The use of external fixation in the emergency department: applications, common errors, complications and their treatment

Retrospective analysis of external pin fixation of mandibular fractures: A 25-year single institution experience

External fixation of mandible fractures is an infrequently utilized fixation treatment modality in comparison to open reduction internal fixation (ORIF) or closed reduction techniques. However, external fixation still provides a necessary modality in the management of select mandibular fractures. Therefore, we aim to draw trends, outcomes, and treatment timelines through a retrospective analysis to better guide, advise and predict realistic treatment outcomes in the future for our patients. This abstract shows trends in indications, complications, airway management and timeline to definitive reconstruction through the experience of a single institution (University Hospital, Newark, NJ) over a period of 25 years. IRB approval was obtained from Rutgers University and University Hospital, Newark, NJ. Twenty-nine instances of external fixation of mandible fractures were found over 25 years. The charts, imaging, and notes were individually reviewed. The data points collected included age of the patient at time of injury, etiology of injury, duration of external fixation, numbers of Schanz screws, type of extraoral connecting bar, airway management, time to reconstruction, type of reconstruction, type of bone graft used, incidence of multiple space infections, and complications. The duration of study was from 1997 - 2023. The patients were found using CPT codes 21452 (percutaneous treatment of mandibular fracture, with external fixation) and 21454 (open treatment of mandibular fracture with external fixation). Twenty-nine instances of external fixation were found, 28 of the 29 had extensive documentation about the surgery and post operative period. The average age at the time of injury was 37 years old, 2 females and 26 males. 5 different types of etiologies were found. 14 gunshot wounds, 3 motor vehicle collisions (MVCs), 6 osteomyelitis with nonunion from a previous ORIF management of a mandible fracture, 4 pathologic fractures and 1 patient with a one-week-old unrepaired open fracture that developed a significant deep neck infection. The average duration of the external fixator was 88 days, ranging from 18 - 291 days. 10 patients were electively intubated and extubated for the external fixator surgery. 15 patients underwent tracheostomy due to airway compromise or expected prolonged intubation. The most common number of Schanz screws placed were 4, with a range of 4-6. The most common stabilizing system used to connect the screws were carbon fiber rods (61%). Prior to 2008, pre-adapted titanium was never used, after 2008 it was used in more than half of the cases. The most common complication was infection, occurring in 4 cases. With regards to secondary reconstruction, 55% of the cases required autologous harvesting of the anterior iliac crest. In summary, our research showed the average duration of external fixation duration to be dependent on the mechanism of injury. Failure of previous ORIF with non-union and concomitant osteomyelitis had an average external fixation duration of 107 days. Gunshot wounds had an average external fixation duration of 79 days. Motor vehicle accidents had an average external fixation duration of 18 days. Pathologic fractures had an average external fixation duration of 16 days. The most common complication was infection, occurring in 4 (14%) cases. For airway management, 100% of GSW injuries received tracheostomy, 66.7% of MVCs, 14% of osteomyelitis status-post prior ORIF, and no patients with pathologic fractures associated with malignancy received tracheostomy. This research aims to consolidate 25 years' worth of surgical experience and patterns for external fixation to better guide, advise and predict realistic treatment outcomes.

Perioperative Risks Associated with the Use of External Fixators in Adult and Pediatric Patients with Trauma

External fixation is used in acute and elective cases in both adult and pediatric patients. Adequate selection of patients for external fixation is critical, especially in patients with polytrauma where the application of damage control orthopedics is considered. Deterioration of the bone-pin interface is the most common source of local postoperative complications. Pin loosening and pin track infection are the 2 most common complications. Treatment of pin loosening without infections consists of pin removal and reinsertion outside the affected area. Pin track infections are managed according to the infection severity, which is assessed using the Checketts-Otterburn classification.

Trends and Regional Differences in Usage of Primary External Fixation From 2018 to 2022 in Japan: A Retrospective Observational Study Using Open Data from the National Database of Health Insurance Claims

