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

Smoking Impairs Hematoma Formation and Dysregulates Angiogenesis as the First Steps of Fracture Healing

Bone fracture healing is an overly complex process in which inflammation, osteogenesis, and angiogenesis are tightly coupled, and delayed fracture repair is a very common health risk. One of the major causes of delayed healing is the formation of insufficient vasculature. Precise regulation of blood vessels in bone and their interplay with especially osteogenic processes has become an emerging topic within the last years; nevertheless, regulation of angiogenesis in (early) diseased fracture repair is still widely unknown. Here, we aim to develop an in vitro model for the analysis of early fracture healing which also enables the analysis of angiogenesis as a main influencing factor. As smoking is one of the main risk factors for bone fractures and developing a delay in healing, we model smoking and non-smoking conditions in vitro to analyze diverging reactions. Human in vitro fracture hematomas mimicking smokers' and non-smokers' hematomas were produced and analyzed regarding cell viability, inflammation, osteogenic and chondrogenic differentiation, and angiogenic potential. We could show that smokers' blood hematomas were viable and comparable to non-smokers. Smokers' hematomas showed an increase in inflammation and a decrease in osteogenic and chondrogenic differentiation potential. When analyzing angiogenesis, we could show that the smokers' hematomas secrete factors that drastically reduced HUVEC proliferation and tube formation. With an angiogenesis array and gene expression analysis, we could identify the main influencing factors: Anpgt1/2, Tie2, and VEGFR2/3. In conclusion, our model is suitable to mimic smoking conditions in vitro showing that smoking negatively impacts early vascularization of newly formed tissue.

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.

Tobacco smoking is associated with more pain and worse functional outcomes after torsional ankle fracture

OBJECTIVE

The purpose of this study was to assess the impact of current and remote tobacco smoking on clinical and functional outcomes after torsional ankle fracture.

METHODS

Nine hundred thirty-five patients treated surgically for torsional ankle fracture over 9 years were reviewed. Tobacco smoking status at the time of injury was defined as current (48.3%), former (11.7%), and nonsmoker (40.0%). Complications, unplanned secondary procedures, pain medication use, and functional outcome scores, as measured by Foot Function Index and Short Musculoskeletal Function Assessment (SMFA) surveys.

RESULTS

Mean age was 44.8 years, with 50.3% male. More than 6 months following injury current smokers were more likely than former smokers and nonsmokers to report ankle pain (67.8% vs 45.8% vs 47.5%) and to use prescription pain medicines (23.0% vs 10.4% vs 6.3%), all P < .05. Multiple logistic regression found current tobacco use to be an independent predictor for prescription pain medication use, and worse scores for the Foot Function Index, SMFA Dysfunction, and SMFA Bothersome scores, all P < .05. Complications occurred in 15.5% of all patients, and 10.7% underwent unplanned secondary operations. Tobacco smoking was not associated with more complications or secondary procedures.

CONCLUSION

Current smokers are more likely to use prescription pain medications several months after injury and have worse patient-reported functional outcome scores after surgical treatment of torsional ankle fractures than former smokers and nonsmokers.

Anterior screw fixation for type II odontoid process fractures: A single-center experience with the double Herbert screw fixation technique (Retrospective cohort study)

Background

Methods

Results

Conclusions

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Type II odontoid fractures with intact transverse ligament is challenging for anterior cervical surgery.

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Double screw technique in anterior odontoid surgery using a headless 3.0-mm.-diameter cannulated Herbert screw on patients with odontoid process fractures.

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This study of satisfactory clinical results demonstrates that double anterior screw fixation of type II odontoid process fractures using 3.0-mm screws is highly effective.

Smoking and degenerative spinal disease: A systematic review

Smoking is a major cause of morbidity and mortality worldwide and is responsible for the death of more than 8 million people per year globally. Through a systematic literature review, we aim to review the harmful effects of tobacco smoking on degenerative spinal diseases (DSD). DSD is a debilitating disease and there is a need to identify if smoking can be an attributable contender for the occurrence of this disease, as it can open up avenues for therapeutic options. Sources such as PubMed and Embase were used to review literature, maintaining tobacco smoking and spinal diseases as inclusion factors, excluding any article that did not explore this relationship. Risk of bias was assessed using analysis of results, sample size and methods and limitations. Upon review of the literature, tobacco smoking was found to be a major risk factor for the occurrence of DSDs, particularly lumbar spinal diseases. Smokers also experienced a greater need for surgery and greater postoperative wound healing complications, increased pain perception, delay in recovery and decreased satisfaction after receiving surgery. These effects were noted along the entire spine. Many mechanisms of action have been identified in the literature that provide plausible pictures of how smoking leads to spinal degeneration, exploring possible primary targets which can open up opportunities to develop potential therapeutic agents. More studies on cervical and thoracic spinal degeneration would be beneficial in identifying the effect of nicotine on these spinal levels. Some limitations included insufficient sample size, inconclusive evidence and lack of sufficient repeat studies. However, there appears to be a sufficient amount of research on smoking directly contributing to lumbar spinal pathology.

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Smoking is a risk factor for the occurence of degenerative spinal disease (DSD).

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There are numerous pathological mechanisms attributed to spinal pathology by smoking.

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Smoking appears to be a significant risk factor for lumbar DSDs, with smoke studies also suggesting its role in cervical DSDs.

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There is insufficient research on the effect of smoking on the thoracic spine.

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Smoking leads to worse outcomes and potential complications post-surgery, as well as increased pain perception and poorer subjective response post-surgery.

Smoking and Dental Implants: A Systematic Review and Meta-Analysis

Background and Objectives: Tobacco is today the single most preventable cause of death, being associated with countless diseases, including cancer and neurological, cardiovascular, and respiratory diseases. Smoking also brings negative consequences to oral health, potentially impairing treatment with dental implants. The present review aimed to evaluate the influence of smoking on dental implant failure rates and marginal bone loss (MBL). Materials and Methods: Electronic search was undertaken in three databases, plus a manual search of journals. Meta-analyses were performed, in addition to meta-regressions, in order to verify how the odds ratio (OR) and MBL were associated with follow-up time. Results: The review included 292 publications. Altogether, there were 35,511 and 114,597 implants placed in smokers and in non-smokers, respectively. Pairwise meta-analysis showed that implants in smokers had a higher failure risk in comparison with non-smokers (OR 2.402, p < 0.001). The difference in implant failure between the groups was statistically significant in the maxilla (OR 2.910, p < 0.001), as well as in the mandible (OR 2.866, p < 0.001). The MBL mean difference (MD) between the groups was 0.580 mm (p < 0.001). There was an estimated decrease of 0.001 in OR (p = 0.566) and increase of 0.004 mm (p = 0.279) in the MBL MD between groups for every additional month of follow-up, although without statistical significance. Therefore, there was no clear influence of the follow-up on the effect size (OR) and on MBL MD between groups. Conclusions: Implants placed in smokers present a 140.2% higher risk of failure than implants placed in non-smokers.

Fracture, nonunion and postoperative infection risk in the smoking orthopaedic patient: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to analyse negative effects of smoking in orthopaedic and trauma patients.

A PubMed search was carried out for studies published until July 2020 regarding effects of smoking on fracture risk, nonunion, infection after orthopaedic surgery, and persisting nonunion after scaphoid nonunion surgery. Random effects models calculated for outcome parameters, and relative risks (RR) with 95% confidence intervals are provided. No adjustments for covariates were made. Heterogeneity was assessed with Higgins’ I2, publication bias with Harbord’s p (Hp), sensitivity analysis performed on funnel plots and quality of studies was analysed using the Newcastle-Ottawa Scale.

