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Background Now, using a suture-button device to treat distal tibiofibular syndesmotic injuries is overwhelming due to its advantages over screw fixation. Current systematic review was conducted to make a comparison between suture-button fixation and traditionally screw fixation in the treatment of syndesmotic injuries. The outcomes included functional outcomes, implant removal, implant failure, malreduction, post-operative complications (except implant failure and malreduction), and cost-effectiveness aspects. Method A literature search in the electronic databases of Medline, Embase, the Cochrane Library, Web of Science was conducted to identify studies until March 2017. The references of the included articles were also checked for potentially relevant studies. Only English articles were included. We followed the Preferred Reporting Items for Systematics reviews and Meta-Analysis (PRISMA) guidelines in this review. Results Finally, 10 studies were identified, encompassing a total of 390 patients. The mean American Orthopaedic Foot and Ankle Society ankle score (AOFAS) score of 150 patients treated with the suture-button device was 91.06 points, with an average follow-up of 17.58 months, and the mean AOFAS score of 150 patients treated with syndesmotic screws was 87.78 points, with an average follow-up of 17.73 months. Implant removal was reported in 5 of 134 (3.7%) patients treated with the suture-button device, and in 54 of 134 (40.2%) patients treated with the syndesmotic screw. No patient in the suture-button fixation group had implant failure, however the rate of implant failure in the screw fixation group was 30.9%. Malreduction was reported in 1 of 93 (1.0%) patients treated with the suture-button device, and in 12 of 95 (12.6%) patients treated with the syndesmotic screw. The rate of post-operative complications in the suture-button fixation group was 12.0% and 16.4% in the screw fixation group. There was only one publication demonstrated about cost-effectiveness aspects, it showed that patients treated with the suture-button device spent on average $1482 less and had a higher quality of life by 0.058 quality-adjusted life-year compared with patients who received fixation with 2 syndesmotic screws in supination-external rotation type 4 injuries. Conclusion Based on our research, though the suture-button fixation group had similar functional outcome (measured on the AOFAS score) and post-operative complication rate compared with the syndesmotic screw fixation group, the suture-button device could lead to better objective range of motion (ROM) measurements and earlier return to work. Besides, the suture-button fixation group had lower rate of implant removal, implant failure, and malreduction. However, high-quality randomized controlled trials with more uniformity in outcome reporting are desirable to determine the long-term effects and cost-effectiveness of the suture-button device.

Finite element analysis is commonly used to assist in the development and evaluation of orthopedic devices. The physics of these models are simplified through approximations that enable more efficient simulations, without compromising the accuracy of the relative comparisons between implant designs or configurations. This study developed and evaluated a technique to approximate the behavior of a finely threaded screw using a smooth cylinder with the threads implicitly represented through interfacial contact conditions. This pseudo-threaded model was calibrated by comparing to simulations that explicitly modeled the thread geometry with frictional contact. A parametric analysis was performed with a single screw-in-bone system, five loading directions, and three Young׳s moduli that span the range of cancellous bone (200, 600, and 1,000MPa). Considering that screw cut-out from cancellous bone is a critical clinical issue in the osteoporotic proximal humerus, the pseudo-threaded model was compared with a bonded interface to examine three different screw configurations in a 3-part proximal humerus fracture across 10 patients. In the single screw-in-bone system, the pseudo-threaded model predicted the screw displacement of the explicitly threaded model with 1–5% difference and estimated the strain distributions and magnitudes more accurately than a bonded interface. Yet, the relative comparisons of implant stability across the three different screw configurations in the proximal humerus were not affected by the modeling choice for the bone–screw interface. Therefore, the bonded interface could serve as a more efficient methodology for making relative comparisons between implants that utilize the same thread profile.

