The effects of smoke carcinogens on bone

Impact of tobacco usage on readmission and complication rates following shoulder replacement surgery: A study of 164,527 patients

Background

Tobacco carcinogens have adverse effects on bone health and are associated with inferior outcomes following orthopedic procedures. The purpose of this study was to assess the impact tobacco use has on readmission and complication rates following shoulder arthroplasty.

Methods

The 2016-2018 National Readmissions Database was queried to identify patients who underwent anatomical, reverse, and hemi-shoulder arthroplasty. ICD-10 codes Z72.0 ×  (tobacco use disorder) and F17.2 ×  (nicotine dependence) were used to define "tobacco-users." Demographic, 30-/90-day readmission, surgical complication, and medical complication data were collected. Inferential statistics were used to analyze complications for both the cohort as a whole and for each procedure separately (i.e. anatomical, reverse, and hemiarthroplasty).

Results

164,527 patients were identified (92% nontobacco users). Tobacco users necessitated replacement seven years sooner than nonusers (p < 0.01) and were more likely to be male (52% vs. 43%; p < 0.01). Univariate analysis showed that tobacco users had higher rates of readmission, revisions, shoulder complications, and medical complications overall. In the multivariate analysis for the entire cohort, readmission, revision, and complication rates did not differ based on tobacco usage; however, smokers who underwent reverse shoulder arthroplasty in particular were found to have higher 90-day readmission, dislocation, and prosthetic complication rates compared to nonsmokers.

Conclusion

Comparatively, tobacco users required surgical correction earlier in life and had higher rates of readmission, revision, and complications in the short term following their shoulder replacement. However, when controlling for tobacco usage as an independent predictor of adverse outcomes, these aforementioned findings were lost for the cohort as a whole. Overall, these findings indicate that shoulder replacement in general is a viable treatment option regardless of patient tobacco usage at short-term follow-up, but this conclusion may vary depending on the replacement type used.

Spine Bracing: When to Utilize-A Narrative Review

Spinal bracing is a common non-surgical technique that allows clinicians to prevent and correct malformations or injuries of a patient's spinal column. This review will explore the current standards of practice on spinal brace utilization. Specifically, it will highlight bracing usage in traumatic injuries, pregnancy, pediatrics, osteoporosis, and hyperkyphosis; address radiological findings concurrent with brace usage; and provide an overview of the braces currently available and advancements in the field. In doing so, we aim to improve clinicians' understanding and knowledge of bracing in common spinal pathologies to promote their appropriate use and improve patient outcomes.

The impact of tobacco use on clinical outcomes and long-term survivorship after anatomic total shoulder arthroplasty

Introduction

Postoperative outcomes following total shoulder arthroplasty can be affected by preoperative health factors such as tobacco usage.

Methods

The charts of patients who underwent anatomic total shoulder arthroplasty were retrospectively analyzed and stratified based on smoking status. The primary data included range of motion and patient reported outcomes. Additionally, demographic, radiographic, and survivorship analyses were conducted. All data were analyzed using statistical inference.

Results

There were 78, 49, and 16 non-smoker, former smoker, and current smoker shoulders respectively with no significant differences in sex, American Society of Anesthesiologists status, body mass index, or mean follow-up time (average: 10.7 yrs). Smokers (51.5 ± 10.4 years) were younger than both non-smokers (64.9 ± 8.1 years; p < 0.01) and former smokers (65.1 ± 9.1years; p < 0.01) at the time of surgery. For non-smokers and former smokers, all range of motion and patient reported outcome scores significantly improved. Smokers reported significant improvements in all patient reported outcomes and external and internal rotation. Visual Analog Scale, American Shoulder and Elbow, and Simple Shoulder Test scores were lower for smokers comparatively, but these differences did not reach significance. Forward elevation was higher postoperatively for non-smokers (149.7o ± 17.2o) and former smokers (147.1o ± 26.0o) compared to current smokers (130.9o ± 41.2o; p = 0.017). No differences between the cohorts were found in the radiographic analysis. Revision rates were lower in the non-smoking cohort (7.7%) compared to both former (20.4%; p = 0.036) and current smokers (37.5%; p < 0.01). Survival curves showed that non-smoker implants lasted longer than those of current smokers.

Conclusion

After a decade, patients generally had improved shoulder range of motion, functionality, and pain regardless of smoking status. However, current smokers required shoulder replacements sooner and revision surgery more frequently.

Outcomes in Thoracolumbar and Lumbar Traumatic Fractures: Does Restoration of Unfused Segmental Mobility Correlated to Implant Removal Time?

BACKGROUND

Posterior fixation without fusion can treat thoracolumbar and lumbar traumatic fractures effectively in certain cases. However, whether patients benefit from implant removal and the correlation between the range of motion (ROM) of the involved segments and the removal time have not been determined.

METHODS

From 2018 to 2020, we retrospectively reviewed data of patients with AO spine type A or B thoracolumbar or lumbar traumatic fractures who underwent implant removal. A total of 17 patients (group A), 21 patients (group B), and 12 patients (group C) underwent implant removal after the index surgery within 12 months, between 12 and 24 months, and over 24 months, respectively. Clinical and radiological outcomes, including visual analog scale for back pain, patient satisfaction, Oswestry disability index, and EuroQol 5 dimensions questionnaire, for quality of life and segmental ROM were analyzed.

