Biomechanical evaluation of internal fixation for the treatment of comminuted subtrochanteric femur fractures.

BACKGROUND: Several biomechanical studies on subtrochanteric femur fractures have reported that use of an intramedullary nail is superior to extramedullary implant. However, the optimal choice of intramedullary nail for the treatment of comminuted subtrochanteric femur fracture remains unclear. Here, we evaluated the biomechanical properties of comminuted subtrochanteric femur fracture treated with four different internal fixations. METHODS: A comminuted subtrochanteric femur fracture model was created with a 2-cm gap below the lessor trochanter in 20 synthetic femurs. The fractures were fixed with one of four implants - Antegrade Femoral Nail (AFN), Trochanteric Fixation Nail Advanced with a femoral neck blade (TFNA blade), TFNA with a femoral neck screw (TFNA screw), and the reversed distal femoral locking compression plate (DF-LCP) - all manufactured by DePuy Synthes. Axial compression tests and torsion tests were performed and the stiffness of each implant was compared. RESULTS: For compression, the TFNA blade, TFNA screw, and AFN provided significantly higher stiffness than DF-LCP (p < 0.001, p < 0.001, p = 0.001, respectively), and the TFNA blade provided significantly higher stiffness than AFN (p = 0.049). For torsion, there were no significant differences among the groups in internal rotation, while the TFNA screw had significantly lower torsional stiffness than the AFN, TFNA blade and DF-LCP in external rotation (p = 0.036, p = 0.034, p = 0.037, respectively). CONCLUSIONS: These findings could help to provide biomechanical evidence regarding choice of implant for the treatment of comminuted subtrochanteric femur fracture. The TFNA blade may be more suitable for the treatment of comminuted subtrochanteric femur fracture.

Surgical outcomes of intramedullary nailing for diaphyseal atypical femur fractures: is it safe to modify a nail entry in bowed femur?

INTRODUCTION: The purpose of the study was to determine the surgical outcomes of intramedullary nailing in diaphyseal atypical femoral fractures (AFFs) and to evaluate the clinical outcomes of nail entry modification technique. MATERIALS AND METHODS: We retrospectively reviewed diaphyseal AFFs treated with IMN at nine institutions. In total, 82 patients were included. Surgical outcomes such as complication, union time, and femoral bowing were evaluated. We modified the nail entry of the straight nail from piriformis fossa to the tip of the greater trochanter in the bowed femur and compared the surgical outcomes between the original group and the modification group. RESULTS: The average union time was 20.1 weeks, and the union rate was 89.0%. The average union time was 13.1 weeks and 21 weeks in incomplete and complete AFFs, respectively. There was no nonunion in incomplete AFFs, but 13.8% in complete AFFs. Complete AFFs had 86.2% of union rate. There were 46 cases of group 1 with original entry point and 19 cases of group 2 with modified entry. In group 2, the union rate was similar to group 1 and union time was shorter. CONCLUSION: Changing the entry point laterally allowed the nail to be accommodated in bowed femurs, decreasing the risk of deformity and improving healing time. In severely varus femur, the lateral entry of the straight nail can be a useful technique.

Management of open fracture and related complications: the Japanese way.

Open fractures continue to be a challenging clinical problem throughout the world, and Japan is no exception. Surgeons are faced with critical decisions throughout the care of these injuries that can have significant effects in clinical outcome, ranging from the type and timing of antibiotic administration, fixation, soft-tissue management, and interventions for postfracture complications. In October 2022, the Japanese Society for Fracture Repair (JSFR) was invited to represent Japan as the Guest Nation society at the 38th Annual Meeting of the Orthopaedic Trauma Society held in Tampa, Florida. The JSFR organized a symposium, entitled "Management of Open Fracture and related complications-the Japanese way," that featured cutting-edge approaches to open fractures in their country, including presentations on the "fix-and-flap" approach, local antibiotics perfusion delivery, and a "chipping" method for the stimulation of bone healing. This article summarizes the content of these 3 presentations from that symposium.

Differences in macrophage expression in induced membranes by fixation method - Masquelet technique using a mouse's femur critical-sized bone defect model.