The interference screw fixation method is used to secure a graft in the tibial tunnel during anterior cruciate ligament reconstruction surgery. However, several complications have been reported, such as biodegradable screw breakage, inflammatory or foreign body reaction, tunnel enlargement, and delayed graft healing. Using additive manufacturing (AM) technology, we developed a titanium alloy (Ti6Al4V) interference screw with chemically calcium phosphate surface modification technology to improve bone integration in the tibial tunnel. After chemical and heat treatment, the titanium screw formed a dense apatite layer on the metal surface in simulated body fluid. Twenty-seven New Zealand white rabbits were randomly divided into control and additive manufactured (AMD) screw groups. The long digital extensor tendon was detached and translated into a tibial plateau tunnel (diameter: 2.0 mm) and transfixed with an interference screw while the paw was in dorsiflexion. Biomechanical analyses, histological analyses, and an imaging study were performed at 1, 3, and 6 months. The biomechanical test showed that the ultimate pull-out load failure was significantly higher in the AMD screw group in all tested periods. Micro-computed tomography analyses revealed early woven bone formation in the AMD screw group at 1 and 3 months. In conclusion, AMD screws with bioactive surface modification improved bone ingrowth and enhanced biomechanical performance in a rabbit model.

Surgery for intertrochanteric fractures using intramedullary hip nails (IHNs) is among the most common surgical procedures in the orthopedic field. Although IHNs provide good overall outcomes, they sometimes cause complications, such as loss of reduction and cut-out. Here, we investigated the usefulness of IHNs with an anterior offset (Best Fit Nail® [BFN]) in maintaining fragment reduction and ensuring proper lag screw position compared with conventional non-offset nails (Proximal Femoral Nail Antirotation® [PFNA]), using postoperative computed tomography (CT). Fifty consecutive patients with intertrochanteric fractures who underwent surgery with BFNs (BFN group) and 50 patients who underwent surgery with PFNAs (PFNA group) were retrospectively analyzed. Indices evaluated by postoperative CT were displacement distance of proximal fragment relative to distal fragment, reduction status (intramedullary, anatomical, and extramedullary types), lag screw direction, and angle between lag screw and femoral neck axis (deviation angle). Median [interquartile range] displacement distance was significantly smaller in the BFN group (0 [0, 0] mm) compared with the PFNA group (5.2 [3.6, 7.1] mm) (p<0.001). Reduction status was significantly better in the BFN group (anatomical type, 40 cases; intramedullary type, in 9 cases, and extramedullary type in 1 case) than in the PFNA group (anatomical type, 6 cases; intramedullary type, 43 cases; extramedullary type, 1 case) (p<0.001). Deviation of lag screw direction was observed in significantly fewer cases in the BFN group (20 cases; 40%) compared with the PFNA group (36 cases; 72%). Lag screw deviation angle was significantly smaller in the BFN group (-0.71°±4.0°) compared with the PFNA group (6.9°±7.1°). No adverse events related to surgery were observed in either group. Intertrochanteric fracture surgery using offset BFNs exhibited significantly smaller displacement distance, better reduction status, and higher frequency of no deviation with central lag screw position, compared with surgery using non-offset PFNAs.

Objectives To examine and compare the stability of buccal shelf mini-screws using self-drilling and pre-drilling implant placement techniques. Methodology It was a split-mouth, randomized controlled trial comprising of 7 patients, each receiving two buccal shelf bone screws. The screws were placed using a self-drilling protocol in one quadrant and a pre-drilling protocol in the opposing quadrant decided via coin toss randomization. Stability was examined at the time of placement and 1,2, 3 and 4 months thereafter, using the Resonance Frequency Analysis method with the Osstell Beacon TM device. The Implant Stability Quotient (ISQ) obtained was then compared and assessed between both quadrants. Friedman’s Two-Way Analysis of Variance and the Wilcoxon signed rank test were utilized for the intergroup comparison. A statistically significant result was defined as one with a p-value of less than 0.05. Results A statistically significant difference between the mean ISQ reading in the pre-drilling and self-drilling group was observed, indicating higher stability of bone screws placed with the pre-drilling protocol. The primary stability of the buccal shelf screws decreased after placement, but the secondary stability remained stable. Conclusion Buccal shelf bone screws placed with a pre-drilling protocol depicted greater primary and secondary stability as compared to the self-drilling protocol, as depicted by the ISQ readings obtained. Resonance Frequency Analysis can be used as a valuable tool to assess the stability of buccal shelf bone screws. Clinical relevance The use of buccal shelf screws has increased tremendously over the past few years due to their myriad applications and have now become an essential part of an orthodontist’s armamentarium. It is therefore essential for clinicians to be well-informed about all aspects of their use including insertion techniques. The results of this trial indicate that the pre-drilling protocol provides better stability and therefore treatment outcomes.

