Freehand distal interlocking of intramedullary nails is technical demanding and prone to handling issues. It requires the surgeon to precisely place a screw through the nail under x-ray. If not performed accurately it can be a time consuming and radiation expensive procedure. The aims of this study were to assess construct and face validity of a new training device for distal interlocking of intramedullary nails. 53 participants (29 novices and 24 experts) were included. Construct validity was evaluated by comparing simulator metrics (number of x-rays, nail hole roundness, drill tip position and accuracy of the drilled hole) between experts and novices. Face validity was evaluated by means of a questionnaire concerning training potential and quality of simulated reality using a 7-point Likert scale (range 1-7). Mean realism of the training device was rated 6.3 (range 4-7) and mean training potential as well as need for distal interlocking training was rated 6.5 (range 5-7) with no significant differences between experts and novices, p≥0.236. All participants stated that the simulator is useful for procedural training of distal nail interlocking, 96% would like to have it at their institution and 98% would recommend it to their colleagues. Total number of x-rays were significantly higher for novices (20.9±6.4 vs. 15.5±5.3), p=0.003. Successful task completion (hit the virtual nail hole with the drill) was significantly higher in experts (p=0.04; novices hit: n=12; 44,4%; experts hit: n=19; 83%). The evaluated training device for distal interlocking of intramedullary nails yielded high scores in terms of training capability and realism. Furthermore, construct validity was established as it reliably discriminates between experts and novices. Participants see a high further training potential as the system may be easily adapted to other surgical task requiring screw or pin position with the help of x-rays

Unstable distal tibia fractures are challenging injuries requiring surgical treatment. Intramedullary nails are frequently used; however, distal fragment fixation problems may arise, leading to delayed healing, malunion or nonunion. Recently, a novel angle-stable locking nail design has been developed that maintains the principle of relative construct stability, but introduces improvements expected to reduce nail toggling, screw migration and secondary loss of reduction, without the requirement for additional intraoperative procedures. The aim of this study was to investigate the biomechanical competence of a novel angle-stable intramedullary nail concept for treatment of unstable distal tibia fractures, compared to a conventional nail in a human cadaveric model under dynamic loading. Ten pairs of fresh-frozen human cadaveric tibiae with a simulated AO/OTA 42-A3.1 fracture were assigned to 2 groups for reamed intramedullary nailing using either a conventional (non-angle-stable) Expert Tibia Nail with 3 distal screws (Group 1) or the novel Tibia Nail Advanced system with 2 distal angle-stable locking low-profile screws (Group 2). The specimens were biomechanically tested under conditions including quasi-static and progressively increasing combined cyclic axial and torsional loading in internal rotation until failure of the bone-implant construct, with monitoring by means of motion tracking. Initial axial construct stiffness, although being higher in Group 2, did not significantly differ between the 2 nail systems, p=0.29. In contrast, initial torsional construct stiffness was significantly higher in Group 2 compared to Group 1, p=0.04. Initial nail toggling of the distal tibia fragment in varus and flexion was lower in Group 2 compared to Group 1, being significant in flexion, p=0.91 and p=0.03, respectively. After 5000 cycles, interfragmentary movements in terms of varus, flexion, internal rotation, axial displacement and shear displacement at the fracture site were all lower in Group 2 compared to Group 1, with flexion and shear displacement being significant, p=0.14, p=0.04, p=0.25, p=0.11 and p=0.04, respectively. Cycles to failure until both interfragmentary 5° varus and 5° flexion were significantly higher in Group 2 compared to Group 1, p=0.04. From a biomechanical perspective, the novel angle-stable intramedullary nail concept has the potential of achieving a higher initial axial and torsional relative stability and maintaining it with a better resistance towards loss of reduction under dynamic loading, while reducing the number of distal locking screws, compared to conventional locking in intramedullary nailed unstable distal tibia fractures