RESULTS

The average follow-up time was 9.1 ± 5.7 months after implant removal. There were no significant differences in visual analog scale and patient satisfaction among the 3 groups at the same observation time point. Among the 3 groups, patients in group A gained the lowest Oswestry disability index and highest EuroQol 5 dimensions questionnaire scores after removal and at the final follow-up. The best ROM was obtained in group A followed by groups B and C (11.5° ± 6.2°, 5.5° ± 1.6°, and 2.4° ± 0.6°, respectively).

CONCLUSIONS

Immobilization of the involved segments over 24 months may lead to loss of ROM. Regained segmental ROM is correlated negatively with implant removal time, and removal within 12 months promises a better ROM and quality of life.

Smoking Is Associated with Sex-Specific Effects on Bone Microstructure in Older Men and Women

BACKGROUND

Smoking is a risk factor for fracture, but the mechanism by which smoking increases fracture risk is unclear.

METHODS

Musculoskeletal health was compared with dual energy X-ray absorptiometry (DXA), high resolution peripheral quantitative computed tomography (HR-pQCT), trabecular bone score, and vertebral fracture assessment in current and past smokers and nonsmokers from a multiethnic study of adults ≥ age 65. Skeletal indices were adjusted for age and weight.

RESULTS

Participants (n = 311) were mean age (±SD) 76.1 ± 6.5 years, mostly female (66.0%) and non-white (32.7% black/39.4% mixed race/26.3% white). Mean pack-years was 34.6 ± 20.4. In men (n = 106), weight and BMI were lower (both p < 0.05) in current vs past smokers. Male smokers consumed half the calcium of never and past smokers. BMD by DXA did not differ by smoking status at any skeletal site in either sex. Current male smokers had 13.5%-15.3% lower trabecular bone score vs never and past smokers (both p < 0.05). By HR-pQCT, trabecular volumetric BMD was 26.6%-30.3% lower and trabeculae were fewer, thinner and more widely spaced in male current vs past and never smokers at the radius (all p < 0.05). Cortical indices did not differ. Tibial results were similar, but stiffness was also 17.5%-22.2% lower in male current vs past and never smokers (both p< 0.05). In women, HR-pQCT trabecular indices did not differ, but cortical porosity was almost twice as high in current vs never smokers at the radius and 50% higher at the tibia (both p < 0.05).

CONCLUSIONS

In summary, current smoking is associated with trabecular deterioration at the spine and peripheral skeleton in men, while women have cortical deficits. Smoking may have sex-specific skeletal effects. The consistent association with current, but not past smoking, suggests the effects of tobacco use may be reversible with smoking cessation.

Association between maternal smoking during pregnancy and risk of bone fractures in offspring: a systematic review and meta-analysis

This study aimed to investigate the effect of maternal smoking during pregnancy (MSDP) on the risk of bone fractures in the offspring through a systematic review and meta-analysis. The PubMed, Web of Science, and Scopus databases were systematically searched for relevant articles published through July 2019. According to heterogeneity, the pooled risk ratio (RR) and odds ratio (OR) and their corresponding 95% confidence interval (CI) were obtained using fixed or random effects models. The heterogeneity and quality of the included studies were assessed by the I-squared (I2 ) statistic and the Newcastle-Ottawa scale, respectively. Sensitivity analyses were performed to test the effect of MSDP misclassification on the results. The review of 842 search records yielded 5 studies including 8,746 mother-child pairs that were included in the meta-analysis. Pooling adjusted effect measures showed that MSDP was not associated with a later risk of bone fractures in the offspring (pooled RR, 1.15; 95% CI, 0.84-1.58; I2 =66.8%; P=0.049). After the adjustment for misclassification, MSDP may be associated with a 27% increased risk of bone fracture (pooled OR, 1.27; 95% CI, 1.00-1.62; I2 =0%; P=0.537). After the adjustment for misclassification, MSDP is associated with an increased risk of bone fractures among children whose mothers smoked during pregnancy.

The use of tobacco is a modifiable risk factor for poor outcomes and readmissions after shoulder arthroplasty

Aims

The impact of tobacco use on readmission and medical and surgical complications has been documented in hip and knee arthroplasty. However, there remains little information about the effect of smoking on the outcome after total shoulder arthroplasty (TSA). We hypothesized that active smokers are at an increased risk of poor medical and surgial outcomes after TSA.

Methods

Data for patients who underwent arthroplasty of the shoulder in the USA between January 2011 and December 2015 were obtained from the National Readmission Database, and 90-day readmissions and complications were documented using validated coding methods. Multivariate regression analysis was performed to quantify the risk of smoking on the outcome after TSA, while controlling for patient demographics, comorbidities, and hospital-level confounding factors.

Results

A total of 196,325 non-smokers (93.1%) and 14,461 smokers (6.9%) underwent TSA during the five-year study period. Smokers had significantly increased rates of 30- and 90-day readmission (p = 0.025 and 0.001, respectively), revision within 90 days (p < 0.001), infection (p < 0.001), wound complications (p < 0.001), and instability of the prosthesis (p < 0.001). They were also at significantly greater risk of suffering from pneumonia (p < 0.001), sepsis (p = 0.001), and myocardial infarction (p < 0.001), postoperatively.

Conclusion

Smokers have an increased risk of readmission and medical and surgical complications after TSA. These risks are similar to those found for smokers after hip and knee arthroplasty. Many surgeons choose to avoid these elective procedures in patients who smoke. The increased risks should be considered when counselling patients who smoke before undertaking TSA. Cite this article: Bone Joint J 2020;102-B(11):1549–1554.

