Cultivation of hierarchical 3D scaffolds inside a perfusion bioreactor: scaffold design and finite-element analysis of fluid flow

The use of porous 3D scaffolds for the repair of bone nonunion and osteoporotic bone is currently an area of great interest. Using a combination of thermally-induced phase separation (TIPS) and 3D-plotting (3DP), we have generated hierarchical 3DP/TIPS scaffolds made of poly(lactic-co-glycolic acid) (PLGA) and nanohydroxyapatite (nHA). A full factorial design of experiments was conducted, in which the PLGA and nHA compositions were varied between 6‒12% w/v and 10‒40% w/w, respectively, totaling 16 scaffold formulations with an overall porosity ranging between 87%‒93%. These formulations included an optimal scaffold design identified in our previous study. The internal structures of the scaffolds were examined using scanning electron microscopy and microcomputed tomography. Our optimal scaffold was seeded with MC3T3-E1 murine preosteoblastic cells and subjected to cell culture inside a tissue culture dish and a perfusion bioreactor. The results were compared to those of a commercial CellCeram™ scaffold with a composition of 40% β-tricalcium phosphate and 60% hydroxyapatite (β-TCP/HA). Media flow within the macrochannels of 3DP/TIPS scaffolds was modeled in COMSOL software in order to fine tune the wall shear stress. CyQUANT DNA assay was performed to assess cell proliferation. The normalized number of cells for the optimal scaffold was more than twofold that of CellCeram™ scaffold after two weeks of culture inside the bioreactor. Despite the substantial variability in the results, the observed improvement in cell proliferation upon culture inside the perfusion bioreactor (vs. static culture) demonstrated the role of macrochannels in making the 3DP/TIPS scaffolds a promising candidate for scaffold-based tissue engineering.

The predictive value of preoperative paraspinal muscle morphometry on complications after lumbar surgery: a systematic review

Purpose The effect of paraspinal muscles atrophy and fat infiltration (FI) on the complications of spinal surgery has not been established. Methods A review of the literature was conducted from a search of the PubMed, EMBASE, and Web of Science databases from inception through January 2021. The literature was searched and assessed by independent reviewers based on criteria that included an assessment of preoperative paraspinal muscle morphology in addition to measuring its relationship to surgical complications. All relevant papers were assessed for risk of bias according to the modified Newcastle Ottawa Scale and the Joanna Briggs Institute Critical Appraisal Tools. A narrative synthesis was conducted. Results The initial search yielded 5632 studies, of which 16 studies were included in the analysis. All included studies were at a low risk of bias. There existed strong evidence that the atrophy and FI of paraspinal muscles had an association with the development of bone nonunion (two high quality studies), pedicle screw loosening (two high quality studies), adjacent segment degeneration (three high quality studies) and proximal junctional kyphosis (five high quality studies) after lumbar surgery. Besides, there is also limited evidence for association between atrophy and FI of paraspinal extensor muscles and less local and global curve improvement. Conclusions Strong evidence was found for an association between preoperative paraspinal muscle degeneration and multiple postoperative complications after lumbar surgery. However, the findings should be interpreted with caution due to the small quantity of the available literature and high heterogeneity among studies.

Clinical efficacy of bone transport technology in Chinese older patients with infectious bone nonunion after open tibial fracture

