Dual-functional thermosensitive hydrogel for reducing infection and enhancing bone regeneration in infected bone defects.

The contamination of bone defects is a serious therapeutic problem. The treatment of infected bone defects involves rigorous infection control followed by bone reconstruction. Considering these two processes, the development of biomaterials possessing antibacterial and osteogenic properties offers a promising approach for the treatment of infected bone defects. In this study, a dual-functional, thermosensitive, and injectable hydrogel composed of chitosan (CS), quaternized CS (QCS), and nano-hydroxyapatite (nHA) was designed, and the ratio of CS to QCS in the hydrogel was optimized to enhance the antibacterial efficacy of CS while reducing the cytotoxicity of QCS. In vitro studies demonstrated that the hydrogel with an 85 %:15 % ratio of CS to QCS exhibited excellent biocompatibility and antibacterial properties while also possessing suitable mechanical characteristics and degradability. The incorporation of nHA into the hydrogel enhanced MC3T3-E1 proliferation and osteogenic differentiation. Moreover, this hydrogel demonstrated superior in vivo therapeutic effectiveness in a rabbit model of infected bone defect. In summary, this study provides a promising material design and a comprehensive one-step treatment strategy for infected bone defects.

A Novel Navigation Device for Precise Percutaneous Placement of the Guidewire in Femoral Neck Fracture Cannulated Screw Fixation Surgery.

The accuracy of screw placement is a key factor for the stability of the cannulated screws used in the fixation of femoral neck fractures. In this study we designed a navigation device for ensuring the screw reaches the ideal position for optimal fixation. From March 2019 to September 2020, 66 patients with femoral neck fracture were enrolled and divided into 2 groups, one group was treated using the traditional free-hand cannulated screw fixation and the other using the new navigation device with assisted fixation. The effectiveness of the 2 methods was compared based on surgery duration, intraoperative bleeding, number of fluoroscopic examination and guidewire insertion attempts, screw parallelism, and effective fixation area. Fracture healing, complications and hip joint function were assessed after operation. The new navigation device reduced the duration of surgery without causing additional intraoperative bleeding, and significantly reduced number of fluoroscopy examination and guidewire insertion attempts (4.00±1.58 vs. 6.09±1.94 with traditional surgery). The accuracy of screw implantation was improved, as demonstrated by increased screw parallelism (0.71±0.57° vs. 1.66 ±1.01° with traditional surgery) and higher effective fixed area (64.88±10.52 vs. 58.61±9.19 mm2 with traditional surgery). In the postoperative follow-up, except for one case of femoral head necrosis and one case of bone nonunion in the traditional surgical group, the other patients showed fracture healing. There was no significant difference in hip joint function between the 2 groups. The new navigation device enables rapid and accurate guidewire positioning for cannulated screw fixation through simple operation procedures, resulting in good prospect for clinical transformation.

Surgical flip-dislocation of the bicolumnar approach without olecranon osteotomy versus olecranon osteotomy in type AO 13C3 distal humeral fracture: a matched-cohort study.

BACKGROUND: Our experience with the surgical flip-dislocation of the bicolumnar (SFDB) approach for type AO 13C3 humeral fractures indicates that this surgical approach can be performed safely and effectively in appropriately selected patients. We aimed to evaluate the clinical outcomes of the SFDB approach without olecranon osteotomy (OO) for type AO 13C3 distal humeral fractures. METHODS: We retrospectively reviewed 65 cases of type AO 13C3 distal humeral fractures treated between April 2008 and July 2018; 33 patients were treated with the SFDB approach, and the remaining were treated with OO. Propensity score matching was used to control for sex, age, and the American Society of Anesthesiology score. Elbow pain, range of motion, stability, and function were assessed using the Mayo Elbow Performance Index (MEPI) and the Disabilities of the Arm, Shoulder, and Hand questionnaire. Clinical complications, reoperation rates, and radiographic results were compared between the groups. RESULTS: Operative time and blood loss were significantly lower in the SFDB group than in the OO group (P = 0.001, P = 0.002, respectively). At the final follow-up, the mean postoperative MEPI did not significantly differ between the groups (P = 0.628). According to Morrey's criteria, a typical functional range of elbow motion was achieved in 12 and 15 patients in the SFDB and OO groups, respectively. CONCLUSIONS: The SFDB approach achieves superior exposure of the articular surface without injury to the extensor mechanism in type 13C3 articular surface fracture treatment. This approach also results in good early functional recovery and clinical outcomes, with a low risk of complications.

