The aseptic femoral and tibial shaft non-union in healthy patients - an analysis of the health-related quality of life and the socioeconomic outcome

CGRP promotes osteogenic differentiation by regulating macrophage M2 polarization through HDAC6/AKAP12 signaling pathway

Aim: To determine the mechanism of Calcitonin gene-related peptide (CGRP) in bone healing.Materials & methods: Alkaline phosphatase (ALP) activity and inflammatory-factor levels were detected using ELISA. Osteogenic differentiation was assessed using Alizarin red staining technique. The interaction between histone deacetylase 6 (HDAC6) and A-kinase anchoring protein 12 (AKAP12) was investigated through Co- immunoprecipitation.Results: CGRP treatment promoted rat bone marrow-derived macrophages (BMDMs) M2 polarization. CGRP facilitated osteogenic differentiation by enhancing M2 polarization of BMDMs. Mechanistically, CGRP promoted AKAP12 acetylation to activate the extracellular regulated protein kinases pathway by HDAC6 inhibition.Conclusion: CGRP promoted M2 polarization of rat BMDMs and facilitated osteogenic differentiation through the HDAC6/AKAP12/extracellular regulated protein kinases signaling pathway, thereby promoting bone healing.

Long-Term Outcomes Following Single-Stage Reamed Intramedullary Exchange Nailing in Apparently Aseptic Femoral Shaft Nonunion with Unsuspected Proof of Bacteria

Background: The aim of this study was to evaluate detection rates and risk factors for unsuspected proof of bacteria, as well as clinical and radiologic outcomes following femoral shaft nonunion without clinical signs of infection treated by a single-stage surgical revision procedure including reamed intramedullary exchange nailing. Methods: A retrospective cohort study was performed in a European level I trauma center between January 2015 and December 2022. Fifty-eight patients were included who underwent reamed intramedullary exchange nailing as a single-step procedure for surgical revision of posttraumatic diaphyseal femoral nonunion without any indications of infection in medical history and without clinical signs of local infection. Clinical details of the patients were analyzed and functional and radiologic long-term outcomes were determined. Results: In all patients, with and without proof of bacteria osseous, healing could be observed. The physical component summary of the SF-12 demonstrated significantly better results at least one year after the final surgical revision in case of a negative bacterial culture during exchange nailing. Conclusions: Clinical long-term outcomes demonstrated a trend towards better results following femoral shaft nonunion revision if there was no evidence for the presence of low-grade infected nonunion. In this case, a single-stage surgical procedure may be recommended.

The effect of post-traumatic long bone non-unions on health-related quality of life

BACKGROUND

Fracture non-unions have a detrimental effect on patients due to reduced mobility and severe pain. Current literature on the quality of life in non-unions is limited, hence the purpose of this study, to quantify the health-related quality of life (HRQoL) among patients with post-traumatic long bone non-unions. It was hypothesized that the HRQoL of these patients is lower than the Dutch population standard as well as for multiple chronic diseases and musculoskeletal disorders.

PATIENTS AND METHODS

From January 2020 to December 2021, this study included consecutive patients who were referred to a multidisciplinary (trauma, orthopedic and plastic surgery), non-union clinic at the Maastricht UMC+. All non-unions were evaluated using the Non-Union Scoring System (NUSS) questionnaire. Patient reported HRQoL outcomes were acquired using the EQ-5D-5L questionnaire and the Lower Extremity Functional Scale (LEFS).

RESULTS

50 patients were included, 18 females and 32 males, with a mean age of 55 years (± 15.5 SD). Eighteen patients presented with an open fracture, nine non-unions were infected and 39 patients had a lower extremity non-union. The mean NUSS score was 39.61 (± 14.6 SD). The mean EQ-5D-5L index score was 0.490 (± 0.261 SD), where patients experienced most problems with mobility. The mean EQ-5D-5L VAS was 61.4 (± 19.6 SD). The patients had a mean LEFS score of 28.7 (± 16.4 SD). The health-related quality of life was well below the age-corrected normative score of the Dutch population (EQ-5D-5L 0.857(p < 0.001); LEFS 77(p < 0.001)). This cohort's HRQoL was significantly lower than the HRQoL of multiple chronic and musculoskeletal disorders, including different forms of cancer and osteoarthritis.

CONCLUSIONS

This study has quantified the detrimental effect of post-traumatic long bone non-unions on patient's health-related quality of life, being significantly lower than the HRQoL of the Dutch population as well as for multiple chronic and musculoskeletal medical conditions. This cohort demonstrates a patient population in need of more specialized care with a low health-related quality of life.

No decay in outcomes at a mean 8 years following surgical treatment for aseptic fracture nonunion

PURPOSE

The purpose of this study is to compare medium to long term patient reported outcomes to one-year data for patients treated surgically for an aseptic fracture nonunion.

