1. Scoliosis Complications: Spinal Infection David H. Clements, MD Professor of Orthopaedic Surgery & Neurosurgery Cooper Medical School of Rowan University Camden, New Jersey USA

2. Goals of the Presentation u Review the Natural History u Discuss the latest research on Etiology u Discuss traditional treatment options u Present new treatment options u Make it interactive and interesting enough to keep everyone awake!

3. History of Spinal Deformity Correction The Dark Ages u Longitudinal gravity traction u Compliance variable u No documented long term results

4. The Enlightenment

5. Early 20 th Century

6. Advent of Spinal Instrumentation 1960 u Paul Harrington- distraction- up to 650 Newtons u Unable to control sagittal plane u No correction of rotation u Introduction of metal implants increases infection risk

7. Natural History of Spinal Infection u Acute infection u Several weeks after surgery u 2-9% incidence u Late onset infection u Present after 1 year u 0.2-6.7% incidence u Mainly posterior spinal instrumented procedures u Anterior procedures minimal rate u Risk factors: Diabetes, obesity, 2 or more assistants Risk factors for surgical site infection following orthopaedic spine procedures Olsen MA et al JBJS Am 2008: 90: 62-69

8. Presence of intraoperative bacterial contamination in posterior pediatric spinal deformity surgery Nandyala M, Schwend RM; Spine 38(8) E482-486 Apr 18, 2013 u Prevalence: u 21% in idiopathic scoliosis u 37% neuromuscular scoliosis u Propionibacterium acnes 69% u Staphylocxoccus 23% u Risk factors: age>11, fusion to pelvis, > 6 hours

9. Late surgical infections in Adolescent Idiopathic Scoliosis u Hematogenous seeding of pathogens u Activation of dormant organisms by motion metal on metal Delayed infection after instrumented spine surgery Bose B: Spine J 2003: 3:394-399 Delayed infection after posterior TSRH spinal instrumentation for AIS Richards BR eta la Spine 2001:26:1990-1996

10. Factors promoting risk of delayed infection u Failure to use a drain u Intraoperative homologous blood transfusion u Bone allograft u Metal fretting u Number of levels fused does NOT increase risk u Prevalence: 0.2-6.9% Delayed infection after elective spinal instrumentation and fusion Viola RW et al. Spine, 1997;22:2444-50

11. Clinical presentation u Early acute infection: wound erythema, drainage, tenderness, wound dehiscence u Late infection: spontaneous drainage, fluctulence u Erythrocyte sedimentation rate u Postop peak day 5, elevated 3-6 weeks u C-reactive protein u Postop peak day 3, elevated 1-2 weeks u Labs may not be abnormal in late infection Quantitation of C-reactive protein levels and ESR after spinal surgery Thelander U et al Spine 1992: 17: 400-404

12. Pathogens u Early infection: Staph aureus (MSSA, MRSA), gram negative (Pseudomonas, E. coli) u Late infection: may be culture negative, Propionibacterium, Staph epidermidis

13. Imaging studies How much help? u X-ray: not much u MRI: maybe (metal interference) u CT scan: maybe (poor for soft tissue) u Ultrasound: better (soft tissue collection)

14. Debridement, irrigation, retain spinal instrumentation Pro u Prevent loss of correction u Prevent failed fusion Con u Bacterial biofilm remains on metal u Lymphocytes not as effective on bacteria adherent to metal u Wound difficult to completely debride

15. Implant material and biofilm u Biofilm: bacteria adheres to metal u Create matrix of extracellular polymeric substances u Protects bacteria against antibiotics, phagocytes, humoral immune response u Seroma, hematoma promotes biofim u Pure titanium less susceptible Stainless steel and titanium alloy, PEEK more Late postoperative infection following spinal instrumentation: Stainless steel vs. titanium implants Soultanis KC et al: J Surg Orthop Adv. 2008; 17: 193-9

16. Success of retaining instrumentation in acute infection u 24/26 patients healed Postop deep wound infection in adults after PSF with instrumentation Picada R Winter RB et al Jour Spinal Disorders 2000; 13:42-45 u 50% persistent infection Management of infection after instrumented posterior spinal fusion in pediatric scoliosis Ho C, Skaggs D et al Spine 2007;32:2739-2744

17. Success of removing instrumentation in chronic infection 23/23 wounds healed, 1 worse deformity Delayed infection after PSF for idiopathic scoliosis Richards BR et al Spine 2001;26:1990-1996

18. Treatment recommendations u Prompt aggressive debridement u Culture wound, appropriate intravenous antibiotic 6-8 weeks u Delayed infection: add suppressive oral antibiotic up to 1 year u Acute infection: retain instrumentation u Delayed infection: remove instrumentation u Future treatments: enzymes to dissolve biofilm

19. Innovation is accepted quicker by patients