The use of tobacco is a modifiable risk factor for poor outcomes and readmissions after shoulder arthroplasty

AIMS

The impact of tobacco use on readmission and medical and surgical complications has been documented in hip and knee arthroplasty. However, there remains little information about the effect of smoking on the outcome after total shoulder arthroplasty (TSA). We hypothesized that active smokers are at an increased risk of poor medical and surgial outcomes after TSA.

METHODS

Data for patients who underwent arthroplasty of the shoulder in the USA between January 2011 and December 2015 were obtained from the National Readmission Database, and 90-day readmissions and complications were documented using validated coding methods. Multivariate regression analysis was performed to quantify the risk of smoking on the outcome after TSA, while controlling for patient demographics, comorbidities, and hospital-level confounding factors.

RESULTS

A total of 196,325 non-smokers (93.1%) and 14,461 smokers (6.9%) underwent TSA during the five-year study period. Smokers had significantly increased rates of 30- and 90-day readmission (p = 0.025 and 0.001, respectively), revision within 90 days (p < 0.001), infection (p < 0.001), wound complications (p < 0.001), and instability of the prosthesis (p < 0.001). They were also at significantly greater risk of suffering from pneumonia (p < 0.001), sepsis (p = 0.001), and myocardial infarction (p < 0.001), postoperatively.

CONCLUSION

Smokers have an increased risk of readmission and medical and surgical complications after TSA. These risks are similar to those found for smokers after hip and knee arthroplasty. Many surgeons choose to avoid these elective procedures in patients who smoke. The increased risks should be considered when counselling patients who smoke before undertaking TSA.

Smoking increases the risk of infectious diseases: A narrative review

Smoking is relevant to infectious diseases resulting in increased prevalence and mortality. In this article, we aim to provide an overview of the effects of smoking in various infections and to explain the potential mechanisms. We searched PubMed and other relevant databases for scientific studies that explored the relationship between smoking and infection. The mechanisms of susceptibility to infection in smokers may include alteration of the structural, functional and immunologic host defences. Smoking is one of the main risk factors for infections in the respiratory tract, digestive tract, reproductive tract, and other systems in humans, increasing the prevalence of HIV, tuberculosis, SARS-CoV, and the current SARS-CoV-2. Smoking cessation can reduce the risk of infection. Smoking increases the incidence of infections and aggravates the progress and prognosis of infectious diseases in a dose-dependent manner. Smoking cessation promotion and education are the most practical and economical preventive measures to reduce aggravation of disease infection owing to tobacco use.

Genetic analysis of osteoblast activity identifies Zbtb40 as a regulator of osteoblast activity and bone mass

Osteoporosis is a genetic disease characterized by progressive reductions in bone mineral density (BMD) leading to an increased risk of fracture. Over the last decade, genome-wide association studies (GWASs) have identified over 1000 associations for BMD. However, as a phenotype BMD is challenging as bone is a multicellular tissue affected by both local and systemic physiology. Here, we focused on a single component of BMD, osteoblast-mediated bone formation in mice, and identified associations influencing osteoblast activity on mouse Chromosomes (Chrs) 1, 4, and 17. The locus on Chr. 4 was in an intergenic region between Wnt4 and Zbtb40, homologous to a locus for BMD in humans. We tested both Wnt4 and Zbtb40 for a role in osteoblast activity and BMD. Knockdown of Zbtb40, but not Wnt4, in osteoblasts drastically reduced mineralization. Additionally, loss-of-function mouse models for both genes exhibited reduced BMD. Our results highlight that investigating the genetic basis of in vitro osteoblast mineralization can be used to identify genes impacting bone formation and BMD.

The Utility of Cervical Spine Bracing As a Postoperative Adjunct to Multilevel Anterior Cervical Spine Surgery

Background

Use of cervical bracing/collar subsequent to anterior cervical spine discectomy and fusion (ACDF) is variable. Outcomes data regarding bracing after ACDF are limited. Here, we study the impact of bracing on short-term outcomes related to safety, quality of care, and direct costs in multilevel ACDF.

Methods

Retrospective cohort analyses of all consecutive patients undergoing multilevel ACDF with or without bracing from 2013 to 2017 was undertaken (n = 616). Patient demographics and comorbidities were analyzed. Tests of independence and logistic regressions were used to assess differences in length of stay (LOS), discharge disposition (home, assisted rehabilitation facility [ARF], or skilled nursing facility [SNF]), quality-adjusted life year (QALY), direct cost, readmission within 30 days, and emergency room (ER) visits within 30 days.

Results

Amongst the study population, 553 were braced and 63 were not braced. There was no difference in comorbidities (P > .05) such as obesity, smoking, chronic obstructive pulmonary disease, hypertension, coronary artery disease, congestive heart failure, and problem list number. A significant difference in American Society of Anesthesiologists (ASA) score was found, with more ASA 2 patients in the braced cohort and more ASA 3 patients in the unbraced cohort (P = .007). LOS was extended for the unbraced group (median 156.9 ± 211.4 versus 86.67 ± 130.6 h, P = .003), and ER visits within 30 days were 0.21 times less likely in the braced group (P = .006). There was no difference in readmission (P = .181), QALY gain (P = .968), and direct costs (P = .689).

Conclusion

Bracing following multilevel cervical fixation does not alter short-term postoperative course or reduce the risk for early adverse outcomes in a significant manner.