METHODS

305 patients surgically treated for a fracture-nonunion were prospectively followed. Data collected included pain scores measured by the Visual Analog Scale (VAS), clinical outcomes assessed by the Short Musculoskeletal Functional Assessment (SMFA), and range of motion. 75% of patients in this study had lower extremity fracture nonunions and 25% had upper extremity fracture nonunions. Femur fracture nonunions were the most common. Data at latest follow-up was compared to one-year follow-up using the independent t-test.

RESULTS

Sixty-two patients were available for follow-up data at an average of eight years. There were no differences in patient reported outcomes between one and eight years according to the standardized total SMFA (p = 0.982), functional index SMFA (p = 0.186), bothersome index SMFA (p = 0.396), activity index SMFA (p = 0.788), emotional index SMFA (p = 0.923), or mobility index SMFA (p = 0.649). There was also no difference in reported pain (p = 0.534). Range of motion data was collected for patients who followed up in clinic for an average of eight years after their surgical treatment. 58% of these patients reported a slight increase in range of motion at an average of eight years.

CONCLUSION

Patient functional outcomes, range of motion, and reported pain all normalize after one year following surgical treatment for fracture nonunion and do not change significantly at an average of eight years. Surgeons can feel confident in counseling patients that their results will last and they do not need to follow up beyond one year, barring pain or other complications.

LEVEL OF EVIDENCE

Level IV.

Small residual fracture gaps delay time to union in length stable femur fractures treated with intrameduallary fixation

OBJECTIVES

The purpose of this study was to investigate whether residual fracture gapping and translation at time of intramedullary nail (IMN) fixation for diaphyseal femur fractures were associated with delayed healing or nonunion.

DESIGN

Retrospective cohort study SETTING: Level 1 trauma hospital, quaternary referral center PATIENTS/PARTICIPANTS/INTERVENTION: Length stable Winquist type 1 and 2 diaphyseal femur fractures treated with IMN at a single Level I trauma center were retrospectively reviewed.

MAIN OUTCOME MEASURE

The largest fracture gap and translation were evaluated on immediate anteroposterior (AP) and lateral postoperative radiographs. Radiographic healing was assessed using Radiographic Union Score in Femur (RUSF) scores at each follow-up. Radiographic union was defined as a RUSF score ≥8 and consolidation of at least 3 cortices. ANOVA and student's t-tests were used to evaluate the influence of fracture gap parameters on time to union (TTU) and nonunion rate. Patients were stratified to measured average gap and translation distances <1mm, 1-3mm and >3mm for portions of the analysis.

RESULTS

Sixty-six patients who underwent IMN with adequate follow-up were identified. A total of 93.9% of patients achieved union at an average of 2.8 months. Fractures with average AP/lateral gaps of <1mm, 1-2.9 mm, and >3mm had an average TTU of 70.1, 91.7, and 111.9 days respectively; fractures with larger residual gap sizes had a significantly longer TTU (p=0.009). Fractures with an average gap of 1-2.9mm and >3 mm had a significantly higher nonunion rate (1.5% and 4.5% respectively) compared to 0% nonunion in the <1 mm group (p=0.003).

CONCLUSION

Residual gapping following intramedullary fixation of length stable diaphyseal femur fractures is associated with a significant increase in likelihood of nonunion.

SUMMARY

Residual displacement of length stable femoral shaft fractures following intramedullary nailing can have a significantly negative impact on fracture healing. An average 3 mm AP/lateral residual fracture gap or a total of 6 mm of the AP + lateral fracture gap appeared to be a critical gap size with increased rates of nonunion and time to union. Therefore, we suggest minimizing the sum of the residual AP and lateral fracture gap to less than a total of 6 mm.

Development and characterization of a predictive microCT-based non-union model in Fischer F344 rats

INTRODUCTION

Non-unions remain a clinical problem and are characterised by the failure to heal after a defined period of time. Current preclinical non-union models apply a wide variety of techniques to diminish intrinsic healing potential deviating from the clinical situation. The aim of this study was to develop and characterise a non-union model in rats using internal plate fixation without the need for additional healing insults, whereby bone healing can be longitudinally assessed using microCT. It was hypothesized that healing/non-unions can be accurately predicted at early time points by microCT.

MATERIALS AND METHODS

Female, skeletally mature Fischer F344 rats received a 2 mm or 1 mm femoral osteotomy, stabilized with either a 2 mm thick plate or a 1.25 mm thick plate. Healing was monitored by microCT over 14 weeks and histological analysis at euthanasia. The mechanical environment was characterised using finite element (FE) modelling and biomechanical testing.

RESULTS

The majority of animals receiving the 2 mm thick plate displayed poor healing responses in both the 2 mm and 1 mm defect size groups. Bone and cartilage formation were markedly improved using the 1.25 mm thick plate. MicroCT could accurately predict bone forming capacity at early time points (3-4 weeks).

