The Relationship Between Falling Distance and Trauma Severity Among Fall Injury Survivors Who Were Transported to a Trauma Center.

Introduction Falls from >6 meters have been shown to cause multiple traumas and serious injuries. However, especially among fall survivors who were transported to trauma centers, the relationship between falling distance and trauma severity remains unclear. This study aimed to investigate the relationship between falling distance and trauma severity among fall injury survivors who were transported to a trauma center and clarify the characteristics of trauma among survivors of falls from high places from an orthopedic surgeon's perspective. Methods We retrospectively reviewed the medical records of 65 fall injury survivors who were transported to a trauma center for falling distance; whether the fall was a suicide attempt; abdominal, chest, and head trauma; the numbers of upper-limb, lower-limb, and spinal vertebral fractures; McCormack load-sharing classification score; unstable pelvic fracture; Frankel classification; injury severity score (ISS); and duration of intensive care unit (ICU) and hospital stay. We evaluated the correlations between falling distance and the other factors and compared all factors between those falling <6 meters and those falling >6 meters. Results Falling distance was weakly positively correlated with durations of ICU and hospital stay. The percentage of cases that were suicide attempts, the number of lower-limb fractures, the McCormack load-sharing classification score, and the durations of ICU and hospital stay were significantly higher among those falling from >6 meters than among those falling from <6 meters. Conversely, there were no significant differences in abdominal trauma, chest trauma, head trauma, number of upper-limb fractures, number of vertebral fractures, unstable pelvic fracture, or Frankel classification between the two groups. Conclusion The findings indicate that falling from a higher distance may increase lower-limb and vertebral fracture severity and may lead to longer ICU and hospital stays among fall injury survivors who are transported to trauma centers.

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.

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.

Experience of an Orthopaedic Surgery Department Early During the COVID-19 Outbreak in Japan Including Real-Time Polymerase Chain Reaction Assay Results for SARS-CoV-2.

Introduction The coronavirus disease 2019 (COVID-19) epidemic beginning December 2019 in China has now become a worldwide pandemic. With the need to develop an approach to manage orthopaedic surgeries, we aimed to evaluate the most current data on all the surgical cases in our department including the results of the reverse-transcriptase polymerase chain reaction (RT-PCR) assay for infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods The monthly number of surgical cases from 2016 were reviewed, and compared the numbers of surgical cases both in elective and emergency surgery during the pandemic with the pre-pandemic period. The results of RT-PCR for SARS-CoV-2 in 94 orthopaedic surgery cases from May 13 to June 30, 2020, and clinical signs/symptoms, and laboratory data of 48 consecutive cases within a month from May 13 were also evaluated. Results The mean monthly number of surgeries from January to May 2020 was significantly lower than the mean number in 2019 (73.8 vs 121.9, respectively, p=0.01). The proportion of emergency surgeries in all surgeries performed in May 2020 was 35.5%, which is significantly more than the mean rate of 20.4% in 2019 (p=0.04). Hip arthroplasties and spine surgeries showed the greatest reduction, at greater than 80% and 65%, respectively. Although none of the 94 patients were positive for SARS-CoV-2, 66.7% showed signs/symptoms typical of COVID-19. The most frequent signs/symptoms were production of nasal mucus (25.5%), followed by dry cough (19.1%); and fatigue, headache, and dizziness (17.0% each). The incidence of abnormal values, which are commonly noted in COVID-19 patients, were eosinopaenia 37.5%; lymphopaenia 18.8%; thrombocytopaenia 8.3%; and elevated prothrombin time 10.4%. Conclusions Our results show that our RT-PCR negative patients showed signs/symptoms and abnormal laboratory values typical of COVID-19, indicating surgeons should be aware of these abnormalities in patients and the need to rule out COVID-19 before proceeding with surgery.

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.

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.

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.

Spinal Epidural Hematoma after Thoracolumbar Posterior Fusion Surgery without Decompression for Thoracic Vertebral Fracture.

