Fracture healing in the elderly: A review

Clinical management and innovation in fracture non-union

INTRODUCTION

With the introduction and continuous improvement in operative fracture fixation, even the most severe bone fractures can be treated with a high rate of successful healing. However, healing complications can occur and when healing fails over prolonged time, the outcome is termed a fracture non-union. Non-union is generally believed to develop due to inadequate fixation, underlying host-related factors, or infection. Despite the advancements in fracture fixation and infection management, there is still a clear need for earlier diagnosis, improved prediction of healing outcomes and innovation in the treatment of non-union.

AREAS COVERED

This review provides a detailed description of non-union from a clinical perspective, including the state of the art in diagnosis, treatment, and currently available biomaterials and orthobiologics.Subsequently, recent translational development from the biological, mechanical, and infection research fields are presented, including the latest in smart implants, osteoinductive materials, and in silico modeling.

EXPERT OPINION

The first challenge for future innovations is to refine and to identify new clinical factors for the proper definition, diagnosis, and treatment of non-union. However, integration of in vitro, in vivo, and in silico research will enable a comprehensive understanding of non-union causes and correlations, leading to the development of more effective treatments.

Age-related changes to macrophage subpopulations and TREM2 dysregulation characterize attenuated fracture healing in old mice

Fracture healing complications increase with age, with higher rates of delayed unions and nonunions and an associated increase in morbidity and mortality in older adults. Macrophages have a dynamic role in fracture healing, and we have previously demonstrated that age-related changes in macrophages are associated with attenuated fracture repair in old mice. Here, we provide a single cell characterization of the immune cells involved in the early phase of fracture healing. We show that there were multiple transcriptionally distinct macrophage subpopulations present simultaneously within the healing tissue. Fracture healing was attenuated in old mice compared to young, and macrophages from the fracture callus of old mice demonstrated a pro-inflammatory phenotype compared to young. Interestingly, Trem2 expression was decreased in old macrophages compared to young. Young mice lacking Trem2 demonstrated attenuated fracture healing and inflammatory dysregulation similar to old mice. Trem2 dysregulation has previously been implicated in other age-related diseases, but its role in fracture healing is unknown. This work provides a robust characterization of the macrophage subpopulations involved in fracture healing, and further reveals the important role of Trem2 in fracture healing and may be a potential driver of age-related inflammatory dysregulation. Future work may further examine macrophages and Trem2 as potential therapeutic targets for management of fracture repair in older adults.

RUTIN, a widely consumed flavonoid, that commonly induces hormetic effects

Rutin is a flavonoid present in numerous fruits and vegetables and therefore widely consumed by humans. It is also a popular dietary supplement of 250-500 mg/day. There is considerable consumer interest in rutin due to numerous reports in the biomedical literature of its multi-system chemo-preventive properties. The present paper provides the first assessment of rutin-induced hormetic concentration/dose responses, their quantitative features and mechanistic basis, along with their biological, biomedical, clinical, and public health implications. The findings indicate that rutin-induced hormetic dose responses are widespread, being reported in numerous biological models and cell types for a wide range of endpoints. Of critical importance is that the optimal hormetic findings shown in in vitro systems are currently not achievable for human populations due to low gastrointestinal tract bioavailability. These findings have the potential to strengthen future experimental studies with rutin, particularly concerning study design parameters.

Complex elbow fracture-dislocations- what factors are associated with a poor post-operative outcome?

PURPOSE

Despite standardized treatment algorithms, patients with complex elbow fracture-dislocation frequently suffer from poor post-operative elbow function leading to reduced quality of life. Up to now, there is no valuable data regarding risk factors that lead to poor post-operative outcome after surgical reconstruction of complex elbow fracture-dislocations.

METHODS

From 06/2010 to 12/2020 134 patients (51.3 ± 15.1 years, 44% women) undergoing surgical treatment of complex elbow fracture-dislocations could be included in this study. Follow-up period was 4.4 years (SD 2.5). All patients were clinically evaluated for elbow movement, elbow stability and common elbow scores (MEPS, OES, DASH-Score). Potential risk factors for poor post-operative outcome were identified using bi- and multivariate analyses.

RESULTS

Overall good post-operative outcome has been achieved, mean MEPS was 88.8 ± 17.6. Post-operative complications occurred in 31.3% of the cases, while 25.4% required surgical revision. Patients with transolecranon dislocation fractures showed the significantly worst functional outcomes (p = 0.01). In addition, it has been shown that a patient's age of more than 70 years (OR = 10, p = 0.003) and a BMI of more than 35 kg/m2 (OR = 7.6, p = 0.004) are independent risk factors for a poor post-operative outcome. In contrast, gender and time to surgery showed no significant influence on post-operative outcome.

CONCLUSION

In most cases, good post-operative functional results can be achieved using standardized treatment protocols. However, complication and revision rates remain high. Patients older than 70 years of age or with a BMI over 35 kg/m2 are at risk for an inferior outcome and require close follow-up monitoring.

Fragment excision and triceps V-Y advanced reattachment using suture anchor for olecranon nonunion: A case report

RATIONALE

The nonunion of olecranon fractures is uncommon in simple fractures, and it is challenging to treat surgically due to the disruption of the anatomy of the elbow joint. There is limited literature on surgical options, and several factors to determine the treatment, including the amount and quality of bone stock, age, and degree of articular damage.

PATIENT CONCERNS

A 58-year-old man presented at the clinic with neglected olecranon fracture for 1 year (case 1). A 74-year-old man (case 2) presented with consistent pain and limited of motion after surgery for olecranon fracture.

DIAGNOSIS

Both patients were diagnosed with olecranon nonunion.

INTERVENTION

Both patients received the excision of nonunited fragment and reattaching with V-Y advancement of triceps.

OUTCOMES

Range of motion and Mayo elbow performance score were improved after surgery.

LESSONS

This technique is useful in patients who cannot undergo other surgical options due to insufficient bone quality and elbow function, and it can lead to satisfactory outcomes with an acceptable range of motion and pain relief.

The impact of osteoporosis and diabetes on fracture healing under different loading conditions

BACKGROUND

Osteoporosis and diabetes are two prevalent conditions among the elderly population. Each of these conditions can profoundly influence the fracture healing process by disturbing the associated inflammatory process. However, the combined effects of osteoporosis and diabetes on fracture healing remain unclear. Therefore, the purpose of the present study is to investigate the role of osteoporosis and diabetes in fracture healing and the underlying mechanisms by developing numerical models.

METHOD

This study introduces a numerical model that consists of a three-dimensional model of a tibia fracture stabilized by a Locking Compression Plate (LCP), coupled with a two-dimensional axisymmetric model which illustrates the transport and reactions of cells and cytokines throughout the inflammatory phase in early fracture healing. First, the model parameters were calibrated using available experimental data. The model was then implemented to predict the healing outcomes of fractures under five varied conditions, consisting of both osteoporotic and non-osteoporotic bones, each subjected to different physiological loads.

RESULTS

The instability of the fracture callus can significantly escalate in osteoporotic fractures (e.g., when a 150 N physiological load is applied, the unstable region of the osteoporotic fracture callus can reach 26 %, in contrast to 12 % in non-osteoporotic fractures). Additionally, the mesenchymal stem cells (MSCs) proliferation and differentiation can be disrupted in osteoporotic fracture compared to non-osteoporotic fractures (e.g., on the 10th day post-fracture, the decrease in the concentration of MSCs, osteoblasts, and chondrocytes in osteoporotic fractures is nearly double that in non-osteoporotic fractures under a 150 N). Finally, the healing process of fractures can suffer significant impairment when osteoporosis coexists with diabetes (e.g., the concentration of MSCs can be drastically reduced by nearly 37 % in osteoporotic fractures under diabetic conditions when subjected to a load of 200 N) CONCLUSIONS: Fracture calluses destabilized by osteoporosis can negatively affect the fracture healing process by disrupting the proliferation and differentiation of mesenchymal stem cells (MSCs). Moreover, when osteoporosis coexists with diabetes, the fracture healing process can severely impair the fracture healing outcomes.

