Post op knee infection image
Abcess  Infection s/p ORIF
Antibiotic cement  
Bite Wounds Osteomyelitis (adult)
Cellulitis Osteomyelitis (pediatric)
Felon Periprosthetic Infection
Infected IM Nail Prophylaxis Recommendations
Infection Risk Factors Septic Arthritis (Adult)
Intraoperative Infection Factors Septic Arthritis (Pediatric)
Lyme Disease Total Joint Infection
MRSA Work-up for possiible infection
MRSA Decolinization  



  • ICD-9 681.10 cellulitis, abcess unspecified
  •  L03.119  Cellulitis of unspecified part of limb
  • spreading, diffuse inflammation, erythema, swelling and pain without abscess formation.
  • Most commonly pathogens: Group A b-hemolytic Streptococcus. Also consider S aureus, MRSA. Group A strep, S Aureus, Enterobacter in diabetics.
  • MRSA is becoming increaseingly prevalent, especially in hand infections. Consider Bactrim DS +/- rifampin. If group A streptococcus is strongly suspected add Keflex.
  • Initial treatment: Dicloxacillin, 250-500 mg PO q6h
  • Treatment non diabetics: Patients who fail to respond in 24-48 hours should be admitted and treated with IV antibiotics. Any fluctuant or questionable areas should be treated with irrigation and debridement. Nafcillin 1-2 g IV q4-6h or Cephalexin 1 g IV q8h PCN allergy: Erythromycin 250-500 mg PO q6h
  • Treatment diabetics: Bactrim DX 2 tabs PO BID and Rifampin 300 mg PO BID. Severe cases: imipenem 500mg IV Q6hrs or Etrapeneum 1 g IV q24hr and vancomycin 1g IV q12hrs


  • spreading, diffuse inflammation, erythema, swelling and pain with an area of fluctuance.
  • Most commonly pathogens: S aureus.
  • MRSA is becoming increaseingly prevalent, especially in hand infections. Consider Bactrim DS +/- rifampin. If group A streptococcus is strongly suspected add Keflex
  • Treatment: Incision and debridement. Get aerobic and anaerobic cultures and gram stain before starting antibiotics. IV antibiotics are started after cultures are taken and are adjusted based on culture results. Cefazolin 1 g IV q8h, or Ampicillin-sulbactam 1.5 mg IV q6h. Consider Nafcillin 1-2 g IV q4-6h plus gentamicin or Imipenem, 0.5-1.0 g IV q6h for IV drug abusers or diabetics with more severe abcesses.

Antibiotic cement / Antibiotic cement

  • Commercially available pre-mixed antibiotic cement is low-dose and indicated for prophylaxis, not treatment of infection.
  • High dose:. 3.6g tobramycin and 1g vancomycin per 40g of bone cement. (Penner MJ, J Arthroplasty 1996;11:939).
  • Addition of more than 4.5 g of powder substantially weakens bone cement;
  • Approx 8 grams of antibiotic powder per 40 gm of cement is the highest amount that can be added
  • See also Wheeles antibiotic cement notes.

Antibiotic Beads

  • 11981 Insertion, non-biodegradable drug delivery implant
  • 11982 Removal, non biodegradable drug delivery implant
  • 11983 Removal with reinsertion, non-biodegradable drug delivery implant

Methicillin-Resistant Staph Aureous (MRSA)

  • may be hospital acquired (HA) or community associated (CA).
  • infections include skin, osteomyelitis, septic arthritis, endocarditis, meningitis, pneumonia
  • can be spread by direct contact, towels, sheets, wound dressings, clothes, workout areas, sports equipment, whirlpools
  • Associated with contact sports: football, wrestling, rugby.
  • Risk factors: artificial turf skin abrasion, shaving of skin, sharing towels or equipement, high body mass index, improperly cleaned team whirlpools.
  • diagnosed by wound culture with antibiotic susceptibilities
  • Treatment = Incision and drainage and antibiotics
  • Empiric Treatment: Bactrim DS 1tab PO BID (8-12mg TMP/40-60SMX per kg/day divided BID for Peds); Doxyxycline 100mg PO BID(do not use in peds); Clindamycin 300-450mg PO QID (10-20mg/kg/day divided QID for PEDS); consider adding rifampin.
  • Definitive antiobiotic treatment should be based on culture susceptibilities, consider Infectious disease consultation when available.
  • HA-MRSA first line antibiotics: Vancomycin, consider gentamicin or rifampin for synergy. Other agents = daptomycin, linexolid, tigecycline, bactrim.
  • CA-MRSA first line antibiotics: doxycycline or clindamycin, or bactrim.
  • Prevention: no equipement sharing between players, no sharing towels, routine cleaning of all whirlpools / shared resources, athletes should pre-scrub with chlorhexidine soaps prior to whirlpool use, all open wounds should be occlusively dressed during practice and games,