Freehand distal interlocking of intramedullary nails remains a challenging task. If not performed correctly it can be a time consuming and radiation expensive procedure. Recently, the AO Research Institute developed a new training device for Digitally Enhanced Hands-on Surgical Training (DEHST) that features practical skills training augmented with digital technologies, potentially improving surgical skills needed for distal interlocking. Aim of the study: To evaluate weather training with DEHST enhances the performance of novices without surgical experience in free-hand distal nail interlocking compared to a non-trained group of novices. 20 novices were assigned in two groups and performed distal interlocking of a tibia nail in an artificial bone model. Group 1: DEHST trained novices (virtual locking of five nail holes during one hour of training). Group 2: untrained novices without DEHST training. Time, number of x-rays, nail hole roundness, critical events and success rates were compared between the groups. Time to complete the task (sec.) and x-ray exposure (µGcm2) were significantly lower in Group1 414.7 (290–615) and 17.8 (9.8–26.4) compared to Group2 623.4 (339–1215) and 32.6 (16.1–55.3); p=0.041 and 0.003. Perfect circle roundness (%) was 95.0 (91.1–98.0) in Group 1 and 80.8 (70.1–88.9) in Group 2; p<0.001. In Group 1 90% of the participants achieved successful completion of the task (hit the nail with the drill), whereas only 60% of the participants in group 2 achieved this; p=0.121. Training with DEHST significantly enhances the performance of novices without surgical experience in distal interlocking of intramedullary nails. Besides radiation exposure and operation time the com-plication rate during the operation can be significantly reduced

Objectives. The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method. Methods. In this matched case study, 16 adult patients underwent 19 tibial lengthening over nails (LON) procedures. For the matched case group, 17 patients who underwent 19 Ilizarov tibial lengthenings were retrospectively matched to the LON group. Results. The mean external fixation time for the LON group was 2.6 months and for the matched case group was 7.6 months. The mean lengthening amounts for the LON and the matched case groups were 5.2 cm and 4.9 cm, respectively. The radiographic consolidation time in the LON group was 6.6 months and in the matched case group 7.6 months. Using a clinical and radiographic outcome score that was designed for this study, the outcome was determined to be excellent in 17 and good in two patients for the LON group. The outcome was excellent in 14 and good in five patients in the matched case group. The LON group had increased blood loss and increased cost. The LON group had four deep infections; the matched case group did not have any deep infections. Conclusions. The outcomes in the LON group were comparable with the outcomes in the matched case group. The LON group had a shorter external fixation time but experienced increased blood loss, increased cost, and four cases of deep infection. The advantage of reducing external fixation treatment time may outweigh these disadvantages in patients who have a healthy soft-tissue envelope. Cite this article: J. E. Herzenberg. Tibial lengthening over intramedullary nails: A matched case comparison with Ilizarov tibial lengthening. Bone Joint Res 2016;5:1–10. doi: 10.1302/2046-3758.51.2000577

The fixation of comminuted femoral fractures with intramedullary nails is commonplace but there remains little work on the mechanical ability of the different diameters of nail available to resist bending. What previous work there is has produced conflicting conclusions. The bending stiffness against the intramedullary nail diameter and the extent of the comminuted fracture is clinically important due to the impact on fracture healing and implant failure. Intramedullary nails of differing diameters (10 mm, 11 mm and 13 mm) were loaded axially in fourth generation composite femurs with increasing mid shaft bone defects, namely 3cm, 5cm, 8cm and 10cm bones. The loading versus the displacement was recorded for each nail. A one-way ANOVA analysis demonstrated a significant difference between intramedullary nail diameters and the bending stiffness, with p values of less than 0.012; 3cm mean 12.26 (CI 9.06-15.46) mm, p=0.012; 5 cm mean 10.63 (CI 8.35-12.92) mm, p=<0.001; 8 cm mean 11.04 (CI 8.35-13.74) mm, p=<0.001; 10 cm mean 11.68 (CI 7.86-15.50) mm, p=<0.001. For the 11 mm diameter intramedullary nail, failure occurred at around two times the body weight of an average individual or 1400 to 1800 N. A repeated measure ANOVA analysis of the effect of the increasing bone defect showed a mixed picture, with a significant difference between the 5 cm and 8 cm gap and only a trend towards significance between 5 cm and 10 cm. Caution should be advised when considering using a cannulated femoral intramedullary nail in a patient with a fracture gap of greater than 5 cm. Further, the mechanical effect of comminuted fractures treated with nails suggests reduced stiffness with increasing length of fracture gap although the picture is complex and explains the divergence of research conclusions

