The Treatment of Acute Diaphyseal Long-bones Fractures with Orthobiologics and Pharmacological Interventions for Bone Healing Enhancement: A Systematic Review of Clinical Evidence

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.

Effect of Hydroxyapatite/β-Tricalcium Phosphate on Osseointegration after Implantation into Mouse Maxilla

In our previous study we established an animal model for immediately placed implants using mice and clarified that there were no significant differences in the chronological healing process at the bone-implant interface between immediately and delayed placed implants blasted with hydroxyapatite (HA)/β-tricalcium phosphate (β-TCP) (ratio 1:4). This study aimed to analyze the effects of HA/β-TCP on osseointegration at the bone-implant interface after immediately placed implants in the maxillae of 4-week-old mice. Right maxillary first molars were extracted and cavities were prepared with a drill and titanium implants, blasted with or without HA/β-TCP, were placed. The fixation was followed-up at 1, 5, 7, 14, and 28 days after implantation, and the decalcified samples were embedded in paraffin and prepared sections were processed for immunohistochemistry using anti-osteopontin (OPN) and Ki67 antibodies, and tartrate-resistant acid phosphatase histochemistry. The undecalcified sample elements were quantitatively analyzed by an electron probe microanalyzer. Bone formation occurred on the preexisting bone surface (indirect osteogenesis) and on the implant surface (direct osteogenesis), indicating that osseointegration was achieved until 4 weeks post-operation in both of the groups. In the non-blasted group, the OPN immunoreactivity at the bone-implant interface was significantly decreased compared with the blasted group at week 2 and 4, as well as the rate of direct osteogenesis at week 4. These results suggest that the lack of HA/β-TCP on the implant surface affects the OPN immunoreactivity on the bone-implant interface, resulting in decreased direct osteogenesis following immediately placed titanium implants.

Acetabular Revision Surgery with Tantalum Trabecular Metal Acetabular Cup for Failed Acetabular Cage Reconstruction with Bone Allografts: A Retrospective Study with Mid- to Long-Term Follow-Up

Background: Acetabular cage reconstruction with bone allografts is among the successful strategies to deal with massive acetabular bone loss. However, the nonbiological fixation nature of cages can compromise long-term success. Tantalum trabecular metal acetabular cups (TM cups) have been used in acetabular revision surgery because of their increased initial stability and good bone ingrowth features. This study was performed to determine whether the bone stock of the acetabulum is enough to support a hemispheric TM cup after failed cage reconstruction with bone allografts. Methods: We retrospectively reviewed patients who received acetabular revision surgery with TM cups after failed cage reconstruction with bone allografts from 2006 to 2017. There were 12 patients (5 males and 7 females) included in this study, with a mean age of 61.5 years (38 to 81) at the time of re-revision surgery. The mean follow-up after re-revision surgery was 8.6 years (2.6 to 13.3). The endpoint was defined as the aseptic loosening of the TM cup and reoperation for any causes. The change in bone stock of the acetabulum between index revision and re-revision was assessed according to the Gross classification for acetabular bone loss. Results: One patient died after eight years of follow-up of a cause not related to hip surgery. Two patients received two-stage revision arthroplasty due to PJI after 3.2 and 9.4 years of follow-up, respectively. The bone stock of the acetabulum was significantly improved between index revision and re-revision surgery (p < 0.0001). The Kaplan−Meier survivorship was 100% with aseptic loosening as the endpoint and 90% and 75% at five- and ten-year follow-up, respectively, with reoperation for any reason as the endpoint. Even cage reconstruction with bone allografts will fail eventually, and the bone stock of the acetabulum will improve after union and incorporation between host bone and allografts. The restored bone stocks will facilitate further revision surgery with hemispheric TM cups. The biological fixation between host bone and tantalum trabecular metal can provide longstanding stability of the TM cup. Conclusions: The results of our study offer a viable option for patients with failed cage reconstruction with bone allografts.

Radiographic outcomes of the treatment of complex femoral shaft fractures (AO/OTA 32-C) with intramedullary nailing: a retrospective analysis of different techniques

OBJECTIVES

To assess the results of open versus closed reduction in intramedullary nailing (IMN) for complex femoral fractures (Arbeitsgemeinschaft für Osteosynthesefragen Foundation/Orthopaedic Trauma Association [AO/OTA]: 32-C) and to determine the factors involved in bone healing.

METHODS

This retrospective study involved 47 consecutive patients with complex femoral diaphyseal fractures who underwent reduction and fixation.

RESULTS

All open-reduction and 12 closed-reduction patients (52.17%) had an anatomical-to-small gap. The closed-small group had the highest bone union rate (100%), followed by the open-reduction (79.17%) and closed-large groups (72.73%); intergroup differences were significant. The closed-small group had the shortest mean union time (7.31 months), followed by the open-reduction group (7.58 months). The closed-large group had a significantly longer union time (9.75 months) than those in the closed-small and open-reduction groups. Femoral radiographic union scores in the closed-small and open-reduction groups were similar at three timepoints; scores were higher than those in the closed-large group, with a significant difference 6 and 9 months post-operatively.

