bruising by heavy object in 3 cases, and falling from height in 2 cases. The interval between injury and operation ranged from 4-13 days (mean, 6.8 days). There were 2 cases of Tile type B1 fractures, 1 case of Tile type B2 fracture, and 7 cases of Tile type B3 fractures. After closed reduction under assistance of reduction robot, the anterior ring was fixed with percutaneous screws with or without internal fixator, and the posterior ring was fixed with sacroiliac joint screws under assistance of navigation robot. The time of fracture reduction assisted by the reduction robot was recorded and the quality of fracture reduction was evaluated according to the Matta scoring criteria. The operation time, intraoperative fluoroscopy frequency and time, intraoperative bleeding volume, and incidence of complications were also recorded. During follow-up, the X-ray film of pelvis was taken to review the fracture healing, and the Majeed score was used to evaluate hip joint function. Results: The time of fracture reduction was 42-62 minutes (mean, 52.3 minutes). The quality of fracture reduction according to the Matta scoring criteria was rated as excellent in 4 cases, good in 5 cases, and poor in 1 case, with excellent and good rate of 90%. The operation time was 180-235 minutes (mean, 215.5 minutes). Intraoperative fluoroscopy was performed 18-66 times (mean, 31.8 times). Intraoperative fluoroscopy time was 16-59 seconds (mean, 28.6 seconds). The intraoperative bleeding volume was 50-200 mL (range, 110.0 mL). No significant vascular or nerve injury occurred during operation. All patients were followed up 13-18 months (mean, 16 months). X-ray films showed that all fractures healed with the healing time of 11-14 weeks (mean, 12.3 weeks). One case of ectopic ossification occurred during follow-up. At last follow-up, the Majeed score was 70-92 (mean, 72.7), and the hip joint function was rated as excellent in 2 cases and good in 8 cases, with the excellent and good rate of 100%. Conclusion: The reduction robot combined with navigation robot-assisted minimally invasive treatment for Tile type B pelvic fractures has the characteristics of intelligence, high safety, convenient operation, and minimally invasive treatment, which can achieve reliable effectiveness.

[Effectiveness analysis of biplanar vertical fixation and inverted triangle fixation with hollow screw for Pauwels type â ¢ femoral neck fracture in young and middle-aged patients].

Objective: To compare the effectiveness of biplanar vertical fixation and inverted triangle fixation with hollow screw for Pauwels type Ⅲ femoral neck fracture in young and middle-aged patients. Methods: The clinical data of 55 young and middle-aged patients with Pauwels type Ⅲ femoral neck fracture between June 2021 and December 2022 was retrospectively analyzed. All patients were treated with closed reduction and internal fixation with hollow screws, 25 cases were treated with biplanar vertical fixation (study group), 30 cases with inverted triangle fixation (control group). There was no significant difference in gender, age, affected side, cause of injury, underlying diseases, and time from injury to operation between the two groups ( P>0.05). The operation time, intraoperative blood loss, fluoroscopy times, guide needle puncture times, starting time of weight bearing, time of full weight bearing, time of fracture healing, and complications were recorded and compared between the two groups. The hip joint function was evaluated by Harris score at 1 day, 6 months, 12 months after operation, and at last follow-up, and the pain relief was evaluated by visual analogue scale (VAS) score. The femoral neck shortening was measured on the X-ray film at last follow-up. Results: All patients were followed up 12-31 months (mean, 22.0 months), and there was no significant difference in follow-up time between the two groups ( P>0.05). The operation time, intraoperative blood loss, and fluoroscopy times in the study group were higher than those in the control group, but the difference was not significant ( P>0.05). The guide needle puncture times in the study group was more than that in the control group, and the time of starting weight bearing and the time of full weight bearing in the study group were shorter than those in the control group, the differences were significant ( P<0.05). Bony healing was achieved in both groups, and there was no significant difference in fracture healing time between the two groups ( P>0.05). No osteonecrosis of the femoral head and incision-related complication was found in the two groups during follow-up, and the femoral neck shortening length in the study group was significantly shorter than that in the control group at last follow-up ( P<0.05). There was no significant difference in Harris score between the two groups at 1 day after operation ( P>0.05), and the Harris score of the study group was significantly better than that of the control group at other time points ( P<0.05); there was no significant difference in VAS score between the two groups at each time point after operation ( P>0.05). Conclusion: Compared with the inverted triangle fixation, the treatment of Pauwels type Ⅲ femoral neck fracture with biplanar vertical fixation can effectively reduce femoral neck shortening without affecting fracture healing, and improve hip joint function in early stage.

