Overview
Bacteremia is common (it is estimated to follow simple tooth brushing about 25% of the time), but the presence of bacteria alone is insufficient to cause osteomyelitis. Infection is established when enough sufficiently virulent organisms overcome host inflammatory and immune defenses. Within bone, pus spreads through Haversian and Volkmann canals and lifts the periosteum; medullary plus subperiosteal pus causes cortical necrosis (sequestrum), which harbors bacteria beyond the reach of antibiotics and inflammatory cells. Up to 80% of patients have at least one modifiable risk factor for surgical site infection (SSI), but no single measure eliminates risk, so multiple tactics are combined. (Campbell)
Patient-Dependent Factors (Campbell)
Nutrition: over half of patients with musculoskeletal infection may be malnourished, including obese patients. Malnutrition impairs humoral and cell-mediated immunity and neutrophil function. Consider nutritional support before elective surgery with recent weight loss over 10 lb, albumin under 3.5 g/dL or lymphocytes under 1500 cells/mm3; use enteral feeding when the gut works. Check and correct vitamin D deficiency.
Obesity: BMI over 40 has been associated with up to an eightfold increase in SSI; recommend weight loss before elective surgery and increase antibiotic dosing in morbid obesity.
Glycemic control: HbA1c under 7% is advocated. Fructosamine (over 292 mmol/L reflects hyperglycemia in the prior 2 to 3 weeks) correlates more strongly with SSI and periprosthetic infection. Undiagnosed hyperglycemia is common before arthroplasty; keep postoperative glucose at 110 to 150 mg/dL for 24 to 48 hours.
Alcohol doubles SSI risk; stop at least 1 month before elective surgery. Smoking raises infection risk about 3.5 times; counsel cessation (ideally 30 days before).
Immune status: neutrophil defects (diabetes, alcoholism, hematologic malignancy, cytotoxic therapy) predispose to S. aureus, gram-negative and fungal infection; hypogammaglobulinemia or splenectomy to encapsulated organisms; cell-mediated defects (steroids, malnutrition, lymphoma, SLE, HIV, aging) to fungal, mycobacterial and viral infection.
DMARDs: periprosthetic joint infection is 1.6 times more common in rheumatoid arthritis. Stop DMARDs according to half-life and resume 2 weeks after surgery, in consultation with the rheumatologist.
Withhold intraarticular injections for 3 to 6 months before arthroplasty. Asymptomatic patients need no urinalysis; treat remote infections before elective surgery. Retained bullet fragments do not increase risk.
Surgeon-Dependent Factors (Campbell)
Skin and hair
Bathe the night before and the day of surgery, with chlorhexidine wipes if possible. Avoid shaving; if needed, clip in the operating room.
Use an alcohol-containing prep (chlorhexidine-alcohol or povidone-iodine-alcohol); recent trials favor povidone-alcohol in closed fractures. Apply from the incision outward in concentric circles and let alcohol dry to avoid fire risk. In shoulder surgery, 3% hydrogen peroxide for 5 minutes reduces Cutibacterium acnes.
Hands, gloves and attire
Hand hygiene is the single most important measure against nosocomial infection; a 2-minute scrub is as effective as 5 minutes, and alcohol-based hand rubs are as effective as traditional scrubbing.
Glove perforation occurs in up to 48% of operations, usually unnoticed, most often on the nondominant index finger. Double gloving reduces exposure by up to 87%. Change gloves after draping, before handling implants, every 2 hours and when perforated.
Skull caps are preferable to bouffant hats.
Operating room
People shed 5,000 to 55,000 particles per minute; minimize door openings and traffic. Laminar flow and ultraviolet light are not currently recommended.
Maintain normothermia (warm 30 minutes before and 2 hours after surgery). Change the scalpel after the skin incision and the suction tip hourly; remove the back-table splash basin.
Irrigation, time and closure
Low-pressure (bulb) lavage is as effective as pulsed lavage with less tissue damage. The traditional 3, 6 and 9 L for Gustilo I to III open fractures lacks evidence, and excessive fluid harms tissue.
Antibiotics in irrigation add nothing. Dilute povidone-iodine (0.3%) irrigation reduces SSI about 2.3-fold, but avoid it when articular cartilage is exposed.
SSI risk rises about 37% for every 60 minutes of operating time; keeping surgery under about 2.5 hours may help, without rushing.
Minimize blood loss and transfusion (tranexamic acid helps). Incisional negative-pressure or silver-impregnated dressings reduce SSI in high-risk arthroplasty. Prefer subcuticular closure with skin adhesive and avoid excessive electrocautery. Local vancomycin powder may reduce SSI.
Prophylactic Antibiotics (Campbell)
The first 6 hours after contamination are the "golden period" before exponential bacterial growth; prophylaxis extends it.
Target skin flora (S. aureus, increasingly S. epidermidis) plus E. coli and Proteus. A first-generation cephalosporin is standard: 1 g under 60 kg, 2 g for 60 to 120 kg, 3 g over 120 kg.
