Osteomyelitis classification

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Nate Michalak, B.A., Seyedmahdi Pahlavani, M.D. [2]

Overview

There are many classification systems for osteomyelitis. In general, there are three major classification systems which include; classification according to the symptom chronology, Lew and Waldvogel classification, and Cierny and Mader classification. Osteomyelitis may be classified according to the symptom chronology into acute, sub-acute (further subdivided into the Glendhill and Robert et al. systems), and chronic. Chronic osteomyelitis may be subdivided into Lew and Waldvogel’s classification system and Cierny and Mader’s classification system. Osteomyelitis may be classified according to Lew and Waldvogel’s system based on the duration and mechanism of infection into 3 subtypes which are; hematogenouos osteomyelitis, contiguous-focus osteomyelitis, and osteomyeltis secondary to vascular insufficiency. Osteomyelitis may be classified according to Cierny and Mader’s classification system based on the anatomy of bone infection (4 stages) and host physiology (3 levels of compromise).

Classification

There are many classification systems for osteomyelitis:

Osteomyelitis may be classified according to symptom chronology into acute, sub-acute (further subdivided into the Glendhill and Robert et al. systems), and chronic
Lew and Waldvogel classified osteomyelitis according to the duration and mechanism of infection (traditional classification)^[1]
Cierny and Mader classified osteomyelitis according to the anatomy of bone infection and host physiology^[2]

The Cierny and Mader system offers a guide to treatment

Classification based on symptom chronology

Acute osteomyelitis: Osteomyelitis is classified as acute if the duration of the disease has been less than 2 weeks.
Sub-acute: Sub-acute hematogenous osteomyelitis has a more insidious onset and lacks the severity of symptoms, which makes the diagnosis of this disorder difficult. Typically, diagnosis is delayed for more than 2 weeks.

TYPE	GLEDHILL CLASSIFICATION	ROBERT ET AL. CLASSIFICATION
Sub-acute osteomyelitis
I	Solitary localized zone of radiolucency surrounded by reactive new bone formation	Ia—Punched-out radiolucency Ib—Punched-out radiolucent lesion with sclerotic margin
II	Metaphyseal radiolucencies with cortical erosion	—
III	Cortical hyperostosis in diaphysis; no onion skin reaction	Localized cortical periosteal reaction
IV	Subperiosteal new bone and onion skin layering	Onion skin periosteal reaction
V	—	Central radiolucency in epiphysis
VI	—	Destructive process involving vertebral body

Chronic Ostemyelitis: Chronic osteomyelitis is defined as persistent pain, erythema, or swelling, sometimes in association with a draining sinus tract that mostly lasts for more than 4 weeks.

The following table describes the classification schemes for chronic osteomyelitis.

Lew and Waldvogel Etiologic System

Mechanism of Infection	Description
Hematogenous Osteomyelitis	Osteomyelitis develops after bacteremia
Contiguous-focus Osteomyelitis	Direct inoculation of bone via trauma/fracture, surgery, prosthetic devices, or spread from soft tissue
Osteomyelitis Secondary to Vascular Insufficiency	Reduced blood supply, usually in diabetic patients

Cierny and Mader Staging System

Classification		Description
Anotomic Type	Stage 1	Medullary osteomyeltitis: infection confined to the intramedullary bone surfaces
	Stage 2	Superficial osteomyelitis: true contiguous infection (bone surface undergoes necrosis at the base of a soft tissue wound)
	Stage 3	Localized osteomyelitis: full-thickness, cortical sequestration
	Stage 4	Diffuse osteomyelitis: through-and-through process requiring intercalary reconstruction of bone
Physiological Class	A Host	Normal physiological, metabolic, and immunologic states
	B Host	Local compromise, systemic compromise, or both
	C Host	Morbidity of treatment is worse than disease

References

↑ Lew, Daniel P.; Waldvogel, Francis A. (1997). “Osteomyelitis”. New England Journal of Medicine. 336 (14): 999–1007. doi:10.1056/NEJM199704033361406. ISSN 0028-4793.
↑ Mader, Jon T.; Shirtliff, Mark; Calhoun, Jason H. (1997). “Staging and Staging Application in Osteomyelitis”. Clinical Infectious Diseases. 25 (6): 1303–1309. doi:10.1086/516149. ISSN 1058-4838.

[LewWaldvogel1997-1] Lew, Daniel P.; Waldvogel, Francis A. (1997). “Osteomyelitis”. New England Journal of Medicine. 336 (14): 999–1007. doi:10.1056/NEJM199704033361406. ISSN 0028-4793.

[MaderShirtliff1997-2] Mader, Jon T.; Shirtliff, Mark; Calhoun, Jason H. (1997). “Staging and Staging Application in Osteomyelitis”. Clinical Infectious Diseases. 25 (6): 1303–1309. doi:10.1086/516149. ISSN 1058-4838.

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