CONCLUSIONS

The 2 mm thick plating system confers poor healing responses in female Fischer F344 rats, comparable to atrophic non-unions. By reducing plate thickness to increase interfragmentary strain within the defect site healing is improved, leading to borderline healing situations or increased abundance of cartilage tissue present in the defect site with ultimate failure to bridge the defect (hypertrophic non-union). Furthermore, microCT can reliably identify delayed/non-healing animals within 4 weeks, thereby allowing their selective targeting for the testing of novel, clinically relevant treatment strategies in different clinical situations aimed at restoring impaired bone healing.

Silk-Based Bioengineered Diaphyseal Cortical Bone Unit Enclosing an Implantable Bone Marrow toward Atrophic Nonunion Grafting

Postnatal fracture healing of atrophic long bone diaphyseal nonunions remains a challenge for orthopedic surgeons. Paucity of autologous spongiosa has potentiated the use of tissue engineered bone grafts to improve success rates of bone marrow engraftment used in plate reosteosynthesis. Herein, the development and in vitro validation of a "sandwich-type" biofabricated diaphyseal cross-sectional unit, with an outer mechanically robust bioprinted cortical bone shell, encompassing an engineered bone marrow, are reported. Channelized silk fibroin blend sponges derived from Bombyx mori and Antheraea assama help in developing compartmentalized endosteum, exhibiting specialized osteoblasts (endosteal niche) and discontinuous endothelium (vascular niche). The cellular cross-talk between these two niches triggered via integrin-mediated cell adhesion, enables in preserving quiescence state of CD34⁺ /CD38^- hematopoietic stem cells and their recycling in the engineered marrow. The outer cortical bone strut is developed through multimaterial microextrusion bioprinting strategy. Osteogenically primed mesenchymal stem cells-laden silk fibroin-nano-hydroxyapatite bioink is bioprinted alongside paramagnetic Fe-doped bioactive glass-polycaprolactone blend thermoplastic ink, reinforcing it for mechanical stability. Pulsed magnetic field actuation positively influences the osteogenic commitment and maturation of the bioprinted constructs via mechanotransductory route. Therefore, the assembled engineered marrow and bioprinted cortical shell hold promise as potential orthobiologic substitutes toward atrophic nonunion repairs.

Non-union bone fractures

The human skeleton has remarkable regenerative properties, being one of the few structures in the body that can heal by recreating its normal cellular composition, orientation and mechanical strength. When the healing process of a fractured bone fails owing to inadequate immobilization, failed surgical intervention, insufficient biological response or infection, the outcome after a prolonged period of no healing is defined as non-union. Non-union represents a chronic medical condition not only affecting function but also potentially impacting the individual's psychosocial and economic well-being. This Primer provides the reader with an in-depth understanding of our contemporary knowledge regarding the important features to be considered when faced with non-union. The normal mechanisms involved in bone healing and the factors that disrupt the normal signalling mechanisms are addressed. Epidemiological considerations and advances in the diagnosis and surgical therapy of non-union are highlighted and the need for greater efforts in basic, translational and clinical research are identified.

Long-term patient-related quality of life after successfully treated aseptic non-unions of the long bones

BACKGROUND

Non-union after fracture depicts a devastating complication in trauma surgery and studies assessing patient-reported outcome measures after stable bone consolidation are rare. Therefore, we aimed to evaluate the long-term impact of aseptic long bone non-union on the patients' physical health state and psychological wellbeing. For this purpose, quality of life after successful surgical treatment of long bone non-union was assessed.

METHODS

Sixty-one patients with aseptic long bone non-union surgically treated in our department between November 2009 and March 2019 with achieved bone consolidation were included. Quality of life was evaluated with the EQ-5D and SF-36 outcome instruments as well as with an ICD-10 based symptom rating (ISR) and compared to normative data.

RESULTS

With a minimum follow-up time of one year after the last surgery (mean 4.7 ± 2.7 years) the mean physical health component score of the SF-36 was 38.9 ± 13.7 and the mean mental health component score of the SF-36 was 49.0 ± 5.9, indicating lower quality of life compared to German normative values of 48.4 ± 9.4 (p < .001) and 50.9 ± 8.8 (p = 1.61), respectively. The mean EQ-5D index value reached 0.827 ± 0.18 with an EQ-5D VAS rating of 64.4 ± 21.5 compared to scores of 0.922 (p < .001) and 72.9 ± 1.1 (p < .001) obtained from an age-matched reference population. Mean scores of the ISR did not reveal significant psychological symptom burden in any scale, while an individual analysis showed moderate to severe impairments in 11.5% of the patients in total.

CONCLUSION

Even 4.7 years on average after surgically successful treatment of aseptic long bone non-union, patients still report significant lower quality of life in comparison to normative data. Future clinical studies on non-unions should focus on patient-related outcome measures. Newly emerging treatment strategies and interdisciplinary approaches should be implemented to improve the overall quality of life of non-union patients.