INTRODUCTION: Masquelet's induced membrane technique (MIMT) is an emerging method for reconstructing critical-sized bone defects. However, an incomplete understanding of the underlying biological and physical processes hinders further optimization. This study investigated the effect of different bone-defect fixation methods on macrophage expression in an induced membrane using a novel mouse plate-fixed Masquelet model. METHODS: Mice were divided into Plate-fixed Masquelet (P-M), Intramedullary-fixed Masquelet (IM-M), Plate-fixed Control (P-C), and Back subfascial (B) groups. In the P-M and IM-M groups, a polymethylmethacrylate (PMMA) spacer was implanted into a 3 mm bone defect, while the defect in the P-C group remained unfilled. In group B, a spacer was inserted under the back fascia to examine membrane formation caused by a simple foreign body reaction. Tissues were collected at 1, 2, and 4 weeks postoperatively. Hematoxylin and eosin (H&E) staining and immunohistochemistry (CD68 and CD163: macrophage markers) were performed to assess macrophage expression within the membrane. qPCR was performed to measure the expression of CD68, CD163, and fibroblast growth factor 2 (FGF2). RESULTS: Four weeks post-operation, the P-M group presented with minimal callus growth, whereas the IM-M group exhibited vigorous growth. The P-M and IM-M groups displayed a tri-layered membrane structure, which is consistent with the results of previous studies. The IM-M group had significantly thicker membranes, whereas the P-M group exhibited higher expression levels of CD68, CD163, and FGF2. Group P-C showed no osteogenesis, whereas group B maintained a thin, cell-dense membrane structure. The P-M group consistently showed higher gene expression levels than the P-C and P-B groups. CONCLUSION: This study introduced a mouse plate fixation model for MIMT. The induced membranes could be adequately evaluated in this model. Induced membranes are formed by foreign body reactions to PMMA spacers; however, their properties are clearly different from those of simple foreign body reaction capsules and granulation tissues that infiltrate bone defects, suggesting that they are more complex tissues. The characteristics and expression of macrophages within these induced membranes varied according to the bone defect fixation method.

Open fractures: Current treatment perspective.

Severe open fractures present challenges to orthopaedic surgeons worldwide, with increased risks of significant complications. Although different global regions have different resources and systems, there continue to be many consistent approaches to open fracture care. Management of these complex injures continues to evolve in areas ranging from timing of initial operative debridement to the management of critical-sized bone defects. This review, compiled by representative members of the International Orthopaedic Trauma Association, focuses on several critical areas of open fracture management, including antibiotic administration, timing of debridement, bone loss, soft tissue management, and areas of need for future investigation.

Transcutaneous CO2 Pressure Monitoring Increases Salvage Rates after Free Tissue Transplantation for Extremity Reconstruction.

Although free tissue transplantation (FTT) is an essential technique in extremity functional reconstruction, postoperative blood flow disturbance is one of the critical complications leading to transplanted tissue necrosis. Early detection of this complication may prevent tissue failure by prompt improvement of blood flow. The aim of this study was to determine whether transcutaneous carbon dioxide pressure (TcPCO2) monitoring increases the salvage rates after FTT. Methods: We retrospectively reviewed 75 consecutive patients who underwent FTT for extremity reconstruction with TcPCO2 monitoring postoperatively between December 2016 and September 2021. Results: Extremity reconstruction was performed in 53 cases due to trauma, 20 cases due to infection, and two cases due to tumor resection for tissue defects. The overall success rate of the FTT was 98.7%, with 13 complications. Of the 11 patients who underwent reoperation, nine had thrombosis and two had vascular strangulation. However, when reoperation was decided, none of the reoperation cases still exhibited any deterioration in the Doppler or clinical assessment. All reoperated cases were salvaged. Of the two patients who did not undergo reoperation, one had failed flaps and one had partial skin necrosis. With a TcPCO2 cutoff value of 70 mm Hg, the sensitivity and specificity for detecting complications due to impaired blood flow were 100% and 93.5%, respectively. Conclusions: TcPCO2 monitoring was performed after FTT for extremity reconstruction, and all cases of reoperation were salvaged. TcPCO2 monitoring can detect impaired postoperative blood flow critically earlier than clinical assessments and may increase salvage rates of transplanted tissue.

Fragility Fracture Systems: International Perspectives - Asia & Australia.