Comparative study of locking neutralization plate construct versus tension band wiring with a cannulated screw for patella fractures: experimental and finite element analysis

Transverse patella fractures, accounting for approximately 1% of Orthopedic injuries, pose intricate challenges due to their vital role in knee mechanics. This study aimed to compare the biomechanical performance of a construct, integrating cannulated screws and an anterior locking neutralization plate, with the conventional tension band wiring technique for treating these fractures. Experimental testing and Finite Element Analysis were employed to evaluate the constructs and gain profound insights into their mechanical behavior. Sixteen cadaveric knees were prepared, and transverse patella fractures were induced at the midpoints using a saw. The plate construct and tension band wire fixation were randomly assigned to the specimens. A cyclic test evaluated the implants' durability and stability, simulating knee movement during extension and flexion. Tensile testing assessed the implants' maximum failure force after cyclic testing, while Finite Element Analysis provided detailed insights into stress distribution and deformation patterns. Statistical analysis was exclusively performed for the experimental data. Results showed the plate enhanced stability with significantly lower deformation (0.09 ± 0.12 mm) compared to wire fixation (0.77 ± 0.54 mm) after 500 cycles (p = 0.004). In tensile testing, the construct also demonstrated higher failure resistance (1359 ± 21.53 N) than wire fixation (780.1 ± 22.62N) (p = 0.007). Finite Element Analysis highlighted distinct stress patterns, validating the construct's superiority. This research presents a promising treatment approach for transverse patella fractures with potential clinical impact and future research prospects. This study presents a promising advancement in addressing the intricate challenges of transverse patella fractures, with implications for refining clinical practice. The construct's improved stability and resistance to failure offer potential benefits in postoperative management and patient outcomes.

Black Phosphorus Accelerates Bone Regeneration Based on Immunoregulation

A fundamental understanding of inflammation and tissue healing suggests that the precise regulation of the inflammatory phase, both in terms of location and timing, is crucial for bone regeneration. However, achieving the activation of early inflammation without causing chronic inflammation while facilitating quick inflammation regression to promote bone regeneration continues to pose challenges. This study reveals that black phosphorus (BP) accelerates bone regeneration by building an osteogenic immunological microenvironment. BP amplifies the acute pro-inflammatory response and promotes the secretion of anti-inflammatory factors to accelerate inflammation regression and tissue regeneration. Mechanistically, BP creates an osteoimmune-friendly microenvironment by stimulating macrophages to express interleukin 33 (IL-33), amplifying the inflammatory response at an early stage, and promoting the regression of inflammation. In addition, BP-mediated IL-33 expression directly promotes osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), which further facilitates bone repair. To the knowledge, this is the first study to reveal the immunomodulatory potential of BP in bone regeneration through the regulation of both early-stage inflammatory responses and later-stage inflammation resolution, along with the associated molecular mechanisms. This discovery serves as a foundation for the clinical use of BP and is an efficient approach for managing the immune microenvironment during bone regeneration.

Risk for total knee arthroplasty after tibial plateau fractures: a systematic review

PURPOSE

Tibial plateau fractures (TPFs) may lead to posttraumatic osteoarthritis and increase the risk for total knee arthroplasty (TKA). The aim of this systematic review was to analyse the conversion rate to TKA after TPF treatment.

METHODS

A systematic search for studies reviewing the conversion rate to TKA after TPF treatment was conducted. The studies were screened and assessed by two independent observers. The conversion rate was analysed overall and for selected subgroups, including different follow-up times, treatment methods, and study sizes.

RESULTS

A total of forty-two eligible studies including 52,577 patients were included in this systematic review. The overall conversion rate of treated TPF to TKA in all studies was 5.1%. Thirty-eight of the forty-two included studies indicated a conversion rate under 10%. Four studies reported a higher percentage, namely, 10.8%, 10.9%, 15.5%, and 21.9%. Risk factors for TKA following TPF treatment were female sex, age, and low surgeon and hospital volume. The conversion rate to TKA is particularly high in the first 5 years after fracture.

CONCLUSION

Based on the studies, it can be assumed that the conversion rate to TKA is approximately 5%. The risk for TKA is manageable in clinical practice.

PROSPERO REGISTRATION NUMBER

CRD42023385311.

LEVEL OF EVIDENCE

IV.

Guided Bone Regeneration Using Barrier Membrane in Dental Applications

Guided bone regeneration (GBR) is a widely used technique in preclinical and clinical studies due to its predictability. Its main purpose is to prevent the migration of soft tissue into the osseous wound space, while allowing osseous cells to migrate to the site. GBR is classified into two main categories: resorbable and non-resorbable membranes. Resorbable membranes do not require a second surgery but tend to have a short resorption period. Conversely, non-resorbable membranes maintain their mechanical strength and prevent collapse. However, they require removal and are susceptible to membrane exposure. GBR is often used with bone substitute graft materials to fill the defect space and protect the bone graft. The membrane can also undergo various modifications, such as surface modification and biological factor loading, to improve barrier functions and bone regeneration. In addition, bone regeneration is largely related to osteoimmunology, a new field that focuses on the interactions between bone and the immune system. Understanding these interactions can help in developing new treatments for bone diseases and injuries. Overall, GBR has the potential to be a powerful tool in promoting bone regeneration. Further research in this area could lead to advancements in the field of bone healing. This review will highlight resorbable and non-resorbable membranes with cellular responses during bone regeneration, provide insights into immunological response during bone remodeling, and discuss antibacterial features.

Biodegradable Implants for Internal Fixation of Fractures and Accelerated Bone Regeneration

Bone fractures have always been a burden to patients due to their common occurrence and severe complications. Traditionally, operative treatments have been widely used in the clinic for implanting, despite the fact that they can only achieve bone fixation with limited stability and pose no effect on promoting tissue growth. In addition, the nondegradable implants usually need a secondary surgery for implant removal, otherwise they may block the regeneration of bones resulting in bone nonunion. To overcome the low degradability of implants and avoid multiple surgeries, tissue engineers have investigated various biodegradable materials for bone regeneration, whereas the significance of stability of long-term bone fixation tends to be neglected during this process. Combining the traditional orthopedic implantation surgeries and emerging tissue engineering, we believe that both bone fixation and bone regeneration are indispensable factors for a successful bone repair. Herein, we define such a novel idea as bone regenerative fixation (BRF), which should be the main future development trend of biodegradable materials.

Bone Healing Gone Wrong: Pathological Fracture Healing and Non-Unions-Overview of Basic and Clinical Aspects and Systematic Review of Risk Factors

Bone healing is a multifarious process involving mesenchymal stem cells, osteoprogenitor cells, macrophages, osteoblasts and -clasts, and chondrocytes to restore the osseous tissue. Particularly in long bones including the tibia, clavicle, humerus and femur, this process fails in 2-10% of all fractures, with devastating effects for the patient and the healthcare system. Underlying reasons for this failure are manifold, from lack of biomechanical stability to impaired biological host conditions and wound-immanent intricacies. In this review, we describe the cellular components involved in impaired bone healing and how they interfere with the delicately orchestrated processes of bone repair and formation. We subsequently outline and weigh the risk factors for the development of non-unions that have been established in the literature. Therapeutic prospects are illustrated and put into clinical perspective, before the applicability of biomarkers is finally discussed.

Operative treatment of nonunions in the elderly: Clinical and radiographic outcomes in patients at minimum 75 years of age

BACKGROUND

Limited information exists on nonunion treatment in the elderly. This retrospective study evaluates whether results of operative treatment of nonunion of the humerus or femur in patients aged ≥ 75 years are comparable to those in younger patients.

METHODS

We identified patients age ≥ 75 years with a nonunion of humerus or femur treated with open reduction and internal fixation. The Non-Union Scoring System was calculated. Complications, clinical outcome, and radiographic findings were assessed. Primary endpoint was nonunion healing. A literature review compared time to healing of humeral and femoral nonunion in younger populations.

RESULTS

We identified 45 patients treated for a nonunion of humerus or femur with > 12 months follow-up. Median age was 79 years (range 75-96). Median time to presentation was 12 months (range 4-127) after injury, median number of prior surgeries was 1 (range 0-4). Union rate was 100%, with median time to union 6 months (range 2-42). Six patients underwent revision for persistent nonunion and healed without further complications.

CONCLUSIONS

Using a protocol of debridement, alignment, compression, stable fixation, bone grafting and early motion, patients aged 75 years or older can reliably achieve healing when faced with a nonunion of the humerus or femur.

LEVEL OF EVIDENCE

IV.

Proximal ulna non-union: treatment concept and postoperative outcome

PURPOSE

Non-union of the proximal ulna is a serious complication after surgical treatment of olecranon and complex elbow fractures, frequently leading to poor functional outcome. To date, there is a lack of data regarding optimal treatment strategies and functional outcome parameters after surgical revision.

