CE: The Effects of Smoking on Bone Health and Healing

The effect of coffee consumption on three main bone disorders: a Mendelian randomization trial

INTRODUCTION

Despite a large number of observational studies examining the effect of coffee consumption(CC) on bone disorders(BDs), particularly, osteoarthritis(OA), osteoportic fracture(OF), and rheumatoid arthritis(RA), the conclusions are highly controversial. Thus, it is essential to examine the causal association between CC and BDs.

MATERIALS AND METHODS

Mendelian randomization (MR) analysis was performed to assess the causal influence of CC on OF, RA, and OA. The main endpoint was the odds ratio (OR) of the inverse variance weighted (IVW) approach. In addition, the weighted median (WM), MR-Egger regressions, MR-pleiotropy residual sum and outlier (MR-PRESSO) and multivariable MR (MVMR) were included in sensitivity analyses. Furthermore, the function of causal SNPs was evaluated by gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and protein-protein interaction networks.

RESULTS

Primary MR analysis based on the IVW method suggested that changes in CC alter risk of OF (OR = 1.383, 95%CI 1.079-1.853, P = 0.039), RA(OR: 1.623, 95%CI 1.042-2.527, P = 0.032) and HOA (hip osteoarthritis, OR = 1.536, 95% CI 1.044-2.259, P = 0.021). However, these causal relationships were not robust in sensitivity analyses. In contrast, there is a positive causal relationship between increased CC and the risk of KOA (knee osteoarthritis, OR: 2.094, 95%CI: 1.592-2.754, P = 1.41 × 10-7), as evidenced by the IVW using random effect. A similar effect size was observed across all MR sensitivity analyses, with no evidence of horizontal pleiotropy.

CONCLUSION

Based on our MR analysis, increased CC was causally linked to an increase in the risk of KOA. Genetic predictions suggested that CC reduction may have benefits for bone health.

Pack Years of Tobacco Cigarette Smoking as a Predictor of Bony Fusion after Anterior Cervical Discectomy and Fusion

OBJECTIVE

Smoking tobacco cigarettes negatively impacts bone healing after spinal fusion. Smoking history is often assessed based on current smoker and nonsmoker status. However, in current research, smoking history has not been quantified in terms of pack years to estimate lifetime exposure and assess its effects. Our goal was to investigate the influence of smoking history, quantified in pack years, on bony fusion after anterior cervical discectomy and fusion (ACDF).

METHODS

A retrospective chart review of consecutive patients who underwent ACDF for cervical disc degeneration between September 21, 2017 and October 17, 2018 was conducted. Patient demographics, procedural variables, and postoperative outcomes were analyzed. Multivariate logistic regression analysis was performed to identify predictive factors for bony fusion following ACDF. Receiver operating characteristic curve analysis was used to determine the optimal discrimination threshold for smoking history pack years in association with nonfusion.

RESULTS

Among 97 patients identified, 90 (93%) demonstrated bony fusion on postoperative imaging. Mean number of smoking history pack years was 6.1 ± 13 for the fusion group and 16 ± 21 for the nonfusion group. Multivariate logistic regression analysis suggested that increased pack years of tobacco cigarette smoking was a significant predictor of nonfusion (95% confidence interval, [1.0,1.1], P = 0.045). The receiver operating characteristic curve analysis revealed that 6.1 pack years best stratified the risk for nonfusion (area under the curve, 0.8).

CONCLUSIONS

Patients with a history of tobacco cigarette smoking ≥6.1 pack years may have an increased risk of nonfusion after ACDF.

Decline in Separate Incision Autograft for Spine Surgery Over the Past Decade: A Fading "gold standard"

BACKGROUND

Spinal fusion is a common procedure for which bone grafting is a critical component. Although iliac crest (separate incision autograft) is typically referred to as the "gold standard" grafting material, it seems to be used less and less frequently.

METHODS

The 2010 to Q3 2020 MSpine PearlDiver data set was used to identify patients receiving separate incision autograft versus local autograft/allograft/graft supplement for spinal fusion. Grafting trends over the decade were determined. Patient age, sex, Elixhauser Comorbidity Index, smoking status, insurance plan, region of the country where the surgery was conducted, and surgeon specialty were characterized and compared by the type of bone graft using univariate and multivariate analyses.

RESULTS

Of 373,569 spinal bone grafting procedures, separate incision autografts were used for 32,401 (8.67%). A gradual decline was observed from 2010 (10.57% of spinal grafting procedures) to 2020 (4.69%, P -value < 0.00001). Independent predictors of having had a separate incision autograft in order of decreasing odds included surgeon specialty (relative to neurosurgery, orthopaedic odds ratio [OR], 2.45), smoking status (relative to nonsmokers, smokers OR, 1.45), region of the country (relative to Midwest, Northeast OR, 1.11; West OR, 1.42; and South OR, 1.48), insurance (relative to commercial, Medicare OR, 1.14), younger age (OR, 1.04 per decade increase), and lower Elixhauser Comorbidity Index (OR, 0.95 per two-point increase) ( P < 0.0001 for each).

CONCLUSION

Iliac crest autograft continues to be referred to as the gold standard grafting material for spine fusions. However, the use of this has faded over the past decade to only 4.69% of spinal fusions in 2020. While some patient factors had an effect on when separate incision autograft was used, nonsurgical factors, including surgeon specialty, geographic region where the surgery was conducted, and insurance factors, suggested that external factors/physician training influence this choice.