Effects of smoking habit change on hospitalized fractures: a retrospective cohort study in a male population

We examined effects of smoking habit change on fracture risk in men. Long-term quitters and never smokers showed decreased risk for overall fractures, lumbar fractures, and other site fractures. Short-term quitters did not show decreased risk. Longer time since smoking cessation may lead to decreased fracture risk in men.

PURPOSE

Cigarette smoking is a well-known modifiable risk factor of osteoporosis and fractures. This study investigated the effects of change in smoking habits on risks of all types of fractures in men using a nationwide health claims database.

METHODS

Retrospective study was performed using the Korean National Health Insurance Service-National Sample Cohort Data. Cox proportional hazards regression analyses were performed to estimate risks of all types of hospitalized fractures, hip fractures, lumbar fractures, and other site fractures (all other fractures excluding the lumbar and hip areas).

RESULTS

Compared to continued smokers, long-term quitters and never smokers showed decreased risk for all types of fractures (adjusted hazard ratio (aHR) 0.83, 95% confidence interval (CI) 0.78-0.88 and aHR 0.84, 95% CI 0.80-0.89, respectively). According to skeletal site, long-term quitters and never smokers showed decreased risk for lumbar fractures (aHR 0.82, 95% CI 0.68-0.98 and aHR 0.85, 95% CI 0.73-0.99, respectively) and other site fractures (aHR 0.83, 95% CI 0.78-0.89 and aHR 0.85, 95% CI 0.81-0.90, respectively). Hip fractures were decreased in never smokers (aHR 0.77, 95% CI 0.62-0.94). Short-term quitters did not show decreased risk for fractures.

CONCLUSIONS

Longer time since smoking cessation in men may lead to decreased risk for fractures, especially lumbar and other site fractures. Physicians should counsel patients at risk for fractures both to quit smoking and to maintain abstinence from smoking. Further studies may be required to help comprehend how smoking cessation can affect fracture risk.

The Utility of Cervical Spine Bracing as a Postoperative Adjunct to Single-level Anterior Cervical Spine Surgery

Background Context:

Use of cervical bracing/collar subsequent to anterior cervical spine discectomy and fusion (ACDF) is variable. Outcomes data regarding bracing after ACDF are limited.

Purpose:

The purpose of the study is to study the impact of bracing on short-term outcomes related to safety, quality of care, and direct costs in single-level ACDF.

Study Design/Setting:

This retrospective cohort analysis of all consecutive patients (n = 578) undergoing single-level ACDF with or without bracing from 2013 to 2017 was undertaken.

Methods:

Patient demographics and comorbidities were analyzed. Tests of independence (Chi-square, Fisher's exact, and Cochran–Mantel–Haenszel test), Mann–Whitney–Wilcoxon tests, and logistic regressions were used to assess differences in length of stay (LOS), discharge disposition (home, assisted rehabilitation facility-assisted rehabilitation facility, or skilled nursing facility), quality-adjusted life year (QALY), surgical site infection (SSI), direct cost, readmission within 30 days, and emergency room (ER) visits within 30 days.

Results:

Among the study population, 511 were braced and 67 were not braced. There was no difference in graft type (P = 1.00) or comorbidities (P = 0.06–0.73) such as obesity (P = 0.504), smoking (0.103), chronic obstructive pulmonary disease hypertension (P = 0.543), coronary artery disease (P = 0.442), congestive heart failure (P = 0.207), and problem list number (P = 0.661). LOS was extended for the unbraced group (median 34.00 + 112.15 vs. 77.00 + 209.31 h, P < 0.001). There was no difference in readmission (P = 1.000), ER visits (P = 1.000), SSI (P = 1.000), QALY gain (P = 0.437), and direct costs (P = 0.732).

Conclusions:

Bracing following single-level cervical fixation does not alter short-term postoperative course or reduce the risk for early adverse outcomes in a significant manner. The absence of bracing is associated with increased LOS, but cost analyses show no difference in direct costs between the two treatment approaches. Further evaluation of long-term outcomes and fusion rates will be necessary before definitive recommendations regarding bracing utility following single-level ACDF.

Efficacy, safety, and economics of bracing after spine surgery: a systematic review of the literature

BACKGROUND CONTEXT

Bracing is often used after spinal surgery to immobilize the spine, improve fusion, and relieve pain. However, controversy exists regarding the efficacy, necessity, and safety of various bracing techniques in the postsurgical setting.

PURPOSE

In this systematic review, we aimed to compare the effectiveness, safety, and cost-effectiveness of postoperative bracing versus no postoperative bracing after spinal surgery in patients with several common operative spinal pathologies.

STUDY DESIGN/SETTING

A systematic review was carried out to compare postoperative bracing and no postoperative bracing.

METHODS

A systematic search was conducted of MEDLINE, Embase, and the Cochrane Collaboration Library from 1970 to May 2017, supplemented by manual searching of the reference list of relevant studies and previously published reviews. Studies were included if they compared disability, quality of life, functional impairment, radiographic outcomes, cost-effectiveness, or complications between patients treated with postoperative bracing and patients not receiving any postoperative bracing. Each article was critically appraised independently by two reviewers, and the overall body of evidence was rated using guidelines outlined by the Grading of Recommendation Assessment, Development and Evaluation (GRADE) Working Group.

RESULTS

Of the 858 retrieved citations, 5 studies met the inclusion criteria and were included in this review, consisting of 4 randomized controlled trials and 1 prospective cohort study. Low to moderate evidence suggests that there are no significant differences in most measures of disability, pain, quality of life, functional impairment, radiographic outcomes, and safety between groups. Isolated studies reported statistically significant and inconsistent differences between groups with respect to Neck Disability Index at 6 weeks postoperatively or Short Form-36 Physical Component Score at 1.5, 3, 6, and 12 months postoperatively.