METHODS

From 02/2010 to 12/2018, 31 patients undergoing surgical treatment of proximal ulna non-union could be included. Follow-up period was seven years (SD 2.5 years). All patients were clinically assessed using a clinical assessment tool set and standard elbow scores (MEPS, OES, DASH score). All complications and unplanned revision surgeries were recorded and all radiographic material was analyzed.

RESULTS

Initial non-union procedures were performed at an average of 6.6 months (SD 3 months) after the index procedures. Those included the use of autologous spongiosa graft in all patients and concomitant compression re-osteosynthesis in 28 patients. Radiological consolidation was achieved in all patients. Overall, patients achieved a good to fair functional outcome with Mayo elbow performance score measuring 78.5 (SD 9.1), DASH score 34.7 (SD 14.4), and Oxford elbow score 31.2 (SD 6.6) points. Initial malreduction/implant-malposition could be identified as a main reason for the occurrence of the non-union. Furthermore, inferior postoperative outcome was detected in patients > 60 years and BMI > 30 kg/m².

CONCLUSION

Using a standardized protocol, bony union and acceptable functional outcomes can be achieved in proximal ulna non-unions. However, surgeons should be aware of potential risk factors and proper initial fracture reduction as key to achieve sufficient bone healing.

Functionalized TiCu/TiCuN coating promotes osteoporotic fracture healing by upregulating the Wnt/β-catenin pathway

Osteoporosis results in decreased bone mass and insufficient osteogenic function. Existing titanium alloy implants have insufficient osteoinductivity and delayed/incomplete fracture union can occur when used to treat osteoporotic fractures. Copper ions have good osteogenic activity, but their dose-dependent cytotoxicity limits their clinical use for bone implants. In this study, titanium alloy implants functionalized with a TiCu/TiCuN coating by arc ion plating achieved a controlled release of copper ions in vitro for 28 days. The coated alloy was co-cultured with bone marrow mesenchymal stem cells and showed excellent biocompatibility and osteoinductivity in vitro. A further exploration of the underlying mechanism by quantitative real-time polymerase chain reaction and western blotting revealed that the enhancement effects are related to the upregulation of genes and proteins (such as axin2, β-catenin, GSK-3β, p-GSK-3β, LEF1 and TCF1/TCF7) involved in the Wnt/β-catenin pathway. In vivo experiments showed that the TiCu/TiCuN coating significantly promoted osteoporotic fracture healing in a rat femur fracture model, and has good in vivo biocompatibility based on various staining results. Our study confirmed that TiCu/TiCuN-coated Ti promotes osteoporotic fracture healing associated with the Wnt pathway. Because the coating effectively accelerates the healing of osteoporotic fractures and improves bone quality, it has significant clinical application prospects.

Lateral-Opening Injection Tool Used in Percutaneous Vertebroplasty to Treat Asymptomatic Osteoporotic Vertebral Burst Fractures: A Retrospective Study

OBJECTIVE

The adequate management of asymptomatic osteoporotic vertebral burst fractures (OVBFs) was still controversial. Percutaneous vertebroplasty (PVP) could achieve quick recovery with minor trauma, but there were certain safety problems by traditional bone cement injection method. Thus, the aim of this study was to assess the efficacy of lateral-opening injection tool used in PVP treating patients with asymptomatic OVBFs.

METHODS

This was a retrospective study of OVBFs treated in our institute from March 2016 to March 2020. A total of 66 patients (mean age 72.10 ± 7.98 years, with 21 men and 45 women) who were diagnosed with acute asymptomatic OVBFs with mild spinal canal compromise were treated with PVP by using a lateral-opening injection tool. Two puncture needles were simultaneously placed transpedicularly in the fractured vertebra, and the inner core was removed, and the lateral-opening injection tool was inserted. The adjustment of lateral hole was to improve the distribution height of bone cement and avoid the entry of bone cement into the posterior wall of vertebral body. Related clinical outcomes and images were assessed, including back pain (visual analog scale [VAS]), vertebral height ratio (fractured vertebral height/average adjacent nonfractured vertebral height), kyphosis Cobb angle, union of the fractured vertebral posterior wall, distribution of bone cement, surgical data, and complications.

RESULTS

The average follow-up time of all cases was 21.23 ± 9.35 months. The mean amount of bone cement was 3.28 ± 0.35 ml in the vertebrae and the mean operative time was 34.02 ± 5.23 min. There were 60 cases of bone cement that contacted the upper and lower endplates on at least one side. There was no cement leakage into the spinal canal or fracture displacement of the posterior wall of the vertebral body in all cases. The VAS scores were 3.78 ± 0.42 at 1 day postoperatively and 0.53 ± 0.40 at the last follow-up, significantly lower than 8.40 ± 0.48 preoperatively (p < 0.05). The average height ratio of anterior, middle, and posterior vertebral body after operation increased compared with that pre-operation (p < 0.05), and the postoperative kyphosis angle decreased (p < 0.05). At 6 months follow-up, there was no significant height loss of the vertebral body. Computed tomography examination 3 months postoperatively showed that the fracture of posterior vertebral wall healed well in all cases. There were seven cases of bone cement leakage without clinical symptoms and two adjacent vertebral fractures caused by falling. There were no cases of deep vein embolism, lower limb muscle atrophy, pneumonia, decubitus.

CONCLUSION

The lateral opening tool can be safely and effectively used in the PVP treatment on asymptomatic OVBFs with mild spinal canal compromise.

Bone regeneration: A message from clinical medicine and basic science

Population aging is a global phenomenon and with it, the number of bone fractures increases due to higher incidences of osteoporosis. Bone fractures in the elderly increase the risk of bedridden status and mortality. Therefore, the control of osteoporosis and bone fracture is important for healthy life expectancy, and the fundamental understanding of its pathogenesis and its application in treatment is of great social significance. To solve these clinical problems, it is necessary to integrate clinical medicine and basic research. Bone regeneration after a fracture is an essential function of the living body. The prevailing view is that a small number of resident skeletal stem cells are solely responsible for regenerative capacity. Although these cells have long been considered to be in the bone marrow, it has been shown that they are also present in the growth plate and periosteum. More recently, distinct types of cells in the bone marrow, including bone marrow stromal cells, osteoblast progenitor cells, and osteoblasts, have been shown to participate in bone regeneration. Interestingly, the cellular plasticity of differentiated cells, rather than active recruitment of resident stem cell populations, may largely account for regeneration of bone tissues; terminally differentiated cells de-differentiate into a stem cell-like state, and then re-differentiate into regenerating bone. In this review, we discuss the clinical risk and preventive therapy of bone fractures and the current concept of bone regeneration in basic mechanical insights, which may prove useful to both clinicians and researchers.

Outcomes of early versus delayed weight-bearing with intramedullary nailing of tibial shaft fractures: a systematic review and meta-analysis

PURPOSE

Early weight bearing (EWB) is often recommended after intramedullary nailing of tibial shaft fractures, however, the risks and benefits have not been critically evaluated in a systematic review or meta-analysis. Therefore, the aims of this study were to perform a systematic review and meta-analysis comparing EWB and delayed weight-bearing (DWB) after intramedullary nailing of tibial shaft fractures and assess the relationship between weight-bearing, fracture union and healing.

METHOD

This review included studies comparing the effects of EWB, defined as weight-bearing before 6 weeks, and DWB on fracture union and healing. PubMed, Embase, CINAHL, and the Cochrane Library were searched from inception to 9 May 2021. Risk of bias was assessed using the Down's and Black Checklist and Cochrane Risk of Bias Tool 2.0. Data were synthesised in a meta-analysis, as well as narrative and tabular synthesis.

RESULTS

Eight studies were included for data extraction and meta-analysis. The analysis produced mixed results and found a significant decrease in mean union time (-2.41 weeks, 95% confidence interval: -4.77, -0.05) with EWB and a significant Odd's Ratio (OR) for complications with DWB (OR: 2.93, 95% CI: 1.40, 6.16). There was no significant difference in rates of delayed union, non-union, re-operation and malunion.

CONCLUSION

The included studies were of moderate risk of bias and demonstrated shorter union time and fewer complications with EWB. However, current evidence is minimal and has significant limitations. The role of EWB in high-risk patients is yet to be examined. Further well-designed, randomised studies are required on the topic.