Reverse-traction skin-stretching device for primary closure of large skin defects.

The tension in the skin margin of a wound is the major determinant for wound healing. The difficulty of primary closure for large skin defects due to excessive wound tension has long been a clinical challenge. In this study, we designed and fabricated a reverse-traction skin-stretching device (RT-SSD) to relieve the skin tension of a large skin defect and thereby allow primary wound closure. The novel RT-SSD designed in this study drives the fixing device fixed on the skin edge of the wound by rotating the pulling device, thus exerting a reverse tensile force on both sides of the wound, causing creep and stress relaxation, thus reducing the skin tension. Through the tension analyses; microcirculation detection; clinical scores; and a series of histological staining in vivo, it is verified that intraoperative application of RT-SSD can stretch and straighten collagen and fragment elastin, thus effectively reducing skin tension of large skin defect of miniature pigs. In addition, its special linear and planar traction protects the subcutaneous microcirculation of the wound site. The evaluation of wound healing confirmed that RT-SSD had negligible negative impact on wounds, reduced the incidence of complications, and promoted the healing of large skin defects. Therefore, this study provides a new safe and effective device for the primary closure of large skin defects.

Novel Covert-Inferior Pelvic Approach with a Subpubic Plate for Anterior Pelvic Ring Fractures: Preliminary Results.

BACKGROUND: Anterior pelvic ring injuries can be treated via Pfannenstiel, modified Stoppa, or ilioinguinal approaches, but these require exposing the abdominal soft tissues and may damage pelvic organs. The scar on the abdominal wall is also unacceptable for some patients. The minimally invasive anterior pelvic ring internal fixator (INFIX) is not ideal for thin patients with easily irritated skin, and it is associated with complications such as femoral nerve palsy, vascular occlusion, and lateral femoral cutaneous nerve injury. In this study, we designed a new external pelvic approach for the treatment of an anterior pelvic ring fracture. METHODS: We retrospectively reviewed 28 patients with 36 pubic ramus fractures that had been treated via the covert-inferior pelvic approach. All patients underwent a surgical procedure between August 2019 and January 2021. According to the Nakatani classification, there were 6 cases of type-I fracture, 25 cases of type-II fracture, and 5 cases of type-III fracture. Operative time, blood loss, and postoperative radiographic and computed tomographic (CT) findings were recorded. Patients were followed for fracture healing time, functional status, esthetic satisfaction, and complications. RESULTS: A total of 27 patients had follow-up for at least 12 months (range, 12 to 29 months). Postoperative radiographs and CT scans showed well-positioned plates and screws. The mean preoperative time was 9.4 ± 3.8 days, the mean operative time was 61.3 ± 22.67 minutes, the mean intraoperative blood loss was 63.6 ± 42.62 mL, the mean fracture healing time was 4.1 ± 1.6 months, and the mean Majeed score was 89.74 ± 8.07. There were no complications of nonunion, internal fixation failure, vascular injury, nerve palsy, or hernia. All of the patients were esthetically satisfied with the scar. CONCLUSIONS: The covert-inferior pelvic approach combined with a subpubic plate effectively fixed Nakatani type-I, II, and III fractures. The advantages of this method include rapid recovery after the surgical procedure, safety, simplicity, a short learning curve, no damage to abdominal soft tissue, no effect on pubic symphysis micromotion, and esthetic benefits. It may be another option for anterior pelvic ring fractures and can supplement other approaches. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Thermosensitive vancomycin@PLGA-PEG-PLGA/HA hydrogel as an all-in-one treatment for osteomyelitis.

Osteomyelitis is a difficult-to-treat infectious disease. Treatment, which includes controlling the infection and removing necrotic tissues, is challenging. Considering the side effects and drug resistance of systemic antibiotics, local drug delivery systems are being explored. Antibiotic-loaded bone cement is the main treatment strategy; however, it has several disadvantages. Thus, based on its thermosensitive gelation properties, poly(D, L-lactide-co-glycolide)-poly(ethylene glycol)-poly(D, L-lactide-co-glycolide) (PLGA-PEG-PLGA) copolymer was used as a sustained-release drug carrier by calibrating its synthesis parameters. We prepared and characterized vancomycin@PLGA-PEG-PLGA/hydroxyapatite (HA) thermosensitive hydrogel with an LA/GA ratio of 15:1. The rheological characteristics, sol-gel phase-transition properties, and critical micelle concentration value of the PLGA-PEG-PLGA/HA complex confirmed that it undergoes a temperature-sensitive sol-gel phase transition. Furthermore, the HA in the composite increased the storage modulus of the system. FT-IR, XRD, and TEM findings showed that HA could be dispersed uniformly in the PLGA-PEG-PLGA polymer. Moreover, HA neutralized acidity during polymer degradation, improving in vitro cytocompatibility. In vitro and in vivo antibacterial experiments showed that the composite sustained-release system exhibited good bone repair characteristics owing to its efficacy in infection treatment. Therefore, vancomycin@PLGA-PEG-PLGA/HA allows sustained release of antibiotics and promotes bone tissue repair, showing potential for wide clinical applicability.