CONCLUSIONS

Based on limited evidence, postoperative bracing does not result in improved outcomes after spinal surgery. Future high-quality randomized trials will be required to confirm these findings.

Cigarette smoking and hip volumetric bone mineral density and cortical volume loss in older adults: The AGES-Reykjavik study

This study aimed to explore the relationships of several indicators of cigarette smoking habits (smoking status, pack-years, age at smoking initiation and smoking cessation) with quantitative computed tomographic (QCT)-derived proximal femur bone measures (trabecular vBMD, integral vBMD and the ratio of cortical to total tissue volume (cvol/ivol)) and with subsequent change in these measures over the next five years. A total of 2673 older adults (55.9% women), aged 66-92 years at baseline from the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study, who had two QCT scans of the hip were studied. In multivariable linear regression models, compared to never-smokers, current smokers had lower cvol/ivol at baseline and former-smokers had poorer measures on all outcomes (lower trabecular vBMD, integral vBMD and cvol/ivol), even when adjusted for several potential confounders. Further, among former smokers, those with higher pack-years had worse bone outcomes and those with longer duration since smoking cessation had better bone health at baseline. Analyses of change in bone measures revealed that compared to never-smokers, current smokers had significantly greater loss of trabecular vBMD, integral vBMD, and cvol/ivol. The regression models included adjustment for sex, age, education, and baseline body mass index, creatinine, % weight change from age 50, 25OHD, physical activity level, high-sensitive C-Reactive protein levels, alcohol and coffee consumption, history of diabetes mellitus, arthritis, and respiratory diseases. In conclusion, both current and former smoking showed adverse associations with bone health assessed with QCT. Results suggest that current smoking in particular may aggravate the rate of bone loss at older age and highlight implications for targeting this risk factor in populations that present higher smoking prevalence and vulnerability to bone fragility.

Bone density loss on computed tomography at 3-year follow-up in current compared to former male smokers

OBJECTIVES

Cigarette smoking negatively affects bone quality and increases fracture risk. Little is known on the effect of smoking cessation and computed tomography (CT)-derived bone mineral density (BMD) decline in the spine. We evaluated the association of current and former smoking with BMD decline after 3-year follow-up.

METHODS

Male current and former smokers participating in a lung cancer screening trial who underwent baseline and 3-year follow-up CT were included. BMD was measured by manual placement of a region of interest in the first lumbar vertebra and expressed in Hounsfield Unit (HU). Multiple linear regression analysis was used to evaluate the association between pack years smoked and smoking status with BMD decline.

RESULTS

408 participants were included with median (25th-75th percentile) age of 59.4 (55.9-63.5) years. At the start of the study, 197 (48.3%) participants were current smokers and 211 (51.7%) were former smokers and had a similar amount of pack years. Current smokers had quit smoking for 6 (4-8) years prior to inclusion. There was no difference in BMD between current and former smokers at baseline (109±34 HU vs. 108±32 HU, p=0.96). At 3-year follow-up, current smokers had a mean BMD decline of -3±13 HU (p=0.001), while BMD in former smokers did not change as compared to baseline (1±13 HU, p=0.34). After adjustment for BMD at baseline and body mass index, current smoking was independently associated with BMD decline (-3.8 HU, p=0.003). Age, pack years, and the presence of a fracture at baseline did not associate with BMD decline.

CONCLUSIONS

Current smokers showed a more rapid BMD decline over a 3-year period compared to former smokers. This information might be important to identify subjects at risk for osteoporosis and emphasizes the importance of smoking cessation in light of BMD decline.

Effect of smoking on complications following primary shoulder arthroplasty

BACKGROUND

The purpose of this study was to examine the effect of smoking on the incidence of complications after primary anatomic total shoulder arthroplasty (TSA) and reverse shoulder arthroplasty (RSA).

METHODS

All patients who underwent primary TSA or RSA at our institution between 2002 and 2011 and had a minimum 2-year follow-up were included. Smoking status was assessed at the time of surgery. Current smokers, former smokers, and nonsmokers were compared for periprosthetic infection, fractures (intraoperative and postoperative), and loosening after surgery.

RESULTS

The cohort included 1834 shoulders in 1614 patients (814 in smokers and 1020 in nonsmokers). Complications occurred in 73 patients (75 shoulders; 44 in smokers and 31 in nonsmokers). There were 20 periprosthetic infections (16 in smokers and 4 in nonsmokers), 27 periprosthetic fractures (14 in smokers and 13 in nonsmokers), and 28 loosenings (14 in smokers and 14 in nonsmokers). Smokers had lower periprosthetic infection-free survival rates (95.3%-99.4% at 10 years; P = .001) and overall complication-free survival rates (78.4%-90.2%; P = .012) than nonsmokers. Multivariable analyses showed that both current and former smokers had significantly higher risk of periprosthetic infection in comparison with nonsmokers (hazard ratio [HR], 7.27 and 4.56, respectively). In addition, current smokers showed a higher risk of postoperative fractures than both former smokers (HR, 3.63) and nonsmokers (HR, 6.99).

CONCLUSIONS

This study demonstrates that smoking is a significant risk factor of complications after TSA and RSA. These findings emphasize the need for preoperative collaborative interventions, including smoking cessation programs.