This is an experimental study on human cadaver spines. The objective of this study is to compare the pullout forces between three screw augmentation methods and two different screw designs. Surgical interventions of patients with osteoporosis increase following the epidemiological development. Biomechanically the pedicle provides the strongest screw fixation in healthy bone, whereas in osteoporosis all areas of the vertebra are affected by the disease. This explains the high screw failure rates in those patients. Therefore PMMA augmentation of screws is often mandatory. This study involved investigation of the pullout forces of augmented transpedicular screws in five human lumbar spines (L1–L4). Each spine was treated with four different methods: non-augmented unperforated (solid) screw, perforated screw with vertebroplasty augmentation, solid screw with vertebroplasty augmentation and solid screw with balloon kyphoplasty augmentation. Screws were augmented with Polymethylmethacrylate (PMMA). The pullout forces were measured for each treatment with an Instron testing device. The bone mineral density was measured for each vertebra with Micro-CT. The statistical analysis was performed with a two-sided independent student t test. Forty screws (10 per group and level) were inserted. The vertebroplasty-augmented screws showed a significant higher pullout force (mean 918.5 N, P  = 0.001) than control (mean 51 N), the balloon kyphoplasty group did not improve the pullout force significantly (mean 781 N, P  > 0.05). However, leakage occurred in some cases treated with perforated screws. All spines showed osteoporosis on Micro-CT. Vertebroplasty-augmented screws, augmentation of perforated screws and balloon kyphoplasty augmented screws show higher pullout resistance than non-augmented screws. Significant higher pullout forces were only reached in the vertebroplasty augmented vertebra. The perforated screw design led to epidural leakage due to the position of the perforation in the screw. The position of the most proximal perforation is critical, depending on screw design and proper insertion depth. Nevertheless, using a properly designed perforated screw will facilitate augmentation and instrumentation in osteoporotic spines.

Purpose Cancellous bone harvested from the distal radius has been used in various hand surgeries, but studies on its use in scaphoid waist nonunions are insufficient. We investigated the usefulness of cancellous bone graft from the distal radius and headless screw fixation in unstable scaphoid waist nonunion. Methods Thirty-one patients who underwent cancellous bone graft from the distal radius and headless screw fixation for unstable scaphoid waist nonunion with follow-up for at least 1 year were included. Bone union time, the number of patients with bone union at six and 12 weeks, total number of patients with bone union at last follow-up, and bone union on the computed tomography (CT) image at postoperative six weeks were evaluated. Further, pre- and postoperative radiological measurements, such as scaphoid length and height, lateral intra-scaphoid angle, and height-to-length ratio, and functional outcomes were compared. Additionally, inter-observer reliability of radiologic parameters was checked. Results Bone union was achieved in 29 patients. There were two nonunions (6.5%). Bone union time was 10.7 (range, 6–26) weeks. Eighteen (58%) and 25 patients (80.6%) were diagnosed with bone union on the plain radiographs at six and 12 weeks, respectively. Twenty-two patients (71%) were diagnosed with bone union on CT performed at six weeks. Radiological measurements and functional outcomes improved postoperatively. The scaphoid length showed good inter-observer agreement. Conclusions In treating unstable scaphoid waist nonunion, cancellous bone graft from the distal radius and headless screw fixation achieved 93.5% union and improved radiological measurements as well as functional outcomes.

