OSTEOMYELITIS INFECTIOUS ARTHRITIS D.Goldberg WRAMC

Osteomyelitis Laboratory Tests Erythrocyte sedimentation rate White blood cell count Erythrocyte sedimentation rate C-reactive protein Bone aspirate Blood culture Antigen Assay

Osteomyelitis Etiologic agents by age Organism Total <2 2-5 6-10 >10 S. aureus 198 (50%) 33 56 66 43 Streptococci 37 (9%) 13 13 6 5 HIb 16 (4%) 14 2 0 0 CNS 10 (3%) 7 1 0 2 Ps. aeruginosa 10 (3%) 1 2 5 2 S. pneumoniae 6 (2%) 6 0 0 0 Salmonella 6 (2%) 3 3 0 0 E. coli 2 1 1 0 0

Osteomyelitis Specimen site No. done No. Pos Blood 381 138 (36%) Needle aspirate/surg spec 357 134 (38%) Joint fluid 86 56 (65%) Wound drainage 31 22 (70%) Nelson IDCNA 1995

Osteomyelitis BONE MONOSTEAL POLYSTEAL Femur 92 12 Tibia 89 18 Humerus 50 8 Fibula 16 10 Phalanx 18 5 Calcaneos 18 0 Radius 13 4 Ischium 15 1 Metatarsal 8 0 Ulna 6 3 Ilium 7 0 Vertebra 7 2

Osteomyelitis Neonatal Osteomyelitis Nonspecific signs absent Indolent process Nonspecific signs absent Swelling/tenderness Multiple sites in 50% Secondary joint space involvement S. aureus, group B strep, coliforms

Osteomyelitis Sickle Cell Disease GNR’s 6% Staphylococcus 8% Salmonella 60% GNR’s 6% Staphylococcus 8% Pneumococcus 5%

Radiologic Diagnosis X-rays: soft tissue swelling periosteal elevation focal osteopenia 2 week lag

Radiologic Diagnosis Tc scan: accumulation in areas of inc blood flow and bone formation positive in 48 hrs Three-phase scan false-neg due to poor blood flow

Radiologic Diagnosis gallium scan: inc uptake in areas of PMN’s, macrophages do not show bone well imaging at 24h and 72h high sens/high radiation MRI scan: bone vs soft tissue T2-inc signal in bone not for screening

Septic Arthritis S.A. Inf Arth Non-IA Volume +/+++ +/+++ + Color turbid turbid sl turbid Viscosity reduced reduced normal WBC’s >50-100 5-50 1-5 PMN’s >80% >60-80% <50% Glucose <0.25 >0.50 >0.80 Bacteria 50-75% 0 0

Distribution of Infected Joints Septic Arthritis Distribution of Infected Joints Knee 30% Hip 30 Ankle 17 Elbow 11 PIP/MCP 7 Shoulder 2 Nelson PED 1972

Septic Arthritis Organism 0-1m 1m-5y >5 (4%) (70%) (26%) (4%) (70%) (26%) S. aureus 36% 11% 33% Hib 7% 31% 1% Streptococci 21% 11% 18% GNR 14% 2% 3% N. gonnorrhea 7% 2% 7% Unknown 35% 34%

Therapy Initial regimes: Neonates nafcillin and cefotaxime children < 5 cefuroxime children > 5 nafcillin/cefuroxime Sickle cell nafcillin and ceftriaxone

Therapy: Minimal duration- (clinical response, dec ESR) Gram negative 4-6 weeks Staph 4-6 weeks H. influenzae 2-4 weeks N. meningitis 2-4 weeks streptococci 2-4 weeks Dagan JPID 1992

Contraindications to oral therapy Inability to swallow Etiologic agent not established Inability to perform bacteriocidal levels No effective oral therapy Failure of parental abiotics