Effect of Smoking on the Healing of Tibial Shaft Fractures in a Rural Indian Population

Background

Tibial shaft fractures account for 17% of all lower limb fractures. Nonunion and infection rates are estimated to be between 2% and 10%. Bone healing is a complex process that is influenced by biological, mechanical, and systemic factors. Adverse smoking effects on cardiovascular and respiratory systems have been well documented. An increasing interest in the effect of smoking on fracture healing following trauma has been noted in recent years. The biological consequence of smoking is relevant, especially in trauma surgery where no way of preventing presurgical smoking has been noted, hence increasing the patient’s risk of nonunion. Cigarette smoking has been shown to impair fracture union and wound healing and lead to an increased risk of fracture site infection. Smoking and high-energy trauma are considered important risk factors for the delayed union of tibial shaft fractures.

Objectives

This study aims to assess the adverse effects of smoking in patients with tibial shaft fractures following trauma and fracture fixation.

Materials and methods

A retrospective cohort study was done on 110 (55 smokers and 55 nonsmokers) patients treated with intramedullary nailing or plating for tibial shaft fractures between July 2017 and January 2021 in the hospital of the current study. Fracture healing was assessed at the end of months 1, 3, and 6 and year 1.

Results

The mean time of healing in smokers was >48 weeks, whereas the average time to union was 24 weeks in nonsmokers. The majority (54.6%) of smokers took >48 weeks to heal, whereas 81.8% of patients in the nonsmoking group took 24-28 weeks to heal.

Conclusion

Similar to the results obtained in previous studies, our study showed that smoking hinders fracture healing after surgical fixation, and smokers have a higher chance of developing surgical site infection and osteomyelitis. Smokers take a longer time for radiological union and also have a high chance of delayed union and nonunion when compared with nonsmokers, which was shown in our study and is consistent with the results obtained in previous studies. Postoperative smoking cessation is as important as preoperative smoking cessation, and patients should be strictly counseled regarding the same.

Smoking and the patient with a complex lower limb injury

Smoking is known to increase the risk of peri-operative complications in Orthoplastic surgery by impairing bone and wound healing. The effects of nicotine replacement therapies (NRTs) and electronic cigarettes (e-cigarettes) has been less well established. Previous reviews have examined the relationship between smoking and bone and wound healing separately. This review provides surgeons with a comprehensive and contemporaneous account of how smoking in all forms interacts with all aspects of complex lower limb trauma. We provide a guide for surgeons to refer to during the consent process to enable them to tailor information towards smokers in such a way that the patient may understand the risks involved with their surgical treatment. We update the literature with recently discovered methods of monitoring and treating the troublesome complications that occur more commonly in smokers effected by trauma.

Time Course of Immune Response and Immunomodulation During Normal and Delayed Healing of Musculoskeletal Wounds

Single trauma injuries or isolated fractures are often manageable and generally heal without complications. In contrast, high-energy trauma results in multi/poly-trauma injury patterns presenting imbalanced pro- and anti- inflammatory responses often leading to immune dysfunction. These injuries often exhibit delayed healing, leading to fibrosis of injury sites and delayed healing of fractures depending on the intensity of the compounding traumas. Immune dysfunction is accompanied by a temporal shift in the innate and adaptive immune cells distribution, triggered by the overwhelming release of an arsenal of inflammatory mediators such as complements, cytokines and damage associated molecular patterns (DAMPs) from necrotic cells. Recent studies have implicated this dysregulated inflammation in the poor prognosis of polytraumatic injuries, however, interventions focusing on immunomodulating inflammatory cellular composition and activation, if administered incorrectly, can result in immune suppression and unintended outcomes. Immunomodulation therapy is promising but should be conducted with consideration for the spatial and temporal distribution of the immune cells during impaired healing. This review describes the current state of knowledge in the spatiotemporal distribution patterns of immune cells at various stages during musculoskeletal wound healing, with a focus on recent advances in the field of Osteoimmunology, a study of the interface between the immune and skeletal systems, in long bone fractures. The goals of this review are to (1) discuss wound and fracture healing processes of normal and delayed healing in skeletal muscles and long bones; (2) provide a balanced perspective on temporal distributions of immune cells and skeletal cells during healing; and (3) highlight recent therapeutic interventions used to improve fracture healing. This review is intended to promote an understanding of the importance of inflammation during normal and delayed wound and fracture healing. Knowledge gained will be instrumental in developing novel immunomodulatory approaches for impaired healing.