Background Primary external fixation (EF) is a crucial method in orthopedic trauma, particularly for complex fractures with soft tissue damage. Despite its importance in damage control surgery, the patterns of EF use in Japan remain underexplored. This study aimed to elucidate the trends and regional differences in EF usage for fracture treatment in Japan and identify factors associated with its variation across regions. Methods We analyzed data from the National Database of Health Insurance Claims (NDB) covering inpatient surgeries from 2018 to 2022. The primary outcome was the EF usage ratio, calculated as the number of primary EFs procedures divided by the total number of internal fixations. The trend of the EF usage ratio over five-year period was assessed by Cochrane-Armitage trend test for temporal trends. We also evaluated the associations between EF usage and factors such as population, region, and emergency care availability. Results A total of 610,326 internal fixations and 29,546 EF procedures were identified, with the EF usage ratio increasing from 4,532 out of 119,223 cases (3.8%) in 2018 to 6,861 out of 126,000 cases (5.4%) in 2022 (p < 0.01). Regional EF usage in total of five-year period ranged from 228 out of 8,103 cases (2.8%) in Oita to 814 out of 9,075 cases (9.0%) in Nagasaki, representing a threefold difference. While 12 prefectures showed statistically significant increases in EF usage, no specific factors were found to explain the regional variations in EF utilization. Conclusion EF usage in Japan has risen over the past five years, with notable regional differences. Further research is needed to identify the causes of these variations and promote consistent trauma care across the country.

Case-Based Virtual Reality Simulation for Severe Pelvic Trauma Clinical Skill Training in Medical Students: Design and Pilot Study

BACKGROUND

Teaching severe pelvic trauma poses a significant challenge in orthopedic surgery education due to the necessity of both clinical reasoning and procedural operational skills for mastery. Traditional methods of instruction, including theoretical teaching and mannequin practice, face limitations due to the complexity, the unpredictability of treatment scenarios, the scarcity of typical cases, and the abstract nature of traditional teaching, all of which impede students' knowledge acquisition.

OBJECTIVE

This study aims to introduce a novel experimental teaching methodology for severe pelvic trauma, integrating virtual reality (VR) technology as a potent adjunct to existing teaching practices. It evaluates the acceptability, perceived ease of use, and perceived usefulness among users and investigates its impact on knowledge, skills, and confidence in managing severe pelvic trauma before and after engaging with the software.

METHODS

A self-designed questionnaire was distributed to 40 students, and qualitative interviews were conducted with 10 teachers to assess the applicability and acceptability. A 1-group pretest-posttest design was used to evaluate learning outcomes across various domains, including diagnosis and treatment, preliminary diagnosis, disease treatment sequencing, emergency management of hemorrhagic shock, and external fixation of pelvic fractures.

RESULTS

A total of 40 students underwent training, with 95% (n=38) affirming that the software effectively simulated real-patient scenarios. All participants (n=40, 100%) reported that completing the simulation necessitated making the same decisions as doctors in real life and found the VR simulation interesting and useful. Teacher interviews revealed that 90% (9/10) recognized the VR simulation's ability to replicate complex clinical cases, resulting in enhanced training effectiveness. Notably, there was a significant improvement in the overall scores for managing hemorrhagic shock (t39=37.6; 95% CI 43.6-48.6; P<.001) and performing external fixation of pelvic fractures (t39=24.1; 95% CI 53.4-63.3; P<.001) from pre- to postsimulation.

CONCLUSIONS

The introduced case-based VR simulation of skill-training methodology positively influences medical students' clinical reasoning, operative skills, and self-confidence. It offers an efficient strategy for conserving resources while providing quality education for both educators and learners.

Incorporation of cerium oxide nanoparticles into the micro-arc oxidation layer promotes bone formation and achieves structural integrity in magnesium orthopedic implants

Biodegradable metals offer significant advantages by reducing the need for additional surgeries following bone fixation. These materials, with their optimal mechanical and degradable properties, also mitigate stress-shielding effects while promoting biological processes essential for healing. This study investigated the in vitro and in vivo biocompatibility of ZK60 magnesium alloy coated with a micro-arc oxidative layer incorporated with cerium oxide nanoparticles in orthopedic implants. The results demonstrated that the magnesium substrate undergoes gradual degradation, effectively eliminating long-term inflammation during bone formation. The micro-arc oxidative coating forms a dense ceramic layer, acting as a protective barrier that reduces corrosion rates and enhances the biocompatibility of the magnesium substrate. The incorporation of cerium oxide nanoparticles improves the tribological properties of the coating, refining degradation patterns and improving osteogenic characteristics. Furthermore, cerium oxide nanoparticles enhance bone reconstruction by facilitating appropriate interconnections between newly formed bone and native bone tissue. Consequently, cerium oxide nanoparticles contribute to favorable biosafety outcomes and exceptional bone remodeling capabilities by supporting bone healing and sustaining a prolonged degradation process, ultimately achieving dynamic equilibrium in bone formation. STATEMENT OF SIGNIFICANCE: This study comprehensively examined the incorporation of cerium oxide nanoparticles into biodegradable magnesium through a micro-arc oxidative process for use in orthopedic implants. This study conducted a comprehensive analysis involving material characterization, biodegradability testing, in vitro osteogenesis assays, and in vivo implantation, highlighting the potential benefits of the distinctive properties of cerium oxide nanoparticles. This research emphasizes the ability of cerium oxide nanoparticles to enhance the biodegradability of magnesium and facilitate remarkable bone regeneration, suggesting promising advantages for additive materials in orthopedic implants.