Chitosan-Based Biomaterial Scaffolds for the Repair of Infected Bone Defects.

The treatment of infected bone defects includes infection control and repair of the bone defect. The development of biomaterials with anti-infection and osteogenic ability provides a promising strategy for the repair of infected bone defects. Owing to its antibacterial properties, chitosan (an emerging natural polymer) has been widely studied in bone tissue engineering. Moreover, it has been shown that chitosan promotes the adhesion and proliferation of osteoblast-related cells, and can serve as an ideal carrier for bone-promoting substances. In this review, the specific molecular mechanisms underlying the antibacterial effects of chitosan and its ability to promote bone repair are discussed. Furthermore, the properties of several kinds of functionalized chitosan are analyzed and compared with those of pure chitosan. The latest research on the combination of chitosan with different types of functionalized materials and biomolecules for the treatment of infected bone defects is also summarized. Finally, the current shortcomings of chitosan-based biomaterials for the treatment of infected bone defects and future research directions are discussed. This review provides a theoretical basis and advanced design strategies for the use of chitosan-based biomaterials in the treatment of infected bone defects.

Minimally invasive plate osteosynthesis for complex comminuted bone fractures in the Fraser's type II floating knee: a case report.

OBJECTIVE: Floating knee type IIC, according to Fraser's classification, is an uncommon severe injury that typically occurs in polytrauma. In such cases, intra-articular fracture and the high degree of comminution and deformity of the mid-distal femur make fixation challenging. The purpose of this study was to demonstrate that minimally invasive plate osteosynthesis (MIPO) technology can simplify these complex problems and improve patient prognosis. CASE PRESENTATION: A 38-year-old man injured his left leg in a car accident, causing pain, swelling, deformity, and limited mobility on his left knee and thigh, and two small open wounds were noted mainly of the anterior aspect of the mid-distal thigh. Physical examination and computed tomography angiography of the lower limb confirmed that there was no damage to the neurovascular system. The clinical diagnosis was closed intra-articular fracture of the proximal tibia, open intra-articular fracture of the distal femur with extension to the diaphysis, and a patellar fracture on the ipsilateral knee. The treatment strategy involved a locking plate system applying MIPO technology. Postoperative evaluation of the patient was satisfactory, with immediate functional exercise, full weight-bearing after three months, and return to daily activity without pain. Final follow-up taken 3 years after surgery showed good lower limb alignment and complete plasticity of the bone structure, by which time the patient showed good limb function. CONCLUSIONS: Minimally invasive techniques can provide a simple and effective treatment for some complex fractures.

Protective effect of Sika Deer bone polypeptide extract on dexamethasone-induced osteoporosis in rats

BACKGROUND: Osteoporosis attacks approximately 10% of the population worldwide. Sika Deer (Cervus nippon), one of China's precious traditional medicinal animals, has been widely recorded in ancient Chinese medical books and claimed for centuries to have numerous medical benefits including bone strengthening. This study aimed to find the use of Sika Deer bone in treating osteoporosis according to traditional records and to investigate the protective effect of Sika Deer bone polypeptide extract on glucocorticoidinduced osteoporosis (GIOP) in rats. RESULTS: Sika Deer bone polypeptide extract could increase serum Ca2+ and BGP, decrease serum P3+, ALP, PTH, and CT, but had no effect on serum NO in rats with GIOP. The immunohistochemical iNOS results of the rats' distal femur were negative in each group. Besides the model group, the eNOS color reaction in osteoblasts was strongly positive in the other three groups. CONCLUSIONS: Sika Deer bone polypeptide extract can improve pathological changes in the microstructure and stimulate the expression of eNOS in osteoblasts. The protective effect on bone might be mediated by eNOS-dependent NO generation.

Accurate fixation of complicated comminuted femur fracture with customized LCP referencing a life-size 3D-printed model: a case report.

