Table of Contents
Definition / general | Terminology | Zurich Classification of Osteomyelitis | Sites | Pathophysiology | Etiology | Clinical features | Diagnosis | Radiology description | Prognostic factors | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Differential diagnosis | Additional referencesCite this page: Morrison A. Secondary chronic. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/mandiblemaxillasecondaryosteo.html. Accessed November 29th, 2023.
Definition / general
- Chronic suppurative osteomyelitis is generally regarded as a secondary, chronic osteomyelitis characterized by a defensive response that leads to production of granulation tissue which subsequently forms dense scar tissue in an attempt to wall off the infected area; the encircled dead space acts as a reservoir for bacteria and antibiotic medications have great difficulty reaching the site
- Acute and secondary chronic osteomyelitis of the jaws is caused mostly by a bacterial focus (e.g. odontogenic disease, pulpal and periodontal infection, extraction wounds, foreign bodies, infected fractures); they are essentially the same disease separated by the arbitrary time limit of 1 month after disease onset
- Chronic secondary osteomyelitis: infection is more advanced than in acute cases, by definition, therefore radiographic imaging is usually more conclusive; suppuration, fistula formation and sequestration are characteristic features but are not required for diagnosis
Terminology
- Acute suppurative osteomyelitis:
- Early phase of osteomyelitis, usually a suppurative (pus forming) condition
- Exists when an acute inflammatory process moves away from the site of initial infection and spreads through the medullary space; in most cases, insufficient time has passed for the body to react to the presence of the inflammatory infiltrate
- Acute phase may lead to the chronic phase, arbitrarily defined as an osseous infection lasting at least 1 month
- Alveolar osteitis / fibrinolytic alveolitis
- After tooth extraction, a blood clot is formed at extraction site with eventual organization by granulation tissue and gradual replacement by bone (Oral Maxillofac Surg Clin North Am 2011;23:401)
- Destruction of the initial clot may delay the steps required for uneventful extraction site healing and leads to alveolar osteitis
- Clot is lost secondary to transformation of plasminogen to plasmin with subsequent lysis of fibrin and formation of kinins, potent pain mediators
- Biofilm
- Collection of microorganisms often embedded in a self produced extracellular polymeric matrix which allows them to adhere to or coat the surface of a living or inanimate structure
- Chronic osteomyelitis:
- May be classified as primary chronic osteomyelitis (PCO) or secondary chronic osteomyelitis (SCO) and as suppurative or non-suppurative
- Chronic recurrent multifocal osteomyelitis (CRMO)
- Characterized by an inflammatory process presenting with findings similar to infectious osteomyelitis but with no identifiable infectious source
- Often preteen and teenage patients
- Disease is often polyostotic and may affect the mandible
- May represent a widespread variant of primary chronic osteomyelitis
- CRMO and SAPHO (see below) are distinguished from other forms of osteitis / osteomyelitis as these two diseases may have extragnathic skeletal involvement
- Chronic sclerosing osteomyelitis / diffuse sclerosing osteomyelitis
- Primarily descriptive of the radiological appearance of the pathological bone reaction; however, although usually used synonymously with primary chronic osteomyelitis, it represents a description of a strictly radiological appearance that can be caused by several similar processes, including:
- Primary and secondary chronic osteomyelitis
- Chronic tendoperiostitis
- Ossifying periostitis or Garrè osteomyelitis
- Medullary osseous infection, probably bacterial, which induces the complete sclerosis
- Favors young women, is painful and appears radiographically as medullary sclerosis
- Therapy includes antibiotics, surgical debridement and hyperbaric oxygen therapy in refractory cases
- Primarily descriptive of the radiological appearance of the pathological bone reaction; however, although usually used synonymously with primary chronic osteomyelitis, it represents a description of a strictly radiological appearance that can be caused by several similar processes, including:
- Chronic tendoperiostitis
- Initially thought to be an obscure infectious process, the clinical presentation is similar to primary chronic osteomyelitis
- May represent a reactive alteration of bone initiated and exacerbated by chronic overuse of the masticatory muscles, predominantly the masseter and digastric
- Patients usually present with a history of parafunctional complaints
- Palpation of the temporal, masseter, medial pterygoid and digastric muscles reveals tenderness in one or more of these locations