Therapeutic Mechanism of Chinese Medicine on the Healing of Early and Middle Fractures in Rabbits Under the Expression Level of Bone Morphogenetic Protein-2 (BMP-2) in Bone Tissue

In order to explore the therapeutic mechanism of Chinese medicine on the healing of rabbits early and middle fractures, a rabbit fracture model was established in this study. The study was divided into several groups, i.e., treatment group (TG) (fed with Chinese medicine Capsule) and control group (CG) (fed with normal saline (NS)). The materials were collected at 1, 3, and 5 weeks after the start of the experiment for analysis. The experiment content included: callus Hematoxylin-Eosin staining (HE staining); Bone Morphogenetic protein-2 (BMP-2) protein level detection; Type I and type II bone collagen (BC) detection; and serum biochemical factors detection. The experimental results showed that the formation of callus in the TG was better than in the CG; the BMP-2 protein expression level in the TG was higher than in the CG, and there were statistically significant differences (SSDs); the type I and type II BC levels in the TG were higher than the CG, there were SSDs; the levels of serum calcium (SC), phosphorus ion (PI), and alkaline phosphatase (ALP) in the TG were also higher than in the CG, and there were SSDs.

Changes of Migration, Immunoregulation and Osteogenic Differentiation of Mesenchymal Stem Cells in Different Stages of Inflammation

Bone infection has always been the focus of orthopedic research. Mesenchymal stem cells (MSCs) are the natural progenitors of osteoblasts, and the process of osteogenesis is triggered in response to different signals from the extracellular matrix. MSCs exert important functions including secretion and immune regulation and also play a key role in bone regeneration. The biological behavior of MSCs in acute and chronic inflammation, especially the transformation between acute inflammation and chronic inflammation, has aroused great interest among researchers. This paper reviews the recent literature and summarizes the behavior and biological characteristics of MSCs in acute and chronic inflammation to stimulate further research on MSCs and treatment of bone diseases.

Development of a murine model of ischemic osteonecrosis to study the effects of aging on bone repair

Age at onset is one of the most important predictors of outcome following ischemic osteonecrosis (ON). Currently, there is no well-established animal model to study the effects of age on the repair process following ischemic ON. The purpose of this study was to further advance a murine model of ischemic ON using four age groups of mice to determine the effects of aging on revascularization and bone repair following ischemic ON. Ischemia was surgically induced in the distal femoral epiphysis of four age groups of skeletally immature and mature mice; juvenile (5 weeks), adolescent (12 weeks), adult (22 weeks), and middle age (52 weeks). Mice were euthanized at 2 days or 4 weeks post-ischemia surgery to evaluate the extent of ON, revascularization, and bone repair. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining showed extensive cell death in the epiphysis of all four age groups at 2 days post-ischemia surgery. At 4 weeks, the juvenile mice followed by the adolescent mice had significantly greater revascularization and repair of the necrotic marrow space, increased osteoblast and osteoclast numbers, and increased bone formation rates compared to the adult and middle-age mice. Faster revascularization and bone healing were observed in the skeletally immature mice compared to the skeletally mature mice following ischemic ON. The findings resemble the clinical observation of aging on bone repair following ischemic ON. The mouse model may serve as a useful tool to investigate the mechanisms underlying the age-related impairment of bone repair in adolescent and adult ON and to develop novel therapeutic strategies.

Addressing Smoking in Musculoskeletal Specialty Care

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Physicians who advise patients to quit smoking substantially improve cessation rates, but cessation counseling is currently underperformed.

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Counseling, pharmacotherapy, and additional interventions can improve the chance of successful smoking cessation. Most patients require multiple attempts at quitting to be successful.

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A list of referral contacts and resources should be developed and routinely offered to these patients. The national Quitline (1-800-QUIT-NOW) provides free access to trained counselors and "quit coaches" for each state program in the United States.

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Government and private insurance plans in the United States are required (in most cases) to cover the cost of 2 quitting attempts per year including counseling referrals and medications.

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Several biopsychosocial factors that affect orthopaedic outcomes (weight, anxiety, depression, etc.) are also relevant to smoking cessation; management of these factors is thus potentially aggregately advantageous.

The effects of bone morphogenetic protein 2 and thrombopoietin treatment on angiogenic properties of endothelial cells derived from the lung and bone marrow of young and aged, male and female mice

With an aging world population, there is an increased risk of fracture and impaired healing. One contributing factor may be aging-associated decreases in vascular function; thus, enhancing angiogenesis could improve fracture healing. Both bone morphogenetic protein 2 (BMP-2) and thrombopoietin (TPO) have pro-angiogenic effects. The aim of this study was to investigate the effects of treatment with BMP-2 or TPO on the in vitro angiogenic and proliferative potential of endothelial cells (ECs) isolated from lungs (LECs) or bone marrow (BMECs) of young (3-4 months) and old (22-24 months), male and female, C57BL/6J mice. Cell proliferation, vessel-like structure formation, migration, and gene expression were used to evaluate angiogenic properties. In vitro characterization of ECs generally showed impaired vessel-like structure formation and proliferation in old ECs compared to young ECs, but improved migration characteristics in old BMECs. Differential sex-based angiogenic responses were observed, especially with respect to drug treatments and gene expression. Importantly, these studies suggest that NTN1, ROBO2, and SLIT3, along with angiogenic markers (CD31, FLT-1, ANGPT1, and ANGP2) differentially regulate EC proliferation and functional outcomes based on treatment, sex, and age. Furthermore, treatment of old ECs with TPO typically improved vessel-like structure parameters, but impaired migration. Thus, TPO may serve as an alternative treatment to BMP-2 for fracture healing in aging owing to improved angiogenesis and fracture healing, and the lack of side effects associated with BMP-2.

Clinical outcomes of frozen autograft reconstruction for the treatment of primary bone sarcoma in adolescents and young adults

Age affects the clinical outcomes of cancer treatment, including those for bone sarcoma. Successful reconstruction using frozen autograft after excision of bone sarcoma has been reported; however, little is known about the clinical outcomes of frozen autograft reconstruction according to age. The purpose was to evaluate the clinical outcomes of the frozen autograft reconstruction focusing on skeletally mature adolescents and young adults (AYAs) that was 15 to 39 years of age. A total of 37 AYA patients with primary bone sarcoma on the appendicular skeleton were enrolled in this study. The mean follow-up period was 89 months. The graft survival (GS), overall survival (OS), recurrence-free survival (RFS), complications and the function were retrospectively evaluated using medical records. The 10-year GS, OS, and RFS rates were 76%, 84%, and 79%, respectively. Bone union was achieved with a rate of 94% within 1 year after surgery, and nonunion (n = 1) and fracture (n = 2) were infrequently observed. Graft removal was performed in 7 cases, and the most common reason for the removal was infection (n = 5). The Musculoskeletal Tumor Society score was excellent in 23 cases of the available 29 cases. Frozen autograft reconstruction for AYAs showed excellent clinical outcomes, although the long-term follow-up is required.

Troxerutin Stimulates Osteoblast Differentiation of Mesenchymal Stem Cell and Facilitates Bone Fracture Healing

Troxerutin (TRX), a semi-synthetic derivative of the natural bioflavonoid rutin, is a bioactive flavonoid widely abundant in various fruits and vegetables. Known as vitamin P4, TRX has been demonstrated to have several activities including anti-inflammation, anti-oxidants, vasoprotection, and immune support in various studies. Although rutin, the precursor of troxerutin, was reported to have a protective role against bone loss, the function of TRX in skeletal system remains unknown. In the present study, we found that TRX promoted osteogenic differentiation of human mesenchymal stem cells (MSCs) in a concentration-dependent manner by stimulating the alkaline phosphatase (ALP) activity, calcium nodule formation and osteogenic marker genes expression in vitro. The further investigation demonstrated that TRX stimulated the expression of the critical transcription factor β-catenin and several downstream target genes of Wnt signaling, thus activated Wnt/β-catenin signaling. Using a femur fracture rats model, TRX was found to stimulate new bone formation and accelerate the fracture healing in vivo. Collectively, our data demonstrated that TRX could promote osteogenesis in vitro and facilitate the fracture healing in vivo, indicating that TRX may be a promising therapeutic candidate for bone fracture repair.

The mechanism of pyrroloquinoline quinone influencing the fracture healing process of estrogen-deficient mice by inhibiting oxidative stress

It is reported that oxidative stress plays a detrimental role in the process of bone fracture healing. And pyrroloquinoline quinone (PQQ) is used as antioxidant. However, there is no report about whether PQQ supplementation can promote fracture healing by eliminating oxidative stress. To investigate the protective effect of PQQ on fracture healing, open mid-diaphyseal femur fractures model were created in sham, ovariectomized (OVX) mice and PQQ-treated OVX mice. Our results confirmed that PQQ played a preventive and protective role in OVX-induced delay of bone fracture healing by inhibiting oxidative stress, subsequently promoting osteoblastic bone formation and inhibiting osteoclastic bone resorption. The findings of this study not only revealed the mechanism of PQQ supplementation in promoting fracture healing, but also provide experimental and theoretical basis for the clinical application of PQQ in the treatment of bone fracture.