Prediction of interfragmentary movement in fracture fixation constructs using a combination of finite element modeling and rigid body assumptions

The amount of interfragmentary movement has been identified as a crucial factor for successful fracture healing. The aim of our study was to combine finite element analysis with a rigid body assumption to efficiently predict interfragmentary movement in fixed tibial fractures. The interfragmentary movement in a transverse tibial shaft fracture (AO/OTA type 42-A3) fixed with a locked plating construct was simulated using finite element analysis. In order to assess the contribution of the components on the resulting interfragmentary movement, the tibia, screws and embedding was either simulated deformable or as rigid body. The rigid and the deformable model accurately predicted the interfragmentary movement (R² = 0.99). The axial movement ranged between 0.1 mm and 1.3 mm and shear movements were between 0.2 mm and 0.5 mm. Differences between the two models were smaller than 73 μm (axial) and 46 μm (shear). The rigid body assumption reduced computation time and memory usage by up to 61% and 97%, respectively.

The Use of Platelet-Rich Plasma (PRP) for the Management of Non-union Fractures

PURPOSE OF REVIEW

The treatment of non-union fractures represents a significant challenge for orthopaedic surgeons. In recent years, biologic agents have been investigated and utilised to support and improve bone healing. Among these agents, platelet-rich plasma (PRP) is an emerging strategy that is gaining popularity. The aim of this review is to evaluate the current literature regarding the application and clinical effectiveness of PRP injections, specifically for the treatment of non-union fractures.

RECENT FINDINGS

The majority of published studies reported that PRP accelerated fracture healing; however, this evidence was predominantly level IV. The lack of randomised, clinical trials (level I-II evidence) is currently hampering the successful clinical translation of PRP as a therapy for non-union fractures. This is despite the positive reports regarding its potential to heal non-union fractures, when used in isolation or in combination with other forms of treatment. Future recommendations to facilitate clinical translation and acceptance of PRP as a therapy include the need to investigate the effects of administering higher volumes of PRP (i.e. 5-20 mL) along with the requirement for more prolonged (> 11 months) randomised clinical trials.

In Vivo Validation of Spray-Dried Mesoporous Bioactive Glass Microspheres Acting as Prolonged Local Release Systems for BMP-2 to Support Bone Regeneration

Bone morphogenetic protein-2 (BMP-2) is a known key mediator of physiological bone regeneration and is clinically approved for selected musculoskeletal interventions. Yet, broad usage of this growth factor is impeded due to side effects that are majorly evoked by high dosages and burst release kinetics. In this study, mesoporous bioactive glass microspheres (MBGs), produced by an aerosol-assisted spray-drying scalable process, were loaded with BMP-2 resulting in prolonged, low-dose BMP-2 release without affecting the material characteristics. In vitro, MBGs were found to be cytocompatible and to induce a pro-osteogenic response in primary human mesenchymal stromal cells (MSCs). In a pre-clinical rodent model, BMP-2 loaded MBGs significantly enhanced bone formation and influenced the microarchitecture of newly formed bone. The MBG carriers alone performed equal to the untreated (empty) control in most parameters tested, while additionally exerting mild pro-angiogenic effects. Using MBGs as a biocompatible, pro-regenerative carrier for local and sustained low dose BMP-2 release could limit side effects, thus enabling a safer usage of BMP-2 as a potent pro-osteogenic growth factor.

Defective Proliferation and Osteogenic Potential with Altered Immunoregulatory phenotype of Native Bone marrow-Multipotential Stromal Cells in Atrophic Fracture Non-Union

Bone marrow-Multipotential stromal cells (BM-MSCs) are increasingly used to treat complicated fracture healing e.g., non-union. Though, the quality of these autologous cells is not well characterized. We aimed to evaluate bone healing-related capacities of non-union BM-MSCs. Iliac crest-BM was aspirated from long-bone fracture patients with normal healing (U) or non-united (NU). Uncultured (native) CD271highCD45low cells or passage-zero cultured BM-MSCs were analyzed for gene expression levels, and functional assays were conducted using culture-expanded BM-MSCs. Blood samples were analyzed for serum cytokine levels. Uncultured NU-CD271highCD45low cells significantly expressed fewer transcripts of growth factor receptors, EGFR, FGFR1, and FGRF2 than U cells. Significant fewer transcripts of alkaline phosphatase (ALPL), osteocalcin (BGLAP), osteonectin (SPARC) and osteopontin (SPP1) were detected in NU-CD271^highCD45^low cells. Additionally, immunoregulation-related markers were differentially expressed between NU- and U-CD271^highCD45^low cells. Interestingly, passage-zero NU BM-MSCs showed low expression of immunosuppressive mediators. However, culture-expanded NU and U BM-MSCs exhibited comparable proliferation, osteogenesis, and immunosuppression. Serum cytokine levels were found similar for NU and U groups. Collectively, native NU-BM-MSCs seemed to have low proliferative and osteogenic capacities; therefore, enhancing their quality should be considered for regenerative therapies. Further research on distorted immunoregulatory molecules expression in BM-MSCs could potentially benefit the prediction of complicated fracture healing.