Of 3362 retrieved entries, 69 were included in the final analysis. Unadjusted RR for smokers to develop vertebral (six studies, seven entries; RR: 1.61; p = 0.008; I2 = 89.4%), hip (11 studies, 15 entries; RR: 1.28; p = 0.007; I2 = 84.1%), and other fractures (eight studies, 10 entries; RR: 1.75; p = 0.019; I2 = 89.3%) was significantly higher. Postoperative infection risk was generally higher for smokers (21 studies; RR: 2.20; p < 0.001; I2 = 58.9%), and remained upon subgroup analysis for elective spinal (two studies; RR: 4.38; p < 0.001; I2 = 0.0%) and fracture surgery (19 studies; RR: 2.10; p < 0.001; I2 = 58.5%). Nonunion risk after orthopaedic (eight studies; RR: 2.15; p < 0.001; I2 = 35.9%) and fracture surgery (11 studies; RR: 1.85; p < 0.001; I2 = 39.9%) was significantly higher for smokers, as was persisting nonunion risk after surgery for scaphoid nonunion (five studies; RR: 3.52; p < 0.001; I2 = 0.0%). Sensitivity analysis for each model reduced heterogeneity whilst maintaining significance (all I2 < 20.0%).

Smoking has a deleterious impact on fracture incidence, and (subsequent) development of nonunions and postoperative infections.

Cite this article: EFORT Open Rev 2021;6:1006-1019. DOI: 10.1302/2058-5241.6.210058

Risk Factors for Distal Radius Osteotomy Nonunion

BACKGROUND

Osteotomy-site nonunion after distal radius corrective osteotomy is a detrimental complication. This retrospective study aims to identify patient and surgical factors associated with nonunion risk to help mitigate this. The authors hypothesize that patient factors and potentially modifiable surgical factors are contributory.

METHODS

Thirty-three patients who underwent corrective osteotomy of the distal radius for prior fracture malunion were identified. Radiographs and patient records were reviewed for demographics, comorbidities, nutritional status, plate position, angle and length of osteotomy correction, and graft used. The primary study outcome was osteotomy nonunion. Descriptive and bivariate statistics were used to identify covariates relevant to nonunion. Backward, stepwise logistic regression was applied to investigate the multivariate effects on outcome, and regression analysis was adjusted for confounders.

RESULTS

Seven patients (21 percent) experienced nonunion after initial corrective osteotomy. Risk factors associated with nonunion included correction length of osteotomy of 5 mm or greater and prior treatment with open reduction and internal fixation. Autograft use was protective against nonunion. History of osteoporosis showed a trend toward increased risk. Angle of osteotomy correction, nutritional deficit, age, diabetes, smoking status, and obesity were not identified as risk factors by the multivariate model.

CONCLUSIONS

Distraction length at the osteotomy site, graft selection, and prior internal fixation were significant risk factors for distal radius osteotomy nonunion, but other factors traditionally associated with nonunion did not appear to impact risk. The authors recommend using autograft bone augmentation, particularly when distracting the osteotomy beyond 5 mm or after prior internal fixation.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Increased bone resorption by long-term cigarette smoke exposure in animal model

INTRODUCTION

Clinical and experimental studies have been attesting the deleterious effects of smoking mainly due to the stimulation of osteoclastogenesis and inhibition of osteoblastogenesis. However the physiological mechanisms that can explain these changes are not fully understood.

AIMS

To evaluate the trabecular bone resorption effect caused by long-term exposure to cigarette smoke and the action of cytokines and reactive oxygen species involved in this process.

METHODS

Sixty young adult C57BL/6 mice were allocated to two groups: control, 30 animals exposed to filtered air for 1, 3 and 6 months; and smoke, 30 animals exposed to cigarette smoke for 1, 3 and 6 months. Femoral and tibial extraction was performed to evaluate the bone mineral matrix, bone cytokines (Receptor activator of nuclear factor-kappa B ligand - RANKL and Osteoprotegerin - OPG) and oxidative stress markers (Thiobarbituric acid reactive substances - Tbars).

RESULTS

Exposure to cigarette smoke (CS) generated changes in bone structural parameters in the 6th month of follow-up, demonstrating an evident bone loss; reduction in OPG/RANKL ratio from the 3rd month on and increase in Tbars in the first month, both closely related to the increase in osteoclastogenic activity and bone resorption.

CONCLUSION

These findings reinforce the importance of CS-induced oxidative stress in bone compromising the bone cellular activities with a consequent impairment in bone turn over and changes in bone structure.

The influence of smoking and alcohol on bone healing: Systematic review and meta-analysis of non-pathological fractures

BACKGROUND

We aimed to comprehensively evaluate the associations between (i) smoking, (ii) preoperative smoking cessation time, (iii) nicotine replacement therapy (NRT), (iv) vaping, and (v) alcohol consumption and non-pathological fracture healing in adult patients. We also assessed the impacts of preoperative smoking cessation time, NRT, and vaping on wound healing and wound complications after any sort of surgery.

METHODS

We searched the MEDLINE, Embase, Cochrane CENTRAL, CINAHL, and AMED electronic databases from their inceptions until August 9th, 2021. Primary outcomes included delayed union rate, nonunion rate, and time to union. A random effects model was used. (Protocol registration: PROSPERO-CRD42019131454).

FINDINGS

One hundred and twenty-two studies with 417,767 patients were eligible for the systematic review and 71 of the studies with 39,920 patients were eligible for the meta-analysis. After non-pathological fracture treatment, the nonunion rate was significantly greater in the smoker group than in the non-smoker group (odds ratio [OR], 2·50, 95% confidence interval [1·73-3·61]); additionally, there was no significant difference in the nonunion rate (OR, 0·97 [0·40-2·38]) between the alcohol drinker group and the non-drinker group. The rate of wound infection after surgery was significantly reduced in the smoking cessation group (≥four weeks before surgery) compared to the continuous smoker group (OR, 0·37 [0·16-0·89]).

INTERPRETATION

Smoking is associated with higher rates of nonunion and deep surgical site infection after non-pathological fracture treatment. Smoking cessation (≥four weeks before surgery) is associated with a decreased rate of postoperative wound infection.

FUNDING

The China Scholarship Council (no. 201809120013).

Implant failure after externally magnetic-controlled nail lengthening

The number of intramedullary procedures to treat leg length discrepancy (LLD) has risen in the past decade and this has led to increased complications such as nail breakage. The aim of this study was to reveal our experience with implant failure after externally magnetic-controlled telescopic bone lengthening. We observed nail-breakage in 4 out of 24 patients (16.7%) after 6 to 15 months (median 13.5 months) following lower limb lengthening for LLD due to non-union or insufficient bone healing. Three femora and one tibia were treated in one posttraumatic and three congenital cases. Three out of the four patients had an elevated Charleston Comorbidity Index (CCI). Revision surgery involved removal of the broken nail and implantation of a trauma nail. At final follow-up all patients showed subjective satisfaction, achievement of desired lengthening with complete bone healing. Based on our results no unequivocal risk factor including number of previous surgeries, comorbidities and age was identified. In cases of delayed bone formation, early revision surgery with an exchange to a trauma nail has to be considered to prevent breakage of the intramedullary telescopic device.

The Effect of Waterpipe Tobacco Smoking on Bone Healing Following Femoral Fractures in Male Rats

Background: Given the increasing use of waterpipe tobacco smoking in the world and its unknown effects on bone healing, this study investigated the repairing of femoral bone fractures in rats exposed to waterpipe tobacco smoking (WTS).

Main Methods: This study involved 40 male Wistar rats that were divided into two groups, including the femoral fracture (Fx) and the Fx + WTS groups. Each group was divided into two subgroups that were evaluated for bone healing 28 and 42 days after femoral fracture. After fixing the fractured femur, the healing process was evaluated by radiography, pathological indicators, and a measurement of the blood levels of vascular endothelial growth factor (VEGF), parathyroid hormone (PTH), Ca ++, transforming growth factor-beta (TGF-β), and insulin-like growth factor 1 (IGF-1). Additionally, the density of VEGF and CD34 in fracture tissue was investigated by immunohistochemistry.