There is a growing trend towards using pre-clinical models of atrophic non-union. This study investigated different fixation devices, by comparing the mechanical stability at the fracture site of tibia bone fixed by either intramedullary nail, compression plate or external fixator. 40 tibias from adult male Wistar rats' cadavers were osteotomised at the mid-shaft and a gap of 1 mm was created and maintained at the fracture site to simulate criteria of atrophic non-union model. These were divided into five groups (n=8 in each): the first group was fixed with 20G intramedullary nail, the second group with 18G nail, the third group with 4-hole plate, the fourth group with 6-hole plate, and the fifth group with external fixator. Tibia was harvested by leg disarticulation from the knee and ankle joints, the soft tissues were carefully removed from the leg, and tibias were kept hydrated throughout the experiment. Each group was then subdivided into two subgroups for mechanical testing: one for axial loading (n=4) and one for 4-point bending (n=4). Statistical analysis was carried out by ANOVA with a fisher post-hoc comparison between groups. A p-value less than 0.05 was considered statistically significant. Axial load to failure data and stiffness data revealed that intramedullary nails are significantly stronger and stiffer than other devices, however there was no statistically significant difference axially between the nail thicknesses. In bending, load to failure revealed that 18G nails are significantly stronger than 20G. We concluded that 18G nail is superior to the other fixation devices, therefore it has been used for in-vivo experiments to create a novel model of atrophic non-union with stable fixation

Background. Currently about 4–6% of all femur fractures consist of distal femoral fractures. Different methods and implants have been used for the surgical treatment of distal femoral fractures, including intramedullary nails. Retrograde nail. By contrast with antegrade nails, surgical approach or retrograde nailing exposes the knee joint which may lead to tendency of infection and increased knee pain. Present study aims to compare the biomechanical behaviour of distal angular condyler femoral intramedullary nail (DACFIN), retrograde nail and plate fixation. Methods. Fifteen 4th generation Saw bones were used to evaluate the biomechanical differences between the groups (Group 1: Plate fixation, Group 2: Retrograde nailing, Group 3: DACFIN; (n=5)). Biomechanical test was performed by using an electromechanical test device Shimadzu (AG-IS 5kN, Japan). Displacement values were recorded by using a Non-contact Video Extensometer (DVE-101/201, Shimadzu, Japan) during the loading each femur with 5 cycles of 500 N at a rate of 10 N/s to determine axial stiffness. The faliure stiffness was measured by axial load to each constructat a displacement rate of 5 mm/min. Torsional loading applied to all groups in amount of 6 Nm of torque with a velocity of 18 degrees/min. Results. The mean torsion stiffness value of Group 3 (6.33 Nm/degree) was signifacantly higher than Group 1 (1.18 Nm/degree) and Group 2 (2.11Nm/degree), p<0.05). The failure stiffness, Group 3 (1725 N/mm) was significantly higher than Group 1 (1275 N/ mm) and Group 2 (1290 N/mm). However, In axial stiffness, the mean value of Group 2 (2554 N/mm) was higher than Group 3 (1822 N/mm), and signifantly higher than Group 1(468 N/mm), p<0.05). Conclusions. DACFIN is more stiffer than retrograde nail and plate fixation during torsional and failure load conditions. But in axial stiffness retrograde nail was stiffer. DACFIN provide intramedullary femur condyle fracture fixations without open knee joint. Level of evidence. Level 5. Disclosure. Authors declare that there is no conflict of interest related to the present study

Malpositioning of the trochanteric entry point during the introduction of an intramedullary nail may cause iatrogenic fracture or malreduction. Although the optimal point of insertion in the coronal plane has been well described, positioning in the sagittal plane is poorly defined. . The paired femora from 374 cadavers were placed both in the anatomical position and in internal rotation to neutralise femoral anteversion. A marker was placed at the apparent apex of the greater trochanter, and the lateral and anterior offsets from the axis of the femoral shaft were measured on anteroposterior and lateral photographs. Greater trochanteric morphology and trochanteric overhang were graded. The mean anterior offset of the apex of the trochanter relative to the axis of the femoral shaft was 5.1 mm (. sd. 4.0) and 4.6 mm (. sd. 4.2) for the anatomical and neutralised positions, respectively. The mean lateral offset of the apex was 7.1 mm (. sd. 4.6) and 6.4 mm (. sd. 4.6), respectively. Placement of the entry position at the apex of the greater trochanter in the anteroposterior view does not reliably centre an intramedullary nail in the sagittal plane. Based on our findings, the site of insertion should be about 5 mm posterior to the apex of the trochanter to allow for its anterior offset. Cite this article: Bone Joint J 2014;96-B:1274–81