- Radiographically may be similar to primary chronic osteomyelitis with diffuse sclerosing of the marrow and the cortical plate but no pus formation or sequestration
- Condensing osteitis
- Localized areas of radiographic bone sclerosis associated with apices of inflamed dead or dying teeth (pulpitis or pulpal necrosis)
- The association with inflammation, usually a neighboring tooth, is critical, because these lesions can resemble other intrabony processes that produce a somewhat similar pattern
- Is not considered a true osteomyelitis in the classical sense
- Cortical bone:
- Synonymous with compact bone, one of the two types of osseous tissue that forms bone
- Forms the cortex, or outer shell, of most bones
- More dense, hard, strong and stiff than cancellous bone (the second type)
- Garrè sclerosing osteomyelitis
- In 1893, a Swiss physician, Carl Garrè, reported on patterns of acute osteomyelitis
- Garrè did not have any pathologic specimens for microscopic examination or radiographs to augment his descriptions
- Nonetheless, his name is often associated with the condition in which periosteal duplication, or "onion-skinning" pattern of periostitis leads to enlargement of the jaw, usually mandible
- Involucrum:
- Sheath of new bone surrounding the sequestrum (N Engl J Med 2007;356:e7)
- Medullary bone / medullary cavity / marrow cavity:
- Medullary cavity (medulla, innermost part) of bone is the central cavity where red bone marrow or yellow bone marrow (adipose tissue) is stored; hence it is also known as the marrow cavity
- Has walls composed of spongy bone (cancellous bone) and is lined by endosteum, which are osteoprogenitor cells (Wikipedia: Periosteum [Accessed 5 June 2018])
- Osteochemonecrosis of jaws
- Synonyms: bisphosphonate related osteonecrosis of jaws, bisphosphonate induced osteonecrosis of jaw, osteonecrosis of jaw, bisphosphonate osteonecrosis, bis-phossy jaw,
- Necrosis of bone related to long term use of antiresorptive medications such as bisphosphonate and altered bone metabolism
- Osteoclasts may be qualitatively impaired, particularly with intravenous forms of bisphosphonate, which leads to inadequate remodeling of bone and necrosis
- Osteoradionecrosis (ORN)
- Clinically, a chronic non-healing wound of the affected jaw (most commonly mandible), typically with exposure of bone, in a patient with a history of radiation therapy to the head and neck region
- Radiation injury to jaw that leads to ORN results from chronic hypovascularity, hypocellularity of marrow space and ultimately hypoxemia
- More similar to avascular necrosis of bone than primary infection of bone, although infection or bacterial colonization can occur
- Periapical granuloma:
- Acute or chronic inflammation admixed with fibrous or granulation tissue at the apical or periapical region of a necrotic or partially necrotic tooth root
- Is devoid of epithelium (i.e. no cyst lining) which distinguishes it from a periapical cyst
- Proliferative periostitis
- Represents a periosteal reaction to inflammation
- The affected periosteum forms several rows of reactive vital bone that parallel each other and expand the surface of altered bone
- SAPHO syndrome
- Acronym for a complex clinical presentation that includes synovitis, acne, pustulosis, hyperostosis, osteitis
- The osseous lesions mirror primary chronic osteomyelitis and CRMO
- Unknown cause but thought to arise in genetically predisposed individuals who develop an autoimmune disturbance secondary to exposure to dermatologic bacteria
- Increased prevalence of HLA 27
- SAPHO and CRMO are distinguished from other forms of osteitis / osteomyelitis as these two diseases may have extragnathic skeletal involvement
- Sequestrum:
- Predominantly nonviable bone that has become separated during the process of necrosis from the original surrounding native bone (Medical Dictionary: sequestrum [Accessed 5 June 2018])
Zurich Classification of Osteomyelitis
- Primarily based on clinical course and imaging features
- Histopathology is considered a secondary classification criterion because findings are mostly unspecific and inconclusive by themselves; however, tissue examination is irreplaceable to confirm diagnosis, when clinical and radiological appearance are unclear / atypical, and to exclude possible differential diagnoses
- The three major classifications are: (Baltensperger, Osteomyelitis of the Jaws: Definition and Classification (Figure 2.2))
- Acute Osteomyelitis (AO)
- Secondary Chronic Osteomyelitis (SCO)
- Primary Chronic Osteomyelitis (PCO)
- Further subclassification is based on presumed etiology and pathogenesis of disease
- These criteria are considered tertiary classification criteria and are helpful to determine the necessary therapeutic strategies which may differ somewhat among the subgroups
Sites
- Predominantly involves mandible
Pathophysiology
- Chronicity of disease reflects inability of host to eradicate the pathogen, may be due to lack of treatment or inadequate treatment