Key Findings: Radiographic findings showed that factors related to the earlier stages of bone healing had higher scores in the Fx + WTS28 and 42 subgroups in comparison to the Fx groups. The density of VEGF and CD34 showed that the angiogenesis processes were different in the bone fracture area and callus tissue in the Fx +WTS subgroups. The serum levels of VEGF, TGF-β, and IGF-1 were significantly lower in the Fx +WTS42 group, and PTH in the Fx +WTS28 group was higher than that in the other groups.

Significance: The findings showed the disturbance and delay in the femoral fracture union in rats exposed to hookah smoke. This is partly due to the reduction of molecular stimuli of bone synthesis and the attenuation of quantitative angiogenesis.

Different fixation constructs and the risk of non-union following first metatarsophalangeal joint arthrodesis

BACKGROUND

The aim of this study was to determine if a single or separate construct with interfragmentary screw was associated with higher rates non-union following first metatarsophalangeal joint (MTPJ) arthrodesis.

METHODS

A retrospective analysis of patients undergoing first MTPJ arthrodesis between April 2010 and June 2017 was performed. Patients who received either a single (Stryker Anchorage 1 MTP Cross Plate) or separate (Stryker Anchorage 1 MTP locking plate with one Asnis partially threaded compression screw) construct locking plate and interfragmentary compression screw were reviewed. Descriptive statistics were generated for sample demographics and between-group differences were calculated. Multivariable regressions explored internal fixation type and association with non-union.

RESULTS

A total of 280 first MTPJ arthrodesis met the inclusion criteria and were reviewed. The incidence of non-union was 7.9% of procedures (22 joints). Following multivariable binary logistic regression, the single construct locking plate with interfragmentary compression screw was associated with an increased risk of non-union (OR 3.43, 95% CI 1.26-9.33), adjusting for age, gender and comorbidity.

CONCLUSIONS

A single construct interfragmentary screw and locking plate (Stryker Anchorage 1 MTP Cross Plate) was associated with an increased incidence of non-union following first MTPJ arthrodesis.

Delayed Tibial Shaft Fracture Healing Associated with Smoking: A Systematic Review and Meta-Analysis of Observational Studies Conducted Worldwide

Tibial fractures represent a great burden of disease globally, being the most common long-bone fracture; smoking is a known risk factor for delayed skeletal healing and post-fracture complications. This systematic review and meta-analysis aims to analyse the effect of smoking on healing of tibial shaft fractures. PubMed, CINAHL, EMBASE, and Cochrane Library databases were searched from inception to March 2021, with no limitation on language, to find relevant research. All observational studies that assessed the association between cigarette smoking and tibial shaft fracture healing in adults (≥18 years) were included. The quality of studies was evaluated using the Newcastle Ottawa Quality Assessment Scale. A random effects model was used to conduct meta-analysis. Tobacco smoking was associated with an increased rate of non-union and delayed union as well as an increase in time to union in fractures of the tibial shaft. Among the 12 included studies, eight reported an increased rate of non-union, three reported delayed union, and five reported an increase in time to union. However, the results were statistically significant in only three studies for non-union, one for delayed union, and two studies for increased time to union. This review confirms the detrimental impact of smoking on tibial shaft fracture healing and highlights the importance of patient education regarding smoking cessation.

Healing the Index Tibial Nonunion: Risk Factors for Development of a Recalcitrant Nonunion in 222 Patients

OBJECTIVES

To compare and stratify the healing rates after our index nonunion surgery using contemporary methods of fixation, report the prevalence of recalcitrant non-union, and identify specific demographic, injury, and treatment-related risk factors for the development of a recalcitrant nonunion.

DESIGN

Retrospective analysis of a prospectively collected database.

SETTING

Academic Level 1 Trauma Center.

PATIENTS/PARTICIPANTS

Two hundred twenty-two tibial nonunions treated with internal fixation by a single surgeon.

INTERVENTION

Bivariate and multivariate regression analysis were performed to compare healing rates by the type of fixation and graft augmentation and to identify specific demographic, injury, and treatment-related risk factors for the development of a recalcitrant nonunion.

RESULTS

Of the 222 patients, 162 (73%) healed as intended and 51 (23%) required 1 or more subsequent interventions to achieve union (96%). Nine fractures (4%) failed to unite. The 60 fractures (27%) that required a subsequent intervention(s) or failed to consolidate were defined as recalcitrant nonunions. There were no statistically significant differences in the recalcitrant rate when we compared plates versus nails or types of bone graft. Risk factors for developing a recalcitrant nonunion were multifactorial and included grade III open fractures, compartment syndrome, deep infection, and 2 or more prior surgical procedures.

CONCLUSIONS

Internal fixation remains a successful method of treatment for most tibial nonunions. However, 27% of patients required a subsequent intervention because of failure to heal our index nonunion procedure. Factors that are associated with recalcitrant nonunions were a grade III open fracture, compartment syndrome, deep infection, and 2 or more or more prior surgical procedures.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Defining the Mean Angle of Diaphyseal Long Bone Nonunions-Does Shear Prevail?

OBJECTIVES

To define the mean angle of a series of diaphyseal nonunions based on radiographic analysis.

DESIGN

A retrospective cohort study.

SETTING

Two level-1 trauma centers.

PATIENTS

One hundred twenty patients presenting with nonunion.

INTERVENTION

A mean nonunion angle was calculated from a series of AP and lateral X-rays using a standardized technique. The nonunion angle was then estimated in a single plane by considering the greater of the 2 measured angles. Additional data collected included patient age, sex, nonunion site, initial fracture angle, and original fracture pattern.

MAIN OUTCOME MEASUREMENT

Single plane nonunion angle.

RESULTS

The mean angles of all nonunion in coronal plane was 42 degrees (SD 17 degrees) and 42 degrees in sagittal plane (SD 18 degrees) and 48 degrees (SD 15 degrees) in single plane. The single plane nonunion angle in fractures which were originally multiplanar was steeper to those occurring in originally single plane fractures (P 0.002) although both were close to 45 degrees. There was no significant difference in the nonunion angles on subgroup analysis of cohort location, sex, or anatomic location.

CONCLUSIONS

This study demonstrates the mean angle of diaphyseal nonunions from long bones of the lower limb approaches 45 degrees. This is noted in all types of fractures and is irrespective of anatomic location or sex. This confirms the hypothesis that shear is likely to play a role in the development of a nonunion. This study provides further evidence that nonunions occur primarily because of mechanical instability.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Single-cell RNA sequencing of intramedullary canal tissue to improve methods for studying fracture repair biology

The ability to study the bone microenvironment of failed fracture healing may lead to biomarkers for fracture nonunion. Herein the authors describe a technique for isolating individual cells suitable for single-cell RNA sequencing analyses from intramedullary canal tissue collected by reaming during surgery. The purpose was to detail challenges and solutions inherent to the collection and processing of intramedullary canal tissue samples. The authors then examined single-cell RNA sequencing data from fresh and reanimated samples to demonstrate the feasibility of this approach for prospective studies.

The Effect of Smoking on the Fusion Rate of Spinal Fusion Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

To conduct a systematic review and meta-analysis comparing the fusion rate after spinal fusion surgery between smokers and nonsmokers.

METHODS

We searched PubMed, Embase, Cochrane Library, and Web of Science electronic databases through March 10, 2021 for cohort and case-control studies assessing the effect of smoking on the fusion rate of spinal fusion surgery. Two researchers independently screened the literature and extracted data according to the inclusion and exclusion criteria. Statistical analysis was performed using RevMan, version 5.4.