CONCLUSION

IMN with closed reduction for complex femoral shaft fractures had better outcomes and fewer complications versus open reduction. For unsatisfactory closed reduction outcomes (i.e., residual gap >10 mm), minimally invasive techniques or open reduction with minimal stripping should be considered.

Effect of magnesium oxide nanoparticles, hydroxyapatite and hydrogel on regeneration of transverse fracture of distal radius

Study's purpose of this study is to conduct synthesis and evaluate the effect of hydroxyapatite (HA) with hydrogel locally magnesium oxide nanoparticles (MgONPS) locally or intraperitoneally (IP) on the healing of the distal third radial fracture. Concentrations of MgONPs 200μg/ml, dissolved in 1 cc distilled water and the solution stirred by a stirrer for 10 min. HA 0.5 mg in 1ml hydrogel and the solution stirring at the vortex for 15 min. These materials were evaluated in vitro to ensure their suitability with the tissues. Seventy-five healthy adult male rabbits, aged about 1.5- 2 years old with average weighting  1.7- 2.3 Kg. B.W were used. Rabbits were divided into three groups randomly (n=25), group A (HA mixed hydrogel applied locally), group B (HA mixed with hydrogel and MgONPs applied locally) and group C (HA mixed hydrogel applied locally and MgONPs IP). Animals were anesthetized by i.m 40 mg/ kg B.W ketamine hydrochloride and 5mg/ kg B.W xylazine. A 5cm incision had made cranio-medially in the skin of the forelimb (right forelimb) and exposure radius and ulna. The macroscopic evaluation revealed that all groups at 2nd week showed bone reaction in different degrees.

Low-Intensity Pulsed Ultrasound in the Treatment of Nonunions and Fresh Fractures: A Case Series

It is estimated that approximately 5% to 10% of fractures will evolve into nonunions. Nonunions have a significant impact on patient quality of life and on socioeconomic costs. Low-intensity pulsed ultrasound (LIPUS) is a non-invasive therapy widely used within the orthopedic community to accelerate the healing of fresh fractures, to minimize delayed healing, and to promote healing of nonunions. In this case series, 46 nonunions and 19 fresh fractures were treated with LIPUS for at least three months or until fracture healing. Bone healing was assessed both at a radiological and a functional level. Of the nonunions healed, 89% had a mean healing time of 89 ± 53 days. In the group of fresh fractures, the healing percentage was 95% with a mean healing time of 46 ± 28 days. LIPUS treatment is proven to be safe and well tolerated; there were no adverse events related to the use of the device, even in the presence of internal fixations and infections. LIPUS therapy should be considered a low-risk option both as an adjunct to surgery or as a standalone therapy in the management of nonunion and fresh fractures.

Factors Contributing to Residual Low Back Pain after Osteoporotic Vertebral Fractures

Although osteoporotic vertebral fractures (OVFs) are the most common type of osteoporotic fracture, few reports have investigated the factors contributing to residual low back pain in the chronic phase after OVFs by using radiographic evaluation. We examined the contribution of nonunion, vertebral deformity, and thoracolumbar alignment to the severity of residual low back pain post-OVF. This post hoc analysis of a prospective randomized study included 195 patients with a 48-week follow-up period. We investigated the associations between radiographic variables with the visual analog scale (VAS) scores for low back pain at 48 weeks post-OVF using a multiple linear regression model. Univariate analysis revealed that analgesic use, the local angle on magnetic resonance imaging, anterior vertebral body compression percentage on X-ray, and nonunion showed a significant association with VAS scores for low back pain. Multiple regression analysis produced the following equation: VAS for low back pain at 48 weeks = 15.49 + 0.29 × VAS for low back pain at 0 weeks + (with analgesics: +8.84, without analgesics: −8.84) + (union: −5.72, nonunion: −5.72). Among local alignment, thoracolumbar alignment, and nonunion, nonunion independently contributed to residual low back pain at 48 weeks post-OVF. A treatment strategy that reduces the occurrence of nonunion is desirable.

Is a Patient with Paget's Disease of Bone Suitable for Living Kidney Donation?-Decision-Making in Lack of Clinical Evidence

Living donor kidney transplantation is a widely performed medical procedure. Living kidney donation requires an in-depth health assessment of candidates. The potential living kidney donor must remain healthy after kidney removal. A consequence of donation can be a decrease in glomerular filtration rate (GFR), and donors can become at risk of developing chronic kidney disease (CKD). We present a rationale for potential living kidney donor withdrawal due to Paget's disease of bone (PDB) based on a literature review. The treatment for PDB includes the use of, for example, non-steroidal anti-inflammatory drugs (NSAIDs), which can lead to acute kidney injury (AKI) as well as CKD, or bisphosphonates, which are not recommended for patients with decreased GFR.