We present a rare case of spinal epidural hematoma (SEH) after thoracolumbar posterior fusion without decompression surgery for a thoracic vertebral fracture. A 42-year-old man was hospitalized for a thoracic vertebral fracture caused by being sandwiched against his back on broken concrete block. Computed tomography revealed a T12 dislocation fracture of AO type B2, multiple bilateral rib fractures, and a right hemopneumothorax. Four days after the injury, in order to promote early orthostasis and to improve respiratory status, we performed thoracolumbar posterior fusion surgery without decompression; the patient had back pain but no neurological deficits. Three hours after surgery, he complained of acute pain and severe weakness of his bilateral lower extremities; with allodynia below the level of his umbilicus, postoperative SEH was diagnosed. We performed immediate revision surgery. After removal of the hematoma, his symptoms improved gradually, and he was discharged ambulatory one month after revision surgery. Through experience of this case, we should strongly consider the possibility of preexisting SEH before surgery, even in patients with no neurological deficits. We should also consider perioperative coagulopathy in patients with multiple trauma, as in this case.

Comparison of internal fixations for distal clavicular fractures based on loading tests and finite element analyses.

It is difficult to apply strong and stable internal fixation to a fracture of the distal end of the clavicle because it is unstable, the distal clavicle fragment is small, and the fractured region is near the acromioclavicular joint. In this study, to identify a superior internal fixation method for unstable distal clavicular fracture, we compared three types of internal fixation (tension band wiring, scorpion, and LCP clavicle hook plate). Firstly, loading tests were performed, in which fixations were evaluated using bending stiffness and torsional stiffness as indices, followed by finite element analysis to evaluate fixability using the stress and strain as indices. The bending and torsional stiffness were significantly higher in the artificial clavicles fixed with the two types of plate than in that fixed by tension band wiring (P < 0.05). No marked stress concentration on the clavicle was noted in the scorpion because the arm plate did not interfere with the acromioclavicular joint, suggesting that favorable shoulder joint function can be achieved. The stability of fixation with the LCP clavicle hook plate and the scorpion was similar, and plate fixations were stronger than fixation by tension band wiring.

Negative-pressure wound therapy over surgically closed wounds in open fractures.

PURPOSE: To evaluate the outcome of open fracture surgery with negative-pressure wound therapy (NPWT) applied directly over surgical wounds. METHODS: Medical records of 10 men and 4 women aged 6 to 70 (mean, 43.7) years who underwent internal fixation, external fixation, or splint application for open fractures of the lower leg (n=7), foot and ankle (n=5), or knee (n=2), and NPWT were reviewed. The NPWT was applied directly over the surgical wound without a non-adherent contact layer. The foam was changed every 3 days. The standard negative pressure was 125 mm Hg. The NPWT was stopped when the wound discharge became <50 ml per day. The duration of NPWT and the level of negative pressure were recorded, as were wound condition, reasons for NPWT, and outcome. RESULTS: The mean duration of NPWT was 9.1 (range, 3-24) days. Four patients developed maceration of the skin under the foam, whereas 2 patients developed skin blisters under the drape. No necrosis of flap skin or infection occurred, and all the fractures eventually united. CONCLUSIONS: Maceration of the skin was seen in some cases but did not affect the overall outcome. NPWT directly over the skin surface had no deleterious effect on wound and fracture healing.

Repeated freeze-thaw cycles reduce the survival rate of osteocytes in bone-tendon constructs without affecting the mechanical properties of tendons.

Frozen bone-patellar tendon bone allografts are useful in anterior cruciate ligament reconstruction as the freezing procedure kills tissue cells, thereby reducing immunogenicity of the grafts. However, a small portion of cells in human femoral heads treated by standard bone-bank freezing procedures survive, thus limiting the effectiveness of allografts. Here, we characterized the survival rates and mechanisms of cells isolated from rat bones and tendons that were subjected to freeze-thaw treatments, and evaluated the influence of these treatments on the mechanical properties of tendons. After a single freeze-thaw cycle, most cells isolated from frozen bone appeared morphologically as osteocytes and expressed both osteoblast- and osteocyte-related genes. Transmission electron microscopic observation of frozen cells using freeze-substitution revealed that a small number of osteocytes maintained large nuclei with intact double membranes, indicating that these osteocytes in bone matrix were resistant to ice crystal formation. We found that tendon cells were completely killed by a single freeze-thaw cycle, whereas bone cells exhibited a relatively high survival rate, although survival was significantly reduced after three freeze-thaw cycles. In patella tendons, the ultimate stress, Young's modulus, and strain at failure showed no significant differences between untreated tendons and those subjected to five freeze-thaw cycles. In conclusion, we identified that cells surviving after freeze-thaw treatment of rat bones were predominantly osteocytes. We propose that repeated freeze-thaw cycles could be applied for processing bone-tendon constructs prior to grafting as the treatment did not affect the mechanical property of tendons and drastically reduced surviving osteocytes, thereby potentially decreasing allograft immunogenecity.