[Application of improved carpal shoot through view in volar plate internal fixation of distal radius fractures].

Objective: To explore the application of improved carpal shoot through view (ICSTV) method in the treatment of distal radius fractures with volar plate internal fixation. Methods: The clinical data of 67 patients with distal radius fractures who met the selection criteria between January 2020 and January 2023 was retrospectively analyzed. There were 30 males and 37 females with an average age of 53.6 years (range, 18-75 years). According to the AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 25 cases of type B and 42 cases of type C. The time from injury to operation ranged from 2 to 6 days, with an average of 3.8 days. During the operation, bilateral cortical drilling was performed, and the length of the implanted screw was 1-2 mm shorter than that measured by the depth ruler. Standard anteroposterior and lateral (AAL) fluoroscopy and ICSTV fluoroscopy were performed after volar anatomic locking plate fixation, respectively. If the dorsal cortex of the distal radius was detected to be penetrated, the short screw was replaced and ICSTV fluoroscopy was performed again until no screw was penetrated. The detection rate of dorsal cortical screw penetration was compared between AAL fluoroscopy and ICSTV fluoroscopy. Postoperative CT scan was performed to confirm the presence or absence of dorsal cortical screw penetration. Results: Intraoperative AAL fluoroscopy found 5 screws penetrating the dorsal cortex in 4 patients (6.0%), and ICSTV fluoroscopy found 19 screws penetrating the dorsal cortex in 15 patients (22.4%) including the above 4 patients, with a significant difference in the detection rate between the two fluoroscopy methods [ OR=0.267 (0.084, 0.845), P=0.018]; 15 patients were replaced with short screws during operation. At the same time, ICSTV fluoroscopy detected 2 screws penetrating into the distal radioulnar joint in 2 cases (3.0%), which could not be found in AAL fluoroscopy, and the direction of the screws was adjusted and replaced. All patients were reexamined by wrist CT within 3 days after operation, and no dorsal cortical screw penetration or screw penetration into the distal radioulnar joint was found. All the 67 patients were followed up 6-18 months, with an average of 11.3 months. Extensor tendon irritation occurred in 2 patients at 3 months after operation, and no extensor tendon rupture occurred in all patients during follow-up. All fractures healed well, and the healing time was 8-13 weeks, with an average of 10.8 weeks. There was no complication such as internal fixation loosening or fracture displacement. The Gartland-Werley score at last follow-up ranged from 0 to 15, with an average of 5.6. Conclusion: ICSTV fluoroscopy can effectively detect occult dorsal cortical screw penetration of the distal radius that can not be revealed by AAL fluoroscopy.

Three-dimensional assessment of low-level laser therapy on orthodontic miniscrew displacement using CBCT: a retrospective study.

BACKGROUND: This study aimed to assess the effect of Low-Level Laser Therapy (LLLT) on sagittal, transverse and vertical Orthodontic miniscrew displacement. MATERIALS AND METHODS: The study included CBCTs from the records of 12 adult patients who underwent upper first premolar extraction and canine retraction with orthodontic miniscrews for maximum anchorage. The miniscrews on one side received LLL, while the other side served as a control. The Low-Level Laser was applied to assess its effect on the displacement of the miniscrews. The used CBCTs have been taken at two-time points: immediately after miniscrew insertion (T0) and four months after the start of canine retraction (T1) with a total of 24 CBCTs. Miniscrew displacement was assessed by measuring head (HMS) and tail (TMS) displacement to the axial, coronal and mid-sagittal planes on the CBCT at the two time points. Miniscrews displacement (T1-T0) was compared between LLL side and control side. Comparisons were performed using paired samples t-test. The significance level was set at p-value < 0.05. The reproducibility of measurements was assessed by intraclass correlation coefficient (ICC). RESULTS: After four months of canine retraction, HMS and TMS from both laser and control sides showed significant three-dimensional displacement at p < 0.05. No significant difference in mean displacement in the vertical, sagittal, nor transverse planes between both sides was elicited. CONCLUSION: LLL application in the used protocol does not affect the amount of miniscrew displacement in any of the three planes of space. Miniscrew displacement was significant in both groups.