Background Screw loosening is a commonly reported issue following spinal screw fixation and can lead to various complications. The initial cause of screw loosening is biomechanical deterioration. Previous studies have demonstrated that modifications in screw design can impact the local biomechanical environment, specifically the stress distribution on bone-screw interfaces. There are several different designs of screw tips available for clinically used pedicle screws; however, it remains unclear whether these variations affect the local stress distribution and subsequent screw anchorage ability. Methods This study conducted comprehensive biomechanical research using polyurethane foam mechanical tests and corresponding numerical simulations to investigate this topic. Models of pedicle screw-fixed osteoporotic polyurethane foam were created with two different clinically used screw tip designs (flat and steep) featuring varying tip lengths, taper angles, and diameters, as well as identical flank overlap areas and thread designs. The anchorage ability of the different models was assessed through toggle and pull-out test. Additionally, numerical mechanical models were utilized to compute the stress distributions at the screw and bone-screw interfaces in the different models. Results Mechanical tests revealed superior anchorage ability in models utilizing flat-tipped screws. Furthermore, numerical modeling indicated improved anchorage ability and reduced stress concentration tendency in these models. Conclusion Changes in screw tip design can significantly impact the biomechanical anchoring capability of screws. Specifically, flatter tip pedicle screws may mitigate the risk of screw loosening by alleviating stress concentration on bone-screw interfaces.

Bone screws are used in orthopaedic surgery for fracture fixation. Correctly torquing the screws is important for fixation quality. Over-tightening may strip the threads, while under-tightening may result in loosening over time. This paper focuses on testing an approach where strength is estimated using screw insertion data from torque and rotation sensors, and stripping torque is predicted based on this strength. A common type of bone screw was inserted until stripping 10 times each into 8 types of polyurethane surrogate for bone. The torque–rotation data from the insertion was used to identify the material strength and estimate the stripping torque and compared with the experimental maximum torque. A good relationship was found between the estimated/predicted and true stripping torques (r = 0.926, 95% confidence interval (C.I.) [0.886, 0.952]), with a mean error of 18%. Additionally, the intermediate identified strength values were found to be highly correlated with the data-sheet values for the materials (r = 0.977, 95% C.I. [0.964, 0.985]). These outcomes demonstrate the viability and significance of this concept in general, although more development and testing is required for broad clinical applicability; such tests would be extended for more types of bone screws and use a large set of human bone samples to better reflect the natural variability.

Background and Objectives: Valgus-impacted femoral neck fractures (OTA 31B1.1 and 31B1.2) are considered stable fractures with favorable outcomes compared to displaced fractures. However, complications such as femoral neck shortening, screw sliding, and suboptimal recovery can occur, particularly in severe deformities. This study evaluated the outcomes of a sequential fixation technique using short-threaded screws followed by long-threaded screws. Materials and Methods: This prospective study included 135 patients aged 60 years or older with valgus-impacted femoral neck fractures (OTA 31B1.1 and 31B1.2) treated between March 2017 and February 2021. Patients were divided into two groups: those treated solely with short-threaded screws (the control group) and those treated using a sequential fixation technique involving initial compression with short-threaded screws followed by stabilization with long-threaded screws. Exclusion criteria included follow-up < 12 months, pathological fractures, high-energy trauma, or periprosthetic fractures. Clinical outcomes, including the Harris Hip Score (HHS), and radiological parameters, such as screw sliding distance (SDS) and fixation failure, were analyzed. Multivariate regression identified predictors of outcomes to assess the effectiveness of the sequential fixation technique. Results: The mean follow-up was 38.3 months. Multivariate regression revealed that posterior tilt > 15° (β = 2.944, p < 0.001) and the use of long-threaded screws (β = −1.906, p < 0.001) were significant predictors of reduced SDS. Posterior tilt > 15° (OR 15.085, p = 0.002), valgus tilt > 15° (OR 28.616, p = 0.002), and bone mineral density (OR 0.285, p = 0.005) were predictors of fixation failure, while long-threaded screws significantly reduced fixation failure risk (OR 0.062, p = 0.005). Conclusions: The sequential use of short-threaded screws for compression, followed by long-threaded screws for stabilization, effectively reduced screw sliding and fixation failure while improving functional and radiological outcomes. This technique shows promise as an effective treatment for valgus-impacted femoral neck fractures.