Accuracy of robotic arm-assisted versus computed tomography-based navigation in total hip arthroplasty using the direct anterior approach: a retrospective study

BACKGROUND

A robotic arm-assisted and a computed tomography (CT)- based navigation system have been reported to improve the accuracy of component positioning in total hip arthroplasty (THA). However, no study has compared robotic arm-assisted THA (rTHA) to CT-based navigated THA (nTHA) concerning accuracy of cup placement and acetabular fractures using the direct anterior approach (DAA). This study aimed to compare the accuracy of cup placement and the presence of intraoperative acetabular fractures between rTHA and nTHA using DAA in the supine position.

METHODS

We retrospectively investigated 209 hips of 188 patients who underwent rTHA or nTHA using DAA (rTHA using the Mako system: 85 hips of 79 patients; nTHA: 124 hips of 109 patients). After propensity score matching for age and sex, each group consisted of 73 hips. We evaluated clinical and radiographic outcomes, comparing postoperative cup orientation and position, measured using a three-dimensional templating software, to preoperative CT planning. Additionally, we investigated the prevalence of occult acetabular fracture.

RESULTS

Clinical outcomes were not significantly different between the groups at 1 year postoperatively. The mean absolute error of cup orientation was significantly smaller in the rTHA group than in nTHA (inclination: 1.4° ± 1.2° vs. 2.7° ± 2.2°, respectively; p = 0.0001, anteversion: 1.5° ± 1.3° vs. 2.2° ± 1.7°, respectively; p = 0.007). The cases within an absolute error of 5 degrees in both RI and RA were significantly higher in the rTHA (97.3%) than in nTHA group (82.2%) (p = 0.003). The absolute error of the cup position was not significantly different between the two groups. The prevalence of occult acetabular fracture did not differ significantly between the two groups (rTHA: n = 0 [0%] vs. nTHA: n = 1 [1.4%]).

CONCLUSION

Cup placement using DAA in the supine position in rTHA was more accurate with fewer outliers compared to nTHA. Therefore, rTHA performed via DAA in a supine position would be useful for accurate cup placement.

Is fracture management merely a physical process? Exploring the psychological effects of internal and external fixation

BACKGROUND

Internal and external fixation are common surgical procedures for treating fractures. However, the impact of different surgical approaches (including internal and external fixations) on patients' psychological status and Quality of Life (QoL) is rarely examined. Herein, we aimed to investigate the effects of internal and external fixation on anxiety, depression, insomnia, and overall mental and physical health in Distal Radius Fractures (DRF) patients.

METHODS

We performed a retrospective study on 96 fracture patients who underwent internal fixation (57 patients) or external fixation (39 patients). The Visual Analog Scale (VAS), the Hospital Anxiety and Depression Scale (HADS), the Athens Insomnia Scale (AIS), and the Medical Outcomes Study Short Form 36 (SF-36) questionnaire were used to assess the patients' pain, anxiety, depression, sleep, and QoL before surgery and at seven days, one month, and three months post-surgery.

RESULTS

The VAS scores were significantly lower in the Internal Fixation Group (IFG) than in the External Fixation Group (EFG) on the seventh day and one month postoperatively (P < 0.05). Although both groups showed no significant anxiety, depression, or insomnia before surgery (P > 0.05), the EFG showed significantly higher HADS-A, HADS-D, and AIS scores than the IFG at seven days and one and three months postoperatively (P < 0.05). Additionally, changes in HADS-A, HADS-D, and AIS scores were most significant at day seven post-surgery in the EFG (P < 0.05). Furthermore, no significant difference was found between the two groups in the average Physical Component Summary (PCS) and Mental Component Summary (MCS) scores before surgery (P > 0.05). However, both groups showed positive changes in PCS and MCS scores at postoperative day seven and one and three months postoperatively, with the IFG having significantly higher average PCS and MCS scores compared to the EFG (P < 0.05).