Impacted lower third molar relationship with mandibular angle fracture complications

INTRODUCTION

Mandibular angle fractures are very common and are associated with the highest risk of complications. The aim of this study is to evaluate the correlation between impacted lower third molar and mandibular angle fracture complications.

MATERIAL AND METHODS

All patients presenting with a mandibular angle fracture and at least 2 months follow up were retrospectively included. The following complications were recorded: post-traumatic malocclusion, mouth opening limitation, inferior alveolar nerve hypoesthesia, infection, delayed union, hardware loosening. The patients were divided in two groups: impacted lower third molar or erupted/absent lower third molar.

RESULTS

A total of 68 patients were included, lower third molar was impacted in 36 cases and erupted/absent in 32 cases. 40 complications were recorded in 27 patients at 2 months. No statistically significant difference could be found about malocclusion, mouth opening limitation and inferior alveolar nerve hypoesthesia. A lower rate of persistent inferior alveolar nerve hypoesthesia (p = 0.0557) in patients with impacted lower third molar (19.4%) was observed compared to patients without impacted lower third molar (40.6%). There was no occurrence of delayed union and hardware loosening in impacted lower third molar group, whereas 5 delayed unions and 4 hardware loosening were recorded in erupted/absent lower third molar group. Finally, the rate of patients with at least one of the 6 complications is significantly higher in the erupted/absent lower third molar group (17/32, 53.1%) than in the impacted lower third molar group (10/36, 27.8%), p = 0.033.

DISCUSSION

The risk of overall complication is decreased when lower third molar is impacted in mandibular angle fracture. This supports the idea of a role of the impacted lower third molar in fracture reduction and stability.

The Role of Adipose Stem Cells in Bone Regeneration and Bone Tissue Engineering

Bone regeneration is a complex process that is influenced by tissue interactions, inflammatory responses, and progenitor cells. Diseases, lifestyle, or multiple trauma can disturb fracture healing, which might result in prolonged healing duration or even failure. The current gold standard therapy in these cases are bone grafts. However, they are associated with several disadvantages, e.g., donor site morbidity and availability of appropriate material. Bone tissue engineering has been proposed as a promising alternative. The success of bone-tissue engineering depends on the administered cells, osteogenic differentiation, and secretome. Different stem cell types offer advantages and drawbacks in this field, while adipose-derived stem or stromal cells (ASCs) are in particular promising. They show high osteogenic potential, osteoinductive ability, and immunomodulation properties. Furthermore, they can be harvested through a noninvasive process in high numbers. ASCs can be induced into osteogenic lineage through bioactive molecules, i.e., growth factors and cytokines. Moreover, their secretome, in particular extracellular vesicles, has been linked to fracture healing. The aim of this review is a comprehensive overview of ASCs for bone regeneration and bone tissue engineering.

Wnt/β-catenin signalling promotes more effective fracture healing in aged mice than in adult mice by inducing angiogenesis and cell differentiation

To investigate whether activating the Wnt/β-catenin signalling pathway differentially promotes fracture healing in aged and adult individuals. CatnbTM2Kem, Catnblox(ex3) and wild-type adult and aged mice were used in this study. The femur was electroporated through a hole with a diameter of 0.6 mm. On the 7th, 14th and 21st days after fracture establishment, repair of the femoral diaphyseal bone was examined using X-ray and CT, the levels of mRNAs related to Wnt/β-catenin signalling were detected using real-time polymerase chain reaction (RT-PCR), and angiogenesis and cell differentiation were observed using immunohistochemistry. The numbers of osteoclasts were determined by TRAP staining. Wnt/β-catenin activation accelerated fracture healing in adult mice, with more pronounced effects on aged mice. Compared with wild-type mice at the corresponding ages, Wnt/β-catenin signalling activation induced higher levels of angiogenesis and cell differentiation in aged mice than in adult mice and promoted fracture healing. The administration of medications targeting Wnt/β-catenin signalling to aged patients may accelerate fracture healing to a greater extent.

Biological applications of copper-containing materials

Copper is an indispensable trace metal element in the human body, which is mainly absorbed in the stomach and small intestine and excreted into the bile. Copper is an important component and catalytic agent of many enzymes and proteins in the body, so it can influence human health through multiple mechanisms. Based on the biological functions and benefits of copper, an increasing number of researchers in the field of biomaterials have focused on developing novel copper-containing biomaterials, which exhibit unique properties in protecting the cardiovascular system, promoting bone fracture healing, and exerting antibacterial effects. Copper can also be used in promoting incisional wounds healing, killing cancer cells, Positron Emission Tomography (PET) imaging, radioimmunological tracing and radiotherapy of cancer. In the present review, the biological functions of copper in the human body are presented, along with an overview of recent progress in our understanding of the biological applications and development of copper-containing materials. Furthermore, this review also provides the prospective on the challenges of those novel biomaterials for future clinical applications.

Assessment of plasma BMP-2, BMP-7, BMP-10, vitamin D, and TGF β1 in simple fractures among Sudanese patients

Background

Bone morphogenetic proteins (BMP) are multifunctional proteins. They work as cytokines regulating osteogenesis during fracture healing process. The objectives of this study were to assess changes in BMPs during fracture and their correlations to Fracture’s healing.

Methods

Case-Control hospital–based study conducted from January 2018 to January 2019. Demographic data, anthropometric measurements, and blood samples were collected from patients and controls (18–65 years old). Plasma concentrations of selected BMPs and vitamin D were measured using quantitative enzyme linked immunosorbent assay (ELISA). SPSS version 25 was used to calculate frequencies, Pearson correlation tests, chi-square and unpaired t-test.

Results

Sixty-five patients with fractures and Sixty-five controls were studied. Means of plasma concentrations were (TGFβ1 = 21.07 ng/ml ±8.49 and 19.8 ng/ml ±7.2) (BMP-2 = 76.3 pg/ml ± 156.6 and 55.5 ng/ml ± 127.9) (BMP-7 = 13.02 pg/ml ±43.5 and 64.6pg/ml ±250) (BMP-10 = 8.14 pg/ml ±12.7 and 5.48 pg/ml ±11.3) (Vitamin D mean was 24.94 ng/ml ±13.2 and 26.2 ng/ml ±11.6) in patients and controls, respectively. Forty-five subjects were enrolled into follow up study: 30 males, 15 females. Healing time mean was 4.13± 2.6 months. No significant correlation between BMP-2/BMP-7 with healing time.

Conclusions

BMP-7 was significantly lowers in the plasma of patients that controls (P = 0.042). Low Vitamin D was observed among Sudanese participants.

Is Decreased Local Bone Quality an Independent Risk Factor for Complications Following Fracture Fixation of Facial Bones

PURPOSE

Although osteoporosis is associated with increased risks of complications of fracture fixation in the orthopedic literature, the association between local bone quality (LBQ) and complications of facial fracture fixation is unknown. The authors aim to identify that if decreased LBQ is an independent risk factor for complications following facial fracture fixation?

METHODS

The authors conducted a prospective cohort study on patients over age of 50 years who underwent open reduction and rigid internal fixation for facial fractures. The primary predictor was LBQ (low or normal), decided by a combination of 3 panoramic indices. Other predictors included age, gender, body mass index (BMI), comorbidities, trauma-related characteristics, etc. The outcome variable was the presence of hardware-related, fracture-healing, wound, or neurosensory complications during 2-year follow-up. Univariate and multivariate regressions were performed to identify any significant association between predictor and outcome variables.

RESULTS

The sample was composed of 69 patients (27 females) with an average age of 58.6 ± 8.6 years and BMI of 25 ± 3.8. Low-LBQ patients were significantly older, more females, had lower BMI, mainly injured from falls, had more complications compared to their normal-LBQ counterparts. However, multivariable logistic regressions demonstrated that only age (adjusted OR: 1.12, P = 0.031, 95% CI: 1.01, 1.23) and diabetes (adjusted OR: 12.63, P = 0.029, 95% CI: 1.3, 122.53) were significantly associated with overall complications after confounding adjustment.

CONCLUSIONS

The results of the present study indicate that reduced LBQ is not an independent risk factor for complications following facial fracture fixation. The increased risk of complications in low-LBQ patients is more likely to be attributed to other age-related comorbidities such as diabetes. Therefore, the authors recommend detailed workup and good control of comorbidities in elderly trauma patient.

