A Novel Mouse Model to Study Fracture Healing of Tibia

Background Delayed union of most tibial fractures due to their special anatomical structures.So an effective animal model is very important to study the mechanism and method of fracture healing.However, due to the small tibia of mice, the operation is difficult, and the surgical model requires high surgical skills. The construction of the fixation model of intramedullary nail for this fracture has improved and simplified the traditional fixation model of intramedullary nail, which not only achieves the purpose of constructing the fracture model, but also makes it more simple and effective.Therefore, the aim of the current study was to develop a new mouse model to study fracture healing of tibia. Methods We chose a combination between an open osteotomy and intramedullary stabilization. The 22G needle was inserted into the fracture end in a closed manner by using an open approach for osteotomy at the middle and lower 1/3 level of the tibia.Fractured tibia were analyzed using microcomputed tomography and histology at days 7,14,21and 28after surgery. All animals displayed normal limb loading and a physio-logical gait pattern within the first three days after fracture. No animals were lost due to surgery or anesthesia. Results X-ray confirmed that the fracture types obtained by the fracture modeling method were transverse fractures. X-ray, Micro-CT, immunohistochemistry, histological staining and Real-time PCR showed that the fracture healing of mice was typical endochondral ossification, with high repeatability. Conclusion The mouse tibial fracture model established by intramedullary nailing is safe, rapid and simple. Its fracture healing is a typical intrachondral ossification with high repeatability, which can be better used for the study of molecular mechanism and clinical transformation of fracture healing and bone metabolism.

Iliac intramedullary stabilization for Type IIIA fragility fractures of the pelvis

There have been few reports on fixation of Rommens classification Type IIIA fragility fractures of the pelvis (FFPs). Here, we present our less invasive surgical technique, called iliac intramedullary stabilization (ILIS), for the internal fixation of Type IIIA FFPs. The technique involves a closed reduction, termed the femur internal rotation reduction method (FIRM), whereby the fracture fragments are repositioned using lateral rotators by internally rotating the femur while the patient is in the prone position. Two iliac screws are inserted on the ilium bilaterally via the supra-acetabular bone canal during FIRM and connected with two transverse rods and two cross connectors. We refer to this internal fixation procedure as ILIS. We retrospectively recruited patients with Type IIIA fractures, treated using this procedure, at our institute between October 2017 and October 2019. We evaluated operative and post-operative outcomes. We enrolled 10 patients (9 women and 1 man; mean age, 85.2 years) who were followed up for over 6 months. All patients suffered FFPs after falling from a standing position. The mean operative time was 145.1 (range, 94–217) minutes, and the mean blood loss was 258.5 (range, 100–684) ml. All patients were allowed full weight bearing from post-operative day 1. All patients achieved bone union and regained their pre-injury walking ability at 6 months after surgery without evident secondary displacement. In conclusion, our ILIS technique allows less invasive internal fixation of Type IIIA FFPs with adequate stability for full weight bearing from post-operative day 1.

Treatment of femoral fractures in children aged two to six

Aims Current American Academy of Orthopaedic Surgeons (AAOS) guidelines for treating femoral fractures in children aged two to six years recommend early spica casting although some individuals have recommended intramedullary stabilization in this age group. The purpose of this study was to compare the treatment and family burden of care of spica casting and flexible intramedullary nailing in this age group. Methods Patients aged two to six years old with acute, non-pathological femur fractures were prospectively enrolled at one of three tertiary children’s hospitals. Either early closed reduction with spica cast application or flexible intramedullary nailing was accomplished under general anaesthesia. The treatment method was selected after discussion of the options by the surgeon with the family. Data were prospectively collected on patient demographics, fracture characteristics, complications, pain medication, and union. The Impact on Family Scale was obtained at the six-week follow-up visit. In all, 75 patients were included in the study: 39 in the spica group and 36 in the nailing group. The mean age of the spica group was 2.71 (2.0 to 6.9) years and the mean age of the nailing group was 3.16 (2.0 to 6.9) years. Results All fractures healed without evidence of malunion or more than 2.0 cm of shortening. The mean Impact on Family score was 70.2 for the spica group and 63.2 (55 to 99) for the nailing group, a statistically significant difference (p = 0.024) in a univariate analysis suggesting less impairment of the family in the intramedullary nailing group. There was no significant difference between pain medication requirements in the first 24 hours postoperatively. Two patients in the spica group and one patient in the intramedullary nailing group required additional treatment under anaesthesia. Conclusion Both early spica casting and intramedullary nailing were effective methods for treating femoral fractures in children two to six years of age. Intramedullary stabilization provides an option in this age group that may be advantageous in some social situations that depend on the child’s mobility. Fracture treatment should be individualized based on factors that extend beyond anatomical and biological factors. Cite this article: Bone Joint J 2020;102-B(8):1056–1061.

Intramedullary Stabilization of Pubic Ramus Fractures in Elderly Patients With a Photodynamic Bone Stabilization System (IlluminOss)

Introduction: A photodynamic bone stabilization system (PBSS) is a percutaneous operating method that provides intramedullary stabilization. The purpose of the study was to assess the clinical and radiological outcome after treatment of pubic ramus fractures with the PBSS. Materials and Methods: In a retrospective study, patients with osteoporotic pubic ramus fractures were included. The patients were treated with the PBSS in a percutaneous method. In the routine follow-up examination, pain was measured with the visual analog scale (VAS) and the type of mobilization was verified. Computer tomography of the pelvis was carried out in the follow-up examination (mean of 7.5 months after surgery) to investigate bone healing. Results: A total of 32 patients (25 females and 7 males) were included in the study. The average hospital stay was 16.5 ± 7.9 days (range: 5-37 days) and the mean operation time was 116.8 ± 47.1 minutes (range: 33-255 minutes). Two cases of wound infections and 1 case of misplacement of the PBSS implant with revision surgery have been documented. The mean VAS score for pelvic/hip pain at the day of inpatient discharge was 4.4 ± 1.4 (range: 2-7). A total of 25 patients could attend the follow-up examination 7.5 ± 1.7 months (range: 6-14) after the procedure, reporting a mean VAS for pelvic/hip pain of 3.0 ± 2.2 (range: 0-8). A total of 11 patients could walk without an orthopedic walking device, 7 patients needed underarm crutches, 6 patients used a walker-rollator, and 1 patient was immobilized. Consolidated pubis ramus fractures were described in 24 (96%) cases. Discussion: The results of our study reveal adequate clinical and radiological outcomes after treatment of osteoporotic pubic ramus fractures with the PBSS. This is the first study investigating the outcome after treating pubic ramus fractures with the PBSS. Conclusion: Based on our findings, the PBSS is an alternative to known techniques for the stabilization of the pubic ramus.