- After local blood supply is compromised by acute phase of infection, bone undergoes necrosis and nonviable fragments become sequestra
- Periosteum still contains osteogenic potential in most cases which contributes to formation of a bony shell (involucrum) covering the sequestra
- The involucrum may interfere with extrusion of the sequestrum, which may perpetuate the process, in combination with a compromised blood supply and the presence of organisms
- The role of biofilms in chronic osteomyelitis of the jaws is not well studied
Etiology
- Possible polymicrobial bacterial focus: odontogenic disease, pulpal and periodontal infection, extraction wounds, foreign bodies, and infected fractures
- Specific etiologies:
- Actinomyces: cervicofacial actinomycosis is a slowly progressive infection with granulomatous and suppurative features
- Candida albicans: extremely rare, despite being a known commensal of oral cavity
- Nocardiosis: chronic disease that may resemble actinomycotic infection; primary target is usually lung, then hematogenous spread to other organs, cervicofacial region, occasionally including bone
- Tuberculosis: osteomyelitis of jaws caused by Mycobacterium tuberculosis; uncommon, usually NOT confined to bone
- Underlying malignancy and associated osteomyelitis: clinical and radiographic signs of secondary chronic osteomyelitis may be similar to malignant neoplasm complicated by secondary bone infection
- Underlying additional pathology and associated osteomyelitis: clinical and radiographic signs of secondary chronic osteomyelitis may be difficult or impossible to distinguish from a pre-existing, presently infected pathologic disease in the same anatomic area (example: florid cemento-osseous dysplasia)
Clinical features
- Clinical presentation of secondary chronic osteomyelitis of jaws may be variable, based on intensity of disease, the host, the organisms and length of time the disease has been in place
- Clinically and radiographically, ranges from aggressive osteolytic putrefactive phase to a 'dry' osteosclerotic phase
- Deep pain frequently observed in acute phase, may be less intense or a dull pain in the chronic phase
- Firm tenderness caused by a periosteal reaction may be seen more often in chronic osteomyelitis rather than the exquisitely painful swelling due to abscess formation in the acute phase
- Sequestra and fistula formation are more commonly associated with secondary chronic osteomyelitis
Diagnosis
- Initial correct diagnosis of secondary chronic osteomyelitis must be established prior to any successful treatment
- Adequate diagnosis can usually be achieved based on history, clinical evaluation, imaging studies
- In special situations when an underlying malignancy is suspected, biopsy prior to the actual surgical intervention is advisable
Radiology description
- Features:
- Clinically and radiographically, a spectrum ranging from an aggressive osteolytic putrefactive phase to a 'dry' osteosclerotic phase
- Early: osteolysis may be predominant feature
- Advanced: osteolysis and sclerosis, may mimic fibro-osseous lesion of bone
- Radiographic differential diagnosis (broad since radiologic features are variable)
- Acute suppurative osteomyelitis
- Cemento osseous dyplasia (COD) often confused with primary chronic osteomyelitis in literature
- May be a predisposing factor for bone infection
- Florid cemento osseous dysplasia appears on radiographs as sclerosing opaque and dense masses
- The bone changes are often adjacent to apices of teeth and are restricted to alveolar process in either or both jaws
- Chronic sclerosing osteomyelitis / diffuse sclerosing osteomyelitis
- Ossifying periostitis and diffuse sclerosing osteomyelitis are descriptive radiological features
- Both primary and secondary chronic osteomyelitis may demonstrate these patterns with extensive sclerosis, variable amounts of osteolysis and periosteal reaction on diagnostic imaging
- CRMO
- Garrè sclerosing osteomyelitis
- Osteochemonecrosis
- Osteoradionecrosis
- Primary chronic osteomyelitis
- SAPHO syndrome
- Tendoperiostitis
- Malignancy or benign aggressive intraosseous neoplasms inducing proliferative periostitis:
- Ewing sarcoma
- Langerhans cell histiocytosis
- Leukemia / lymphoma
- Metastatic disease to jaws
- Osteosarcoma
- Paget disease (deforming ostitis)
- Due to disturbed bone metabolism, unknown origin
- Usually occurs in advanced age and affects spine, pelvic skeleton, cranial vault
- Long bones and facial skeleton are rarely involved
- If jaws are affected, maxilla is somewhat more often involved than mandible
- Osteopetrosis (Albers-Schonberg disease)
- Genetically inherited disease which involves all bones
- Two major types: autosomal recessive form is "malignant" with anemia, manifests at birth; autosomal dominant form is "benign"
- Malignant form is more dramatic, with severe impairment and systemic complications, patients rarely living beyond age 10 years