Background: The incidence and burden of fragility fractures have reached the level where comprehensive systematic care is warranted to optimize the care of these patients. Hip fractures are the most frequently lethal and independence level changing fragility fractures, responsible for 30-day mortality comparable to high-energy trauma patients with injury severity scores over 12. It is a reasonable expectation that countries have a hip fracture treating system of care in place for this high-risk population. This review explores the systems of care from the Asia-Pacific Perspective. Methods: From the International Orthopaedic Trauma Association's member societies, nations from the Asia-Pacific Region were requested to contribute with an overview of their fragility fracture management systems. The content or the review was standardized by a template of headings, which each country endeavored to cover. Results: Australia, Japan, and South Korea contributed voluntarily from the 5 member countries of the region. Each country has made considerable efforts and achievements with diverse approaches to standardize and improve the care of fragility fractures, particularly hip fractures. Beyond the individual nations' efforts there is also an existing Asia-Pacific Collaborative. The data collection and in some counties the existence of a registry is promising; funding and recognition of the problem among competing health care budget priorities are common. Conclusions: Our review covers some of the countries with strongest economy and highest health care standards. The lack of a universal robust system for hip fracture care is apparent. The data collection from registry initiations is expected to drive system development further in these countries and hopefully fast track the development in other countries within the most populous geographical region of the Earth.

A new technique for seeding chondrocytes onto solvent-preserved human meniscus using the chemokinetic effect of recombinant human bone morphogenetic protein-2.

Many investigators are currently studying the use of decellularized tissue allografts from human cadavers as scaffolds onto which patients' cells could be seeded, or as carriers for genetically engineered cells to aid cell transplantation. However, it is difficult to seed cells onto very dense regular connective tissue which has few interstitial spaces. Here, we discuss the development of a chemotactic cell seeding technique using solvent-preserved human meniscus. A chemokinetic response to recombinant human bone morphogenetic protein-2 (rhBMP-2) was observed in a monolayer culture of primary chondrocytes derived from femoral epiphyseal cartilage of 2-day-old rats. The rhBMP-2 significantly increased their migration upto 10 ng/ml in a dose-dependent manner. When tested with solvent-preserved human meniscus as a scaffold, which has few interstitial spaces, rhBMP-2 was able to induce chondrocytes to migrate into the meniscus. After a 3-week incubation, newly-formed cartilaginous extracellular matrix was synthesized by migrated chondrocytes throughout the meniscus, down to a depth of 3 mm. These findings demonstrate that rhBMP-2 may be a natural chemokinetic factor in vivo, which induces migration of proliferative chondrocytes into the narrow interfibrous spaces. Our results suggest a potential application of rhBMP-2 for the designed distribution of chondrocytes into a scaffold to be used for tissue engineering.

Biomechanical Evaluation of Extramedullary Versus Intramedullary Reduction in Unstable Femoral Trochanteric Fractures.

INTRODUCTION: The failure rate of operations involving the cephalomedullary nail technique for unstable femoral trochanteric fractures is 3-12%. Changing the reduction strategy may improve the stability. This study aimed to confirm whether reducing the proximal fragment with the medial calcar contact, as opposed to utilizing an intramedullary reduction, would improve the stability of such fractures. MATERIALS AND METHODS: The unstable femoral trochanteric fracture model was created with fixation by cephalomedullary nails in 22 imitation bones. The 2 reduction patterns were as follows: one was with the proximal head-neck fragment external to the distal bone in the frontal plane and anterior in the sagittal plane as "Extramedullary," while the other was the opposite reduction position, that is, bone in the frontal plane and sagittal plane as "Intramedullary." We evaluated the tip-apex distance, compression stiffness, change in femoral neck-shaft angle, amount of blade telescoping, and diameter of the distal screw hole after the compression test. Statistical analysis was conducted using the Mann-Whitney U test. RESULTS: No significant differences were seen in compression stiffness (p = 0.804) and femoral neck-shaft angle change (p = 0.644). Although the "Extramedullary" tip-apex distance was larger than the "Intramedullary" distance (p = 0.001), it indicated clinically acceptable lengths. The amount of blade telescoping and the distal screw hole diameter were significantly larger in "Intramedullary" than in "Extramedullary" (p < 0.001, p = 0.019, respectively). Our results showed that "Intramedullary" had significantly larger blade telescoping and distal screw hole diameters than "Extramedullary," and contrary to our hypothesis, no significant differences were seen in compression stiffness and femoral neck-shaft angle change. CONCLUSIONS: As opposed to the "Intramedullary" reduction pattern, the biomechanical properties of the "Extramedullary" reduction pattern improved stability during testing and decreased sliding.