Objective This study was designed for the first time to analyze clinical efficacy of bone transport technology in Chinese older patients with infectious bone nonunion after open tibial fracture. Methods This study retrospectively analyzed 220 older patients with infectious bone nonunion after open tibial fracture. There were 110 patients receiving bone transport technology (Group A) and 110 patients receiving membrane induction technique with antibiotic bone cement (Group B). Results There were 164 male patients and 56 female patients, with an age range of 65 to 71 years and an average age of 67 ± 1.3 years. Traffic accident, high-fall injury and crush injury account for 45.5, 27.7 and 26.8%, respectively. Age, gender, histories, causes and fracture location had no significant difference between the two groups (P > 0.05 for all). Operation time in the Group A was significantly shorter than that in the Group B (P < 0.05). Linear and positional alignment (70.9 vs. 57.3), American Knee Society knee function score (167.7 ± 14.9 vs. 123.8 ± 15.7), Baird-Jackson ankle function score (89.9 ± 3.5 vs. 78.4 ± 4.9), bone healing index (43.0 ± 2.0 vs. 44.3 ± 3.0) and clinical recovery (8.2 vs. 4.5) of patients in the Group A were significantly better than those in the Group B (P < 0.05 for all). Wound infection in the Group A (7.3%) was significantly less than that in the Group B (16.4%; P < 0.05). There were neither a neurovascular complication nor a recurrence of infection in the two groups. Conclusion Bone transport technology achieved better knee and ankle joint function recovery and superior bone healing and clinical efficacy than membrane induction technique with antibiotic bone cement, suggesting that bone transport technique is worthy of extensive promotion to improve clinical condition of older patients with infectious bone nonunion after open tibial fracture.

The Clinical Value of Extracorporeal Shock Wave Therapy Evaluated by Contrast-Enhanced Ultrasound for Noninfectious Nonunion

Objectives: The aim of this study was to investigate the clinical value of Contrast-enhanced ultrasound (CEUS) in evaluating Extracorporeal shock wave therapy (ESWT) for noninfectious nonunion. Methods: Thirty-eight patients with long bone nonunion fractures whose were treated in our hospital from October 2016 to October 2019 were included (20 males and 18 females). The patients received ESWT once a week for 12 consecutive weeks. CEUS was performed before and after the first ESWT session. According to the ratio of the perfusion area to the callus area, neovascular blood flow observed in CEUS was divided into 4 grades: grade 0 = 0%, grade 1 = 0–30%, grade 2 = 30–70% and grade 3 = 70–100%. The peak values of microbubbles perfusion in the callus area were recorded before and after ESWT. Each patient was followed up for 12 months to record the healing time. Nonunion over 12 months was considered a nonhealing fracture. To compare the ultrasonic data before and after ESWT, paired T test was used and the correlation between the ultrasonic data and the nonunion healing time, the pearson analysis was used. Results: Of the 38 patients, 35 patients achieved nonunion healing. The healing time ranged from 5 months to 12 months. Among the 38 patients, 24 patients had a microvascular health score of 0 points and 14 patients had a score of 1 point before treatment. After therapy, the neovascular health score was 0, 1, 2 and 3 in 5, 10, 15 and 8 patients, respectively. There was a statistically significant difference before and after treatment (P < 0.05). The peak value of microbubbles perfusion in the fracture site after ESWT was significantly higher than that before ESWT (P < 0.05). The greater of difference, the shorter of healing time. Conclusion: Under the supervision of CEUS, the changes in microvascular perfusion of noninfectious nonunion patients before and after ESWT effectively reflected the therapeutic effect. CEUS could predict the ESWT on bone nonunion at an early stage. Level of evidence: Level III.

TIBIAL BONE NONUNION PLASTIC WITH THE USE OF MONOLOCAL OSTEOSYNTHESIS BY RING FIXATORS

Actuality. Monolocal extrafocal osteosynthesis by ring fixators (RF) of tibial nonunion is not a generally accepted method, there are no systematic guidelines for its implementation. These issues need to be further studied. Task. Formulate situational predominant properties of RF; features of application in different condi-tions. To offer a method of nonunion plastics and features of monolocal osteosynthesis of RF and to study its efficiency. Materials and methods. The data of treatment of 16 patients with aseptic nonunion of tibia, who required complex comprehensive specialized medical care with a possible positive result (scores from 51 to 75 according to the evaluation system Non-Union Scoring System - NUSS). Implementation of monolocal extrafocal osteosynthesis of RF nonunion of shin bones after fractures was performed by us taking into account the features that distinguished it from that by fractures. The principal requirement of surgical intervention was the need to treat the center of nonunion, local stimulation of repara-tive processes. The technical features of all components of the intervention in the future were of great im-portance. The so-called blood-saving tactics were used, which were carried out using squeezing and hemostatic tourniquets, tranexamic acid. The results obtained. The results of treatment of victims with nonunion of the tibia with the use of RF in monolocal mode were as follows. Taking in consideration the severity of the lesion, we consider this result to be good. Given the insufficient number of observations, it is necessary to continue the use of the proposed method of treatment and to investigate its effectiveness. Conclusions. 1. The use of monolocal RF in patients with nonunion of tibia after fractures has the advantage of use in cases with episodes of septic inflammation in the past, extensive scarring of soft tissues, short distal fragment and osteoporosis. 2. The peculiarities of monolocal osteosynthesis of RF were the use of thick Ilizarov needles Ø 2.0 mm with their conduction at an angle of two planes. The obtained results of treatment of victims with nonunion of the tibia with the use of RF in the monolocal mode should be considered encouraging.