There is a growing trend towards using pre-clinical models of atrophic non-union. This study investigated different fixation devices, by comparing the mechanical stability at the fracture site of tibia bone fixed by either intramedullary nail, compression plate or external fixator. 40 tibias from adult male Wistar rats' cadavers were osteotomised at the mid-shaft and a gap of 1 mm was created and maintained at the fracture site to simulate criteria of atrophic non-union model. These were divided into five groups (n=8 in each): the first group was fixed with 20G intramedullary nail, the second group with 18G nail, the third group with 4-hole plate, the fourth group with 6-hole plate, and the fifth group with external fixator. Tibia was harvested by leg disarticulation from the knee and ankle joints, the soft tissues were carefully removed from the leg, and tibias were kept hydrated throughout the experiment. Each group was then subdivided into two subgroups for mechanical testing: one for axial loading (n=4) and one for 4-point bending (n=4). Statistical analysis was carried out by ANOVA with a fisher post-hoc comparison between groups. A p-value less than 0.05 was considered statistically significant. Axial load to failure data and stiffness data revealed that intramedullary nails are significantly stronger and stiffer than other devices, however there was no statistically significant difference axially between the nail thicknesses. In bending, load to failure revealed that 18G nails are significantly stronger than 20G. We concluded that 18G nail is superior to the other fixation devices, therefore it has been used for in-vivo experiments to create a novel model of atrophic non-union with stable fixation

The stress response to trauma is the summation of the physiological response to the injury (the ‘first hit’) and by the response to any on-going physiological disturbance or subsequent trauma surgery (the ‘second hit’). Our animal model was developed in order to allow the study of each of these components of the stress response to major trauma. High-energy, comminuted fracture of the long bones and severe soft-tissue injuries in this model resulted in a significant tropotropic (depressor) cardiovascular response, transcardiac embolism of medullary contents and activation of the coagulation system. Subsequent stabilisation of the fractures using intramedullary nails did not significantly exacerbate any of these responses

Tibial shaft fractures require surgical stabilization preferably by intramedullary nailing. However, patients often report functional limitations even years after the injury. This study investigates the influence of the surgical approach (transpatellar vs. parapatellar) on gait performance and patient reported outcome six months after surgery. Twenty-two patients with tibial shaft fractures treated by intramedullary nailing through a transpatellar approach (TP: n=15, age 41±15, BMI 24±3) or a parapatellar approach (PP: n=7, age 34±15, BMI 23±2) and healthy, matched controls (n=22, age 39±13, BMI 24±2) were assessed by instrumented motion analysis six months after intramedullary nailing. Short musculoskeletal function assessment questionnaire (SMFA) as well as kinematic and kinetic gait data were collected during level walking. Comparisons among approach methods and control group were performed by analysis of variance and Mann-Whitney test. Six months after surgery, knee kinetics in both groups differed significantly compared to controls (p <.04). The approach method affected gait speed (TP: p = .002; PP: p = .08) and knee kinematics in the early stance phase (TP: p = .011; PP: p = .082), with the parapatellar approach showing a more favorable outcome. However, the difference between patient groups was not significant for any of the assessed gait parameters (p > .2). Also, no differences could be found in the bother index (BI) or function index (FI) of SMFA between surgical approach methods (BI: TP: Mdn = 7.2, PP: Mdn = 9.4; FI: TP: Mdn = 10.3, PP: Mdn = 9.2, p > .7). Our study demonstrates, that six months after surgery for tibial shaft fractures functional limitations remain. These limitations appear not to be different for either a trans- or a parapatellar approach for the insertion of the intramedullary nail. The findings of this study are limited by the relatively short follow up time period and small number of patients. Future studies should investigate the source of the functional limitation after intramedullary nailing of tibial shaft fractures