RESULTS

A total of 26 studies, including 4 case-control studies and 22 cohort studies, with 4409 patients, were included in the present meta-analysis. Follow-up was at least 6 months. Overall, the pooled results demonstrated that the fusion rate of smokers after spinal fusion was significantly lower than that of nonsmokers. The odds ratio (OR) was 0.55 (95% confidence interval [CI] 0.45-0.67, P < 0.0001). Subgroup analyses by fusion level showed the adverse effect of smoking on the fusion rate at single level (OR 0.61, 95% CI 0.41-0.91, P = 0.02) was more significant than that of multiple levels (OR 0.55, 95% CI 0.38-0.80, P = 0.0010). Subgroup analysis according to the type of bone graft revealed an apparent association between smoking and fusion rate in the autograft subgroup (OR 0.47, 95% CI 0.33-0.66, P < 0.0001) but not in the allograft subgroup (OR 0.69, 95% CI 0.47-1.01, P = 0.06).

CONCLUSIONS

The fusion rate of smokers is significantly lower than that of nonsmokers in spinal fusion surgery. Smokers should be encouraged to quit smoking to improve the outcome of spinal fusion surgery.

Skeletal System Biology and Smoke Damage: From Basic Science to Medical Clinic

Cigarette smoking has a negative impact on the skeletal system, as it reduces bone mass and increases fracture risk through its direct or indirect effects on bone remodeling. Recent evidence demonstrates that smoking causes an imbalance in bone turnover, making bone vulnerable to osteoporosis and fragility fractures. Moreover, cigarette smoking is known to have deleterious effects on fracture healing, as a positive correlation between the daily number of cigarettes smoked and years of exposure has been shown, even though the underlying mechanisms are not fully understood. It is also well known that smoking causes several medical/surgical complications responsible for longer hospital stays and a consequent increase in the consumption of resources. Smoking cessation is, therefore, highly advisable to prevent the onset of bone metabolic disease. However, even with cessation, some of the consequences appear to continue for decades afterwards. Based on this evidence, the aim of our review was to evaluate the impact of smoking on the skeletal system, especially on bone fractures, and to identify the pathophysiological mechanisms responsible for the impairment of fracture healing. Since smoking is a major public health concern, understanding the association between cigarette smoking and the occurrence of bone disease is necessary in order to identify potential new targets for intervention.

Nonunion Rates in Hind- and Midfoot Arthrodesis in Current, Ex-, and Nonsmokers

BACKGROUND

Nonunion rates in hind or midfoot arthrodesis have been reported as high as 41%. The most notable and readily modifiable risk factor that has been identified is smoking. In 2018, 14.4% of the UK population were active smokers. We examined the effect of smoking status on union rates for a large cohort of patients undergoing hind- or midfoot arthrodesis.

METHODS

In total, 381 consecutive primary joint arthrodeses were identified from a single surgeon's logbook (analysis performed on a per joint basis, with a triple fusion reported as 3 separate joints). Patients were divided based on self-reported smoking status. Primary outcome was clinical union. Delayed union, infection, and the need for ultrasound bone stimulation were secondary outcomes.

RESULTS

Smoking prevalence was 14.0%, and 32.2% were ex-smokers. Groups were comparable for sex, diabetes, and body mass index. Smokers were younger and had fewer comorbidities. Nonunion rates were higher in smokers (relative risk, 5.81; 95% CI, 2.54-13.29; P < .001) with no statistically significant difference between ex-smokers and nonsmokers. Smokers had higher rates of infection (P = .05) and bone stimulator use (P < .001). Among smokers, there was a trend toward slower union with heavier smoking (P = .004).

CONCLUSION

This large retrospective cohort study confirmed previous evidence that smoking has a considerable negative effect on union in arthrodesis. The 5.81 relative risk in a modifiable risk factor is extremely high. Arthrodesis surgery should be undertaken with extreme caution in smokers. Our study shows that after cessation of smoking, the risk returns to normal, but we were unable to quantify the time frame.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Can financial payments incentivize short-term smoking cessation in orthopaedic trauma patients? Evidence from a discrete choice experiment

BACKGROUND

Smoking increases the risk of complications and related costs after an orthopaedic fracture. Research in other populations suggests that a one-time payment may incentivize smoking cessation. However, little is known on fracture patients' willingness to accept financial incentives to stop smoking; and the level of incentive required to motivate smoking cessation in this population. This study aimed to estimate the financial threshold required to motivate fracture patients to stop smoking after injury.

METHODS

This cross-sectional study utilized a discrete choice experiment (DCE) to elicit patient preferences towards financial incentives and reduced complications associated with smoking cessation. We presented participants with 12 hypothetical options with several attributes with varying levels. The respondents' data was used to determine the utility of each attribute level and the relative importance associated with each attribute.

RESULTS

Of the 130 enrolled patients, 79% reported an interest in quitting smoking. We estimated the financial incentive to be of greater relative importance (ri) (45%) than any of the included clinical benefits of smoking cessations (deep infection (ri: 24%), bone healing complications (ri: 19%), and superficial infections (ri: 12%)). A one-time payment of $800 provided the greatest utility to the respondents (0.64, 95% CI: 0.36 to 0.93), surpassing the utility associated with a single $1000 financial incentive (0.36, 95% CI: 0.18 to 0.55).

CONCLUSIONS

Financial incentives may be an effective tool to promote smoking cessation in the orthopaedic trauma population. The findings of this study define optimal payment thresholds for smoking cessation programs.

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.

Smoking as a risk factor for complications following arthroscopic rotator cuff repair

Background

The purpose of this study was to investigate the association between smoking status and postoperative complications within 30 days of arthroscopic rotator cuff repair (ARCR).

Methods

The American College of Surgeons National Surgical Quality Improvement Program database was queried to identify all patients who underwent ARCR from 2015 to 2017. Smokers were defined as patients who reported smoking cigarettes in the year prior to rotator cuff repair. Patients who used chewing tobacco, cigars, or electronic cigarettes were not included in the smoking cohort. Postoperative complications were reported within 30 days of the procedure. Multivariate logistic regression was performed to investigate the relationship between smoking status and postoperative complications.

Results

There were 18,594 patients included in this study. Of these patients, 2834 (15.2%) were current smokers. Smokers were more likely to be men, to be aged < 65 years, and to have a body mass index < 30. Smokers were also more likely to have chronic obstructive pulmonary disease, to be functionally dependent, and to have an American Society of Anesthesiologists (ASA) class ≥ 3. After adjustment for all significantly associated patient demographic characteristics and comorbidities, smoking was identified as a significant predictor of surgical complications (odds ratio [OR], 1.955; P = .022), return to the operating room (OR, 2.547; P = .003), readmission (OR, 1.570; P = .014), and sepsis or septic shock (OR, 4.737; P = .021). Smoking was not a significant predictor of medical complications (OR, 1.105; P = .687) or surgical-site infections (OR, 1.216; P = .713).

Conclusion

Smoking may be a risk factor for surgical complications, readmission, and sepsis or septic shock within 30 days of ARCR.

Does Smoking Status Influence Health-Related Quality of Life Outcome Measures in Patients Undergoing ACDF?

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

Whereas smoking has been shown to affect the fusion rates for patients undergoing an anterior cervical discectomy and fusion (ACDF), the relationship between smoking and health-related quality of life outcome measurements after an ACDF is less clear. The purpose of this study was to evaluate whether smoking negatively affects patient outcomes after an ACDF for cervical degenerative pathology.

METHODS

Patients with tumor, trauma, infection, and previous cervical spine surgery and those with less than a year of follow-up were excluded. Smoking status was assessed by self-reported smoking history. Patient outcomes, including Neck Disability Index, Short Form 12 Mental Component Score, Short Form 12 Physical Component Score (PCS-12), Visual Analogue Scale (VAS) arm pain, VAS neck pain, and pseudarthrosis rates were evaluated. Outcomes were compared between smoking groups using multiple linear and logistic regression, controlling for age, sex, and body mass index (BMI), among other factors. A P value <.05 was considered significant.