MRSA Decolinization

  • MRSA carriers (anterior nares) are 2-9 times more likely to develop surgical site infections than noncarriers
  • Consider pre-op for: immunocompromised, recent nursing home/hospital admission, antibiotic exposure within 1 yr.
  • Options: Chorhexicine 2% topical wash QD for 3-7 days: Doxycycline 100mg PO BID x 7 days: Mupirocin 1cm applied to nares TID for 5-7 days: Providone-Iodine 5% 4x per day for 5 days: Rifampin 300mg PO BID x7days.
  • Larkin S, Orthopedics 2008;31:37

Infection Risk Factors / Prevention

  • Diabetes Mellitis: risk of infection increases with increasing glucose levels. Strict perioperative glucose control should maintain levels 200mg/dl. (Golden SH, Diabetes Care 1999;22:1408).
  • Urinary tract infection: Chronic uncorrectable UTI should be managed with antibiotic suppression, and is relative contra-indication to elective surgery.
  • Chronic renal failure: Patients on dialysis should recieve hemodialysis the day before elective surgery. Prior renal transplant patients are not at as high a risk of infection as dialysis patients.
  • Rheumatoid Disease: RA medications such as penicillamine, indomethacin, cyclosporine, choroquine and prednisolone have been shown to increase the risk of surgical site infection.
  • Immunocompromise:
  • Smoking: Cessation of smoking during the peri-operative period decreases the risk of surgical site infection. (Craig S, Plas Reconstr Surg 1985;75:842).
  • Medical Problems (HTN, CAD, COPD, etc)
  • Blood Transfusion: In patients undergoing hip replacement or spine surgery, the postoperative infection rate with allogeneic blood transfusion appears to be 7- to 10-fold higher than with autologous blood or no transfusion. (Blumberg N, Semin Hematol 1997;34:34). The need for allogeneic transfusions should be reduced by proper pre-operative planning. 
  • Hypothermia
  • Obesity
  • Malnutrition: Can be assessed by serum protein and albumin levels. Pre=operative nutritional supplementation has been shown to decrease infections rates (Synderman CH, Laryngoscope 1999;109:915).

Intraoperative Infection Factors

  • Pre-operative antibiotics should be given within 30 minutes before surgery. (Classen DC, N Engl J Med 1992;326:337).
  • Hair removal should be performed with electric clippers immediately before surgery.
  • Risk of infection increases as the number of people in the OR increases. (Pryor F, AORN J 1998;68:649).
  • Laminar air flow and keeping the doors closed during surgery reduces risks of infection. (Ritter MA, CORR 1999;369:103).
  • The length of surgery correlates with the infection rate.

Infected IM nail

  • treatment generally requires exchange nailing with reaming of canal and 6wks IV antibiotics
  • Healed fx with infected IM nail=mail removal, reaming, antibiotic nail placement. Use high dose antibiotic cement; 3.6g tobramycin and 10g vancomycin per 40g of bone cement. (Penner MJ, J Arthroplasty 1996;11:939). fill large chest tube with antibiotic cement, place guide wire in center of cement.  Remove chest tube once cement hardens, then place nail.

Coagulase postive staph = Staph aureus

Coagulase negative staph = staph epidermidis

Septic Arthrits (Adult)

Prophylaxis Recommendations

  • Cefazolin dosing is 2 g for adult patients or 3 g when the weight is greater than 120 kg every 4 hours. Pediatric dosing is 30 mg/kg.   May Consider Cefuroxime 1.5g IVPB.
  • Clindamycin dosing is 900 mg in adult patients every 6 hours. Pediatric dosing is 10 mg/kg.