CONCLUSION

Compared to external fixation, internal fixation did not significantly impact patients' emotions regarding anxiety and depression in the early postoperative period, and physical and mental health recovery was better during the postoperative rehabilitation period. Furthermore, when there are no absolute indications, the impact on patients' psychological well-being should be considered as one of the key factors in the treatment plan during surgical approach selection.

Availability and use of resources for emergency fracture care of pelvic trauma associated with haemorrhagic shock in Latin America: A cross-sectional study

Determining the true availability of resources and understanding the level of training of surgeons involved in the treatment of patients with pelvic fractures and haemorrhagic shock is critical. In the herein study, the availability of technical, technological, and human resources for the care of this injury in Latin America region was analysed, and the preferences of orthopaedic trauma surgeons when performing interventions for the diagnosis and treatment of patients with pelvic trauma and associated haemorrhagic shock was described. A cross sectional web-based survey containing questions on knowledge, attitudes, and practices with respect to imaging resources, emergency pelvic stabilization methods, and interventions used for bleeding control was sent to 948 Latin America orthopaedic trauma surgeons treating pelvic fractures in the emergency department. Differences between regional clusters, level of training, type of hospital, and pelvic surgery volume were assessed. 368 responses were obtained, with 37.5% of respondents reporting formal training in pelvic surgery and 36.0% having available protocol for managing these patients. The most frequently used interventions were the supra-acetabular pelvic external fixator and pelvic packing. Limited hospital and imaging resources are available for the care of patients with pelvic trauma and associated haemorrhagic shock throughout Latin America. In addition, the training of orthopaedic trauma surgeons dealing with this type of injury and the volume of pelvic surgeries per year is heterogeneous. It should be urgently considered to develop management protocols adapted to Latin America according to the availability of resources, as well as to promote training in this severe life-threatening traumatic condition.

Adequacy of in-mission training to treat tibial shaft fractures in mars analogue testing

Long bone fractures are a concern in long-duration exploration missions (LDEM) where crew autonomy will exceed the current Low Earth Orbit paradigm. Current crew selection assumptions require extensive complete training and competency testing prior to flight for off-nominal situations. Analogue astronauts (n = 6) can be quickly trained to address a single fracture pattern and then competently perform the repair procedure. An easy-to-use external fixation (EZExFix) was employed to repair artificial tibial shaft fractures during an inhabited mission at the Mars Desert Research Station (Utah, USA). Bone repair safety zones were respected (23/24), participants achieved 79.2% repair success, and median completion time was 50.04 min. Just-in-time training in-mission was sufficient to become autonomous without pre-mission medical/surgical/mechanical education, regardless of learning conditions (p > 0.05). Similar techniques could be used in LDEM to increase astronauts' autonomy in traumatic injury treatment and lower skill competency requirements used in crew selection.

An Easy-To-Use External Fixator for All Hostile Environments, from Space to War Medicine: Is It Meant for Everyone's Hands?

Long bone fractures in hostile environments pose unique challenges due to limited resources, restricted access to healthcare facilities, and absence of surgical expertise. While external fixation has shown promise, the availability of trained surgeons is limited, and the procedure may frighten unexperienced personnel. Therefore, an easy-to-use external fixator (EZExFix) that can be performed by nonsurgeon individuals could provide timely and life-saving treatment in hostile environments; however, its efficacy and accuracy remain to be demonstrated. This study tested the learning curve and surgical performance of nonsurgeon analog astronauts (n = 6) in managing tibial shaft fractures by the EZExFix during a simulated Mars inhabited mission, at the Mars Desert Research Station (Hanksville, UT, USA). The reduction was achievable in the different 3D axis, although rotational reductions were more challenging. Astronauts reached similar bone-to-bone contact compared to the surgical control, indicating potential for successful fracture healing. The learning curve was not significant within the limited timeframe of the study (N = 4 surgeries lasting <1 h), but the performance was similar to surgical control. The results of this study could have important implications for fracture treatment in challenging or hostile conditions on Earth, such as war or natural disaster zones, developing countries, or settings with limited resources.

Optimum timing of conversion from DCO to definitive fixation in closed fractures of the lower limb: When and how?