RESULTS

A total of 264 patients were included, with a mean follow-up of 19.8 months, age of 53.1 years, and BMI of 29.6 kg/m2. There were 43 current, 69 former, and 152 nonsmokers in the cohort. At baseline, nonsmokers had higher PCS-12 scores than current smokers (P = .010), lower VAS neck pain than current (P = .035) and former (P = .014) smokers, as well as lower VAS arm pain than former smokers (P = .006). Postoperatively, nonsmokers had higher PCS-12 scores than both current (P = .030) and former smokers (P = .035). Smoking status was not a significant predictor of change in patient outcome in multivariate analysis.

CONCLUSIONS

Whereas nonsmokers had higher function and lower pain than former or current smokers preoperatively, smoking status overall was not found to be an independent predictor of outcome scores after ACDF. This supports the notion that smoking status alone should not deter patients from undergoing ACDF for cervical degenerative pathology.

Systematic Review of Osteochondral Allograft Transplant Immunology: How We Can Further Optimize Outcomes

Despite the growing success for osteochondral allograft (OCA) transplantation in treating large articular cartilage lesions in multiple joints, associated revision and failure rates are still higher than desired. While immunorejection responses have not been documented, the effects of the host's immune responses on OCA transplantation failures have not been thoroughly characterized. The objective of this study was to systematically review clinically relevant peer-reviewed evidence pertaining to the immunology of OCAs to elucidate theragnostic strategies for improving functional graft survival and outcomes for patients undergoing OCA transplantation. This systematic review of Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, MEDLINE, PubMed, and EMBASE suggests that host immune responses play key roles in incorporation and functional survival of OCA transplants. OCA rejection has not been reported; however, graft integration through creeping substitution is reliant on host immune responses. Prolonged inflammation, diminished osteogenic potential for healing and incorporation, and relative bioburden are mechanisms that may be influenced by the immune system and contribute to undesirable outcomes after OCA transplantation. Based on the safety and efficacy of OCA transplantation and its associated benefits to a large and growing patient population, basic, preclinical, and clinical osteoimmunological studies on OCA transplantation that comprehensively assess and correlate cellular, molecular, histologic, biomechanical, biomarkers, diagnostic imaging, arthroscopic, functional, and patient-reported outcome measures are of high interest and importance.

Osteonecrosis of the distal tibia after pilon fractures

BACKGROUND

Pilon fractures are devastating injuries with high complication rates. Osteonecrosis has been previously described after Weber C fracture-dislocations but has not been reported following fixation of pilon fractures.

METHODS

All AO/OTA 43-C pilon fractures from 2007 to 2018 were reviewed. Injury factors and demographics were recorded. Computed tomography (CT) scans of the fracture pattern were analyzed to determine risk factors for ON.

RESULTS

71 pilon fractures in 69 patients were included. Mean follow-up was 21.6 months. 18 patients demonstrated ON at a mean 7.3 months' post-injury. Regression analysis demonstrated no differences between cohorts with respect to smoking status, open injury, or diabetic status. ON was associated with small anterolateral fragment less than 2.0cm² (OR=19.47, p=0.012), higher comminution (OR=3.00, p=0.005), use of calcium phosphate bone substitute (OR=20.72, p=0.013).

CONCLUSIONS

ON of the distal tibia was not associated with patient factors but was associated with fracture characteristics.

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.

Preoperative tendon retraction, not smoking, is a risk factor for failure with continuity after rotator cuff repair

BACKGROUND

Smoking is a poor prognostic factor for healing after rotator cuff repair and is associated with inferior results. We hypothesized that smokers would have higher recurrent tear rates and more postoperative myotendinous junction (MTJ) retraction in healed repairs than nonsmokers three months postoperatively.

METHODS

Rotator cuff repairs (RCRs) were retrospectively reviewed over a 2-year period. Patients underwent magnetic resonance imaging (MRI) within 6 months prior to surgery and again at 3 months postoperatively. Seventy-nine patients were included and stratified by smokers versus nonsmokers. Baseline patient demographics, tear characteristics, and surgical factors were collected. Preoperative and postoperative MRIs were assessed to quantify the MTJ position and to establish the recurrent tear rate.

RESULTS

For the total cohort (nonsmokers, n = 56; smokers, n = 23), significant differences in age, race, and traumatic onset of injury existed between groups. There were no significant differences in recurrent tear between smokers (26%) and nonsmokers (27%), but nonsmokers were more satisfied. For patients with healed RCRs (nonsmokers, n = 41; smokers, n = 17), there were significant differences in race. On univariate analysis, nonsmokers had a significantly more lateral MTJ postoperatively (P = 0.05). On multivariable regression analysis, medialized postoperative MTJ position in healed cuffs was driven only by greater preoperative rotator cuff retraction preoperatively. There were no significant differences in MTJ position based on smoking status for patients with healed RCRs.

CONCLUSION

Smoking does not appear to be an independent risk factor for postoperative MTJ retraction in healed RCRs, also known as failure in continuity. Preoperative tear size and retraction play the biggest roles in predicting postoperative MTJ position, regardless of smoking status. There are no significant differences in patient-reported outcomes for patients with healed RCRs, but nonsmokers had more satisfaction following RCR in the total cohort.

LEVEL OF EVIDENCE

Level III; Retrospective cohort study; Diagnostic study.

Recombinant Human BMP6 Applied Within Autologous Blood Coagulum Accelerates Bone Healing: Randomized Controlled Trial in High Tibial Osteotomy Patients

Bone morphogenetic proteins (BMPs) are potent osteogenic proteins that induce new bone formation in vivo. However, their effect on bone healing in the trabecular bone surfaces remains challenging. We evaluated the safety and efficacy of recombinant human BMP6 (rhBMP6) applied within an autologous blood coagulum (ABC) in a surgically created wedge defect of the proximal tibia in patients undergoing high tibial osteotomy (HTO) for varus deformity and medial osteoarthritis of the knee. We enrolled 20 HTO patients in a randomized, placebo-controlled, double-blinded phase I/II clinical trial. RhBMP6/ABC (1.0 mg/10 mL ABC prepared from peripheral blood) or placebo (10 mL ABC containing excipients) was administered into the tibial wedge defects. Patients were followed for 0 to 24 months by clinical examination (safety) and computed tomography (CT) and serial radiographic analyses (efficacy). The results show that there were no detectable anti-rhBMP6 antibodies in the blood of any of the 20 patients at 14 weeks after implantation. During the 24 months of follow-up, there were no serious adverse reactions recorded. The CT scans from defects of patients treated with rhBMP6/ABC showed an accelerated bone healing compared with placebo at 9 weeks (47.8 ± 24.1 versus 22.2 ± 12.3 mg/cm³ ; p = 0.008) and at 14 weeks (89.7 ± 29.1 versus 53.6 ± 21.9 mg/cm³ ; p = 0.006) follow-up. Radiographic analyses at weeks 6 and 24 and months 12 and 24 suggested the advanced bone formation and remodeling in rhBMP6/ABC-treated patients. In conclusion, we show that rhBMP6/ABC at a dose of 100 μg/mL accelerated bone healing in patients undergoing HTO without serious adverse events and with a good tolerability compared with placebo alone. Overall, for the first time, a BMP-based osteogenic implant was examined against a placebo for bone healing efficacy in the trabecular bone surface, using an objective bone mineral density measurement system. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Validation of Self-Reported Smoking Status Among Orthopedic Hip Surgery Patients

Purpose

The purpose of this study was to determine the accuracy of self-reported non-smoking status in subjects undergoing elective orthopedic surgery as confirmed by serum cotinine levels.

Methods

Institutional Review Board approval was obtained for this retrospective review of consecutive subjects that underwent elective orthopedic surgery by a single fellowship-trained orthopedic surgeon. All patients provided smoking history (active, former, or non-smoker). Serum cotinine levels defined each subject as “non-smoker”, “passive tobacco exposure”, or “active smoker”. Self-reported non-smokers were eligible for inclusion. Subjects were excluded if they failed to provide smoking history, reported themselves as “smokers”, and/or had unavailable serum cotinine levels. Self-reported non-smoking status accuracy was determined by dividing the total number of included subjects by the number of subjects that were defined as “non-smoker” or “passive tobacco exposure” on their serum cotinine test.