Orthopaedic trauma care during the early COVID-19 pandemic in the Asia-Pacific region.

The Asia-Pacific region countries, with their large and socioeconomically diverse populations and infrastructures, were amongst the earliest to have to respond to the COVID-19 pandemic. Although the disease is not one of surgical trauma, its effects on orthopaedic injuries have been significant. Medical systems had to adapt to better focus on patients with a highly communicable disease, while continuing to provide essential services. Even though many countries saw a decrease in traumatic injuries during the initial periods, orthopaedic trauma services nevertheless had to adapt accordingly to system-wide organizational changes. While each country took their individual approaches to address the pandemic, there were also consistencies in how musculoskeletal injuries and conditions were handled during these early stages of the pandemic. This article reviews those early management approaches to musculoskeletal injury care during the COVID-19 pandemic in different countries throughout the Asia-Pacific region following the initial outbreak in China: Australia, South Korea, and Japan.

Poly(POG)n loaded with recombinant human bone morphogenetic protein-2 accelerates new bone formation in a critical-sized bone defect mouse model.

BACKGROUND: Delivery of bone morphogenetic protein-2 (BMP-2) via animal-derived absorbable collagen materials is used for the treatment of large bone defects. However, the administration of bovine proteins to humans is associated with the risk of zoonotic complications. We therefore examined the effect of combining BMP-2 with collagen-like peptides, poly(POG)n, in a critical-sized bone defect mouse model. METHODS: A 2-mm critical-sized bone defect was created in the femur of 9-week-old male C57/BL6J mice. Mice were randomly allocated into one of four treatment groups (n = 6 each): control (no treatment), poly(POG)n only, 0.2 µg, or 2.0 µg BMP-2 with poly(POG)n. New bone formation was monitored using soft X-ray radiographs, and bone formation at the bone defect site was examined using micro-computed tomography and histological examination at 4 weeks after surgery. RESULTS: Administration of 2.0 µg of BMP-2 with poly(POG)n promoted new bone formation and resulted in greater bone volume and bone mineral content than that observed in the control group and successfully achieved consolidation. In contrast, bone formation in all other groups was scarce. CONCLUSIONS: Our findings suggest the potential of BMP-2 with poly(POG)n as a material, free from animal-derived collagen, for the treatment of large bone defects.

Novel transcatheter arterial embolization method for hemodynamically unstable pelvic fractures to prevent complications of gluteal necrosis.

PURPOSE: To validate our previously designed transcatheter arterial embolization (TAE) technique for bilateral iliac arteries in unstable pelvic fractures, which is designed to also prevent gluteal necrosis and avoid vasopressors. METHODS: We retrospectively analyzed the data of patients with pelvic fractures who underwent our new TAE procedure to determine the incidence of subsequent gluteal necrosis. We also compared certain variables between patients who underwent TAE before 2005 using a different technique and developed gluteal necrosis and patients who underwent TAE in 2005 and onward using our technique. Gluteal necrosis was confirmed by a radiologist based on imaging findings. RESULTS: Seventy patients with pelvic fractures who underwent our TAE technique met the inclusion criteria (bilateral iliac arterial embolization and no embolic agent other than a gelatin sponge). Patients' median age was 47.5 years, 33 were male, and 92.9% (65/70) had unstable fractures. Sixty-eight patients had severe multiple trauma. No patients developed gluteal necrosis following our TAE procedure and the overall survival rate was 82.9% (58/70). We found no statistically significant difference in procedure time between the previous and new technique, although the new procedure tended to be shorter. Furthermore, overall survival did not significantly differ between the groups. Multiple regression analysis revealed that TAE procedure time and external pelvic fracture fixation were independently related to gluteal necrosis. CONCLUSIONS: Our non-selective bilateral iliac arterial embolization procedure involves arresting shock quickly, resulting in no post-procedure gluteal necrosis. The procedure involves cutting the gelatin sponge rather than "pumping" and avoids the use of vasopressors.

Hip fracture care and national systems: Australia and Asia.