Introduction. Inaccurate identification of implants on X-rays may lead to prolonged surgical duration as well as increased complexity and costs during implant removal. Deep learning models may help to address this problem, although they typically require large datasets to effectively train models in detecting and classifying objects, e.g. implants. This can limit applicability for instances when only smaller datasets are available. Transfer learning can be used to overcome this limitation by leveraging large, publicly available datasets to pre-train detection and classification models. The aim of this study was to assess the effectiveness of deep learning models in implant localisation and classification on a lower limb X-ray dataset. Method. Firstly, detection models were evaluated on their ability to localise four categories of implants, e.g. plates, screws, pins, and intramedullary nails. Detection models (Faster R-CNN, YOLOv5, EfficientDet) were pre-trained on the large, freely available COCO dataset (330000 images). Secondly, classification models (DenseNet121, Inception V3, ResNet18, ResNet101) were evaluated on their ability to classify five types of intramedullary nails. Localisation and classification accuracy were evaluated on a smaller image dataset (204 images). Result. The YOLOv5s model showed the best capacity to detect and distinguish between different types of implants (accuracy: plate=82.1%, screw=72.3%, intramedullary nail=86.9%, pin=79.9%). Screw implants were the most difficult implant to detect, likely due to overlapping screw implants visible in the image dataset. The DenseNet121 classification model showed the best performance in classifying different types of intramedullary nails (accuracy=73.7%). Therefore, a deep learning model pipeline with the YOLOv5s and DenseNet121 was proposed for the most optimal performance of automating implants localisation and classification for a relatively small dataset. Conclusion. These findings support the potential of deep learning techniques in enhancing implant detection accuracy. With further development, AI-based implant identification may benefit patients, surgeons and hospitals through improved surgical planning and efficient use of theatre time

Proximal humeral shaft fractures are commonly treated with long straight plates or intramedullary nails. Helical plates might overcome the downsides of these techniques as they are able to avoid the radial nerve distally. The aim of this study was to investigate in an artificial bone model: (1) the biomechanical competence of different plate designs and (2) to compare them against the alternative treatment option of intramedullary nails. Twenty-four artificial humeri were assigned in 4 groups and instrumented as follows: group1 (straight 10-hole-PHILOS), group2 (MULTILOCK-nail), group3 (45°-helical-PHILOS) and group4 (90°-helical-PHILOS). An unstable proximal humeral shaft fracture was simulated. Specimens were tested under quasi-static loading in axial compression, internal/external rotation and bending in 4 directions monitored by optical motion tracking. Axial displacement (mm) was significantly lower in group2 (0.1±0.1) compared to all other groups (1: 3.7±0.6; 3: 3.8±0.8; 4: 3.5±0.4), p<0.001. Varus stiffness in group2 (0.8±0.1) was significantly higher compared to groups1+3, p≤0.013 (1: 0.7±0.1; 3: 0.7±0.1; 4: 0.8±0.1). Varus bending (°) was significantly lower in group2 compared to all other groups (p<0.001) and group4 to group1, p=0.022. Flexion stiffness in group1 was significantly higher compared to groups2+4 (p≤0,03) and group4 to group1, p≤0,029 (1: 0.8±0.1; 2: 0.7±0.1; 3: 0.7±0.1; 4: 0.6±0.1). Flexion bending (°) in group4 was higher compared to all other groups (p≤0.024) and lower in group2 compared to groups1+4, p≤0.024. Torsional stiffness remained non significantly different, p≥0.086. Torsional deformation in group2 was significantly higher compared to all other groups, p≤0.017. Shear displacement remained non significantly different, p≥0.112. From a biomechanical perspective, helical plating with 45° and 90° may be considered as a valid alternative fixation technique to standard straight plating of proximal third humeral fractures. Intramedullary nails demonstrated higher axial and bending stiffness as well as lower fracture gap movements during axial loading compared to all plate designs. However, despite similar torsional stiffness they were associated with higher torsional movements during internal/external rotation as compared to all investigated plate designs