Systemic IL-6 Effector Response in Mediating Systemic Bone Loss Following Inhalation of Organic Dust

Airway and skeletal diseases are prominent among agriculture workers. Repetitive inhalant exposures to agriculture organic dust extract (ODE) induces bone deterioration in mice; yet the mechanisms responsible for connecting the lung-bone inflammatory axis remain unclear. We hypothesized that the interleukin (IL)-6 effector response regulates bone deterioration following inhalant ODE exposures. Using an established intranasal inhalation exposure model, wild-type (WT) and IL-6 knockout (KO) mice were treated daily with ODE or saline for 3 weeks. ODE-induced airway neutrophil influx, cytokine/chemokine release, and lung pathology were not reduced in IL-6 KO animals compared to WT mice. Utilizing micro-computed tomography, analysis of tibia showed that loss of bone mineral density, volume, and deterioration of bone micro-architecture, and mechanical strength induced by inhalant ODE exposures in WT mice were absent in IL-6 KO animals. Compared to saline treatments, bone-resorbing osteoclasts and bone marrow osteoclast precursor populations were also increased in ODE-treated WT but not IL-6 KO mice. These results show that the systemic IL-6 effector pathway mediates bone deterioration induced by repetitive inhalant ODE exposures through an effect on osteoclasts, but a positive role for IL-6 in the airway was not demonstrated. IL-6 might be an important link in explaining the lung-bone inflammatory axis.

Predicting the minimum clinically important difference in patients undergoing surgery for the treatment of degenerative cervical myelopathy

OBJECTIVE

The minimum clinically important difference (MCID) is defined as the minimum change in a measurement that a patient would identify as beneficial. Before undergoing surgery, patients are likely to inquire about the ultimate goals of the operation and of their chances of experiencing meaningful improvements. The objective of this study was to define significant predictors of achieving an MCID on the modified Japanese Orthopaedic Association (mJOA) scale at 2 years following surgery for the treatment of degenerative cervical myelopathy (DCM).

METHODS

Seven hundred fifty-seven patients were prospectively enrolled in either the AOSpine North America or International study at 26 global sites. Fourteen patients had a perfect preoperative mJOA score of 18 and were excluded from this analysis (n = 743). Data were collected for each participating subject, including demographic information, symptomatology, medical history, causative pathology, and functional impairment. Univariate log-binominal regression analyses were conducted to evaluate the association between preoperative clinical factors and achieving an MCID on the mJOA scale. Modified Poisson regression using robust error variances was used to create the final multivariate model and compute the relative risk for each predictor.

RESULTS

The sample consisted of 463 men (62.31%) and 280 women (37.69%), with an average age of 56.48 ± 11.85 years. At 2 years following surgery, patients exhibited a mean change in functional status of 2.71 ± 2.89 points on the mJOA scale. Of the 687 patients with available follow-up data, 481 (70.01%) exhibited meaningful gains on the mJOA scale, whereas 206 (29.98%) failed to achieve an MCID. Based on univariate analysis, significant predictors of achieving the MCID on the mJOA scale were younger age; female sex; shorter duration of symptoms; nonsmoking status; a lower comorbidity score and absence of cardiovascular disease; and absence of upgoing plantar responses, lower-limb spasticity, and broad-based unstable gait. The final model included age (relative risk [RR] 0.924, p < 0.0001), smoking status (RR 0.837, p = 0.0043), broad-based unstable gait (RR 0.869, p = 0.0036), and duration of symptoms (RR 0.943, p = 0.0003).

CONCLUSIONS

In this large multinational prospective cohort, 70% of patients treated surgically for DCM exhibited a meaningful functional gain on the mJOA scale. The key predictors of achieving an MCID on the mJOA scale were younger age, shorter duration of symptoms, nonsmoking status, and lack of significant gait impairment.

Variables Prognostic for Delayed Union and Nonunion Following Ulnar Shortening Fixed With a Dedicated Osteotomy Plate

PURPOSE

To examine potential risk factors for the development of delayed or nonunion following elective ulnar shortening osteotomy using a dedicated osteotomy plating system.

METHODS

We performed a retrospective review of all patients who underwent elective ulnar shortening using the TriMed single osteotomy dynamic compression plating system by 1 of 2 fellowship-trained hand surgeons over a 5-year period. Demographic data and medical, surgical, and social histories were reviewed. Time to bony union was determined radiographically by a blinded reviewer. Bivariate statistical analysis was performed to examine the effect of explanatory variables on the time to union and the incidence of delayed or nonunion. Those variables associated with the development of delayed or nonunion were used in a multivariate logistic regression model. Complications, including the need for additional surgery, were also recorded.

RESULTS

Seventy-two ulnar shortening osteotomy procedures were performed in 69 patients. Delayed union, defined as ≥ 6 months to union, occurred in 8 of 72 cases (11%). Of 72 surgeries, 4 (6%) resulted in nonunions, all of which required additional surgery. Hardware removal was performed in 13 of 72 (18%) of the cases. Time to union was significantly increased in smokers (6 ± 3 months) versus nonsmokers (3 ± 1 months). On multivariable analysis, diabetics and active smokers demonstrated a significantly higher risk of developing delayed union or nonunion. Patient age, sex, body mass index, thyroid disease, worker's compensation status, alcohol use, and amount smoked daily did not have an effect on the time to union or the incidence of delayed or nonunion.