Results

A total of 378 patients (mean age of 42.5 (13-78) years and 68% female) self-reported as non-smokers and were included. A total of 369 subjects had serum cotinine levels consistent with “non-smoking” resulting in a self-reported non-smoking status accuracy of 97.6%. None of the former smokers had cotinine levels consistent with active smoker status.

Conclusion

Subjects undergoing elective orthopedic surgery self-report as non-smokers with an accuracy of 97.6%. This suggests that routine serum cotinine testing of non-smokers in this patient population may not be necessary.

Results of plate fixation for humerus fractures in a large single-center cohort

INTRODUCTION

This study aims to describe the results of plate fixation in one of the largest single-center cohorts that employs plate fixation as the golden standard. Additionally, risk factors related to a negative outcome were identified.

MATERIALS AND METHODS

This was a retrospective cohort study of all patients treated for a humeral shaft fracture in a level-one trauma center between January 2010 and December 2017 with a mean follow-up of 1 year.

RESULTS

Plate fixation was performed in 102 patients with a humeral shaft fracture. The mean age was 50 (SD 20) years with 54.9% (n = 56) being male. Forty-eight percent (n = 48) had an AO type-A, 34.3% (n = 35) type-B, and 18.7% (n = 19) type-C fracture. Deep surgical site infections and non-union occurred in 1% (n = 1) and 3.9% (n = 4) of patients, respectively. Revision of the implant was performed in 15.7% (n = 16) mainly due to implant-related complaints. Only one patient developed radial nerve palsy after surgery. The median duration to radiological fracture healing and full-weight bearing was 18 (range 7-65) weeks and 14 (range 6-56) weeks, respectively. Risk factors for negative outcome included higher age, osteoporosis, open and higher AO class fractures, performing surgery during out-office hours, and the use of LCP 3.5-mm plate and an anterolateral approach.

CONCLUSION

Plate fixation for humeral shaft fractures has low risks of complications. It should be emphasized that the complications can be further minimized with a greater surgical expertise and by refraining from performing a surgery during out-office hours.

Implementing Facilitated Access to a Text Messaging, Smoking Cessation Intervention Among Swedish Patients Having Elective Surgery: Qualitative Study of Patients' and Health Care Professionals' Perspectives

Background

There is strong evidence that short-term smoking cessation before surgery can reduce postoperative morbidity. There are, however, several structural problems in health care systems concerning how to implement smoking cessation interventions in routine practice for preoperative patients.

Objective

This study aimed to analyze the implementation of a text messaging, smoking cessation intervention targeting patients having elective surgery. Implementation of facilitated access (ie, referral from practitioners) and the perceived usefulness among patients were investigated. Elective surgery is defined as scheduled, nonacute surgery.

Methods

A qualitative study was carried out at two medium-sized hospitals in the south of Sweden. The implementation of facilitated access was investigated during a 12-month period from April 2018 to April 2019. Facilitated access was conceptualized as specialists recommending the text messaging intervention to patients having elective surgery. Implementation was explored in terms of perceptions about the intervention and behaviors associated with implementation; that is, how patients used the intervention and how specialists behaved in facilitating usage among patients. Two focus groups with smoking cessation specialists and 10 individual interviews with patients were carried out. Qualitative content analysis was used to analyze the data.

Results

Two main categories were identified from the focus group data with smoking cessation specialists: implementation approach and perceptions about the intervention. The first category, implementation approach, referred to how specialists adapted their efforts to situational factors and to the needs and preferences of patients, and how building of trust with patients was prioritized. The second category, perceptions about the intervention, showed that specialists thought the content and structure of the text messaging intervention felt familiar and worked well as a complement to current practice. Two categories were identified from the patient interview data: incorporating new means of support from health care and determinants of use. The first category referred to how patients adopted and incorporated the intervention into their smoking cessation journey. Patients were receptive, shared the text messages with friends and family, humanized the text messages, and used the messages as a complement to other strategies to quit smoking. The second category, determinants of use, referred to aspects that influenced how and when patients used the intervention and included the following: timing of the intervention and text messages, motivation to change, and perceptions of the mobile phone medium.

Conclusions

Smoking cessation specialists adopted an active role in implementing the intervention by adapting their approach and fitting the intervention into existing routines. Patients showed strong motivation to change and openness to incorporate the intervention into their behavior change journey; however, the timing of the intervention and messages were important in optimizing the support. A text messaging, smoking cessation intervention can be a valuable and feasible way to reach smoking patients having elective surgery.

Impact of Cigarette Smoking on Re-operation and Revision Surgery after Femoral Neck Fracture Treatment

INTRODUCTION

Smokers and nicotine users have a higher risk of femoral neck fracture non-union and prolonged time to fracture union. The impact of smoking resulting in revision surgery after fixation of femoral neck fractures, however, rarely has been studied. The aim of this retrospective study was to review if cigarette smoking had an influence on re-operation and revision after femoral neck fracture treatment.

METHODS

Three groups of patients (Group 1: active smokers; Group 2: former smokers; and Group 3: non-smokers) who sustained a femoral neck fracture from January 2012 through August 2018 were included. Outcomes investigated included femoral neck fracture type, operative fixation type, fixation failure, and time interval between initial fixation and revision.

RESULTS

A total of 1,452 subjects were identified (Group 1: 165 subjects; Group 2: 507 subjects; and Group 3: 780 subjects). In the male population, Groups 1 and 2 had higher rates of femoral neck fracture than Group 3. Twelve cases required revisions (Group 1: three cases (6%); Group 2: two cases (2%); Group 3: seven cases (4%)), with all but one revision within the first year following initial fixation. Group 1 patients tended to be younger than the other two groups.

CONCLUSION

Smoking has a positive association with the risk of femoral neck fracture amongst active and former male smokers. This study concluded that active smokers have a higher risk of non-union compared with non-smokers or former smokers. Smoking history, especially heavy or long-term, should play a role in deciding which fixation construct type to use for femoral neck fractures.

Genetic determinants of fracture non-union: A systematic review from the literature

Approximately 10-15% of fracture patients suffer impaired healing, which is either delayed or even results in non-union. We performed a Systematic Review, aiming to examine the types and frequency of specific genetic abnormalities in patients experiencing bone fracture and to ascertain whether a genetic association exists regarding the tendency for some patients to suffer fracture non-union or postoperative non-union events. GO and KEGG analyses were used to identify the likely function of the genes involved. Furthermore, we evaluated the functional significance of single nucleotide polymorphisms using RegulomeDB and GTEx. Seven eligible studies involving 29 genes and 89 SNPs were analyzed in this review. We found that the polymorphisms in gene NOS2, NOG, BMP4, CYR61, IL1β and FGFR1 apparently predisposed patients to fracture non-union, while the polymorphisms in gene MMP13, BMP6 and FAM5C appeared to provide protection from non-union. Bioinformatics analysis suggested that these genes were enriched in inflammatory pathways, suggesting that inflammation may be a potential factor involved in fracture non-union. Three SNPs (rs17563, rs3753793 and rs2853550) had smaller RegulomeDB scores, indicating significant biological function. In conclusion, we have identified a number of genes and their polymorphisms that might contribute to a genetic susceptibility to fracture non-union. Further studies with larger cohorts will enhance our understanding of fracture non-union and may inform and direct early interventions.

The Life of a Fracture: Biologic Progression, Healing Gone Awry, and Evaluation of Union

New knowledge about the molecular biology of fracture-healing provides opportunities for intervention and reduction of risk for specific phases that are affected by disease and medications. Modifiable and nonmodifiable risk factors can prolong healing, and the informed clinician should optimize each patient to provide the best chance for union. Techniques to monitor progression of fracture-healing have not changed substantially over time; new objective modalities are needed.

