An infection of the bone or bone marrow. In adults, 80% of osteomyelitis cases result from contiguous spread. This is seen in patients with DM, prosthetic joints, decubitus ulcers, trauma, and recent neurosurgery. In 20% of cases, the infection is hematogenous in origin. Risk factors include IV drug use, endocarditis, sickle cell disease, and advanced age. Etiologies are as follows:
Common Organism
S. aureus (most common)  
Prosthetic joints or postoperative infections Coagulase (-) staphylococci
Bites, diabetic foot infections, decubitus ulcers Streptococci and anaerobes
Animal Bite Pasturella spp.
Human bites Eikenella corrodens
IV drug use and nail punctures P. aeruginosa
Other Causes:
Sickle cell patients Salmonella spp.
Foreign immigrants, HI Mycobacterium tuberculosis
HIV Bartonella spp.
By Location
Sternoclavicular joint and symphysis pubis P. aeruginosa
Sacroiliac joint, knee, and hip Brucella spp.
Lower thoracic vertebrae (Pott’s disease) TB






Risk Factors, Likely Infecting Organism, and Recommended Initial Empiric Antibiotic Therapy for Osteomyelitis:
Risk Factor Likely Infecting Organism Recommended Initial Empiric Antibiotic Therapy*
Elderly, hematogenous spread Staphylococcus aureus, including MRSA, gram-negative bacteria Vancomycin, 1 g IV,

Piperacillin-tazobactam, 3.375 g IV
Imipenem, 500 milligrams IV
Sickle cell disease Salmonella, gram-negative bacteria, (S. aureus becoming more common) Ciprofloxacin, 400 mg
consider vancomycin, 1 g IV
Diabetes mellitus, or vascular insufficiency Polymicrobial: S. aureus, Streptococcus agalactiae, and S. pyogenes plus coliforms and anaerobes Vancomycin, 1 g IV,

Piperacillin-tazobactam, 3.375 g IV,
Imipenem, 500 mg IV
Injection drug user S. aureus including MRSA, and Pseudomonas Vancomycin, 1 g IV
Developing nations Mycobacterium tuberculosis  
Newborn S. aureus including MRSA, gram-negative bacteria, Group B Streptococcus Vancomycin, 15 m/kg load, then reduce dose,

ceftazidime, 30 mg/kg IV every 12 h
Children S. aureus including MRSA Vancomycin, 10 mg/kg every 6 h,

ceftazidime, 50 mg/kg every 8 h
Postoperative with or without retained orthopedic hardware S. aureus and coagulase-negative staphylococci Vancomycin, 1 g IV
Human bite Streptococci or anaerobic bacteria Piperacillin-tazobactam, 3.375 g IV,
Imipenem, 500 mg IV
Animal bite Pasteurella multocida, Eikenella corrodens Cefuroxime, 500 mg IV if known P. multocida,
Piperacillin-tazobactam, 3.375 g IV
Imipenem, 500 mg IV


Admission Orders: Osteomyelitis

1. Admit to:
2. Diagnosis: Osteomyelitis
3. Condition:
4. Vital Signs: qid. Call physician if BP <90/60; T >38.5°C.
5. Activity: Bed rest with bathroom privileges.
6. Nursing: Keep involved extremity elevated. Range of motion exercises tid.
7. Diet: high fiber.
8. IV Fluids: Heparin lock with flush q shift.
9. Special Medications:
 Adult Empiric Therapy:
  -Vancomycin 1 gm IV q12h (1 gm in 250 cc D5W over 1h).
  -Add 3rd generation cephalosporin if gram negative bacilli on Gram stain.
   Treat for 4-6 weeks.
 Post-Operative or Post-Trauma
  -Vancomycin 1 gm IV q12h
   ceftazidime (Fortaz) 1-2 gm IV q8h.
  -Imipenem/cilastatin (Primaxin) (single-drug treatment) 0.5-1.0 gm IV q6-8h.
  -Ticarcillin/clavulanate (Timentin) (single-drug treatment) 3.1 gm IV q4-6h.
  -Ciprofloxacin (Cipro) 500-750 mg PO bid or 400 mg IV q12h
   Rifampin 600 mg PO qd.

 Osteomyelitis with Decubitus Ulcer:
  -Cefoxitin (Mefoxin), 2 gm IV q6-8h.
  -Ciprofloxacin (Cipro) and metronidazole 500 mg IV q8h.
  -Imipenem/cilastatin (Primaxin), 0.5-1.0 gm IV q6-8h.

10. Symptomatic Medications
  -Norco 7.5/325 mg, 1 tab q4h PO prn pain
  -Docusate (Colace) 100 mg PO qhs.
  -Heparin 5000 U SQ bid.

11. Extras: Technetium/gallium bone scans, multiple X-ray views, CT.
12. Labs: CBC with differential, CMP, blood C&S x 3, MIC, MBC, UA with micro, C&S. Needle biopsy of bone for C&S.