Introduction. Hip fractures, with a global age-standardised incidence rate (per 100,000 population) of 187.2 (2019), are a major public health problem. With a 7.71 billion population worldwide in 2019, hip fractures, in general, are affecting around 14.43 million people per year globally. We aim to provide a nationwide epidemiological analysis of trochanteric fractures and their respective surgical treatments. In this study we research the epidemiology of trochanteric and subtrochanteric fractures, as well as their most common kinds of osteosynthesis, on a nationwide scale in Germany. Method. Data was retrieved from the national database of the German Ministry of Interior. ICD-10-GM and OPS-data from the period of 2006-2020 were analyzed, all patients with trochanteric/subtrochanteric fractures were included. Patients were grouped by age/gender and linear-regression was performed to calculate statistically significant correlations between variables/incidences. Result. 985,104 trochanteric and 178,810 subtrochanteric-fractures were reported during the analyzed period. This calculates to a mean incidence of 80.08±6.34 for pertrochanteric and 14.53±1.50 for subtrochanteric fractures per-million-inhabitants. In both fracture-types, a distinct dependence of incidence on age can be seen. Incidence rates equally rise in both sexes through the age groups with an increase of about 288-fold from those under 60 to those over the age of 90 in pertrochanteric fractures. Intramedullary nailing was the most common kind of treatment for both fracture types with augmentative cerclages on the rise throughout the whole period. Dynamic compression screws were decreasing in frequency. Conclusion. We found an ongoing increase of incidence among the elderly and an increase in intramedullary nailing as well as augmentative cerclages. Not only could we show an age-dependence of the incidences, but also a sex-dependence that seems to remain consistent in its development. While younger males (<60 years) are at a higher risk than their female peers, older females are at significantly higher risk than their male peers

Various technical tips have been described on the placement of poller screws during intramedullary nailing however studies reporting outcomes are limited. Overall, there is no consistent conclusion about whether intramedullary nailing alone, or intramedullary nails augmented with poller screws is more advantageous. In a systematic review, we asked: (1) What is the proportion of non-unions with poller screw usage? (2) What is the proportion of malalignment, infection and secondary surgical procedures with poller screws usage?. We conducted a systematic review of multiple databases including Pubmed, EMBASE, and the Cochrane Library. Seventy-four records were identified, twelve met our inclusion criteria. Twelve studies with a total of 348 participants and 353 fractures were included. Mean follow up time was 21.4 months and mean age of included patients was 40.1 year. Seven studies had heterogenous population of non-unions and/ or malunions in addition to acute fractures. Three studies included only acute fractures and two studies examined non unions only. Four of the twelve studies reported non unions with an overall outcome proportion of 4%. Six studies reported coronal malalignment with an overall outcome proportion of 6%. The secondary surgical procedures rate ranged from 2 – 40% with an overall outcome proportion of 8% and included grafting, revisions and any reported cases of removal of metal work. When compared with existing literature our review suggests intramedullary nailing with poller screws has lower rates of non-unions and coronal malalignment than those reported in the literature for intramedullary nailing alone. Prospective randomized control trial is necessary to fully determine outcome benefits