The Asia-Pacific region includes countries with diverse cultural, demographic, and socio-political backgrounds. Countries such as Japan have very high life expectancy and an aged population. China and India, with a combined population over 2.7 billion, will experience a huge wave of ageing population with subsequent osteoporotic injuries. Australia will experience a similar increase in the osteoporotic fracture burden, and is leading the region by establishing a national hip fracture registry with governmental guidelines and outcome monitoring. While it is impossible to compare fragility hip fracture care in every Asia-Pacific country, this review of 4 major nations gives insight into the challenges facing diverse systems. They are united by the pursuit of internationally accepted standards of timely surgery, combined orthogeriatric care, and secondary fracture prevention strategies.

Osteoarthritic changes of the patellofemoral joint in STR/OrtCrlj mice are the earliest detectable changes and may be caused by internal tibial torsion.

STR/ort mice develop a naturally occurring osteoarthritis (OA) of the knee joints. However, the evaluation of early OA changes has been difficult due to variability caused by gender, individual differences, and differences between the right and left lower limbs. The objective of this study was to analyze the variability of the early OA changes with age in STR/ort mice and to identify the cause of onset. A total of 115 STR/OrtCrlj mice aged 10-45 weeks were examined. In addition to conventional radiological and histological evaluation of the knee joints, histological sections were used to examine the patellofemoral, femorotibial, and growth plate cartilage under similar conditions. A morphological evaluation of tibiae, including micro-3-dimensional computed tomography, was performed. Radiological evaluation showed OA changes in the joints of mice over 35 weeks old and histological evaluation showed early OA changes in the femorotibial joints of mice over 26 weeks old. However, these changes were not common in all individuals. In contrast, most common and reproducible OA changes were observed in the bilateral patellofemoral joints of all individuals, and even in subjects ranging from 10 to 20 weeks of age. Morphological evaluations also demonstrated an abnormal tibial internal torsion that increased with age and was associated with medial patellar dislocation. In conclusion, the earliest histological OA change was observed in the patellofemoral joint prior to similar observations in the femorotibial joint. Internal tibial torsion may be a cause of OA in the patellofemoral joints, which leads to the development of medial femorotibial OA.

Sepsis caused by peripelvic soft tissue infections in critically injured patients with multiple injuries and unstable pelvic fracture.

BACKGROUND: In critically injured patients with multiple injuries and unstable pelvic fracture, late mortality almost invariably results from sepsis. METHODS: We analyzed the clinical features of 11 patients with sepsis caused by soft tissue infections surrounding the fractured pelvis, of 830 patients with pelvic fracture after blunt trauma treated at our level I trauma center over the past 25 years. Soft tissue infection was defined as abscess formation in subcutaneous tissue or muscle diagnosed by computed tomography or an operation. RESULTS: Mean injury severity score was 48, and mean systolic blood pressure on arrival was 66 mm Hg. All patients had multiple concomitant injuries and prolonged hemorrhagic shock. Open pelvic fracture was present in five patients. Mean blood transfusion volume within 24 hours was 12,611 mL. Intra-aortic balloon occlusion was performed in three patients and transcatheter angiographic embolization in nine patients. Embolic sites of transcatheter angiographic embolization were bilateral internal iliac arteries (n = 9), lumbar artery (n = 5), median sacral artery (n = 2), and circumflex femoral artery (n = 2). Infection sites included the gluteal (n = 11), femoral (n = 6), sacral (n = 4), lumbar (n = 4), anterior iliac (n = 2), inguinal (n = 1), and perineal (n = 1) regions. Necrotic changes of infected soft tissue were found in all patients. They underwent open drainage and daily debridement with pulsatile irrigation followed by intravenous antibiotics. All patients developed severe sepsis, five of whom subsequently died of multiple organ failure. CONCLUSIONS: In critically injured patients with multiple injuries and unstable pelvic fracture, peripelvic soft tissue infections occasionally cause sepsis. Peripelvic infections are often accompanied by necrotic changes and easily develop into severe sepsis or multiple organ failure. Identifying high-risk patients and early diagnosis with prompt surgical treatment are indispensable for the patients' survival.

Effect of Single Injection of Recombinant Human Bone Morphogenetic Protein-2-Loaded Artificial Collagen-Like Peptide in a Mouse Segmental Bone Transport Model.