CONCLUSIONS

Despite the use of an osteotomy-specific plating system, smokers and diabetics were at significantly higher risk for both delayed union and nonunion following elective ulnar shortening osteotomy. Other known risk factors for suboptimal bony healing were not found to have a deleterious effect.

Skeletal Effects of Smoking

Smoking is a leading cause of preventable death and disability. Smoking has long been identified as a risk factor for osteoporosis, with data showing that older smokers have decreased bone mineral density and increased fracture risk compared to nonsmokers, particularly at the hip. The increase in fracture risk in smokers is out of proportion to the effects on bone density, indicating deficits in bone quality. Advanced imaging techniques have demonstrated microarchitectural deterioration in smokers, particularly in the trabecular compartment. The mechanisms by which smoking affects skeletal health remain unclear, although multiple pathways have been proposed. Smoking cessation may at least partially reverse the adverse effects of smoking on the skeleton.

The Effect of Smoking on Spinal Cord Healing Following Surgical Treatment of Cervical Myelopathy

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

The purpose of this study was to compare outcomes of surgical treatment of cervical myelopathy between smokers and nonsmokers as assessed by the Nurick score.

SUMMARY OF BACKGROUND DATA

The harmful effects of smoking on healing have been well established. However, the effect of smoking on postoperative outcomes for cervical myelopathy has not been specifically evaluated.

METHODS

The medical records of 212 patients who underwent surgery for cervical spondylotic myelopathy were reviewed. Inclusion criteria were the diagnosis of cervical spondylotic myelopathy with a Nurick score, surgical intervention, and at least 2 years of follow-up. The patients were categorized into 2 groups according to smoking status and stratified according to pack years and packs per day. Age at presentation, sex, preoperative and postoperative Nurick score, duration of symptoms preoperatively, duration of follow-up, procedure performed, surgical approach, number of levels fused, diabetes status, cocaine use, ethanol use, preoperative magnetic resonance imaging signal change, and whether the patient belonged to the Veterans Administration (VA) were recorded. Analysis was done using simple linear regression and multiple regression.

RESULTS

Univariate analysis demonstrated a postoperative improvement in nonsmokers of 1.53 points on the Nurick scale compared with 0.6 points in smokers (P < 0.001). There is a progressive decrease in improvement as the number of pack years and packs per day increase (P < 0.001). There is a greater improvement in Nurick score with greater (worse) preoperative score but only in patients with fewer than 25 pack years. Smoking status is not associated with preoperative Nurick score.

CONCLUSION

Smoking status is associated with poor improvement in Nurick score after surgical treatment of cervical myelopathy. Smoking may have a directly toxic effect on the intrinsic healing capability of the spinal cord, particularly beyond 25 pack years.

LEVEL OF EVIDENCE

3.

Does fetal smoke exposure affect childhood bone mass? The Generation R Study

We assessed the intrauterine influence of maternal smoking on childhood bone mass by comparing parental prenatal and postnatal smoking habits. We observed higher bone mass in children exposed to maternal smoking, explained by higher body weight. Maternal smoking or related lifestyle factors may affect childhood weight gain rather than skeletal growth.

INTRODUCTION

Maternal smoking during pregnancy may adversely affect bone health in later life. By comparing the associations of maternal and paternal smoking and of prenatal and postnatal exposure with childhood bone measures, we aimed to explore whether the suggested association could be explained by fetal programming or reflects confounding by familial factors.

METHODS

In 5565 mothers, fathers and children participating in a population-based prospective cohort study, parental smoking habits during pregnancy and current household smoking habits were assessed by postal questionnaires. Total body bone mineral content (BMC), bone area (BA) and bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry (DXA) at the median age of 6.0 years (IQR 0.37).

RESULTS

In confounder-adjusted models, maternal smoking during pregnancy was associated with a higher BMC of 11.6 g (95 % confidence interval (CI) 5.6, 17.5), a larger BA of 9.7 cm(2) (95 % CI 3.0, 16.4), a higher BMD of 6.7 g/cm(2) (95 % CI 2.4, 11.0) and a higher BMC of 5.4 g (95 % CI 1.3, 9.6) adjusted for BA of the child. Current weight turned out to mediate these associations. Among mothers who did not smoke, paternal smoking did not show evident associations with childhood bone measures. Also, household smoking practices during childhood were not associated with childhood bone measures.

CONCLUSIONS

Our results do not support the hypothesis of fetal smoke exposure affecting childhood bone mass via intrauterine mechanisms. Maternal smoking or related lifestyle factors may affect childhood weight gain rather than skeletal growth.

Bone mineral density and chronic lung disease mortality: the rotterdam study

CONTEXT

Low bone mineral density (BMD) has been associated with increased all-cause mortality. Cause-specific mortality studies have been controversial.

OBJECTIVE

The aim of the study was to investigate associations between BMD and all-cause mortality and in-depth cause-specific mortality.

DESIGN AND SETTING

We studied two cohorts from the prospective Rotterdam Study (RS), initiated in 1990 (RS-I) and 2000 (RS-II) with average follow-up of 17.1 (RS-I) and 10.2 (RS-II) years until January 2011. Baseline femoral neck BMD was analyzed in SD values. Deaths were classified according to International Classification of Diseases into seven groups: cardiovascular diseases, cancer, infections, external, dementia, chronic lung diseases, and other causes. Gender-stratified Cox and competing-risks models were adjusted for age, body mass index, and smoking.

PARTICIPANTS

The study included 5779 subjects from RS-I and 2055 from RS-II.

MAIN OUTCOME MEASUREMENTS

We measured all-cause and cause-specific mortality.