- Benign form is more likely to be seen in daily practice
- The jawbone shows massive sclerosis
- Because of the disturbed physiology of the bone due to insufficient osteoclasts, the osteopetrotic bone cannot be resorbed adequately and sclerosis increases with time jeopardizing bone perfusion; secondary bone infection is common and clinical picture resembles primary or secondary chronic osteomyelitis with predominant sclerosis
- Because bone physiology is generally disturbed, both jaws may be completely affected, contrary to primary chronic osteomyelitis which generally just affects the mandible
Prognostic factors
- Often a prolonged course, difficult to predict
- Risk factors for recurrence: ages 6 - 12 years or > 65 years, pre-admission antibiotic administration, a lesion at the mandibular ramus, concurrent maxillofacial space infection (MSI), and conservation of pathogenic teeth (BMC Infect Dis 2013;13:313)
- Risk factors for life threatening complications: age > 65 years, admission temperature > 39 degree C, admission white blood cell (WBC) count >15×109/L, pre-admission antibiotic administration, concurrent MSI, pre-existing diabetes, and respiratory difficulty
Treatment
- Treatment based on age of patient, presence of underlying additional pathology such as florid cemento osseous dysplasia, presence of systemic disease
- Surgical debridement: dictated by extent of infection, presence of foreign bodies and nonviable tissues included (J Oral Maxillofac Surg 1993;51:1294)
- Culture material: tissue samples are favored over surface swabs of necrotic bone
- Antibiotic therapy: ideally withhold until cultures obtained; initially empiric therapy, often broad spectrum; then Infectious Disease consultation, particularly if considering extended antibiotic regimen
- Hyperbaric oxygen therapy may be offered
Gross description
- In osteomyelitis, surgical therapy intends to remove necrotic bone by "debridement"
- Macroscopy of specimens removed for osteomyelitis is determined by the type of surgery and depends on the extent and duration of disease
- Curettage yields small tan to brown hemorrhagic bone fragments and beige inflammatory exudate
- Small curettage fragments are usually totally embedded in paraffin and normally do not require dissection
- Larger tissue specimens should be oriented and cut perpendicular to osseous surface
- Necrotic bone fragments are pale whitish-gray; sequestra usually show an irregular outline
- Occasionally, a jaw resection is required; on cross section, the bony cortex appears thickened and the cancellous bone sclerosed; osteolytic and osteosclerotic foci may alternate
- Biopsies to confirm a diagnosis of osteomyelitis and rule out neoplasia may be very small
Microscopic (histologic) description
- According to Zurich classification, pathology is a secondary classification criterion serving to confirm the diagnosis of osteomyelitis if clinical judgment and diagnostic imaging are inconclusive (J Craniomaxillofac Surg 2004;32:43)
- Histology of jaw osteomyelitis should always be complemented and interpreted in conjunction with clinical and radiological findings and should NOT be used independently
- Histology is also essential to exclude differential diagnoses
- A clear distinction of primary and secondary chronic osteomyelitis solely based on histopathology is not always possible but may be helpful in context with clinical presentation and imaging studies
- When few clinical signs of suppuration (pus, fistula, sequestra) are evident, histopathology resembles typical appearance of chronic osteomyelitis with no clear distinction of primary and secondary chronic forms
- An important purpose of histopathological investigation - beyond the confirmation of a clinically and radiologically suspected diagnosis of osteomyelitis - consists of typing and grading of the inflammatory activity; this may help distinguish secondary chronic osteomyelitis from primary chronic osteomyelitis in some cases when clinical course and imaging studies are inconclusive
- Histopathology in cases of secondary chronic osteomyelitis with significant suppuration demonstrates similar features as acute osteomyelitis with large amounts of polymorphonuclear leucocytes, macrophages, and plasma cells, accompanied by a variable degree of marrow fibrosis and reactive bone formation
- Cases of secondary chronic osteomyelitis with a less fulminant (e.g., more chronic) course have lymphocytic infiltrate, marrow fibrosis, reactive woven bone formation, minimal marrow adipose
- Periosteum still contains osteogenic potential in most cases, which contributes to formation of a bony shell (involucrum) covering the sequestra
- The involucrum may interfere with extrusion of the sequestrum, which may perpetuate the process, in combination with a compromised blood supply and the presence of organisms
Differential diagnosis
Additional references