Cierny and Mader classified osteomyelitis based on the affected portion of the bone, the physiologic status of the host and the local environment. This classification lends itself to the treatment and prognosis of osteomyelitis; stage 1 (medullary osteomyelitis) can usually be treated with antibiotics alone, while stages 2, 3 and 4 (superficial, localized and diffuse osteomyelitis) usually require aggressive debridement, antimicrobial therapy and subsequent orthopedic reconstruction.

Cierny-Mader staging system for long bone osteomyelitis

 
Anatomic type

Stage 1: Medullary osteomyelitis

Medullary osteomyelitis denotes infection confined to the intramedullary surfaces of the bone. Hematogenous osteomyelitis and infected intramedullary rods are examples of this anatomic type.

Stage 2: Superficial osteomyelitis

Superficial osteomyelitis is a true contiguous focus infection of bone; it occurs when an exposed infected necrotic surface of bone lies at the base of a soft-tissue wound.

Stage 3: Localized osteomyelitis

Localized osteomyelitis is usually characterized by a full thickness, cortical sequestration which can be removed surgically without compromising bony stability.

Stage 4: Diffuse osteomyelitis

Diffuse osteomyelitis is a through-and-through process that usually requires an intercalary resection of the bone to arrest the disease process. Diffuse osteomyelitis includes those infections with a loss of bony stability either before or after debridement surgery.

Physiologic class of host
Class A denotes a normal host
Class B denotes a host with systemic compromise, local compromise, or both
Class C denotes a host for whom the morbidity of treatment is worse than that imposed by the disease itself

Factors affecting immune surveillance, metabolism, and local vascularity

Systemic factors    

• Malnutrition    
• Renal or hepatic failure    
• Diabetes mellitus    
• Chronic hypoxia    
• Immune disease    
• Malignancy    
• Extremes of age    
• Immunosuppression or immune deficiency    

 Local factors

• Chronic lymphedema
• Venous stasis
• Major vessel compromise
• Arteritis
• Small vessel disease
• Extensive scarring
• Radiation fibrosis
• Neuropathy
• Tobacco abuse (>/= 2 packs per day)

References:

1. Calhoun JH, Manring MM, Shirtliff M. Osteomyelitis of the long bones. Semin Plast Surg. 2009 May;23(2):59-72. [Medline]
2. Carek PJ, Dickerson LM, Sack JL. Diagnosis and management of osteomyelitis. Am Fam Physician. 2001 Jun 15;63(12):2413-20. [Medline]
3. Lazzarini L, Mader JT, Calhoun JH. Osteomyelitis in long bones. J Bone Joint Surg Am. 2004 Oct;86-A(10):2305-18. [Medline]

 Created Mar 21, 2012.