Orthobiologics for Bone Healing

Orthobiologics are a group of biological materials and substrates that promote bone, ligament, muscle, and tendon healing. These substances include bone autograft, bone allograft, demineralized bone matrix, bone graft substitutes, bone marrow aspirate concentrate, platelet-rich plasma, bone morphogenetic proteins, platelet-derived growth factor, parathyroid hormone, and vitamin D and calcium. Properties of orthobiologics in bone healing include osteoconduction, osteoinduction, and osteogenesis. This article discusses the important properties of orthobiologics in bone healing, many of the orthobiologics currently available for bone healing, the related literature, their current clinical uses in sports medicine, and systemic factors that inhibit bone healing.

Open Ankle Arthrodesis

First described in 1879, ankle arthrodesis is a procedure that has undergone significant advancements not only in technique but also in technology and fixation. Surgeon preference has often dictated those changes with regard to incisional approaches, fixation methods, and use of bone graft and biologics but one constant has always remained: open ankle arthrodesis is a predictable, time-tested procedure with consistent results when performed in appropriate patients. This article highlights the changes that have occurred since the introduction of this procedure and provides a brief overview of the preferred technique.

Gene markers of fracture healing in early stage and the regulatory mechanism during the process using microarray analysis

BACKGROUND

The aim of this study was to explore crucial markers and uncover the regulatory mechanisms of fracture healing in the early stage.

METHODS

Gene expression profile of GSE45156 was downloaded, in which 3 fractured samples and 3 unfractured samples were used in our present study. Based on the threshold value, differentially expressed genes (DEGs) were selected between two kinds of samples using limma package in R. Enrichment analysis of these DEGs was performed by DAVID software. Furthermore, protein-protein interaction (PPI) network was established integrating information in STRING database, and visualized by Cytoscape software.

RESULTS

We identified a set of 960 DEGs including 509 up-regulated and 451 downregulated genes. Biological processes involving RNA splicing and cell cycle were significantly enriched for the up-regulated genes such as Snrpd2, Eftud2, Plk1 and Bub1b, whereas skeletal system development and bone development processes were predominant for down-regulated genes like Ubc. In the constructed PPI network, all the five genes were the predominant nodes, of which Snrpd2 was linked to Eftud2, while Bub1b was to interact with Plk1.

CONCLUSION

Five candidate genes crucial for indicating the process of fracture in early stage were identified. Eftud2, Snrpd2, Bub1b and Plk1 might function through the involvement of cell-cycle-related BP, while Ubc might influence the protein degradation during bone development. However, more experimental validations are needed to confirm these results.

Do smokers have greater risk of delayed and non-union after fracture, osteotomy and arthrodesis? A systematic review with meta-analysis

OBJECTIVES

Systematic review and meta-analysis of published observational cohort studies. To quantify the increased risk smokers have of experiencing a delayed and/or non-union in fractures, spinal fusion, osteotomy, arthrodesis or established non-unions.

SETTING

Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), Allied and Complementary Medicine Database (AMED) and Web of Science Core Collection from 1966 to 2015.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS

Observational cohort studies that reported adult smokers and non-smokers with delayed and/or non-union or time to union of the fracture, spinal fusion, osteotomy, arthrodesis or established non-union were eligible.

DATA EXTRACTION AND OUTCOME MEASURES

2 authors screen titles, abstracts and full papers. Data were extracted by 1 author and checked independently by a second. The relative risk ratios of smoking versus non-smoking and the mean difference in time to union patients developing a delayed and/or non-union were calculated.

RESULTS

The search identified 3013 articles; of which, 40 studies were included. The meta-analysis of 7516 procedures revealed that smoking is linked to an increased risk of delayed and/or non-union. When considered collectively, smokers have 2.2 (1.9 to 2.6) times the risk of experiencing delayed and/or non-union. In all the subgroups, the increased risk was always ≥1.6 times that of non-smokers. In the patients where union did occur, it was a longer process in the smokers. The data from 923 procedures were included and revealed an increase in time to union of 27.7 days (14.2 to 41.3).

CONCLUSIONS

Smokers have twice the risk of experiencing a non-union after fracture, spinal fusion, osteotomy, arthrodesis or treatment of non-union. Time to union following fracture, osteotomy, arthrodesis or treatment of an established non-union is longer in smokers. Smokers should be encouraged to abstain from smoking to improve the outcome of these orthopaedic treatments.