A presentation given during the AOSpine Advances Course: Degenerative & Aging Spine, May 12-13, 2010, Jeddah, Saudi Arabia

1. Postoperative Spinal Infection Sohail Bajammal, MBChB, MSc, FRCS(C), PhD(c) Consultant Orthopaedic Spine Surgeon, Al-Noor Specialist Hospital Assistant Professor, Umm Al-Qura University Makkah, Saudi Arabia May 13, 2010

2. “A surgeon who has no complications is a surgeon who either does not operate or is not truthful.” Herkowitz HN. Foreword. In An HS, Jenis LG (ed): Complications of Spine Surgery: Treatment and Prevention. Lippincott Williams & Wilkins. 2006.

3. Objectives By the end of the lecture, you will be able to Identify the incidence & risk factors of postoperative spinal infection List the preventive measures Devise a diagnostic plan Formulate a treatment plan

4. Systematic review of 19 articles Early infection (within 3 months)

5. Incidence of Postoperative Spinal Infection <1% to 10.9% 13 studies: <5% 7 studies: between 5% and 11% Superficial versus deep infection Schuster et al., Spine 2010

6. Natural History Pyogenic Source Endplate Capillary Loop Seeding Suppurative Inflammation and Spread Anterior Extension Longitudinal Extension Posterior Extension ParavertebralDiscitis Meningitis Abscess OsteomyelitisMyelitis Adjacent vertebrae Epidural Abscess

7. Risk Factors Patient’s factors Surgical factors Surgical environment factors

8. Patient’s Factors

9. Consistently Significant Factors Odds Ratio Range Age > 60 years Presence of diabetes Malnutrition Obesity ASA score ≥ 3 Higher glucose levels 2.7 3.5 to 6.3 2.5 to 15.6 2.2 to 7.1 2.6 to 9.7 3 to 3.3 Schuster et al., Spine 2010

10. Not Consistently Significant Gender Steroid therapy Smoking Previous spine surgery Schuster et al., Spine 2010

11. Surgical Factors Posterior approach Instrumentation Bone graft harvest Blood loss or blood transfusion Duration of surgery Operative technique: Soft tissue dissection Foreign body Dead space Soft tissue coverage Schuster et al., Spine 2010

12. Consistently Significant Factors OR Range Posterior approach Transfusion 3.4 to 8.2 6.3 to 6.7 Schuster et al., Spine 2010

13. Not Consistently Significant Duration of surgery 2 out of 7 studies showed significant association OR: 2.4 to 4.7 Instrumentation: 2 out of 6 studies showed significant association OR: 2.5 to 3.4 Use of allograft 3 studies showed no difference Schuster et al., Spine 2010

14. Surgical Environment Prepping Draping Room traffic: number, talking Contaminated instruments Use of intraoperativefluoroscopy Schuster et al., Spine 2010

15. Sterile culture swabs 50 gowns after 29 spinal operations 50 control gowns

16. 6% 9% 17% 22%

17. 42% 33% 18% Elbow Crease

18. 5 defined locations of a draped C-arm 25 spinal procedures

19. 56% 28% 20% 12% 16%

20. Prevention

21. It is easier to stay out of trouble than to get out of trouble

23. NASS Guidelines Recommend the use of preoperative antibiotics for instrumented and non-instrumented spinal surgery No superior agent: 1-2 gCefazolin 2 gCeftizoxime or 1 gvancomycin plus 80 mg gentamicin No specific protocol or regimen: Within one hour preoperatively

24. NASS Guidelines Preoperative versus redosingintraoperative: No evidence to support redosing Depends on comorbidities, length of surgery Duration of prophylaxis: No evidence to support longer than 24 hours The use of drains is not recommended as a means to reduce infection rates following single level surgical procedures

25. Prep Solution

26. Prep Solution 849 patients preoperatively scrubbed with an applicator that contained 2% chlorhexidinegluconate and 70% isopropyl alcohol OR preoperatively scrubbed and then painted with an aqueous solution of 10% povidone–iodine