This study aimed to investigate whether a single injection of recombinant human bone morphogenetic protein-2-loaded artificial collagen-like peptide gel (rhBMP-2/ACG) accelerates consolidation at the bone defect site and bone union at the docking site in a mouse segmental bone transport (SBT) model. A critical sized bone defect (2 mm) was created in the femur of mice and subsequently reconstructed using SBT with an external fixator. Mice were divided into four treatment groups: Group CONT (immobile control), Group 0.2 (bone segments moved 0.2 mm/day for 10 days), Group 1.0 (bone segments moved 1.0 mm/day for 2 days), and Group 1.0/BMP-2 (rhBMP-2/ACG injected into the bone defect and segments moved 1.0 mm/day for 2 days). Consolidation at the bone defect site and bone union at the docking site was evaluated radiologically and histologically across eight weeks. Bone volume and bone mineral content were significantly higher in Group 0.2 than in Group 1.0. Group 0.2 showed evidence of rebuilding of the medullary canal eight weeks after surgery at the bone defect site. However, in Group 1.0, maturation of regenerative bone at the bone defect site was poor, with the central area between the proximal and distal bone composed mainly of masses of fibrous and adipose tissue. Group 1.0/BMP-2 had higher bone volume and bone mineral content compared to Group 1.0, and all mice achieved bone union at the bone defect and docking sites. Single injection of rhBMP-2/ACG combined with SBT may be effective for enhancing bone healing in large bone defects.

Long-term functional outcome after unstable pelvic ring fracture.

PURPOSE: In patients with unstable pelvic ring fractures, the factors related to poor outcome are still controversial. The purpose of our study was to evaluate the long-term functional outcome of patients with unstable pelvic ring fractures and correlate it with various other factors. METHODS: Fifty-seven patients who had a minimal follow-up of 2 years completed the three-view plain radiographs, physical examination, and functional assessment with questionnaire. There were 28 male and 29 female patients with an average age of 42.4 years and Injury Severity Score of 24.6 points. The mean time of follow-up was 47.2 months. Thirty-nine patients were Tile type B, and 18 were type C. Twenty-three patients were treated conservatively, 22 with external fixation, and 12 with internal fixation. The results were scored with the Majeed score, the Iowa Pelvic Score, and the Medical Outcomes Study Short-Form 36-item Health Survey (SF-36). Statistical analysis was performed by use of the Pearson correlation coefficient test and multiple regression analysis. RESULTS: The average Majeed score was 79.7, the average IPS was 80.7, and the average physical component summary of the SF-36 was 13.4 points worse than that of the population norm. These scores correlate significantly with each other. The average residual displacement was 7.3 mm anteriorly and 5.2 mm posteriorly. Multiple regression analysis revealed that the Majeed score and the physical component summary of the SF-36 correlated with the presence of neurologic injury, and the Iowa Pelvic Score correlated with the presence of a mental disorder, posterior displacement, and neurologic injury. CONCLUSIONS: The long-term functional outcome after unstable pelvic ring fracture was not associated with Injury Severity Score, fracture location or fracture type. We discovered a close correlation between neurologic injury and functional outcome.

Resuscitative endovascular balloon occlusion of the aorta may increase the bleeding of minor thoracic injury in severe multiple trauma patients: a case report.

BACKGROUND: The resuscitative endovascular balloon occlusion of the aorta, because of its efficacy and feasibility, has been widely used in treating patients with severe torso trauma. However, complications developing around the site proximal to the occlusion by resuscitative endovascular balloon occlusion of the aorta have almost never been studied. CASE PRESENTATION: A 50-year-old Japanese woman fell from a height of approximately 10 m. At initial arrival, her respiratory rate was 24 breaths/minute, her blood oxygen saturation was 95% under 10 L/minute oxygenation, her pulse rate was 90 beats per minute, and her blood pressure was 180/120 mmHg. Mild lung contusion, hemopneumothorax, unstable pelvic fracture, and retroperitoneal bleeding with extravasation of contrast media were observed in initial computed tomography. As her vital signs had deteriorated during computed tomography, a 7-French aortic occlusion catheter (RESCUE BALLOON®, Tokai Medical Products, Aichi, Japan) was inserted and inflated for aortic occlusion at the first lumbar vertebra level and transcatheter arterial embolization was performed for the pelvic fracture. Her bilateral internal iliac arteries were embolized with a gelatin sponge; however, the embolized sites presented recanalization as coagulopathy appeared. Her bilateral internal iliac arteries were re-embolized by n-butyl-2-cyanoacrylate. The balloon was deflated 18 minutes later. After embolization, repeat computed tomography was performed and a massive hemothorax, which had not been captured on arrival, had appeared in her left pleural cavity. Thoracotomy hemostasis was performed and a hemothorax of approximately 2500 ml was aspirated to search for the source of bleeding. However, clear active bleeding was not captured; resuscitative endovascular balloon occlusion of the aorta may have been the cause of the increased bleeding of the thoracic injury at the proximal site of the aorta occlusion. CONCLUSIONS: It is necessary to note that the use of resuscitative endovascular balloon occlusion of the aorta may increase bleeding in sites proximal to occlusions, even in the case of minor injuries without active bleeding at the initial diagnosis.