Physical Health and Psychological Outcomes in Adult Patients with Long-bone Fracture Non-unions: Evidence Today

Background: Research has suggested that bone fractures can hinder the health status of patients’ life. However, limited research has examined the impact that the healing process of a fracture has on the physical health and psychological state of individuals, particularly in considering the short- and long-term impact of having a fracture that fails to heal and drops into a non-union. The aim of this systematic review is to better understand the impact of fracture non-union to physical health and to respective psychological outcomes. Methods: Electronic databases ‘PubMed’, ‘Cochrane’, ‘PsycInfo’, ‘Medline’, ‘Embase’, ‘Web of Science’, and ‘CINAHL’ were used. Search terms used were nonunion OR non-union OR “non union” OR “long bone” OR “delayed union” AND “quality of life” OR qol OR depression OR anxiety OR psycholog* OR PTSD OR “post-traumatic stress disorder”. Studies published in the years 1995 to 2018 were included. Two independent reviewers carried out screening and data extraction. Studies were included if (1) participants were adult (human) patients with a traumatic non-union secondary to fracture/s; (2) outcomes measured included physical health and psychological wellbeing (e.g., PTSD, psychological trauma, depression, anxiety, etc.). Studies received emphasis if they compared those outcomes between: (1) The “non-union” group to a normative, matched population and (2) the “non-union group” to the same group after union was achieved. However, studies that did not use comparison groups were also included. Results: Out of the 1896 papers identified from our thorough literature search, 13 met the inclusion criteria. Quality assessment was done by the Methodological Index for Non-Randomized Studies (MINORS). Findings suggested that non-unions had a detrimental impact on physical health, and psychological difficulties often after recovery. Conclusions: Patients who experience a long bone non-union are at risk of greater psychological distress and lower physical health status. There is a need for early identification of psychological distress in patients with fracture non-unions and psychological provision should become part of the available treatment.

Use of Masquelet technique in treatment of septic and atrophic fracture nonunion

BACKGROUND

Treatment of atrophic non-unions and large bone defects or infections remains a challenging task for the treating surgeon. In the herein study, we present our experience of the 'Masquelet technique' according to the 'diamond concept' for the treatment of complex long bone reconstruction procedures.

METHODS

Between February 2010 and March 2015, 150 patients (mean age 51.4) with atrophic and- /or infected non-unions were included in this prospective study. All patients received autologous bone graft, a graft expander (TCP (tricalcium phosphate)) and BMP (bone morphogenic protein). Clinical and radiological parameters were assessed at 6 weeks, and at 3, 6 and 12 months. The SF-12 questionnaire was used to evaluate the subjective health of patients.

RESULTS

A successful bony consolidation of the non-unions was observed in 120 (80%) cases with a median healing time of 12.1 months. The mean defect gap was 4.4cm. Initial infection was documented in 54 cases. The most frequently identified pathogen was staphylococcus epidermidis and staphylococcus aureus. A successful removal of microorganisms with subsequent healing was achieved in 39 cases (72%). The SF-12 scores of subjective physical and mental health increased from PCS 31.5 preoperatively to 36.7 one year postoperatively, while MCS increased from 45.5 to 48.7.

CONCLUSIONS

Our study showed that the Masquelet technique according to the 'diamond concept' is a valid method to treat complex atrophic non-unions with large bone defects and associated infection. Following the principles of the 'diamond concept' (targeted optimization of tissue engineering and bone regeneration) a high rate of success can be expected in these difficult reconstruction cases.

Predictors of fracture healing in patients with recalcitrant nonunions treated with autologous culture expanded bone marrow-derived mesenchymal stromal cells

The study reports the prospective outcome of treating severe recalcitrant fracture nonunion in patients with autologous bone marrow-derived mesenchymal stromal cells (BMSC) from 2003 to 2010 and analyze predictors of union. Autologous BMSC were culture expanded and inserted at nonunion site with or without carriers in addition to surgical stabilization of the fracture. Radiological union was ascertained by musculoskeletal radiologists on plain radiographs and/or CT scans. A logistic regression analysis was performed with cell-expansion parameters (cell numbers, cell doubling time) and known clinical factors (e.g., smoking and diabetes) as independent variables and fracture union as the dependent variable to identify the factors that influence bony healing. An Eq5D index score assessed the effect of treatment on general quality of health. A total of 35 patients (mean age 51+/-13 years) with established nonunion (median 2.9 years, 1-33) and, at least one failed nonunion surgery (median 4,1-14) received treatment. Fracture union was achieved in 21 patients (60%; 95%CI 44-75) at 2.6 years. Multiple penalized logistic regression revealed faster cell doubling time (p = 0.07), absence of diabetes (p = 0.003), less previous surgeries (p = 0.008), and lower age at cell implantation (p = 0.02) were significant predictors for fracture union. A significant increase in Eq5D index (p = 0.01) was noted with a mean rise of the score by 0.34 units (95%CI 0.11-0.58) at 1 year following the study. In summary, the study revealed cell doubling time as a novel in vitro parameter in conjunction with age, multiple surgeries, and diabetes as being significant predictors of the fracture union. © 2018 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. J Orthop Res 37:1303-1309, 2019.