Epidemiology, Clinical Assessments, and Current Treatments of Nonunions

PURPOSE OF REVIEW

The failure of bony union following a fracture, termed a fracture nonunion, has severe patient morbidity and economic consequences. This review describes current consensuses and future directions of investigation for determining why, detecting when, and effective treatment if this complication occurs.

RECENT FINDINGS

Current nonunion investigation is emphasizing an expanded understanding of the biology of healing. This has led to assessments of the immune environment, multiple cytokines and morphogenetic factors, and the role of skeletogenic stem cells in the development of nonunion. Detecting biological markers and other objective diagnostic criteria is also a current objective of nonunion research. Treatment approaches in the near future will likely be dominated by the development of specific adjunct therapies to the nonunion surgical management, which will be informed by an expanded mechanistic understanding of nonunion biology. Current consensus among orthopedists is that improved diagnosis and treatment of nonunion hinges first on discoveries at the bench side with later translation to the clinic.

Predicting Functional Outcomes Following Fracture Nonunion Repair-Development and Validation of a Risk Profiling Tool

OBJECTIVES

To develop a tool that can be used preoperatively to identify patients at risk of poor functional outcome following operative repair of fracture nonunion.

DESIGN

Retrospective analysis of prospectively collected data.

SETTING

Academic medical center.

PATIENTS/PARTICIPANTS

Three hundred twenty-eight patients who underwent operative repair of a fracture nonunion were prospectively followed for a minimum of 12 months post-operatively.

INTERVENTION

After randomization, 223 (68%) patients comprised an experimental cohort and 105 (32%) patients comprised a separate validation cohort. Within the experimental cohort, forward stepwise multivariate logistic regression was applied to 17 independent variables to generate a predictive model identifying patients at risk of having a poor functional outcome [Predicting Risk of Function in Trauma-Nonunion (PRoFiT-NU) Score].

MAIN OUTCOME MEASUREMENTS

Functional outcomes were assessed using the Short Musculoskeletal Function Assessment (SMFA). Poor outcome was defined as an SMFA function index greater than 10 points above the mean at 12 months post-operatively.

RESULTS

Significant predictors of poor outcome were lower extremity nonunion [odds ratio (OR) = 3.082; P = 0.021], tobacco use (OR = 2.994; P = 0.009), worker's compensation insurance (OR = 3.986; P = 0.005), radiographic bone loss (OR = 2.397; P = 0.040), and preoperative SMFA function index (OR = 1.027; P = 0.001). The PRoFiT-NU model was significant and a good predictor of poor functional outcome (χ(5) = 51.98, P < 0.0005; area under the receiver operating curve = 0.79). Within the separate validation cohort, 16% of patients had a poor outcome at a PRoFiT-NU score below 25% (low risk), 39% of patients had a poor outcome at a PRoFiT-NU score between 25% and 50% (intermediate risk), and 63% of patients had a poor outcome at a PRoFiT-NU score above 50% (high risk).

CONCLUSIONS

The PRoFiT-NU score is an accurate predictor of poor functional outcome following fracture nonunion repair.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence description of levels of evidence.

Cigarette smoke inhalation impairs angiogenesis in early bone healing processes and delays fracture union

Aims

Cigarette smoking has a negative impact on the skeletal system, causes a decrease in bone mass in both young and old patients, and is considered a risk factor for the development of osteoporosis. In addition, it disturbs the bone healing process and prolongs the healing time after fractures. The mechanisms by which cigarette smoking impairs fracture healing are not fully understood. There are few studies reporting the effects of cigarette smoking on new blood vessel formation during the early stage of fracture healing. We tested the hypothesis that cigarette smoke inhalation may suppress angiogenesis and delay fracture healing.

Methods

We established a custom-made chamber with airflow for rats to inhale cigarette smoke continuously, and tested our hypothesis using a femoral osteotomy model, radiograph and microCT imaging, and various biomechanical and biological tests.

Results

In the smoking group, Western blot analysis and immunohistochemical staining revealed less expression of vascular endothelial growth factor (VEGF) and von Willebrand factor (vWF). The smoking group also had a lower microvessel density than the control group. Image and biochemical analysis also demonstrated delayed bone healing.

Conclusion

Cigarette smoke inhalation was associated with decreased expression of angiogenic markers in the early bone healing phase and with impaired bone healing.

Cite this article:Bone Joint Res. 2020;9(3):99–107.

Smoking is associated with increased surgical complications following total shoulder arthroplasty: an analysis of 14,465 patients

HYPOTHESIS

The purpose of this study was to evaluate the association between smoking and postoperative complications following total shoulder arthroplasty. We hypothesized that active smokers would have significantly greater postoperative medical and surgical complications.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients who underwent total shoulder arthroplasties from 2005 through 2016. Patients were stratified based on tobacco use within the past year. Logistic regression was used to assess the relationship between smoking status and postoperative medical and surgical complications. Multivariate logistic regression was used to adjust for demographic and comorbid factors.

RESULTS

We identified 14,465 patients, of whom 10.5% were active smokers. Smokers were more likely to be younger, to be female patients, and to have a lower body mass index compared with nonsmokers (P < .001). Univariate analysis demonstrated that smoking was not associated with postoperative medical complications (P > .05) but was associated with an increased risk of overall surgical complications (odds ratio [OR], 3.259; 95% confidence interval [CI], 1.861-5.709; P < .001). Multivariate modeling showed that smoking increased the risk of wound complications (adjusted OR, 7.564; 95% CI, 2.128-26.889; P = .002) and surgical-site infections (adjusted OR, 1.927; 95% CI, 1.023-3.630; P = .042).

DISCUSSION AND CONCLUSION

This study demonstrates that smoking is associated with an increased risk of surgical complications following total shoulder arthroplasty. On the basis of our available data, medical complications are not significantly increased. This information can help risk stratify patients prior to their procedures.

Smoking and alcohol drinking and risk of non-union or delayed union after fractures: A protocol for systematic review and dose-response meta-analysis

INTRODUCTION

To the best of our knowledge, there is no consensus on dose-response between smoking, alcohol drinking, and bone healing. The aim of the present study is to conduct a comprehensive systematic review and dose-response meta-analysis of studies to estimate the influence of smoking and alcohol use on the success of non-pathologic bone fracture healing in adult patients.

METHODS

A systematic search will be performed using MEDLINE, EMBASE and Cochrane CENTRAL, CINAHL, and AMED databases to identify randomized controlled trials and observational studies which have assessed the effect of smoking or alcohol drinking on fracture healing. Primary outcomes include delayed union or nonunion rate and time to union. Secondary outcomes are common complications which occur during bone healing including malunion and wound infection. Risk of bias will be evaluated using the Quality In Prognosis Studies (QUIPS) tool for quality assessment of each study. Dose-response meta-analysis will be performed between smoking, alcohol drinking, and bone healing. Evaluation of the quality of evidence will be conducted using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

RESULTS

The present study will assess the effects of smoking and alcohol drinking on non-pathologic bone fracture healing in adult patients.

CONCLUSION

We hope that this systematic review and dose-response meta-analysis will provide high quality evidence on dose-response between smoking, alcohol drinking, and bone fracture healing.

PROSPERO REGISTRATION NUMBER

CRD42019131454.

Patient-dependent factors for fractures union failure among Riyadh population 2016

Background:

The primary care has an important role to prevent fractures and make sure of complete healing without any complications like a Malunion which arises when a fracture has healed in a non-anatomical position, and a delayed union which defined as a healing time of more than 12 weeks and a non-union which occurs when absence of fracture healing progression on series of radiographs or with no evidence of healing over 10 weeks.

Objectives:

To identify the proportion of fracture healing failure types and identify Patient-dependent Factors.