Fixation of a comminuted mid-distal femur fracture is challenging in clinical practice due to a high degree of comminution and malformation. Here we describe a procedure involving a series of steps for accurate fracture fixation in a patient diagnosed with comminuted mid-distal femur fracture. Emergency traction of the tibia tubercle was initially performed using a large distractor for temporary external fixation to maintain the femoral force line and to reduce intraoperative fractures. A three-dimensional printed model was then used as a preoperative simulation tool to preshape the customized locking plate, reducing the operation difficulty and improving surgical accuracy. Finally, the comminuted femur fracture was treated with the minimally invasive percutaneous plate osteosynthesis technique for maximum protection of bone fracture fragments and the surrounding blood supply. No postoperative complications were observed at the 3-year follow-up when the plate was removed. This procedure offers new possibilities for orthopedic surgeries and should be considered as an option for accurate fixation of comminuted mid-distal femur fractures.

Platelet-rich plasma-enhanced osseointegration of decellularized bone matrix in critical-size radial defects in rabbits.

BACKGROUND: Bone defects represent a common orthopedic condition. With its vast array of donor sources, xenogeneic bone shows considerable potential as a bone defect repair material but may also be associated with immune rejection and reduced osteogenic capacity. Thus, reducing the risks for immune rejection of xenogeneic bone, while improving its osseointegration, are key technical challenges. METHODS: Decellularized bone matrix scaffolds (DBMs) were fabricated by thorough ultrasonic vibration and subjection to chemical biological agents to remove cells and proteins. The DBMs were then mixed with platelet-rich plasma (PRP) under negative pressure. Growth factor concentrations of PRP, as well as the microstructures and biomechanical properties of the system, were examined. Furthermore, osseointegration capacities in the critical-size radial defect rabbit model were verified. RESULTS: Complete decellularization of the scaffold and limited reductions in mechanical strength were observed. Moreover, the obtained PRP demonstrated various growth factors. Radiographic evaluation and histological analysis verified that more new bone formation occurred in the DBM mixed with PRP group at 6 and 12 weeks after implantation compared with both the blank group and the DBM without PRP group. CONCLUSIONS: Thorough physical and chemical treatments can reduce the probability of immune rejection of DBMs. The novel composite of DBMs mixed with PRP can serve as a promising bone regeneration material.

Single-center experience in the treatment of extremely medial clavicle fractures with vertical fixation of double-plate: A retrospective study.

Patients suffering from extremely medial clavicle fractures combined with distinct displacement generally need surgical intervention. Double-plate fixation is a widely applied technique in the treatment of distal radius fracture, which has been reported to fix lateral clavicle fracture as well. This study reveals the effect of double-plate fixation as an innovative procedure in the treatment of extremely medial clavicle fractures for the first time.Nine patients complaint of extremely medial clavicle fracture were enrolled in this research from May 2017 to March 2019. Patients were operated with an open reduction and internal fixation using the double-plate technique. Postoperative x-ray was taken regularly to observe the fracture healing at each visit, and the related complications were also recorded. The rating score systems of Constant Murley score of treated shoulder and contralateral shoulder, ROWE score as well as American Shoulder and Elbow Surgeons (ASES) were evaluated to comment on the postoperative shoulder joint function.All patients achieved postoperative fracture healing with no complications. Only 1 patient complained of slight restriction, 2 patients complained of pain during overhead work, and another patient was found with plate breakage. Meanwhile, the Constant Murley scores of treated and contralateral shoulder were 94.1 and 98.5 points, respectively, indicating the similar shoulder function. Furthermore, the ROWE and ASES scores of the involved shoulder were 96.7 and 96.3 points at average, respectively.It is the first time to introduce the surgical technique of vertical double-plate fixation implied in stable fixation of extremely medial clavicle fractures, which could provide the surgeons with an alternative method for this type of fracture.

Novel anterior curved incision combined with MIPO for Pilon fracture treatment.