INTRODUCTION

In damage control orthopaedics (DCO), fractures are initially stabilised with external fixation followed by delayed conversion to definitive internal fixation. The aim of this study is to determine whether the timing of the conversion influences the development of deep infection and fracture healing in a cohort of patients treated by DCO after a closed fracture of the lower limb. Furthermore, we wanted to evaluate whether the one-stage conversion procedure is always safe.

MATERIALS AND METHODS

A retrospective cohort study was conducted at a single level 1 trauma centre. Ninety-four cases of closed fractures of lower limb treated by DCO subsequently converted to internal fixation from 2012 to 2019 were included. Development of deep infection, superficial infection, non-union and time to union were recorded. Patients were then divided into three groups according to the timing of conversion: Group A (<7 days), Group B (7-13 days), Group C (> 14 days). Comparison between groups was performed to assess intergroup variabilty.

RESULTS

The mean number of days between DCO and conversion was 6.7±4.52 (range 1-22). We observed one case of deep infection (1.1%), one case of non-union (1.1%), four cases of superficial infection (4.3%) and mean time to union was 4.9±1.38 months months. Comparison between groups demonstrated no significant correlation between timing of conversion and development of superficial or deep infection and non-union, while it highlighted that complexity of the fracture and longer surgical time of conversion procedure were significantly higher in Group C.

CONCLUSIONS

One-stage conversion to definitive internal fixation within 22 days from DCO is a safe and feasible procedure, which does not influence the incidence of infection or non-union.

CT of Sacral Fractures: Classification Systems and Management

CT is often performed as part of a whole-body protocol in the setting of polytrauma and is the standard of care for diagnosing and characterizing sacral fractures. These fractures are not uncommon, occurring in conjunction with pelvic ring disruption in approximately 40%-50% of patients. Knowledge of basic functional anatomy and fracture biomechanics is important in understanding sacral fracture patterns, which only rarely result from direct impact. More often, sacral fractures result from an indirect mechanism with fracture lines that propagate along relative lines of weakness, leading to predictable fracture patterns. Each fracture pattern has implications with respect to neurologic injury, spinopelvic stability, management, and potential complications. The authors explore the Denis, Roy-Camille, Isler, Robles, Sabiston-Wing, and shape-based classification systems for sacral fractures. These form the basis of the subsequently discussed unified AOSpine sacral fracture classification, a consensus system developed by spine and orthopedic surgeons as a means of improving and standardizing communication. The AOSpine sacral fracture classification also includes clinical designations for neurologic status and patient-specific modifiers. When a patient is unexaminable owing to obtundation or sedation, CT is an invaluable indirect marker of nerve compression or traction injury. It also plays an important role in visualizing and characterizing the type and extent of any associated soft-tissue injuries that may warrant a delay in surgery or an alternative operative approach. ©RSNA, 2022.

CT in Patients With External Fixation for Complex Lower Extremity Fractures: Impact of Iterative Metal Artifact Reduction Techniques on Metal Artifact Burden and Subjective Quality

Background: Lower extremity external fixators have complex geometries that induce pronounced metal artifact on CT. Iterative metal artifact reduction (iMAR) algorithms help reduce such artifact, though no dedicated iMAR preset exists for external fixators. Objective: To compare iMAR presets for CT examinations in terms of quantitative metal artifact burden and subjective image quality in patients with external fixators for complex lower extremity fractures. Methods: This retrospective study included 72 CT examinations in 56 patients (20 female, 36 male; mean age 56±18 years) with lower extremity external fixators (regular, hybrid, or monotube tube). Examinations were reconstructed without iMAR (noMAR) and with three iMAR presets (iMARspine, iMARhip, iMARextremity). A radiology resident quantified metal artifact burden using software. Two radiology residents indepenently assessed overall image quality and diagnostic confidence using 4-point scales (4=highest quality). Techniques were compared using Bonferroni-corrected post-hoc tests. Interreader agreement was assessed by intraclass correlation coefficients (ICCs). Post-hoc multinomial regression model was used for predicting overall image quality. Results: Mean quantitative metal artifact burden burden was 100816±45558 (noMAR), 88889±44028 (iMARspine), 82295±41983 (iMARhip), and 81956±41890 (iMARextremity). Overall image quality demonstrated ICC ≥0.94. Using pooled reader data, median overall image quality was, for regular fixator, 2 (noMAR), 3 (iMARspine and iMARhip), and 4 (iMARextremity); for hybrid, 1 (noMAR), 2 (iMARspine), and 3 (iMARhip and iMARextremity); and for monotube, 2 (noMAR), 3 (iMARspine and iMARhip), and 4 (iMARextremity). Metal artifact burden and overall image quality were higher (p<.05) for iMARhip and iMARextremity versus noMAR and iMARspine for all fixators (aside from image quality of iMARhip and iMARextremity vs iMARspine for regular fixators) but not different (all p>.05) between iMARhip and iMARextremity. Median diagnostic confidence was 4 for all fixators and reconstructions. Independent predictors of overall quality relative to noMAR were iMARspine [odds ratio (OR)=1.92-5.51], iMARhip (OR=5.56-31.10), and iMARextremity (OR=7.07-38.21). All iMAR presets introduced new reconstruction artifacts for all examinations for both readers. Conclusion: For the three fixator types, iMARhip and iMARextremity achieved greatest metal artifact burden reduction and highest subjective image quality, though introduced new reconstruction artifacts. Clinical Impact: CT using the two identified iMAR presets may facilitate perioperative management of external fixators.