Identification of miRNA Regulatory Networks and Candidate Markers for Fracture Healing in Mice

Background

It is important to improve the understanding of the fracture healing process at the molecular levels, then to discover potential miRNA regulatory mechanisms and candidate markers.

Methods

Expression profiles of mRNA and miRNA were obtained from the Gene Expression Omnibus database. We performed differential analysis, enrichment analysis, protein-protein interaction (PPI) network analysis. The miRNA-mRNA network analysis was also performed.

Results

We identified 499 differentially expressed mRNAs (DEmRs) that were upregulated and 534 downregulated DEmRs during fracture healing. They were mainly enriched in collagen fibril organization and immune response. Using the PPI network, we screened 10 hub genes that were upregulated and 10 hub genes downregulated with the largest connectivity. We further constructed the miRNA regulatory network for hub genes and identified 13 differentially expressed miRNAs (DEmiRs) regulators. Cd19 and Col6a1 were identified as key candidate mRNAs with the largest fold change, and their DEmiR regulators were key candidate regulators.

Conclusion

Cd19 and Col6a1 might serve as candidate markers for fracture healing in subsequent studies. Their expression is regulated by miRNAs and is involved in collagen fibril organization and immune responses.

Scope and Limits of Teriparatide Use in Delayed and Nonunions: A Case Series

Nonunion is known to occur in up to 10% of all bone fractures. Until recently, the treatment options considered in cases of delayed union and nonunion focused on revision surgery and improvement of local healing. Lately, teriparatide has been introduced as an osteoanabolic factor that induces fracture healing in cases with delayed or nonunions. We report on a series of five cases of delayed and nonunions treated with teriparatide: delayed unions of an atypical femoral fracture, of a multifragmentary clavicle fracture, and of a periprosthetic humeral fracture; nonunion of a tibial and fibular fracture; and infected nonunion of a tibial and fibular fracture. Based on this series, the indications and limits of application of teriparatide in cases of impaired fracture healing are discussed. Due to the “off-label” character of this application, informed consent, and cost coverage from the healthcare insurance must be obtained prior to treatment. In our experience and according to the limited existing literature, teriparatide is a safe feasible treatment in cases of delayed and nonunions with a reasonable need of resources. While adequate biomechanical stability remains the cornerstone of fracture healing, as well as healing of nonunions, teriparatide could help avoid repetitive surgeries, especially in atrophic delayed and nonunions, as well as in patients with impaired fracture healing undergoing bisphosphonate therapy. There is an urgent need for widely accepted definitions, standardized protocols, as well as further clinical trials in the field of impaired fracture healing.

Cordycepin Alleviates Anterior Cruciate Ligament Transection (ACLT)-Induced Knee Osteoarthritis Through Regulating TGF-β Activity and Autophagy

Introduction

Osteoarthritis is the most prevalent articular disease in the elderly. We aimed to explore the role of cordycepin (COR) in the progression and development of osteoarthritis and its correlation with TGF-β activity and autophagy.

Methods

Sprague Dawley rats were induced by anterior cruciate ligament transection (ACLT) to establish knee osteoarthritis model. To investigate the role of COR in knee osteoarthritis, rats were injected with 5, 10, and 20 mg/kg of COR before joint surgery. After surgery, paw withdrawal mechanical threshold (PWMT) was performed. HE staining and Alcian blue staining were carried out to detect cartilage damage. ELISA was used to detect the level of TGFβ in the serum. Protein expression was analyzed by Western blotting.

Results

In this study, we found that the PWMT of rats with osteoarthritis induced by ACLT was decreased significantly, accompanied by obvious histological and cartilage damage. After different doses of COR treatment, the PWMT of osteoarthritis rats induced by ACLT was increased in a dose-dependent manner. In addition, compared with the control group, COR treatment also reversed the effect of ACLT on cartilage injury in rats. Furthermore, the level of TGF-β in serum of ACLT rats was increased significantly, which may be related to the overexpression of TGF-β R1. However, the increase of serum TGF-β level in ACLT rats was reversed by COR treatment in a dose-dependent manner. It is worth noting that TGF-β overexpression reduced the proportion of autophagy-related protein LC3-II/I, thus inhibiting autophagy. In order to further confirm the effect of TGF-β on autophagy, TGF-β was overexpressed or the autophagy inhibitor 3-MA was applied. The results showed that TGF-β overexpression and 3-MA treatment reversed the effect of COR on autophagy.

Conclusion

In summary, our findings declared that COR alleviated ACLT-induced osteoarthritis pain and cartilage damage by inhibiting TGF-β activity and inducing autophagy in rat model with knee osteoarthritis.