What is the management for a patient with cellulitis along the incision site of a recent hip replacement?

Management of Cellulitis Along Hip Replacement Incision Site

For cellulitis along a recent hip replacement incision, immediately initiate IV cefazolin 1-2 grams every 8 hours combined with surgical evaluation to rule out deep infection, while treating any identifiable portal of entry such as tinea pedis or intertrigo. 1, 2

Immediate Assessment and Risk Stratification

Distinguish between superficial incisional cellulitis and deep prosthetic joint infection, as this fundamentally changes management. 1

• Assess for systemic signs including fever >38.5°C, heart rate >110 bpm, WBC >12,000/µL, or altered mental status—these mandate hospitalization and broader coverage 1, 2
• Examine for purulent drainage from the incision, which requires incision and drainage plus MRSA-active antibiotics 1
• Evaluate for signs suggesting deeper infection: severe pain out of proportion to exam, skin anesthesia, rapid progression, or bullous changes 2
• Obtain blood cultures if the patient has systemic features, malignancy, neutropenia, or severe immunodeficiency 2

Antibiotic Selection Algorithm

For Superficial Incisional Cellulitis Without Systemic Toxicity:

First-line therapy is IV cefazolin 1-2 grams every 8 hours for 5 days if clinical improvement occurs, extending only if symptoms persist 1, 2, 3

• Cefazolin provides excellent coverage against S. aureus (including beta-lactamase producers) and S. pyogenes, the primary pathogens in surgical site infections 1, 3
• Alternative IV options include nafcillin or oxacillin for MSSA coverage 2
• Do NOT routinely add MRSA coverage unless specific risk factors are present: purulent drainage, prior MRSA infection, recent hospitalization, or nasal MRSA colonization 1, 2

For Surgical Site Infections With Systemic Signs:

Use vancomycin 15-20 mg/kg IV every 8-12 hours PLUS piperacillin-tazobactam 3.375-4.5 grams IV every 6 hours when erythema extends >5 cm from wound edge, temperature >38.5°C, heart rate >110 bpm, or WBC >12,000/µL 1, 2

• This combination provides broad-spectrum coverage including MRSA, gram-negatives, and anaerobes 1, 2
• Alternative MRSA-active agents include linezolid 600 mg IV twice daily, daptomycin 4 mg/kg IV daily, or telavancin 10 mg/kg IV daily 1, 2

When MRSA Risk Factors Are Present:

Add MRSA coverage with vancomycin, linezolid, daptomycin, telavancin, or ceftaroline if the patient has: 1

• Nasal MRSA colonization
• Prior MRSA infection
• Recent hospitalization or recent antibiotic use
• Purulent drainage from the incision

Critical Surgical Considerations

Suture removal plus incision and drainage must be performed for surgical site infections with purulent drainage 1

• Surgical consultation is mandatory if necrotizing infection is suspected—do not delay 2
• For clean operations on extremities with systemic infection signs, a brief course of systemic antimicrobials is indicated alongside surgical management 1
• Hip replacement infections may present as superficial cellulitis without deep prosthetic involvement, particularly when occurring weeks to years post-surgery secondary to impaired lymphatic drainage 4, 5

Identifying and Treating Portals of Entry

Meticulously examine for and treat predisposing conditions, as these are the primary cause of post-hip surgery cellulitis rather than prosthetic infection: 1, 2, 4

• Inspect interdigital toe spaces for tinea pedis, fissuring, scaling, or maceration 2
• Evaluate gluteal fold for intertrigo 4, 5
• Assess for venous insufficiency, lymphedema, or chronic edema 1, 2
• Treat any identified portal aggressively with appropriate topical or systemic therapy 4, 5

Treatment Duration and Monitoring

Standard duration is 5 days if clinical improvement occurs; extend only if infection has not improved within this timeframe 1, 2

• For complicated infections requiring surgical debridement, continue for 7-14 days guided by clinical response 1, 2
• Reassess within 24-48 hours to verify clinical response 2
• Transition to oral antibiotics (cephalexin, dicloxacillin, or clindamycin) once clinical improvement is demonstrated after minimum 4 days IV treatment 2

Adjunctive Measures

Elevate the affected extremity to promote gravity drainage of edema and inflammatory substances 1, 2

• This intervention hastens improvement and is particularly important in this population 2
• Address underlying venous insufficiency or lymphedema 1, 2

Key Clinical Distinctions

Post-hip surgery cellulitis is typically authentic infectious cellulitis, not hypersensitivity to prosthetic material, despite historical speculation about aseptic inflammation 5

• These infections occur secondary to impaired lymphatic drainage from surgery, creating susceptibility to cellulitis from distant portals of entry 4, 5
• The interval between surgery and cellulitis can range from weeks to years (7-520 weeks reported) 4
• Successful antibiotic treatment with complete resolution within 1-6 days strongly supports infectious rather than hypersensitivity etiology 6, 5
• Long-term follow-up shows no progression to prosthetic joint infection when appropriately treated 6, 4

Common Pitfalls to Avoid

• Do not assume prosthetic joint infection based solely on proximity to the implant—most cases are superficial cellulitis from impaired lymphatic drainage 4, 5
• Do not reflexively add MRSA coverage for typical post-surgical cellulitis without specific risk factors, as beta-lactam monotherapy succeeds in 96% of cases 2
• Do not delay surgical consultation if any signs of necrotizing infection or deep involvement are present, as these require emergent debridement 1, 2
• Do not continue ineffective antibiotics beyond 48 hours—progression despite appropriate therapy indicates resistant organisms or deeper infection 2