Clinical outcomes of intramedullary nailing of femoral shaft fractures with third fragments: a retrospective analysis of risk factors for delayed union

Background

This study retrospectively evaluated the clinical outcomes of intramedullary nailing of femoral shaft fractures with third fragments and analyzed the risk factors for delayed union.

Methods

Retrospective analyses involving 51 patients who underwent intramedullary nailing of femoral shaft fractures with third fragments (AO classification type B, 35 cases; type C, 16 cases) were conducted. Delayed union was defined as either more than 10 months required for callus formation in more than three of the four cortical bone surfaces observed in the frontal and lateral radiographic views or the requirement for additional surgery such as nail conversion or bone transplantation. Seventeen patients developed delayed union (D group). Thirty-four patients achieved bony union within 9 months (U group). The following background variables were compared between groups: age at the time of the injury; AO classification; ratio of open fracture; waiting period before surgery; rate of the infraisthmal fracture; diameter of the intramedullary nail; ratio of the intramedullary nail to the femur; length and displacement of the third fragment; and use of open reduction, poller screws, or dynamization.

Results

Significant differences were found between the D and U groups for age (32.2±14.1 vs. 25.3±9.6 years), open fracture ratio (35.3% vs. 11.8%), and displacement of the third fragment (13.7±6.4 vs. 9±6.3 mm). Multiple logistic regression analysis only identified displacement of the third fragment as a risk factor for delayed union (p=0.03; OR 1.13; 95% CI 1.01 to 1.26).

Discussion

Delayed union was observed in 17 cases (33.3%) after intramedullary nailing of femoral shaft fractures with third fragments. Displacement of the third fragment influenced delayed union.

Level of evidence

Level III.

Clinical and Research Approaches to Treat Non-union Fracture

PURPOSE OF REVIEW

Impaired healing outcomes or even non-unions after bone injury are still a highly relevant problem in the daily clinical life. Especially within an aging population, the occurrence of bone fractures increases and thus novel treatment approaches to overcome compromised bone regeneration are needed.

RECENT FINDINGS

The gold standard to treat delayed or non-healing bone injuries is still the use of autologous bone grafts to foster regeneration. Besides its successful treatment outcome, it also has disadvantages: a second surgery is needed in order to harvest the bone material and the material is highly limited. Looking into the recent literature, a multitude of different research approaches were already conducted to identify new possible strategies to treat impaired bone regeneration: application of mesenchymal stromal cells, platelet lysates, growth factors, interference in the immune system, or bone formation stimulation by ultrasound. This review gives an overview of the treatment approaches actually performed in the clinic as well as at the bench in the context of compromised bone healing. It clearly highlights the complexity of the nature of non-healing bone fractures as well as patient-dependent factors influencing the healing process.

The Irisin Hormone Profile and Expression in Human Bone Tissue in the Bone Healing Process in Patients

Background

Whether or not there is a relationship between the newly-discovered irisin hormone and bone healing is not yet known. The aim of this study was to investigate what effect irisin hormone has on the bone healing process.

Material/Methods

The study included 21 adult patients with a diagnosed fracture of the lower extremity (femur or tibia). Informed consent was obtained from all the patients. A total of four venous blood samples were taken from the patients: before fracture stabilization, then postoperatively on days 1, 10, and 60. In patients with femoral neck fracture who had hip prosthesis applied, bone tissue samples were taken from the removed femur head and irisin was determined immunohistochemically in muscle biopsies taken from the same patients.

Results

In analysis, it was revealed that the mean value of irisin 60 days after operation is significantly higher than the values of irisin before operation, 1 day after operation, and 15 day after operation (p<0.001, p<0.001, p<0.001, respectively). Intense staining was observed in compact bone tissue, muscle tissue, and in hypertrophic vascular endothelium within the Havers canal.

Conclusions

The level of irisin hormone increased in the bone union process and affects fracture healing due to irisin receptors in human bone tissue.

Potential Role of Chemokines in Fracture Repair

Chemokines are a family of small cytokines that share a typical key structure that is stabilized by disulfide bonds between the cysteine residues at the NH₂-terminal of the protein, and they are secreted by a great variety of cells in several different conditions. Their function is directly dependent on their interactions with their receptors. Chemokines are involved in cell maturation and differentiation, infection, autoimmunity, cancer, and, in general, in any situation where immune components are involved. However, their role in postfracture inflammation and fracture healing is not yet well established. In this article, we will discuss the response of chemokines to bone fracture and their potential roles in postfracture inflammation and healing based on data from our studies and from other previously published studies.

Reliability of the radiographic union scale in tibial fractures (RUST)

Objective

This study aimed to evaluate the inter- and intra observer reproducibility of the radiographic score of consolidation of the tibia shaft fractures.