Bone regeneration via skeletal cell lineage plasticity: All hands mobilized for emergencies: Quiescent mature skeletal cells can be activated in response to injury and robustly participate in bone regeneration through cellular plasticity

An emerging concept is that quiescent mature skeletal cells provide an important cellular source for bone regeneration. It has long been considered that a small number of resident skeletal stem cells are solely responsible for the remarkable regenerative capacity of adult bones. However, recent in vivo lineage-tracing studies suggest that all stages of skeletal lineage cells, including dormant pre-adipocyte-like stromal cells in the marrow, osteoblast precursor cells on the bone surface and other stem and progenitor cells, are concomitantly recruited to the injury site and collectively participate in regeneration of the damaged skeletal structure. Lineage plasticity appears to play an important role in this process, by which mature skeletal cells can transform their identities into skeletal stem cell-like cells in response to injury. These highly malleable, long-living mature skeletal cells, readily available throughout postnatal life, might represent an ideal cellular resource that can be exploited for regenerative medicine.

Synergistic use of biomaterials and licensed therapeutics to manipulate bone remodelling and promote non-union fracture repair

Disrupted bone metabolism can lead to delayed fracture healing or non-union, often requiring intervention to correct. Although the current clinical gold standard bone graft implants and commercial bone graft substitutes are effective, they possess inherent drawbacks and are limited in their therapeutic capacity for delayed union and non-union repair. Research into advanced biomaterials and therapeutic biomolecules has shown great potential for driving bone regeneration, although few have achieved commercial success or clinical translation. There are a number of therapeutics, which influence bone remodelling, currently licensed for clinical use. Providing an alternative local delivery context for these therapies, can enhance their efficacy and is an emerging trend in bone regenerative therapeutic strategies. This review aims to provide an overview of how biomaterial design has advanced from currently available commercial bone graft substitutes to accommodate previously licensed therapeutics that target local bone restoration and healing in a synergistic manner, and the challenges faced in progressing this research towards clinical reality.

Non-Union Treatment Based on the "Diamond Concept" Is a Clinically Effective and Safe Treatment Option in Older Adults

Background

Patients >60 years suffering from non-unions are often unable to perform activities of daily living and often become dependent on nursing care. Evidence regarding treatment options and outcome is nonexistent. This study sought to determine the clinical effectiveness and safety of one- or two-step non-union therapy in elderly patients.

Methods

This study was a single-site retrospective database analysis of older adults with long bone non-unions treated via “diamond concept”. All medical records of patients receiving surgical treatment of non-unions between 01/01/2010 and 31/12/2016 were reviewed. Clinical and radiological outcome subsequent to non-union therapy were evaluated.

Results

A total of 76 patients (37 patients were treated with one-step and 39 patients with Masquelet therapy) suffering from a non-union older than 60 years treated between 01/01/2010 and 31/12/2016 in our institution were included into the current study. Bone consolidation was achieved in 91.9% after one-step and 76.9% after the Masquelet therapy. Analysis of age as a risk factor in the outcome of non-union therapy revealed no significant differences in patients treated with the one-step procedure according to the “diamond concept”. On the contrary, age had a significant negative influence on the outcome of the Masquelet therapy (p = 0.027).

Conclusion

Non-union therapy according to the “diamond concept” is an effective and reliable treatment option in elderly patients. According to findings of the current study, older adults suffering from an infected non-union benefit from a two-stage procedure, whereas in patients suffering from a non-infected non-union, a one-step surgical treatment is beneficial.

Evaluation of Risk Factors for Falls in Patients with Rheumatoid Arthritis

Background

The aim of our study was to investigate the risk factors for falls in the rheumatoid arthritis (RA) patient population in Poland. This would be a major step towards the development of new fall prevention programs.

Material/Methods

There were 450 RA patients who met the criteria of the American College of Rheumatology who participated in this study. The average age of patient participants was 54.2 years; the average RA duration was 15.1 years. All patients filled out the study questionnaire regarding falls, medications, and diseases, and they filled out the Polish version of the Health Assessment Questionnaire (HAQ).

Results

Of the 400 patients, 203 patients (51%) experienced falls. Out of the 268 falls experienced by study patients, 113 falls (42%) were due to an environmental cause, the remainder 155 falls were caused by health conditions. The number of falls positively correlated with HAQ scores (r=0.42, P<0.01) and the duration of RA (r=0.39, P<0.05). For individuals who had fallen 3 or more times, there was a stronger positive correlation between the number of falls and the total HAQ score (r=0.61, P<0.01). The main risk factors for falls in the study group were dizziness (odds ratio [OR]=3.42), the use of hypotensive medication (OR=2.82), foot deformities (OR=4.09), and a high HAQ score (OR=2.59). Other factors such as drug use (e.g., glucocorticoids), pain, and duration of RA were measured using a visual analogue scale, and were found not to have increased the risk for falls and fractures (P>0.05).

Conclusions

Knowledge about risk factors can help identify high-risk patients to help decrease their risk of falling, thus preventing fall-related injuries.

Age-related changes to macrophages are detrimental to fracture healing in mice

The elderly population suffers from higher rates of complications during fracture healing that result in increased morbidity and mortality. Inflammatory dysregulation is associated with increased age and is a contributing factor to the myriad of age-related diseases. Therefore, we investigated age-related changes to an important cellular regulator of inflammation, the macrophage, and the impact on fracture healing outcomes. We demonstrated that old mice (24 months) have delayed fracture healing with significantly less bone and more cartilage compared to young mice (3 months). The quantity of infiltrating macrophages into the fracture callus was similar in old and young mice. However, RNA-seq analysis demonstrated distinct differences in the transcriptomes of macrophages derived from the fracture callus of old and young mice, with an up-regulation of M1/pro-inflammatory genes in macrophages from old mice as well as dysregulation of other immune-related genes. Preventing infiltration of the fracture site by macrophages in old mice improved healing outcomes, with significantly more bone in the calluses of treated mice compared to age-matched controls. After preventing infiltration by macrophages, the macrophages remaining within the fracture callus were collected and examined via RNA-seq analysis, and their transcriptome resembled macrophages from young calluses. Taken together, infiltrating macrophages from old mice demonstrate detrimental age-related changes, and depleting infiltrating macrophages can improve fracture healing in old mice.

Modulation of the Inflammatory Response and Bone Healing

The optimal treatment for complex fractures and large bone defects is an important unsolved issue in orthopedics and related specialties. Approximately 5-10% of fractures fail to heal and develop non-unions. Bone healing can be characterized by three partially overlapping phases: the inflammatory phase, the repair phase, and the remodeling phase. Eventual healing is highly dependent on the initial inflammatory phase, which is affected by both the local and systemic responses to the injurious stimulus. Furthermore, immune cells and mesenchymal stromal cells (MSCs) participate in critical inter-cellular communication or crosstalk to modulate bone healing. Deficiencies in this inter-cellular exchange, inhibition of the natural processes of acute inflammation, and its resolution, or chronic inflammation due to a persistent adverse stimulus can lead to impaired fracture healing. Thus, an initial and optimal transient stage of acute inflammation is one of the key factors for successful, robust bone healing. Recent studies demonstrated the therapeutic potential of immunomodulation for bone healing by the preconditioning of MSCs to empower their immunosuppressive properties. Preconditioned MSCs (also known as "primed/ licensed/ activated" MSCs) are cultured first with pro-inflammatory cytokines (e.g., TNFα and IL17A) or exposed to hypoxic conditions to mimic the inflammatory environment prior to their intended application. Another approach of immunomodulation for bone healing is the resolution of inflammation with anti-inflammatory cytokines such as IL4, IL10, and IL13. In this review, we summarize the principles of inflammation and bone healing and provide an update on cellular interactions and immunomodulation for optimal bone healing.