Optimization of a Patient-Specific External Fixation Device for Lower Limb Injuries

The use of external fixation devices is considered a valuable approach for the treatment of bone fractures, providing proper alignment to fractured fragments and maintaining fracture stability during the healing process. The need for external fixation devices has increased due to an aging population and increased trauma incidents. The design and fabrication of external fixations are major challenges since the shape and size of the defect vary, as well as the geometry of the human limb. This requires fully personalized external fixators to improve its fit and functionality. This paper presents a methodology to design personalized lightweight external fixator devices for additive manufacturing. This methodology comprises data acquisition, Computer tomography (CT) imaging analysis and processing, Computer Aided Design (CAD) modelling and two methods (imposed predefined patterns and topology optimization) to reduce the weight of the device. Finite element analysis with full factorial design of experiments were used to determine the optimal combination of designs (topology optimization and predefined patterns), materials (polylactic acid, acrylonitrile butadiene styrene, and polyamide) and thickness (3, 4, 5 and 6 mm) to maximize the strength and stiffness of the fixator, while minimizing its weight. The optimal parameters were found to correspond to an external fixator device optimized by topology optimization, made in polylactic acid with 4 mm thickness.

Injury of the Tibial Nutrient Artery Canal during External Fixation for Lower Extremity Fractures: A Computed Tomography Study

The tibial nutrient artery (TNA) is the major diaphyseal artery of the tibia supplying two thirds of the inner osseous cortex. Hence, iatrogenic injury of the TNA endangers the integrity of the tibial blood supply and may compromise fracture healing. The incidence of its injury in the setting of external fixation for lower limb fractures has not been previously investigated. The aim of this study was to evaluate the incidence of TNA injury in the context of external fixation and to characterize the topography of the fixator pins in relation to the TNA canal (TNAC). Patients who underwent external fixation for distal femoral fractures and for tibial (proximal, shaft, and distal) fractures and had a postoperative computed tomography study were retrospectively included. The following parameters were retrieved: 1) Pin characteristics (orientation and cortical position of the pins), 2) The anatomic relationship between the TNAC and external fixation pin (topography above/below and at the level of the TNAC, and the distance between the pin and medial tibial plateau and/or the medial malleolus), and 3) The incidence of TNAC injury (complete/partial disruption of TNA lumen). A total of 105 patients with 214 tibial pins were analyzed. In 27 patients (26%), the TNAC was completely injured by the pins of the external fixator. In 13 patients (12%), the TNAC was partially injured. Of the 214 analyzed pins, 85 pins (40%) were located at the level of the TNAC (the TNAC and the pin are seen on the same axial slice). Most pins that were applied at the level of the TNAC belonged to a knee-bridging external fixator. Of those, ninety-three percent of the pins were anteromedially applied according to published surgical guidelines. Six percent of the pins were applied through the tibial crest and 1% anterolaterally. Of those 85 pins, 42 pins (49%) injured the TNAC at least partially. Based on the analyzed pins and the incidence of partial and complete injury of the TNAC, we observed that the tibial segment at which the tibial nutrient artery is endangered was located approximately (95% CI: 13–15 cm) from the medial tibia plateau and (95% CI: 22–25 cm) from the medial malleolus. Thus, TNAC injury by external fixation pins in the context of lower limb fractures can be considered common. Almost half of the pins applied at the middle third of the tibia injured the TNA, despite adherence to published surgical guidelines for external fixation. When possible, pin application at the middle third of tibia should be avoided to circumvent iatrogenic injury of the TNA and to safeguard tibial blood supply.