Methods

Fifty-one sets of radiographs in anteroposterior (AP) and profile (P) of the tibial shaft treated with intramedullary nail were obtained. The analysis of X-rays was performed in two stages, with a 21-day interval between assessments by a group of nine evaluators. To evaluate the reproducibility of RUST score between the evaluators, the intra-class correlation coefficient (ICC) with a 95% confidence interval was used. ICC values range from +1, representing perfect agreement, to −1, complete disagreement.

Results

There was a significant correlation among all evaluators: ICC = 0.87 (95% CI 0.81 to 0.91). The intraobserver agreement proved to be substantial with ICC = 0.88 (95% CI 0.85 to 0.91).

Conclusion

This study confirms that the RUST scale shows a high degree of reliability and agreement.

Treatment of atrophic femoral non-unions according to the diamond concept: Results of one- and two-step surgical procedure

BACKGROUND

The treatment of non-unions in long bones poses a great challenge, particularly in cases of infection or large osseous defects. This article evaluates the use of the diamond concept in the treatment of femoral non-unions in a one-step or two-step procedure according to the Masquelet technique.

PATIENTS AND METHODS

Between February 2010 and March 2014, 88 patients with atrophic femoral non-unions were included in our study. The treatment was performed in one step (Group G1) on 41 patients and in two-step Masquelet technique (Group G2) on 47 patients, according to the diamond concept. In 72 cases it was decided to apply the growth factor BMP-7. The mean age of patients was 49.9 ± 15.3. The data were analysed after following up all patients for at least 12 months after surgery.

RESULTS

74% of patients achieved consolidation in an average of 9.3 months. Positive bacterial cultures were found in 16 cases (18%). The consolidation rate in G2 was dependent on the non-union localisation and the osteosynthesis method applied. 83% of patients treated by intramedullary reaming achieved consolidation, while this was the case for only 60% of patients with osteosynthesis plates. Smokers in G2 had a larger average osseous defect and a lower consolidation rate. The quality of life as assessed with the SF-12 questionnaire had improved in both groups, with no significant differences between G1 and G2 one year after surgery.

CONCLUSIONS

One-step therapy is a suitable method of treatment for aseptic femoral non-unions with small osseous defects, using BMP-7 and RIA in the case of primarily failed atrophic non-union treatment. The Masquelet technique is an efficient means of eradicating infections in non-unions. In combination with intramedullary nailing, this technique is the method of choice for the treatment of femoral shaft non-unions with large defects.

Femoral locking plate failure salvaged with hexapod circular external fixation: a report of two cases

Femoral non-unions are difficult to treat even for the experienced orthopaedic trauma surgeon. If the non-union follows failure of modern stable internal fixation, the complexity of the management is further increased. We report two cases of stiff hypertrophic femoral non-unions after failed locking plate fixation that were successfully treated with a new hexapod circular external fixator. In addition to providing the necessary stability for functional rehabilitation and union, the hexapod circular fixator software allows gradual correction of deformities in order to restore the normal mechanical alignment of the limb.

Systemic Treatment with Strontium Ranelate Does Not Influence the Healing of Femoral Mid-shaft Defects in Rats

Strontium ranelate (SrR) has both bone anabolic and anti-resorption properties and has therefore the potential to increase the healing of bone defects. The aim of the present study was to investigate the effect of systemic treatment with SrR during the healing of cortical bone defects in rats. In addition, the vertebral bodies were examined in order to elucidate the effect of short-term treatment with SrR on intact trabecular bone. Sixty 16-week-old female Wistar rats were randomized into four groups. A cylindrical defect was drilled through the anterior cortex of the mid-femoral diaphysis in both hind limbs. Two of the groups were treated with SrR (900 mg/kg b.w.) mixed into the food and two groups served as controls. The animals were euthanized after either 3 or 8 weeks of treatment. Healing of the defects was analyzed with µCT, mechanical testing, and stereology. Treatment with SrR resulted in increased thickness of the defects after 3 weeks of treatment, whereas no effect on bone volume fraction (BV/TV), mechanical properties (maximum strength and maximum stiffness), periosteal callus volume, or osteoclast-covered bone surfaces (Oc.S/BS) after either 3 or 8 weeks of treatment was found. Furthermore, SrR increased the bone material density (ρ) of the vertebral bodies, and tended to increase BV/TV after 8 weeks of treatment (p = 0.087). The mechanical properties of the vertebral bodies were not influenced by SrR treatment. In conclusion, 3 weeks of treatment with SrR increased the thickness of the healing mid-femoral cortical bone defects in rats, but did not influence BV/TV, mechanical properties, periosteal callus volume, or Oc.S/BS after either 3 or 8 weeks. Furthermore, SrR had no effect on the microstructure and mechanical properties of the vertebral bodies.