RESULTS

A significant inverse association between BMD and all-cause mortality was found in males [expressed as hazard ratio (95% confidence interval)]: RS-I, 1.07 (1.01-1.13), P = .020; RS-II, 1.31 (1.12-1.55), P = .001); but it was not found in females: RS-I, 1.05 (0.99-1.11), P = .098; RS-II, 0.91 (0.74-1.12), P = .362. An inverse association with chronic lung disease mortality was found in males [RS-I, 1.75 (1.34-2.29), P < .001; RS-II, 2.15 (1.05-4.42), P = .037] and in RS-I in females [1.72 (1.16-2.57); P = .008], persisting after multiple adjustments and excluding prevalent chronic obstructive pulmonary disease. A positive association between BMD and cancer mortality was detected in females in RS-I [0.89 (0.80-0.99); P = .043]. No association was found with cardiovascular mortality.

CONCLUSIONS

BMD is inversely associated with mortality. The strong association of BMD with chronic lung disease mortality is a novel finding that needs further analysis to clarify underlying mechanisms.

Factors associated with bisphosphonate treatment failure in postmenopausal women with primary osteoporosis

Among 97 postmenopausal women with primary osteoporosis, adequate calcium and vitamin D supplementation, and good compliance to a 36-month bisphosphonate treatment, the 25.8% of patients are inadequate responders. Current smoking and a bone turnover in the upper part of the normal range increase the risk of treatment failure.

INTRODUCTION

To evaluate the prevalence of the bisphosphonate treatment failure and its possible associated factors in women with primary osteoporosis (PO).

METHODS

We studied 97 previously untreated postmenopausal women with PO and fragility fractures and/or a FRAX® 10-year probability of a major osteoporotic fracture ≥ 7.5%, before and after a 36-month treatment with alendronate or risedronate and adequate vitamin D supplementation with good compliance. At baseline and after 36 months, lumbar spine (LS) and femoral bone mineral density (BMD) were assessed by Dual X-ray absorptiometry and vertebral fractures by spinal radiographs. Spinal deformity index (SDI) was calculated. Treatment failure was defined by the presence of ≥ 2 incident fragility fractures and/or a BMD decrease greater than the least significant change.

RESULTS

Bisphosphonate treatment failure was observed in 25.8% of patients. Age, body mass index, years since menopause, familiar history of hip fracture, number of falls, type of bisphosphonate used, 25-hydroxyvitamin D levels (25OHVitD), BMD, SDI, and FRAX® score at baseline were not different between responders and inadequate responders. Treatment failure was associated with current smoking (OR 3.22, 95% CI 1.10-9.50, P = 0.034) and baseline alkaline phosphatase total activity levels ≥ 66.5 U/L (OR 4.22, 95% CI 1.48-12.01, P = 0.007), regardless of age, number of falls, LS BMD, and baseline SDI.

CONCLUSIONS

The 25.8 % of PO postmenopausal women inadequately responds to bisphosphonates, despite a good compliance to therapy and normal 25OHVitD levels. The current smoking and bone turnover in the upper part of the normal range are associated with the inadequate response to bisphosphonates.

The musculoskeletal effects of cigarette smoking

➤ Cigarette smoking decreases bone mineral density and increases the risk of sustaining a fracture or tendon injury, with partial reversibility of these risks with long-term cessation of smoking. ➤ Cigarette smoking increases the risk for perioperative complications, nonunion and delayed union of fractures, infection, and soft-tissue and wound-healing complications. ➤ Brief preoperative cessation of smoking may mitigate these perioperative risks. ➤ Informed-consent discussions should include notification of the higher risk of perioperative complications with cigarette smoking and the benefits of temporary cessation of smoking.

Early initiation of smoking and alcohol drinking as a predictor of lower forearm bone mineral density in late adolescence: a cohort study in girls

Background

Adolescence is a critical stage for bone accrual. It is also decisive for the establishment of behaviors such as smoking and alcohol drinking.

Objective

To quantify the short- and long-term associations between smoking and drinking initiation and bone mineral density in adolescent girls.

Methods

We used prospective data from 731 girls identified in public and private schools in Porto, Portugal. Evaluations were conducted when participants were 13 and 17 years old. Bone mineral density (BMD) was measured at the forearm by dual-energy X-ray absorptiometry and weight, height and fat-free mass were measured. Pubertal development status was estimated using menarche age. Self-administered questionnaires were used to collect data on smoking and alcohol drinking, physical exercise and calcium and vitamin D intakes. BMD in early and late adolescence was analyzed as a continuous or dichotomous (Z-score cutoff: −1.0) variable. Associations were calculated using linear or logistic regression.

Results

Over one quarter of these girls had tried smoking by 13, while 59% had drunk alcoholic beverages and 20% had experienced both behaviors by that age. Lower mean BMD at 17 years of age was observed in girls who had ever smoked by 13, as well as in those who reported drinking at that age. There were no significant cross-sectional associations between experience and frequency of smoking or drinking and BMD at 13 years of age. However, we observed significant associations between BMD z-score<−1 in late adolescence and having ever smoked by 13, after adjustment for menarche age and sports practice, (OR = 1.92; 95% CI: 1.21, 3.05) and with ever smoking and drinking in the same period (OR = 2.33; 95% CI: 1.36, 4.00).

Conclusion

Our study adds prospective evidence to the role of early initiation of smoking and alcohol drinking as relevant markers of lower bone mineral density in late adolescence.