Introduction and Objective. Intramedullary nails are frequently used for treatment of unstable distal tibia fractures. However, insufficient fixation of the distal fragment could result in delayed healing, malunion or nonunion. The quality of fixation may be adversely affected by the design of both the nail and locking screws, as well as by the fracture pattern and bone density. Recently, a novel concept for angular stable nailing has been developed that maintains the principle of relative stability and introduces improvements expected to reduce nail toggling, screw migration and secondary loss of reduction. It incorporates polyether ether ketone (PEEK) inlays integrated in the distal and proximal canal portions of the nail for angular stable screw locking. The nail can be used with new standard locking screws and low-profile retaining locking screws, both designed to enhance cortical fixation. The low-profile screws are with threaded head, anchoring in the bone and increasing the surface contact area due to the head's increased diameter. The objective of this study was to investigate the biomechanical competence of the novel angular stable intramedullary nail concept for treatment of unstable distal tibia fractures, compared with four other nail designs in an artificial bone model under dynamic loading. Materials and Methods. The distal 70 mm of thirty artificial tibiae (Synbone) were assigned to 5 groups for distal locking using either four different commercially available nails – group 1: Expert Tibia Nail (DePuy Synthes); group 2: TRIGEN META-NAIL with Internal Hex Captured Screws (Smith & Nephew); group 3: T2 Alpha with Locking Screws (Stryker); group 4: Natural Nail System featuring StabiliZe Technology (Zimmer) – or the novel angular stable TN-Advanced nail with low-profile screws (group 5, DePuy Synthes). The distal locking in all groups was performed using 2 mediolateral screws. All specimens were biomechanically tested under quasi-static and progressively increasing combined cyclic axial and torsional loading in internal rotation until failure, with monitoring by means of motion tracking. Results. Initial nail toggling of the distal tibia fragment in group 5 was significantly lower as compared with group 3 in varus (p=0.04) or with groups 2 and 4 in flexion (p≤0.02). In addition, the toggling in varus was significantly lower in group 1 versus group 4 (p<0.01). Moreover, during dynamic loading, within the course of the first 10,000 cycles the movements of the distal fragment in terms of varus, flexion, internal rotation, as well as axial and shear displacements at the fracture site, were all significantly lower in group 5 compared with group 4 (p<0.01). Additionally, group 5 demonstrated significantly lower values for flexion versus groups 2 and 3 (p≤0.04), for internal rotation versus group 1 (p=0.03), and for axial displacement versus group 3 (p=0.03). A trend to significantly lower values was detected in group 5 versus group 1 for varus, flexion and shear displacement – with p ranging between 0.05 and 0.07 – and versus group 3 for shear displacement (p=0.07). Cycles to failure were highest in group 5 with a significant difference to group 4 (p<0.01). Conclusions. From a biomechanical perspective, the novel angular stable intramedullary nail concept with integrated PEEK inlays and low-profile screws provides ameliorated resistance against nail toggling and loss of reduction under static and dynamic loading compared with other commercially available intramedullary nails used for fixation of unstable distal tibia fractures

Open limb fractures are typically due to a high energy trauma. Several recent studied have showed treatment's superiority when a multidisciplinary approach is applied. World Health Organization reports that isolate limb traumas have an incidence rate of 11.5/100.000, causing high costs in terms of hospitalization and patient disability. A lack of experience in soft tissue management in orthopaedics and traumatology seems to be the determining factor in the clinical worsening of complex cases. The therapeutic possibilities offered by microsurgery currently permit simultaneous reconstruction of multiple tissues including vessels and nerves, reducing the rate of amputations, recovery time and preventing postoperative complications. Several scoring systems to assess complex limb traumas exist, among them: NISSSA, MESS, AO and Gustilo Anderson. In 2010, a further scoring system was introduced to focus open fractures of all locations: OTA-OFC. Rather than using a single composite score, the OTA-OFC comprises five components grades (skin, arterial, muscle, bone loss and contamination), each rated from mild to severe. The International Consensus Meeting of 2018 on musculoskeletal infections in orthopaedic surgery identified the OTA-OFC score as an efficient catalogue system with interobserver agreement that is comparable or superior to the Gustilo-Anderson classification. OTA-OFC predicts outcomes such as the need for adjuvant treatments or the likelihood of early amputation. An orthoplastic approach reconstruction must pay adequate attention to bone and soft tissue infections management. Concerning bone management: there is little to no difference in terms of infection rates for Gustilo-Anderson types I–II treated by reamed intramedullary nail, circular external fixator, or unreamed intramedullary nail. In Gustilo-Anderson IIIA-B fractures, circular external fixation appears to provide the lowest infection rates when compared to all other fixation methods. Different technique can be used for the reconstruction of bone and soft tissue defects based on each clinical scenario. Open fracture management with fasciocutaneous or muscle flaps shows comparable outcomes in terms of bone healing, soft tissue coverage, acute infection and chronic osteomyelitis prevention. The type of flap should be tailored based on the type of the defect, bone or soft tissue, location, extension and depth of the defect, size of the osseous gap, fracture type, and orthopaedic implantation. Local flaps should be considered in low energy trauma, when skin and soft tissue is not traumatized. In high energy fractures with bone exposure, muscle flaps may offer a more reliable reconstruction with fewer flap failures and lower reoperation rates. On exposed fractures several studies report precise timing for a proper reconstruction. Hence, timing of soft tissue coverage is a critical for length of in-hospital stay and most of the early postoperative complications and outcomes. Early coverage has been associated with higher union rates and lower complications and infection rates compared to those reconstructed after 5-7 days. Furthermore, early reconstruction improves flap survival and reduces surgical complexity, as microsurgical free flap procedures become more challenging with a delay due to an increased pro-thrombotic environment, tissue edema and the increasingly friable vessels. Only those patients presenting to facilities with an actual dedicated orthoplastic trauma service are likely to receive definitive treatment of a severe open fracture with tissue loss within the established parameters of good practice. We conclude that the surgeon's experience appears to be the decisive element in the orthoplastic approach, although reconstructive algorithms may assist in decisional and planification of surgery