Give within 30 to 60 minutes before incision (vancomycin and fluoroquinolones within 2 hours). Redose cephalosporin every 4 hours or when blood loss exceeds 1500 mL.
Do not continue beyond 24 hours, even with drains or catheters; many surgeons stop at skin closure.
Clindamycin is used for penicillin anaphylaxis, but about 95% of patients reporting penicillin allergy are not allergic on testing, so allergy testing is worthwhile. Avoid routine vancomycin; add weight-adjusted vancomycin (15 mg/kg over at least 1 hour) only for specific risk factors.
Prophylaxis for dental procedures, colonoscopy or endoscopy is not recommended in arthroplasty patients.
MRSA (Campbell)
MRSA now accounts for over half of S. aureus isolates and is spreading in community settings (contact athletes, day-care children, military recruits, prisoners, IV drug users). Invasive MRSA carries about 20% mortality.
Carriers have about six times the SSI risk. Decolonize with nasal mupirocin twice daily for 5 days, a single-application nasal antiseptic or intranasal povidone-iodine 2 hours before surgery.
PCR identifies staphylococci within 24 hours. Treat invasive infection with IV vancomycin (or daptomycin, linezolid, rifampin, gentamicin), debride abscesses, avoid quinolone overuse, and involve infectious disease specialists.
Diagnosis Basics (Campbell)
The classic triad is fever, swelling and pain; pain is most common and fever inconsistent. No single test is definitive. Obtain CBC with differential, ESR and CRP at the initial evaluation; the white count is often normal.
Implant-Related Infection After Fracture Fixation (AO)
Implant-related infection occurs in about 5% of surgically treated fractures, usually exogenous (open fracture, surgery or wound-healing problems); late hematogenous infection, a major issue in arthroplasty, is rare after fracture fixation.
Why implants raise risk: host proteins (fibronectin, laminin) coat the implant and promote bacterial adhesion in a "race for the surface." Within hours adherent bacteria form a glycocalyx biofilm that resists host defenses and antibiotics; sessile organisms may be up to 1000 times more resistant, explaining poor in vivo results despite in vitro sensitivity. In one animal model the minimal infecting dose of S. aureus was more than 100,000 times lower with an implant present.
Classification by onset: early (within 2 weeks; persistent pain, erythema, swelling, wound drainage, fever; virulent organisms such as S. aureus and gram-negative bacilli), delayed (3 to 10 weeks) and late (after 10 weeks), the latter two usually with low-virulence organisms (coagulase-negative staphylococci, Cutibacterium) and subtle signs such as pain, implant loosening, instability or a sinus tract.
Postoperative wound problems are not trivial: large or painful fluctuant hematomas need urgent drainage, debridement and cultures (prevented by meticulous hemostasis and compressive dressings); delayed wound healing signals contamination; necrotic wound edges need excision and grafting or flaps. The authors discourage the term "superficial wound infection," which minimizes these complications. Avoid prolonged negative-pressure therapy and obtain definitive soft-tissue cover as early as possible.
Cierny-Mader anatomic types: I medullary, II superficial, III localized full-thickness cortical (such as pin-tract or plate infection) and IV diffuse. Medullary infections carry a better prognosis than those with extensive bone necrosis. Untreated chronic fistulating osteomyelitis can undergo malignant change (Marjolin ulcer). Periarticular infection must be treated promptly to prevent septic arthritis and chondrolysis.
Risk factors: local (open fracture, contamination, venous stasis, arterial disease, extensive scarring, neuropathy, lymphedema, chronic skin disease, vasculitis, radiation fibrosis) and systemic (diabetes, malnutrition, renal or hepatic failure, chronic hypoxia, autoimmune disease, malignancy, age, immunosuppression, agranulocytosis, nicotine, alcohol or drug abuse). Greater bone and soft-tissue damage increases necrosis and contamination risk.
Technique to prevent infection: use the least invasive approach; place incisions away from traumatic skin lesions and close without tension; prefer indirect reduction; preserve living muscle and periosteum in contact with bone while removing all dead tissue; place external fixator pins correctly to avoid thermal necrosis and soft-tissue tethering.
Treatment principles: remove necrotic and avascular tissue including bone and disrupt the biofilm, or acute infection becomes chronic; antibiotics alone are adjunctive or suppressive. Unlike periprosthetic infection, complete eradication is not always the first goal, since the implant can be removed after fracture union. Surgical strategy depends on device type, bone-implant stability, organism, union status, soft tissues and patient health. Rifampin against staphylococci and quinolones against gram-negative organisms can act on biofilm with a stable implant.
References
Cleveland KB. General principles of infection. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Philadelphia: Elsevier; 2026. Chapter 22.
Borens O, Sirkin MS. Acute infection. In: Buckley RE, Moran CG, Apivatthakakul T, eds. AO Principles of Fracture Management. 3rd ed. Thieme; 2017 (Turkish edition). Chapter 5.3.