Does Age Influence the Outcome of Lower Limb Non-Union Treatment? A Matched Pair Analysis

Background: Fractures in elderly patients are common and have severe implications on a socioeconomic level, as musculoskeletal integrity and competence is crucial for independence. Changes in both composition and biology of bones during aging potentially affect fracture healing adversely. The current study sought to determine the influence of age on the outcome of non-union therapy of atrophic and hypertrophic non-unions based on the “diamond concept”, as well as to evaluate the well-known risk factors impairing bone healing. Patients and Methods: All medical records, operative notes, lab data, and radiological imaging of patients that received surgical treatment of both atrophic and hypertrophic non-unions of the femur or tibia between 1 January 2010 and 31 December 2016 were thoroughly reviewed and analyzed. Patients who participated in our standardized follow-up for at least 12 months were included into a database. Patients older than 60 years were matched with patients younger than 60 based on five established criteria. The study was approved by the local ethics committee (S-262/2017). According to our inclusion criteria, a total of 76 patients older than 60 years were eligible for analysis. Via matching, two groups were formed: study group (SG; >60 years; n = 45) and control group (CG; <60 years; n = 45). Results: Twelve months subsequent to treatment, the consolidation rate was equivalent in both groups (SG: 71% vs. CG: 67%). The consolidation for all patients before matching was 73%. The clinical results for the complete collective were no pain or pain with high or medium strain for 62.5%, whereas 29.6% had pain with low strain or constant pain. 7.87% had no pain levels given. Logistic regression modeling showed no influence of age >60 years on radiological or clinical outcome, whereas a significant negative correlation was revealed between patients aged 40–49 years and radiological non-union consolidation (b = −1.145 and p = 0.048). In addition, diabetes had a negative influence on non-union therapy (b = −1.145 and p = 0.048). As expected, the clinical outcome correlated significantly with the radiological outcome (p < 0.001). Conclusion: Surgeons should optimize both modifiable risk factors such as diabetes mellitus, as well as surgical treatment in order to achieve the best possible outcome in elderly patients. Elderly patients benefit from osseous consolidation by enabling and maintaining musculoskeletal competence due to the close correlation between clinical and radiological outcome. Advanced age alone does not negatively influence the outcome of non-union therapy and should, therefore, not be considered a risk factor. In contrast, patients in their fifth decade suffering from lower limb non-unions should be considered as high-risk patients and treatment should be modified accordingly.

The Synergic Effect of Terpenoid and Steroidal Saponins Can Improve Bone Healing, by Promoting the Osteogenic Commitment of Adipose Mesenchymal Stem Cells: An In Vitro Study

Bone regeneration involves several biological processes that consistently impact the quality of tissue healing. An important step consists of the local recruitment and differentiation of mesenchymal stem cells that migrate in the site to regenerate from bone marrow. Mesenchymal stem cells (MSCs) may be pushed towards osteogenic commitment by specific substances, often naturally present in plants. Yunnan Baiyao (YB) is a Chinese herbal medicine, mainly working through the synergic effect of terpenoid and steroidal saponins. YB is well known for its numerous biomedical effects, including the ability to favor improved bone tissue healing. In our in vitro study, we used adipose mesenchymal stem cells (ADSCs) as a study-model: We selected samples to harvest and isolate ADSCs and investigate their viability; moreover, we performed bone-related gene expression to evaluate the differentiation of MSCs. To confirm this behavior, we analyzed alkaline phosphate activity and calcium deposition, with ADSCs cultured in basal and osteogenic media, with YB at different concentrations in the medium, and at different time-points: 7, 14 and 21 days. Our results indicate that the synergic effect of terpenoid and steroidal saponins slightly favor the late ADSCs differentiation towards the osteoblasts phenotype. In osteogenic committed cells, the treatment with the lower dose of YB promoted the up-regulation of the alkaline phosphatase gene (ALPL) at day seven and 14 (p < 0.01); at day 21, the alkaline phosphatase (ALP) activity showed a slight increase, although in basal condition it maintains low rates. We assume that such molecular synergy can promote the osteogenic commitment of adipose mesenchymal stem cells, thus improving the timing and the quality of bone healing.

Bench-to-bedside strategies for osteoporotic fracture: From osteoimmunology to mechanosensation

Osteoporosis is characterized by a decrease in bone mass and strength, rendering people prone to osteoporotic fractures caused by low-energy forces. The primary treatment strategy for osteoporotic fractures is surgery; however, the compromised and comminuted bones in osteoporotic fracture sites are not conducive to optimum reduction and rigid fixation. In addition, these patients always exhibit accompanying aging-related disorders, including high inflammatory status, decreased mechanical loading and abnormal skeletal metabolism, which are disadvantages for fracture healing around sites that have undergone orthopedic procedures. Since the incidence of osteoporosis is expected to increase worldwide, orthopedic surgeons should pay more attention to comprehensive strategies for improving the poor prognosis of osteoporotic fractures. Herein, we highlight the molecular basis of osteoimmunology and bone mechanosensation in different healing phases of elderly osteoporotic fractures, guiding perioperative management to alleviate the unfavorable effects of insufficient mechanical loading, high inflammatory levels and pathogen infection. The well-informed pharmacologic and surgical intervention, including treatment with anti-inflammatory drugs and sufficient application of antibiotics, as well as bench-to-bedside strategies for bone augmentation and hardware selection, should be made according to a comprehensive understanding of bone biomechanical properties in addition to the remodeling status of osteoporotic bones, which is necessary for creating proper biological and mechanical environments for bone union and remodeling. Multidisciplinary collaboration will facilitate the improvement of overall osteoporotic care and reduction of secondary fracture incidence.

Osteocyte numbers decrease only in postcranial but not in cranial bones in humans of advanced age

BACKGROUND

Bone ageing is governed by the linked activities of short-lived osteoblasts and osteoclasts in conjunction with long-lived osteocytes present in osseous structure. Besides their maintenance function, osteogenic cells also gain specific positional information, which may potentially trigger ageing-associated cellular deviations in terminally differentiated osteocytes differently in cranial versus postcranial tissues.

METHODS

We therefore investigated bone taken from deceased aged humans explanted at five distinct anatomical positions throughout the body and assessed physical and biological determinants applying radiologic and histologic measures.

RESULTS

We were able to show that significantly more osteocytes reside in aged cortical bone at cranial positions than within axial or limb skeleton. These cellular states and conditions were not found in the corresponding trabecular bone, where osteocyte numbers remain also high at postcranial positions. Parallel comparative analyses of bone microstructure as analyzed by means of computer tomography showed no significant differences.

CONCLUSIONS

Considering differences and commonalities regarding the bone samples, such as loading, mechanisms of ossification or the surrounding stromal cell compartment, our findings indicate that positional information laid down during ontogenetic processes is instructive during the entire life thus potentially also moulding spatial-specific mechanistic distinctions of bone ageing.

Humeral shaft non-union in the elderly: Results with cortical graft plus stem cells

INTRODUCTION

Humeral shaft is a common site of fracture non-union. Biology and bone quality represent some of the problems that the orthopaedic surgeon has to face up in the elderly. The goals of treatment of humeral shaft non-union are the achievement of mechanical stability and creation of a favourable biologic environment. Bone graft and stem cells are some of the augmentation techniques available to reach these goals.

PURPOSE

Evaluation of the outcomes of humeral shaft non-union in elderly population treated with cortical allograft and stem cells.

MATERIAL AND METHODS

A cohort of 21 patients with humeral shaft non-union was reviewed. Inclusion criteria were patients aged more than 65 years, with a diagnosis of humeral shaft non-union treated with cortical allograft and stem cells. Primary endpoints were 'bone healing' and 'time-to-union'. Secondary endpoints were shoulder and elbow function and patients' quality of life with Oxford Shoulder Score (OSS), Constant score and EuroQol-5D (EQ-5D).

RESULTS

6 patients met the inclusion criteria. In 5 of them, the cortical allograft was opposite to a plate, whereas in the other one a "Sandwich" technique was chosen because of large osteolysis. 'Bone healing' occurred in all patients after a mean of 3.3 months (range 2-5). In all but two patients, the elbow range of motion was in almost normal range (15-130). The mean OSS was 35.8 (+/- 6.4), whereas the mean Constant was 53.3 (+/- 2.2). The mean EQ-5D index was 0.451 (+/- 0.21).

DISCUSSION

Bone healing occurred in all patients, with a time-to-union comparable or even better compared with other series. The use of cortical bone graft provide both stability and biological benefit, whereas stem cells improve the non-union environmental biology. Functional outcomes were lower than other series and patients' quality of life was similar to Italian elderly women.

CONCLUSION

The use cortical allograft with stem cells is a viable strategy to treat humeral shaft non-union in the elderly.