Methodology:

cross sectional study consecutive sampling till completing sample size (90) patients. Data collection tool was Pretested Pre-Coded self-administered questionnaire it was subjected to a probe to test for validity and reliability. Data analyzed Using SPSS P value of less than 0.05 considered as significant results. Chi-square test was the test of significance.

Results:

From 90 adult male participants, 71% were 35 years of age and above and below 55 years. Our result indicated that the commonest risk factor was smoking in 62.2% of respondents, and 27.8% have Diabetes mellitus. 50% of fractures failure was diagnosed as delayed union while non-union accounts for 40% and malunion for 10%. We've noticed that smokers mostly had delayed union, while diabetic patients had mostly non-union.

Conclusion:

the study found that the most associating Patient-dependent Factors were cigarettes smoking and Diabetes mellitus, also most fractures failure were diagnosed as delayed union, non-union, and malunion respectively and we can help prevent these complications by controlling DM and stop cigarettes smoking.

Nonunion - consensus from the 4th annual meeting of the Danish Orthopaedic Trauma Society

Nonunions are a relevant economic burden affecting about 1.9% of all fractures. Rather than specifying a certain time frame, a nonunion is better defined as a fracture that will not heal without further intervention.Successful fracture healing depends on local biology, biomechanics and a variety of systemic factors. All components can principally be decisive and determine the classification of atrophic, oligotrophic or hypertrophic nonunions. Treatment prioritizes mechanics before biology.The degree of motion between fracture parts is the key for healing and is described by strain theory. If the change of length at a given load is > 10%, fibrous tissue and not bone is formed. Therefore, simple fractures require absolute and complex fractures relative stability.The main characteristics of a nonunion are pain while weight bearing, and persistent fracture lines on X-ray.Treatment concepts such as 'mechanobiology' or the 'diamond concept' determine the applied osteosynthesis considering soft tissue, local biology and stability. Fine wire circular external fixation is considered the only form of true biologic fixation due to its ability to eliminate parasitic motions while maintaining load-dependent axial stiffness. Nailing provides intramedullary stability and biology via reaming. Plates are successful when complex fractures turn into simple nonunions demanding absolute stability. Despite available alternatives, autograft is the gold standard for providing osteoinductive and osteoconductive stimuli.The infected nonunion remains a challenge. Bacteria, especially staphylococcus species, have developed mechanisms to survive such as biofilm formation, inactive forms and internalization. Therefore, radical debridement and specific antibiotics are necessary prior to reconstruction. Cite this article: EFORT Open Rev 2020;5:46-57. DOI: 10.1302/2058-5241.5.190037.

The outcome of bone graft surgery for nonunion of fractures of the scaphoid

Data on 806 patients undergoing bone graft surgery for a scaphoid fracture nonunion were retrospectively collected at 19 centres in the United Kingdom. Each centre contributed at least 30 cases. Sufficient data were available in 462 cases to study factors that influenced the outcome of surgery. Overall union occurred in at least 69%, and nonunion in at least 22%, with 9% of cases having 'uncertain union status'. Union appeared to be adversely influenced by smoking and the time between acute scaphoid fracture and nonunion surgery, with adjusted odds ratios of 1.8 and 2.4, respectively, but neither achieved the pre-determined significance level of 0.003. The type of bone graft (vascular vs non-vascular; iliac crest vs distal radius) did not appear to influence outcome. Further large multicentre prospective studies with clear definitions of 'union' and other factors are needed to clarify whether modification of surgical technique can influence union. Level of evidence: IV.

Tobacco and bone fractures: A review of the facts and issues that every orthopaedic surgeon should know

Objectives

The aim of this study was to review the impact of smoking tobacco on the musculoskeletal system, and on bone fractures in particular.

Methods

English-language publications of human and animal studies categorizing subjects into smokers and nonsmokers were sourced from MEDLINE, The Cochrane Library, and SCOPUS. This review specifically focused on the risk, surgical treatment, and prevention of fracture complications in smokers.

Results

Smokers have an increased risk of fracture and experience more complications with delayed bone healing, even if they have already stopped smoking, because some adverse effects persist for a prolonged period. Some risks can be reduced during and after surgery by local and general prevention, and smoking cessation is an important factor in lessening this risk. However, if a patient wants to stop smoking at the time of a fracture, the cessation strategies in reducing tobacco use are not easy to implement. The patient should also be warned that using e-cigarettes or other tobaccos does not appear to reduce adverse effects on health.

Conclusion

The evidence reviewed in this study shows that smoking has a negative effect in terms of the risk and treatment of fractures.

Cite this article: J. Hernigou, F. Schuind. Tobacco and bone fractures: A review of the facts and issues that every orthopaedic surgeon should know. Bone Joint Res 2019;8:255–265. DOI: 10.1302/2046-3758.86.BJR-2018-0344.R1.

Fracture Non-Union: A Review of Clinical Challenges and Future Research Needs

Non-union of bone following fracture is an orthopaedic condition with a high morbidity and clinical burden. Despite its estimated global prevalence of nine million annually, the limit of bone regeneration therapy still results in patients living with pain, a reduced quality of life and associated psychological, social and financial repercussions. This review provides an overview of the current epidemiological and aetiological data, and highlights where the clinical challenges in treating non-union lie. Current treatment strategies are discussed as well as promising future research foci. Development in biotechnologies to treat non-union provides exciting scope for more effective treatment for this debilitating condition.

Optimizing the Host in Fracture Surgery

Multiple factors impact fracture healing; thus, endocrine optimization and nutritional optimization warrant investigation in the acute fracture and nonunion patient. This article presents current evidence regarding the role of the endocrinologists and the dietician in the fracture patient as well as the most recent data assessing the vitamin D axis in these populations. Similarly, the most recent information regarding the use and risks of NSAIDs in fracture healing are presented. The fracture surgeon must consider each individual patient and weigh the benefits versus the costs of host optimization.

Smoking Dependent Alterations in Bone Formation and Inflammation Represent Major Risk Factors for Complications Following Total Joint Arthroplasty

Numerous studies have described a correlation between smoking and reduced bone mass. This not only increases fracture risk but also impedes reconstruction/fixation of bone. An increased frequency of complications following surgery is common. Here, we investigate the effect of smoking on the clinical outcome following total joint arthroplasty (TJA). 817 patients receiving primary or revision (including clinical transfers) TJA at our level-one trauma center have been randomly interviewed twice (pre- and six months post-surgery). We found that 159 patients developed complications (infections, disturbed healing, revisions, thrombosis, and/or death). Considering nutritional status, alcohol and cigarette consumption as possible risk factors, OR was highest for smoking. Notably, mean age was significantly lower in smokers (59.2 ± 1.0a) than non-smokers (64.6 ± 0.8; p < 0.001). However, the number of comorbidities was comparable between both groups. Compared to non-smokers (17.8 ± 1.9%), the complication rate increases with increasing cigarette consumption (1⁻20 pack-years (PY): 19.2 ± 2.4% and >20 PY: 30.4 ± 3.6%; p = 0.002). Consequently, mean hospital stay was longer in heavy smokers (18.4 ± 1.0 day) than non-smokers (15.3 ± 0.5 day; p = 0.009) or moderate smokers (15.9 ± 0.6 day). In line with delayed healing, bone formation markers (BAP and CICP) were significantly lower in smokers than non-smokers 2 days following TJA. Although, smoking increased serum levels of MCP-1, OPG, sRANKL, and Osteopontin as well as bone resorption markers (TRAP5b and CTX-I) were unaffected. In line with an increased infection rate, smoking reduced 25OH vitamin D3 (immune-modulatory), IL-1β, IL-6, TNF-α, and IFN-γ serum levels. Our data clearly show that smoking not only affects bone formation after TJA but also suppresses the inflammatory response in these patients. Thus, it is feasible that therapies favoring bone formation and immune responses help improve the clinical outcome in smokers following TJA.