BACKGROUNDS: Poor prognosis was reported for complex Pilon fractures involving severe soft tissue damage. It is therefore useful to explore the evolution of different treatment strategies in an effort to reconstruct the axial alignment and articular surface, while minimizing additional damage to the surrounding soft tissues. METHODS: Seventeen patients with Pilon fractures were enrolled in this retrospective study from December 2009 to October 2014. The injuries were graded according to AO Classification and the Gustilo-Anderson system. Patients were treated with minimally invasive plate osteosynthesis (MIPO) combined with curved incision on the anterior area of ankle. The ankle function and radiological outcome were assessed by the modified Mazur ankle score and Burwell-Charnley criteria, respectively. Visual analogue score (VAS) score was used to assess the degree of patient's ankle pain, and related complications were also recorded. RESULTS: The mean time for fracture healing was 3.6 months (range: 3-6 months). According to Mazur's criteria, surgical treatment achieved good or excellent outcome in 15 (88.2%) cases, and the average VAS score was 1.19 ± 0.52. On the basis of Burwell-Charnley score, 12 (70.5%) patients achieved anatomic recovery, 4 (23.5%) obtained good reduction, and only 1 (5.9%) patient was diagnosed with valgus deformity. Additionally, 1 (5.9%) patient developed a superficial infection around incision, and 2 (11.8%) experienced superficial peroneal nerve damage. In addition, 2 (11.8%) patients showed radiographic evidence of existing ankle osteoarthritis at the final follow-up. CONCLUSIONS: This retrospective study is the first to assess the application of a curved incision on the anterior area of ankle with MIPO for the treatment of Pilon fractures, which achieves high functional recovery with a low complication rate. However, large randomized controlled trials comparing different approaches and fixation methods are still needed to conclusively identify the optimal treatment protocol.

Minimally Invasive Percutaneous Plate Osteosynthesis (MIPPO) Combined with Onionskin-Like Autologous Bone Grafting: A New Technique for Treatment of Tibial Nonunion.

BACKGROUND Established tibial nonunions rarely heal without secondary intervention; revision surgery is the most common intervention. Herein, we evaluated the clinical outcomes of patients with tibial nonunion treated with a new technique - minimally invasive percutaneous plate osteosynthesis (MIPPO) - combined with a new onionskin-like autologous bone grafting method. MATERIAL AND METHODS From 2010 to 2013, 18 patients with tibial nonunions (average bone defect: 9.5 mm) were treated with MIPPO technology combined with onionskin-like autologous bone grafting. Indices for clinical evaluation included operative time, fluoroscopy time, blood loss, hospital stay, healing time, postoperative complaints, radiographic performances, the Short Musculoskeletal Function Assessment (SMFA) questionnaire, and the American Orthopedic Foot & Ankle Society (AOFAS) ankle-hindfoot score. RESULTS The average operation and fluoroscopy times for tibial nonunion were 65 min and 15.5 s, respectively, with a total blood loss of 107.7 mL. The mean duration of hospital stay was 12.8 days. The mean follow-up time was 11.9 months, and all patients achieved radiologically confirmed bony healing in an average time of 13.1 weeks. No lower-leg deformity, fixation failure, infection, and vascular, or nerve injuries were recorded in any patient, and only 4 patients complained of slight limb pain upon total weight-bearing at the end of follow-up. The SMFA and AOFAS ankle-hindfoot scores of patients were graded excellent in 14 (77.8%) and good in 4 (22.2%), indicating high functional recovery. CONCLUSIONS MIPPO technology combined with onionskin bone grafting is an efficient method to treat patients with tibial nonunion, especially for patients with poor soft tissue condition.

InterTan nail versus Gamma3 nail for intramedullary nailing of unstable trochanteric fractures.

BACKGROUND: Trochanteric fractures (TF) have become a major source of morbidity and mortality in elderly. We conducted this study to compare the outcomes of unstable trochanteric fractures treated with the InterTan nail and Gamma3 nail. METHODS: Between January 2008 and May 2013, patients aged 60 years or older with a diagnosis of unstable TF treated with InterTan nail or Gamma3 nail were included. Patients treated with InterTan nail were pair-matched to patients treated with Gamma3 nail in a 1:2 ratio. Radiographs were obtained at 1, 3, 6, and 12 months follow-up, and all implant position changes, complications, fixation failures and functional scores were recorded. RESULTS: Eighty-seven patients were included in the InterTan nail group, and 174 pair-matched patients were included in the Gamma3 nail group. Preoperative scores were similar between the 2 groups. There are significant improvements postoperatively in both groups. The incidence of cut-out and femoral shaft fracture were significantly higher in the Gamma3 nail group than the InterTan nail group (P=0.024 and P=0.044, respectively). Patients treated with the InterTan nail experienced longer fluoroscopy and operative times. CONCLUSIONS: The InterTan nail may have a tendency in better outcomes for patients with unstable TF. However, the limited period of follow-up and inherent defects of nonrandomized trials indicate that better-designed randomized controlled trials will be required. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_191.