Dysfunctional stem and progenitor cells impair fracture healing with age

Successful fracture healing requires the simultaneous regeneration of both the bone and vasculature; mesenchymal stem cells (MSCs) are directed to replace the bone tissue, while endothelial progenitor cells (EPCs) form the new vasculature that supplies blood to the fracture site. In the elderly, the healing process is slowed, partly due to decreased regenerative function of these stem and progenitor cells. MSCs from older individuals are impaired with regard to cell number, proliferative capacity, ability to migrate, and osteochondrogenic differentiation potential. The proliferation, migration and function of EPCs are also compromised with advanced age. Although the reasons for cellular dysfunction with age are complex and multidimensional, reduced expression of growth factors, accumulation of oxidative damage from reactive oxygen species, and altered signaling of the Sirtuin-1 pathway are contributing factors to aging at the cellular level of both MSCs and EPCs. Because of these geriatric-specific issues, effective treatment for fracture repair may require new therapeutic techniques to restore cellular function. Some suggested directions for potential treatments include cellular therapies, pharmacological agents, treatments targeting age-related molecular mechanisms, and physical therapeutics. Advanced age is the primary risk factor for a fracture, due to the low bone mass and inferior bone quality associated with aging; a better understanding of the dysfunctional behavior of the aging cell will provide a foundation for new treatments to decrease healing time and reduce the development of complications during the extended recovery from fracture healing in the elderly.

Mechanisms Underlying Normal Fracture Healing and Risk Factors for Delayed Healing

PURPOSE OF REVIEW

Substantial advances have been made in understanding the biological basis of fracture healing. Yet, it is unclear whether the presence of osteoporosis or prior or current osteoporosis therapy influences the healing process or is associated with impaired healing. This review discusses the normal process of fracture healing and the role of osteoporosis and patient-specific factors in relation to fracture repair.

RECENT FINDINGS

The definitive association of osteoporosis to impaired fracture healing remains inconclusive because of limited evidence addressing this point. eStudies testing anabolic agents in preclinical models of ovariectomized animals with induced fractures have produced mostly positive findings showing enhanced fracture repair. Prospective human clinical trials, although few in number and limited in design and to testing only one anabolic agent, have similarly yielded modestly favorable results. Interest is high for exploring currently available osteoporosis therapies for efficacy in fracture repair. Definitive data supporting their efficacy are essential in achieving approval for this indication.

Fracture healing in a collagen-induced arthritis rat model: Radiology and histology evidence

This research was designed to investigate the fracture healing pattern in a rheumatoid arthritis (RA) rat model. A mid-shaft femur fracture (RA + F) model and normal fracture (NF) model as control were established. Micro-CT, H&E staining, TB staining, SO staining, tartrate-resistant acid phosphates, and immunohistochemistry test were performed. In the micro-CT images and H&E stains, fracture gaps were evident in the RA + F group 4 and 8 weeks after fracture. In detail, the bone mineral density, the ratio of bone volume to tissue volume, and trabecular thickness of the RA + F group were significantly lower than those of the NF group at all time points. Trabecular number value was significantly lower in the RA + F group 4 weeks after surgery in comparison with that of the NF group. Furthermore, the structure model index test result of the RA + F group was significantly higher than that of the NF group at all time points. TB staining and SO staining test results showed that the NF group had more cartilaginous callus in the earlier stage of bone healing process (4 weeks), and less cartilage callus formation in the later stage (8 weeks) in comparison with that of the RA + F group. Osteoclasts statistics score in the NF group were obviously lower than that of the RA + F group at all time points. MMP-3 and OPN protein levels of the fracture area in the RA + F group were significantly higher than those in the NF group. This study improves the understanding of the bone healing characteristics in patients with RA. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2876-2885, 2018.

Long-lived murine osteocytes are embodied by craniofacial skeleton in young and old animals whereas they decrease in number in postcranial skeletons at older ages

BACKGROUND

Osteocytes are engaged in life-enduring processes such as bone remodelling, fracture healing or osseointegration of implants. Over age, ossification processes and regenerative capacity can greatly differ in mandible and femur.

OBJECTIVE

Mesenchymal stem cells from cranial and postcranial bones are of different embryologic origin. This may be the reason why the regenerative capacity differs between cranial and postcranial bones in old patients. It was hypothesised that different ageing patterns, reflected by osteocyte density, lacunar density and osteoid formation, exist between murine mandibles and femurs.

MATERIAL AND METHODS

Mandible and femur of young (4 months) and old (34-36 months old) male C57Bl/6 mice were histologically investigated to determine the number of lacunae occupied with osteocytes. Osteoid formation was revealed by Masson-Goldner staining, and the spatial distribution of BMP-2 synthesis was examined.

RESULTS

Over lifetime, the number of lacunae occupied with osteocytes only showed a modest decrease in mandibular bone (old 85.63%/young 91.12%) while greatly diverging in the femur (old 55.99%/young 93.28%). In equal measure, old femur exhibited less osteoid formation and decreased BMP-2 expression.

CONCLUSION

Tissue-specific conduct of bone ageing is moulded by osteocytic activities, which was found to vary between postcranial and craniofacial skeleton. The latter harbours long-lived osteocytes also in old animals which assures lifelong bone integrity. Preliminary concurring findings from a human cadaver, also presented in this contribution, provided a rationale for recommending the translatability to humans.

An innovative Mg/Ti hybrid fixation system developed for fracture fixation and healing enhancement at load-bearing skeletal site

Magnesium (Mg) is a potential biomaterial suitable for developing biodegradable orthopaedic implants, especially as internal fixators for fracture fixation at non-load bearing skeletal sites. However, Mg alone cannot provide sufficient mechanical support for stable fracture fixation at load bearing sites due to its rapid degradation in the early stage after implantation. In consideration of the strengths and weaknesses of Mg, we developed an innovative magnesium/titanium (Mg/Ti) hybrid fixation system for long bone fracture fixation and investigated the fixation efficacy. The finite element analysis (FEA) results indicated that the Mg/Ti hybrid fixation system provided sufficient mechanical support for fracture fixation at load-bearing skeletal site. As a proof-of-concept, we performed a "Z-shaped" open osteotomy at the mid-shaft of rabbit tibia. For comparison, the animals were divided into two groups: Mg/Ti group (fixated with Mg screws and Ti fixators) and Ti control group (fixated with Ti screws and Ti fixators). The radiographic, four-point bending mechanical test, histological and histomorphometric analysis were postoperatively performed in a temporal manner up to 12 weeks. Both X-ray and micro-CT images of the Mg/Ti group showed a larger callus (14.7% at 3rd week and 24.8% at 6th week, n = 5-7, p < 0.05) in the regions of interest (ROIs) over time, especially at the opposite cortex of the fixation plate. At the 12th week post-operation, the biomechanical test result indicated that the rabbit tibia in the Mg/Ti group healed better and the overall mechanical strength was approximately 3-fold higher (n = 8, p < 0.05) than that at 6th week. Furthermore, the FEA revealed that the Mg/Ti group had a higher mechanical strength (19.5% at week 6 and 31.5% at week 12) at the specified ROI and resulted in an earlier and faster endochondral ossification (68.0% at week 3 and 71.4% at week 6) with a higher expression of osteocalcin (54.0%) and collagen I (34.2%) than the Ti control group (n = 4, p < 0.05). Further evaluation suggested that a higher expression of calcitonin gene-related peptide (CGRP), a known osteogenic neuron peptide, in the fracture callus of the Mg/Ti group might be a major underlying mechanism of enhanced fracture healing attributed to the release of Mg ions during the degradation of Mg screws.

Lateral locked plating for distal femur fractures by low-energy trauma: what makes a difference in healing?

PURPOSE

The objective of this study is to investigate healing outcome of lateral locked plating for distal femoral fractures caused by low-energy trauma. In addition, we sought to determine predictable factors associated with fracture healing time.

METHODS

Seventy-three patients (73 fractures) with distal femur fractures (AO/OTA type 33) caused by low-energy trauma were recruited. The mean age of patients was 69.8 years (range, 43-87 years). All fractures were stabilized by less invasive osteosynthesis with anatomical periarticular locking system. Patients were followed up for mean 17.3 months (range, 6-44 months).

RESULTS

Of the 73 fractures, 52 (71.2%) fractures showed bony union within 6 months after the index surgery while the remaining 21 (28.8%) fractures showed delayed union or received revision surgery prior to complete healing. Although overall healing rate from the initial surgery was 93.2% (68/73), which seems to be satisfactory, the rate of surgical complications was 11.0% (8/73). Of all 73 fractures, seven received further surgery including three re-osteosynthesis. On multivariable analysis, plate-screw density at the fracture site was an independent predictable factor associated with the problematic healing.

CONCLUSIONS

Our findings suggest that complications related to increased healing time and fixation construct are not infrequent and ongoing problems in managing low-energy distal femur fractures. Specifically, plate-screw density at the fracture site has a significant influence on healing time in these fractures.