RhBMP-7 for the treatment of nonunion of fractures of long bones

We report the outcome of 84 nonunions involving long bones which were treated with rhBMP-7, in 84 patients (60 men: 24 women) with a mean age 46 years (18 to 81) between 2003 and 2011. The patients had undergone a mean of three previous operations (one to 11) for nonunion which had been present for a mean of 17 months (4 months to 20 years). The nonunions involved the lower limb in 71 patients and the remainder involved the upper limb. A total of 30 nonunions were septic. Treatment was considered successful when the nonunion healed without additional procedures. The relationship between successful union and the time to union was investigated and various factors including age and gender, the nature of the nonunion (location, size, type, chronicity, previous procedures, infection, the condition of the soft tissues) and type of index procedure (revision of fixation, type of graft, amount of rhBMP-7) were analysed. The improvement of the patients' quality of life was estimated using the Short Form (SF) 12 score. A total of 68 nonunions (80.9%) healed with no need for further procedures at a mean of 5.4 months (3 to 10) post-operatively. Multivariate logistic regression analysis of the factors affecting union suggested that only infection significantly affected the rate of union (p = 0.004).Time to union was only affected by the number of previous failed procedures (p = 0.006). An improvement of 79% and 32.2% in SF-12 physical and mental score, respectively, was noted within the first post-operative year. Rh-BMP-7 combined with bone grafts, enabled healing of the nonunion and improved quality of life in about 80% of patients. Aseptic nonunions were much more likely to unite than septic ones. The number of previous failed operations significantly delayed the time to union.

Interactions between MSCs and immune cells: implications for bone healing

It is estimated that, of the 7.9 million fractures sustained in the United States each year, 5% to 20% result in delayed or impaired healing requiring therapeutic intervention. Following fracture injury, there is an initial inflammatory response that plays a crucial role in bone healing; however, prolonged inflammation is inhibitory for fracture repair. The precise spatial and temporal impact of immune cells and their cytokines on fracture healing remains obscure. Some cytokines are reported to be proosteogenic while others inhibit bone healing. Cell-based therapy utilizing mesenchymal stromal cells (MSCs) is an attractive option for augmenting the fracture repair process. Osteoprogenitor MSCs not only differentiate into bone, but they also exert modulatory effects on immune cells via a variety of mechanisms. In this paper, we review the current literature on both in vitro and in vivo studies on the role of the immune system in fracture repair, the use of MSCs in the enhancement of fracture healing, and interactions between MSCs and immune cells. Insight into this paradigm can provide valuable clues in identifying cellular and noncellular targets that can potentially be modulated to enhance both natural bone healing and bone repair augmented by the exogenous addition of MSCs.

Long-term functional outcome and quality of life after successful surgical treatment of tibial nonunions

PURPOSE

Our aim was to evaluate quality of life (QoL) and functional outcome of patients with tibial nonunions after completion of surgical treatment with an average follow-up of five years.

METHODS

The following data of 64 patients were retrospectively evaluated: fracture type, type and duration of surgical therapy, range of motion of the knee and ankle and American Orthopaedic Foot and Ankle Society (AOFAS) score. QoL was evaluated with the Short-Form Health Survey (SF-36) questionnaire; pain intensity, patient satisfaction and impairments of daily, professional and sport activities with a ten point visual analogue scale.

RESULTS

QoL, even in cases with successfully completed treatment, was significantly reduced compared with the normal general population. Pain intensity and limited ankle dorsal extension, despite the absence of intra-articular fractures, were significantly correlated with inferior QoL.

CONCLUSIONS

This study emphasises the long-term negative impact of tibial nonunions on patient QoL, even after successful surgical treatment.

Terminally differentiated CD8⁺ T cells negatively affect bone regeneration in humans

There is growing evidence that adaptive immunity contributes to endogenous regeneration processes: For example, endogenous bone fracture repair is modulated by T cells even in the absence of infection. Because delayed or incomplete fracture healing is associated with poor long-term outcomes and high socioeconomic costs, we investigated the relationship between an individual's immune reactivity and healing outcome. Our study revealed that delayed fracture healing significantly correlated with enhanced levels of terminally differentiated CD8(+) effector memory T (TEMRA) cells (CD3(+)CD8(+)CD11a(++)CD28(-)CD57(+) T cells) in peripheral blood. This difference was long lasting, reflecting rather the individual's immune profile in response to lifelong antigen exposure than a post-fracture reaction. Moreover, CD8(+) TEMRA cells were enriched in fracture hematoma; these cells were the major producers of interferon-γ/tumor necrosis factor-α, which inhibit osteogenic differentiation and survival of human mesenchymal stromal cells. Accordingly, depletion of CD8(+) T cells in a mouse osteotomy model resulted in enhanced endogenous fracture regeneration, whereas a transfer of CD8(+) T cells impaired the healing process. Our data demonstrate the high impact of the individual adaptive immune profile on endogenous bone regeneration. Quantification of CD8(+) TEMRA cells represents a potential marker for the prognosis of the healing outcome and opens new opportunities for early and targeted intervention strategies.