  • Vancomycin dosing is 15 mg/kg and needs to be administered 60 to 120 min before incision to achieve minimum inhibitory concentration. 

  • For MRSA colinization / high MRSA rate institutions or PCN allergic patients: Vancomycin 1g IVPB. Consider intranasal mupirocin ointment.
  • IV antibiotics started withing 1 hour of surgical incision and completed before tourniquet is inflated.
  • For obese patients antibiotic dose should be increased appropriately (Ancef 2g IVPN OCTOR). (Forse A, Surgery 1989;106:750).
  • Prophylactic antibiotics shouldbe discontinued within 24 hours of the end of surgery.
  • AAOS Post Arthroplasty Antibiotic Prophylaxis recommendations for elective procedures.

Penicillin Allergy

  • Penicillin allergies are reported by up to 15% of the US population.  95% of these allergies do not correspond to a true allergy when tested
  • Low Risk Penicillin Allergy: Side effects/intolerances (GI symptoms, headache, muscle aches, or psychiatric disturbances) Limited hypersensitivity reactions (self-limited cutaneous rash, urticaria .5 yr ago, or itching) Nonspecific (unknown reaction, or remote childhood reaction). Recommend give cefazolin
  • Moderate Risk Penicillin Allergy: Disseminated hypersensitivity or anaphylaxis (swelling of the face or throat, angioedema, difficulty breathing, or urticaria ,5 yr ago): Recommend allergy skin testing or give Vancomycin or clindamycin.
  • High Risk Penicillin Allergy: Stevens–Johnson syndrome or toxic epidermal necrolysis (diffuse ulceration, blistering, or pustulosis). Multiorgan hypersensitivity response (history of kidney or liver injury).  Recommend give Vancomycin of clindamycin. 
  • Sarfani S, J Am Acad Orthop Surg 2022;30:e1-e5

Infection Work-up

  • CBC with differential, ESR (rises within 2 days, continues to rise for 3-5 days even with treatment), CRP (rises witin 6 hours, peaks at 48 hrs, normal witin 1 week), blood cultures, gram stain, CXR. Consider Acid-fast staining, fungal cultures, prolonged incubation times (especially fro infections after arthroscopic surgery).
  • Serum IL-6 is indicative of early periprosthetic infection (DiCesare PE, JBJS 2005;87A:1921).
  • Xray: demonstrate soft-tissue swelling / loss of tissue planes early. Bone abnormalities require 30-40% bone losss.
  • MRI: highest sensitivity and specificity for infection / osteomyelitis. low signal intensity in bone marrow on T1 images may indicated osteomyelits (bone marrow normally has high-signal intensity on T1 images).
  • Bone scan: technetium 99m; gallium citrate Ga 67; indium-111 leukocyte-labeled etc.

Lyme Disease

  • Most common vector-borne infection in the US.
  • Etiology: spirochete Borrelia burgdorferi; transmitted by infected ticks.
  • Common locations: Northeast, Northwest, Midwest rural wooded areas.
  • Stage 1 (localized infection): skin lesion with expanding erythema migrans. RX= Doxycycline 100mg PO BID times 20 days.
  • Stage 2 (disseminated infection): hematogenous spread (meningitis, neuritis, carditis, AV node block, musculoskeletal pain. RX= Doxycycline 100mg PO BID times 30 days.
  • Stage 3 (persistent infection): intermittent/chronic arthritis, encephalopathy, acrodermatitis.
  • Diagnosis: enzyme-linked immuosorgent assay and Western blot testing. May be negative in first several weeks of disease. Consider spirochete culture from synovial fluid or skin lesion. RX= Doxycycline 100mg PO BID times 60 days.
  • Alternative antiobiotics: Amoxicillin 500mg PO QID, Cetriazone 2g IVPB daily for 14-28 days or Penicillin G 24million units daily or 14-28 days.
  • Vaccination is available for patients in high risk areas.


Infection s/p ORIF

  • Perioperative period: I&D with antibiotic treatment.  May consider conversion to external fixation.
  • Prior to fracture healing: if implants are stable generally treat with supressive antibiotics, wound coverage and implant removal after bone healing.
  • After fracture union:  implant removal, antibiotics.