Influence of hooks and a lag screw on internal fixation plates for lateral malleolar fracture: a biomechanical and ergonomic study.

BACKGROUND: For internal fixation of AO classification Type B lateral malleolar fracture, insertion of lag screws into the fracture plane and fixation with a one-third tubular plate as a neutralization plate are the standard treatment procedures. The one-third tubular plate is processed to a hook shape and hung on the distal end of the fibula. In this study, to compare the function of the hook and lag screws of a one-third tubular plate and LCP for osteosynthesis of lateral malleolar fracture, mechanical indices of internal fixation were compared among the one-third tubular plates with lag screws with and without the hook and a locking compression plate. METHODS: As mechanical tests, a compression test was performed in which compression in the bone axis direction produced by supporting the body weight was simulated, and a torsion test was performed in which external rotation of the bone axis caused by plantar flexion of the ankle joint was simulated. Muscle strength during walking and the force and torque acting on the ankle and knee joints were determined using inverse dynamic analysis. Finite element analysis was performed to analyze the function of hooks and lag screws. The joint reaction force determined by inverse dynamic analysis was adopted as the loading condition of finite element analysis. RESULTS: A stiffness equivalent to that of healthy bone could be achieved by all three internal fixations. It was clarified that the presence of the hook does not make a difference in stiffness. Displacement of the one-third tubular plate was small regardless of the presence or absence of the hook compared with those of locking compression plates. CONCLUSIONS: The presence of the hook did not make any difference in stiffness, suggesting that active preparation of the hook is unnecessary. We also clarified that lag screws inhibit displacement.

Surgical treatment for suicidal jumper's fracture (unstable sacral fracture) with thoracolumbar burst fracture: a report of three cases.

INTRODUCTION: Suicidal jumper's fracture (unstable sacral fracture) is characterized not only by multiple fractures including thoracolumbar fractures, but also major chest and abdominal injuries. Early stabilization of these fractures and early ambulation are required for the treatment and management of chest and abdominal injuries. We present 3 cases of suicidal jumper's fracture with thoracolumbar burst fracture, treated with minimally invasive posterior fixation surgery, which is a combination of percutaneous pedicle screws (PPS) and the mini-open Galveston technique. CASE REPORTS: Case 1. A 50-year-old woman was injured by a fall from the 5th floor of a building as the result of a suicide attempt. Computed tomography revealed an H-shaped unstable sacral fracture and thoracolumbar fractures with major chest and abdominal injuries. For early stabilization of spinopelvic instability and early ambulation, we treated the patient with PPS and the mini-open Galveston technique. Her early postoperative emergence from bedrest contributed to the improvement of her general condition. One year after surgery at the final follow-up, she was able to walk with a T-cane without any motor, bladder, or bowel dysfunction (BBD) and achieved almost complete healing of the fractures. Cases 2 and 3. A 25-year-old woman (Case 2) and a 43-year-old woman were injured in falls. They had multiple injuries including unstable sacral fractures, and thoracolumbar fractures with major chest and abdominal injuries. We treated these patients with PPS and the mini-open Galveston technique. One year after surgery, they were able to walk with a T-cane and achieved almost complete healing of thoracolumbar fractures, but delayed healing of an unstable sacral fracture in Case 2, and remaining BBD in Case 3. CONCLUSION: PPS and the mini-open Galveston technique is a good approach to fixation because they are minimally invasive and provide moderately rigid fixation, especially in patients with multiple trauma whose general condition is poor.