Intramedullary nails (IMNs) are the current gold standard for treatment of long bone diaphyseal and selected metaphyseal fractures. Their design has undergone many revisions to improve fixation techniques, conform to the bone shape with appropriate anatomic fit, reduce operative time and radiation exposure, and extend the indication of the same implant for treatment of different fracture types with minimal soft tissue irritation. The IMNs are made or either titanium alloy or stainless steel and work as load-sharing internal splints along the long bone, usually accommodating locking elements – screws and blades, often featuring angular stability and offering different configurations for multiplanar fixation – to secure secondary fracture healing with callus formation in a relative-stability environment. Bone cement augmentation of the locking elements can modulate the construct stiffness, increase the surface area at the bone-implant interface, and prevent cut-through of the locking elements. The functional requirements of IMNs are related to maintaining fracture reduction in terms of length, alignment and rotation to enhance fracture healing. The load distribution during patient's activities is along the entire bone-nail interface, with nail length and anatomic fit being important factors to avoid stress risers

To conduct a meta-analysis for intertrochanteric hip fractures comparing in terms of efficacy and safety short versus long intralomedullary nails. A pubmed search of the last 10 years for intertrochanteric fracture 31A1-31A3 according to the AO/OTA classification was performed. Baseline characteristics of each article were obtained, complication measures were analyzed: Peri-implant fracture, reoperations, deep/superficial infection, and mortality. Clinical variables consisted of blood loss (mL), length of stay (days), time of surgery (min) and nº of transfusions. Functional outcomes were also recorded. A meta-analysis was performed with Review Manager 5.4. Twelve studies were included, nine were retrospective. The reoperations rate was lower in the short nail group and the peri-implant fracture rate was lower in the long nail group (OR 0.58, 95% CI 0.38 to 0.88) (OR 1.88, 95% CI 1.04 to 3.43). Surgery time and blood loss was significantly higher in the long nail group (MD −12.44, 95% CI −14.60 to −10.28) (MD −19.36, 95% CI −27.24 to −11.48). There were no differences in functional outcomes. The short intramedullary nail has a higher risk of peri-implant fracture; however, the reoperation rate is lower compared to the long nail. Blood loss and surgery time was higher in the long nail group

To test and evaluate the effectiveness of local injection of autologous fat-derived mesenchymal stem cells (MSCs) into fracture site to prevent non-union in a clinically relevant model. 5 male Wistar rats underwent the same surgical procedure of inducing non-union. A mid-shaft tibial osteotomy was made with 1mm non-critical gap. Periosteum was stripped around the two fracture ends. Then, the fracture was fixed by ante-grade intramedullary nail. The non-critical gap was maintained by a spacer with minimal effect on the healing surface area. At the same surgical time, subcutaneous fat was collected from the ipsilateral inguinal region and stem cells were isolated and cultured in vitro. Within three weeks postoperatively, the number of expanded stem cells reached 5×10. 6. and were injected into the fracture site. Healing was followed up for 8 weeks and the quality was measured by serial x-rays, microCT, mechanical testing and histologically. Quality of healing was compared with that of previously published allogenic, xenogeneic MSCs and Purified Buffered Saline (PBS) controls. All the five fractures united fully after 8 weeks. There was a progressive increase in the callus radiopacity during the eight-week duration, the average radiopacity in the autologous fat-MSC injected group was significantly higher than that of the allogeneic MSCs, xenogeneic MSCs and the control group, P < 0.0001 for treatment, time after injection, and treatment-time interaction (two-way repeated measure ANOVA). MicroCT, mechanical testing and histology confirmed radiological findings. The autologous fat-MSCs are effective in prevention of atrophic non-union by stimulation of the healing process leading to a solid union. The quality and speed of repair are higher than those of the other types of cell transplantation tested