The Musculoskeletal effects of Cigarette Smoking and Nicotine

1. The Musculoskeletal effectsof Cigarette Smoking and Nicotine Dr. R Tyler Boone

2. 1960’s- U>S. Surgeon General warned of association between smoking and lung cancer • Smoking rates have declined but 20% of American adults smoke • Smokeless tobacco use increasing

3. Cigarette Smoke Phases

4. Volatile phase (500 gases) carbon monoxide, carbon dioxide, ammonia, hydrogen cyanide, benzene • Particulate phase (3500 chemicals) nicotine, nornicotine, antabine, anabasine. • Most of the carcinogens • 2 to 3mg of nicotine, 20-30ml of carbon monoxide inhaled per cigarette.

5. Nicotine

6. The addictive component of tobacco • “The cigarette should be conceived not as a product but as a package. The product is nicotine. Think of the cigarette pack as a storage container for a day’s supply of nicotine. Think of a cigarette as a dispenser for a dose unit of nicotine.” (Phillip Morris Executive)

7. Named after tobacco plant Nicotania tabacum • Frenchman Jean Nicot de Villemain • 16th century • Alkaloid

8. 17th century use as insecticide • Neurotoxin lethal to insects • 2008 EPA banned use in pesticides • 30 to 60mg lethal to humans (1 to 3 in cigarettes)

9. Nervous system effect • Decreases appetite, boosts mood, relieves depression, improves cognition and memory • Stimulates intestinal motility, increases salivation, increases heart rate and blood pressure • Nausea, vomiting

10. Nicotine Addiction

11. 1mg stimulates brain • Masks neurotransmitters, deceives neurons by replacing acetylcholine on receptors • Stimulates abnormal, extra production of dopamine • Euphoria • After finishing cigarette, the nicotine effect ceases and euphoria disappears • Attempt to recover feeling with another cigarette • Cycle of addiction • Maybe the most addictive drug known to man • Every drag delivers via lungs to brain a dose of nicotine that acts more rapidly than heroin injected via veins

12. Nicotine Withdrawal

13. Intense craving • Anxiety, drowsiness, insomnia, frustration, headaches, weight gain, difficulty with concentration • Symptoms peak at 2-3 days • No physical pain---mainly mental pangs caused by illusion of pleasure deprivation • “feeling normal”

14. Triad of addiction • Physical • Habitual • Emotional

15. Physiologic Effects of Nicotine/Smoking

16. Vasoconstriction thus hypoxia • Platelet adhesion, microvascular thrombosis • Carbon monoxide reduces the amount of oxyhemoglobin • One pack per day leads to 15-20 hrs. tissue hypoxia

17. Physiology Cont’d • Immune suppression • Decreased WBC function, reduced serum immunoglobulins, reduced antibody response, decreased lymphoidtissue, inhibits T-cell lymphocytes. • Negatively impacts wound healing and increases infection rates.

18. Bone Metabolism, Bone Mineral Density and Fracture Risk

19. Bone Metabolism • Reduced blood supply and tissue hypoxia leads to reduced bone metabolic activity • 4-fold increased risk of AVN of femoral head. • Osteoblast function stimulated at low levels of circulating nicotine and inhibited at high levels.

20. Bone Metabolism Cont’d • Osteoclastic function/formation stimulated by nicotine • Decreased calcium absorption in smokers leads to increased bone resorption and decreased formation

21. Bone Mineral Density (BMD) and Fracture Risk • Increased fracture rates of hip, spine and distal radius (osteoporosis) • Exacerbates postmenopausal and age-related bone loss • Decreased peak BMD in adolescents and young adults who smoke • Lifestyle variable associated with smoking • Decreased appetite • Lower calcium intake • Higher consumption of caffeine and alcohol • Lower levels of physical activities

23. Fracture Healing

24. Nonunion and delayed union increased • Lower Extremity Assessment Project (J. Orthopedic Trauma 2005) • Smokers with open tibial fractures • 37% increased nonunion • 3.7 times more osteomyelitis • Twice as likely to develop acute post-op infection • Delayed time to union (4 weeks)

26. Arthrodesis/Fusions

27. Numerous studies show 2.7 to 3.8 times more likely nonunion in ankle/foot procedures • Spinal Fusions • Increased pseudoarthuosis rates • Brown et ‘al (Spine 1986) • 100 pts with lumbar fusion • Pseudoarthrosis rates in smokers 40% vs. 8% in non-smokers.

29. Spine Fusion Cont’d • Bohlman (TBJS 2001) • Lower fusion rates in smokers undergoing multilevel anterior cervical interbody fusions. • Increased infection rates for all spine surgical procedures (Boakye et’al Spine 2006)

30. Soft Tissue Healing

31. Poor wound healing from cigarette smoking due to alteration of normal process of healing • Fibroblasts, stem cells, acute phase proteins and growth factors diminished in forming granulation tissue. • Nicotine increases catecholamines (dopamine, epinephrine) which inhibit epithelialization. • Free-radicals created that damage cells.

32. Soft Tissue Healing Cont’d • Tendon and ligament healing affected • Poorer outcomes in ACL reconstruction • Higher prevalence of degenerative rotator cuff tears

34. Back Pain

35. Smoking associated with increased risk of back pain and degenerative disc disease. • Twin Spine Study (Spine J. 2009) • 18% greater disc degeneration • Reduced perfusion and malnutrition from vasoconstriction/hypoxia • Chronic Pain

37. Smoking Cessation

38. No definitive guidelines on pre-operative cessation • Encourage/mandate all patients contemplating elective procedures quit 4 to 6 weeks in advance • Immune function recovers after 2-6 weeks • Wound healing after 3-4 weeks • Pulmonary function after 6-8 weeks

39. Smoking Cessation Cont’d • Orthopedists ability to express importance of quitting tobacco can have profound effect • Chrin (Spine 2000) • 35.6% quit rate in pts. Whose surgeon placed “high priority” • 19.5% quit rate in “low priority” group

40. Tools

41. 1-800-QUIT-NOW • www.smokefree.gov

42. Pharmaceutical Assistance

43. Nicotine replacement therapy (gum, transdermal patches, nasal spray, inhalers, sublingual tablets, lozenges)

44. Pharmaceutical Assistance Cont’d • Bupropion (Wellbutrin) • Atypical antidepressant • Reduces severity of nicotine cravings

45. Pharmaceutical Assistance Cont’d • Chantix/Varenicline Tartrate • Partial agonist of nicotine receptor • Reports of severe cardiovascular events and neuropsychiatric side effects

46. Pharmaceutical Assistance Cont’d • Electronic or e-cigarettes • Produce aerosol by heating a humectant (propylene glycol) containing nicotine and flavoring • When inhaled aerosol delivers nicotine • Long-term health effects unknown • Not FDA regulated

47. Most effective smoking cessation program has yet to be determined but probably includes a combination of the following: • Counseling • Dedicated “quit line” • Regular follow-up contact • NRT • Pharmaceutical support

48. Nicotine Testing

49. Nicotine and it’s major breakdown product cotinine can be tested for in urine, blood, saliva and hair. • Chewing or inhaling tobacco introduces nicotine into the body where it is metabolized by the liver and excreted in urine. • Cotinine is the primary method of nicotine detection because it has a half-life up to 10 times that of nicotine.

50. Nicotine Testing