Surgical Reconstruction of Nonunion after Iatrogenic Scarf Osteotomy

We present the case of a young patient, 32 years old, with nonunion in the diaphysis of the first metatarsal after scarf osteotomy for correction of hallux valgus. After removal of the failed osteosynthesis material and preparation of the bone fragments, a calcaneal bone autograft, previously extracted from the patient, was placed in the nonunion area. The new physiological position of the first metatarsal in the three planes was checked intraoperatively, and autograft and fragment fixation was performed using a combination of a low-profile plate with six screws and two interfragmentary screws. The advantage of using an autogenous graft is that it provides corticocancellous bone and great osteogenic capacity with little antigenic capacity. This makes it an excellent option in many situations in foot and ankle surgery. Regarding the fixation method, we used the two most commonly used techniques for osteosynthesis of bone grafts in cases of bone nonunion, combining plates with locking screws and two interfragmentary screws. This provides greater stability of the bone fragments in the three planes and makes it possible to bring forward when the patient starts postsurgical loading.

Effect of nandrolone decanoate on healing of experimentally induced radial nonunion in rabbits (Oryctolagus cuniculus)

The aim of this study was to evaluate the effect of nandrolone decanoate (ND) on treatment of bone nonunion in the radius of rabbits. Thirty-one, young adult, New Zealand White rabbits (Oryctolagus cuniculus) were allocated to one of four groups: nandrolone males (NMG), nandrolone females (NFG), placebo males (NPM), and placebo females (NPF). After bone nonunion of a 10 mm ostectomy of the radius was confirmed (45 days after surgery), the animals in the NMG and NFG groups received 10 mg/kg ND intramuscular once a week for four weeks, while placebo groups received intramuscular 0.9% NaCl solution. Radiographic, histopathologic, and densitometric parameters (DXA) were used to compared groups. Results: No significant differences were observed radiographically. However, ND groups showed greater area (P=0.0258) and BMC (P=0.0140) in the densitometric evaluation. Histologically, the placebo group showed a predominance of primary bone tissue. Whereas, lamellary organizations of secondary bone and the presence of fibrocartilage were found in the ND group (P =0.006). In conclusion, ND promoted bone regeneration after the creation of a large defect in the radius of rabbits.

Ilizarov bone transport to treat infected nonunion of long bones: a multicenter retrospective cohort study

Objective To examine the efficacy and safety of Ilizarov bone transport in the treatment of infected nonunion of long bones. Methods Patients who underwent Ilizarov bone transport for treatment of bone nonunion with chronic osteomyelitis in the three largest regional orthopedic trauma centers in China from July 2013 to July 2018 were retrospectively examined. Treatment results were evaluated with Paley’s criteria for bone healing and functional assessment. Results In total, 189 patients were treated during the study period. The study population comprised 135 male and 54 female patients with an average age of 37.5 years (range, 11–61 years). The patients were followed up for at least 24 months. According to Paley’s criteria for bone healing and functional assessment, the bone healing results were excellent in 115 (61%) patients, good in 31 (16%), fair in 21 (11%), and poor in 22 (12%). The functional evaluation results were excellent in 76 (40%) patients, good in 65 (34%), fair in 22 (11%), poor in 26 (14%). Conclusion Infected nonunion of long bones can be effectively and safely treated with Ilizarov bone transport.