The Snuffbox: The Effect of Smokeless Tobacco Use on Scaphoid Fracture Healing

BACKGROUND

Smoking has been demonstrated to be a risk factor for nonunion of scaphoid fractures, but it is unclear if chewing tobacco confers similar risk. The purpose of this study was to evaluate rates of bone-related complications after nonsurgical management of scaphoid fractures in smokeless tobacco users compared with matched control subjects and compared with smokers.

METHODS

A retrospective cohort study was conducted using the PearlDiver database. For patients who underwent nonsurgical management of scaphoid fractures, 212 smokeless tobacco users and 6,048 smokers were matched 1:4 with control subjects (n = 848 and 24,192, respectively) and 212 smokeless tobacco users were matched 1:4 with 848 smokers. Rates of bone-related complications within 2 years of initial injury were compared using multivariable logistic regression.

RESULTS

From weeks 12 through 104 after initial injury, compared with control subjects who do not use tobacco, the smokeless tobacco cohort demonstrated markedly higher rates of nonunion (5.7% vs 2.7%, OR: 2.07). Compared with control subjects who do not use tobacco, the smoking cohort demonstrated markedly higher rates of nonunion (4.3% vs 2.6%, OR: 1.91), repair of nonunion (1.5% vs 0.9%, OR: 1.87), and four corner fusion and proximal row carpectomy (0.3% vs 0.1%, OR: 3.17). Smokeless tobacco use was markedly underdiagnosed in the adult male cohort of unilateral scaphoid fractures with 2 years of follow-up found in the database (372 of 25,704, 1.45%) relative to Centers for Disease Control estimates for adult male smokeless tobacco use (4.5%) (P < 0.001).

CONCLUSION

Given the higher rates of nonunion diagnoses after nonsurgical management in this cohort, surgeons should consider asking all patients with scaphoid fractures if they use smokeless tobacco or smoke and consider adding this to the patient's intake history to further identify patients at risk for nonunions. Tobacco cessation counseling is indicated for all tobacco users, including smokeless with scaphoid fractures.

I'll be back - Predictive validity of adults' expectations for recovery after fractures - A longitudinal observational study

PURPOSE

Recovery after fractures due to accidents relates to all aspects of the biopsychosocial model. Therefore, it is difficult for the patients to foresee the consequences of the fractures. This study aimed to examine 1) patients' expectations regarding the impact of the injury on everyday life, 2) predictive validity of their expectations after six months, and 3) factors that predict a return to work.

PATIENTS AND METHODS

Patients were 18-64 years old and hospitalized with simple or compound/multiple fractures due to an accident. During admission, structured interviews were conducted with a questionnaire covering working conditions, expectations regarding recovery, sports, economy, family, household, and return to work. Additionally, mental and physical status were covered with Short Musculoskeletal Function Assessment questionnaire (SMFA) and Short Form 36, and working conditions were uncovered too. After six months, telephonic interviews were conducted with the 164 available patients to elucidate the impact of the fractures on everyday life, their health status, and sick leave. Likelihood ratios, post-test probabilities, and logistic regression analysis were performed to establish if patients' expectations predicted recovery, economy, sports, family, household, and return to work.

RESULTS

Few patients' baseline expectations about everyday life were met. The likelihood ratios were small, and the post-test probabilities for expectations consistent with outcomes were between 18% and 68%, with recovery as the lowest and participation in sports as the highest. In the multivariate analysis, patients' expectations did not predict short-term (less than two months) or long-term sick leave (more than three months). Self-rated health and the bother index of SMFA were significant short-term and long-term predictors for sick leave. Additionally, vitality, pain, and decision latitude at work predicted sick leave of less than two months.

CONCLUSION

A few days after the accident, patients' expectations about everyday life are not associated with outcomes six months later. Likelihood ratios indicate difficulties for the patients in predicting fractures' consequences on various aspects of everyday life. Return to work was associated with self-rated health and the bother index of SMFA. Future research should examine if fracture patients can benefit from comprehensive, individual counseling during admission to set appropriate expectations.

Serum Uric Acid Level Is Positively Associated With Higher Bone Mineral Density at Multiple Skeletal Sites Among Healthy Qataris

BACKGROUND

Oxidative stress has been implicated as a fundamental mechanism in the decline of bone mass. Although serum uric acid (SUA) has potent antioxidant properties, the findings of many epidemiological and experimental studies couldn't draw a clear conclusion on the relation between SUA and bone health. We aim to investigate the association between SUA and bone mineral density (BMD) at different skeletal sites among healthy Qataris.

METHODOLOGY

A cross-sectional analysis including total-body and site-specific bone mineral density scores and other serological markers of 2981 healthy Qatari adults (36.4 ± 11.1 years) from the Qatar biobank database was conducted. The study participants were divided into quartiles based on the level of SUA, and the BMD was measured using dual-energy X-ray absorptiometry (DXA). Multiple regression analyses were applied to investigate the association between SUA and BMD adjusting for multiple confounding factors.

RESULTS

High levels of SUA were significantly associated with the increased bone mineral density of the total body and at site-specific skeletal locations after adjusting for age and gender (p-value < 0.001). Further adjustment for body mass index (BMI), smoking, vitamin D, alkaline phosphatase, and estimated glomerular filtration rate (eGFR) levels attenuated the association but the association remained significant for individuals with high SUA levels (p-value ≤ 0.01).The association between SUA and BMD was not significant in non-obese, females, young adults, and smokers. However, no interaction was found between SUA and age, gender, BMI and smoking.

CONCLUSION

Higher SUA levels are associated with a high bone density among healthy Qatari adults. However, such observation demands further investigations to outline the underlying mechanisms.