27. Prep Solution The overall rate of surgical-site infection was significantly lower in the chlorhexidine–alcohol group than in the povidone–iodine group (9.5% vs. 16.1%; P = 0.004) Both superficial and deep No difference in organ-specific infection Type of surgery: 73% abdominal 11% thoracic 10% gynecologic 6% urologic 41% reduction

28. Alcohol-based products Flammable  risk of fire & chemical burns Especially with oxygen source & electrocautery Prep carefully: Donot use 26-ml applicator for head and neck surgery, do not useon an area smaller than 8.4 in. x 8.4 in., use a smaller applicatorinstead. Do not drape or use ignition source until solutionis completely dry (minimum of 3 minutes on hairless skin, upto 1 hour in hair). Do not allow solution to pool; remove wetmaterials from prep area."

29. Irrigation Solution Two RCTs reported lower infection rates in patients treated with 3.5% Betadine solution compared with saline solution: Cheng et al, Spine 2005 Chang et al, Eur Spine J 2006 Schuster et al., Spine 2010

30. Prevention - Preoperative Treat other infections before starting elective surgery Hair removal: When? How? Glycemic Control Smoking cessation Nutritional status: lymphoctytes counts, albumin

31. Prevention - Intraoperative Prophylactic antibiotics: When? What? Repeat? Reduce traffic Release retraction regularly Irrigate regularly Strict aseptic technique

32. Prevention - Postoperative Prophylactic antibiotics: how long? Treat concomitant infections Maintain dressing for 48 hours

33. Diagnosis & Treatment

34. Review of 3174 spinal procedure over 10 yr 132 infection (4.2%) 48 superficial 84 deep or superficial & deep Staph. aureusin 65%

35. Clinical Presentation Fever (26%) Pain (28%) Erythema (19%, less common in deep infection) Swelling Warmth Tenderness to palpation Wound drainage (68%, most common sign) Neurological signs & symptoms Pull terGunne et al, Spine 2010

36. Investigation Laboratory: CBC ESR CRP Blood culture Imaging: Plain X-rays CT-guided biopsy MRI with contrast: differentiate infection, scar, recurrence Gallium bone scan

37. Investigation CBC (WBC): Not reliable, elevated in less than 50% ESR: Normal peak at 2 weeks, return to normal at 6 weeks Elevated in 94% of infection CRP: Normally takes 2 weeks to normalize Elevated in 97% of deep infection Blood culture: Positive in 30% of vertebral osteomyelitis Thelander et al, Spine 1992

38. Treatment Goals Appropriate selection of antibiotics & eradicate infection Obtain stable physiological wound closure Restore the mechanical integrity of the spine

39. Decision Making Superficial to the fascia Deep to the fascia

40. Superficial Infection Incision and drainage Inspection of fascia Aspiration of superficial and deep compartments Oral antibiotics (average 2 weeks, follow CRP) Close or secondary intention (wet to dry dressing) Pull terGunne et al, Spine 2010

41. Deep Infection Optimal treatment: Wound debridement Removal of instrumentation IV antibiotics 6-8 weeks, then oral antibiotics 2 weeks (follow CRP)

42. Deep Infection Controversy Instrumentation: retain, replace primarily, replace delayed Wound closure: primary with suction, primary without suction, secondary intention

43. Deep Infected Spinal Instrumentation Retain if stable Weinstein et al, J Spin Disorders 2000 Mok et al, Spine 2009 Pull terGunne et al, Spine 2010 Remove and replace primarily Pull terGunne et al, Spine 2010 Remove and replace later: Bose, Spine J 2003 Tsiodras et al, ClinOrthopRelat Res 2006

44. Deep infection wound management Following debridement: Primary closure: Mok et al, Spine 2009 Pull terGunne et al, Spine 2010 A second look surgery: Weinstein et al, J Spin Disorders 2000 Tsiodraset al, ClinOrthopRelat Res2006

45. Specific Infections Meningitis Psoas Abscess Epidural Abscess Postoperative Discitis Vertebral Osteomyelitis

46. Summary Consider patients, surgical & environmental risk factors Preoperative antibiotics, prep solution & irrigation solution CRP is the most sensitive marker Deep infection controversy re: retention of hardware & wound closure ssbajammal@uqu.edu.sa