OSTEOMYELITIS OF THE JAWS

Dr. Ghulam SaqulainHead of Department of ENT,Capital Hospital

Definition:

Osteomyelitis is an inflammation of the

medullary portion of the bone

However since the process usually also affects the cortical bone and periosteum, therefore osteomyelitis may be considered an inflammatory condition of bone that usually begins as an infection of the medullary cavity which rapidly involves the Haversian system and quickly extends to the periosteum of the area.

Osteomyelitis of the Jaws differs in many important aspects from the one found in long bones.

Stages:

Acute Sub Acute Chronic

Incidence

The incidence of Jaw Osteomyelitis is very low and fungal osteomyelitis is rare.

The low incidence of osteomyelitis of jaws is remarkable considering the high frequency and severity of odontogenic infections.

The low incidence is a result of fine balance b/w the host resistance and the virulence of the microorganisms. The jaw vascularity is also important

Age & Sex Incidence

It can affect any age but most common in infants, children and older adults

Gender: Males> Females

Predisposing Factors

Systemic Conditions that alter the host’s resistance:Diabetes mellitus, Autoimmune disorders,

agranulocystosis, anaemia, AIDS, syphilis, malnutrition, chemotherapy, steroids etc.

Alcohol and tobacco use are frequently associated with osteomyelitis

Conditions that alter the vascularity of bone: Radiation, osteoporosis, fibrous dysplasia, bone malignancy etc.

Etiology & Pathogenesis

In infants and children it occurs most commonly in long bones primarily by Hematogenous Spread

In Adults long bone osteomyelitis and majority of cases of jaw osteomyelitis are initiated by a Contiguous focus

In the jaws contiguous spread of odontogenic infections that originate from pulpal or periapical tissues is the primary cause of disease.

Infection from periostitis after gingival ulcerations, lymph nodes, infected furuncles or lacerations and hematogenous origin account for an additional small number in jaw osteomyelitis.

The extensive blood supply of the maxilla makes it less prone compared to mandible.

The thin cortical plates and the porosity of the medullary portion preclude infection from becoming contained in the bone and facilitate spread of edema and purulent discharge into adjacent tissues.

Trauma, esp. non treated compound fractures, is another leading cause.

Microbiology

Staph.Aureus and epidermidis were, until recently, estimated to be involved in jaw osteomyelitis in 80-90% of times.

With more sophisticated methods of collection and appropriate handling of cultures anaerobes eg., Peptostreptococcus, Fucobacterium and Provotela species.

Eikenella corrodens is isolated in high percentage from cultrues along with Klebsiella, Pseudomonas and Proteus species.

Mycobacterium TB and Fungi like Candida, Coccidiodes, Blastomyces, Cryptoccus Sporothrix Aspergillus species, rarely involve the jaws

It is now recognized that if staph is isolated in cultures probably originates

from skin contamination or through fistulas

Pathophysiology

Infection at the bone locus results in acute inflammation and creates an increase of Intramedullary pressure due to inflammatory exudate that leads to vascular thrombosis followed by avascular bone necrosis and formation of sequestra

These sequestra are surrounded by sclerotic avascular bone.

Haversion canals are blocked with scar tissue.

Periosteal reaction act to circumscribe sequestrum producing a thick sheet of new bone or involucrum.

Classification

Cierny & Mader proposed an anatomic classification of chronic osteomyelitis

Type 1 Endosteal or medullary lesion Type 2 Superfiscial osteomyelitis limited to surface Type 3 Localized, well marked lesion with sequestration and cavity formation Type 4 Diffuse Osteomyelitic lesion

Clinical Findings

Four Clinical Types are Observed: Acute Suppurative (Acute Intramedullary

Osteo) Deep intense pain High intermittent fever Paresthesia or anaesthesia of the lip Clearly identifiable cause No loosening of the teeth, no fistulas and

no or minimal swelling

If not controlled within 10-14 days after onset Subacute suppurative osteomyelitis is established. Pus travels through haversian canals and accumulates under the periosteum and may spread to soft tissues. Deep Pain Malaise Fever Anorexia Teeth are sensitive to percussion and b/c loose Pus may be seen around sulcus of teeth or through

skin fistulas and has fetid odor Overlying skin is warm, erythematous, tender. Firm

cellulitis with lymphadenopathy may be present

If inadequately treated the progression to sub acute or chronic form is warranted. Primary Chronic form is not preceded by an episode of acute symptoms, is insidious in onset with: Mild Pain Slow increase of jaw size Gradual development of sequestra, often

without fistula.

Clinical Presentation

Chronic osteomyelitis causes no acute constitutional symptoms. It can cause: Fever Chronic bone pain which

persists despite treatment Swelling Warmth Redness Tenderness Long discharging sinus Irritability

TB Osteomyelitis Local Symptoms

Pain, Restriction of joint movement, redness, warmth, muscle wasting

General Symptoms Weight loss, Evening

fever, malaise, increased sweating

Fungal Osteomyelitis Swelling Cold Abscess

Investigations

Blood Tests Blood CP (Leukocytosis) Raised ESR Raised C-Reactive Protein

Blood C/S Pus C/S If there is discharging sinus Needle Aspiration or bone biopsy

Radiologic Assessment To evaluate extent To identify soft tissue involvement (Areas of

cellulitis, abscess or sinus tracts)Findings:

Acute/ Sub Acute: Deep soft tissue swelling, periosteal reaction, cortical irregularities, demineralization

Chronic: thick, irregular, sclerotic bone interspersed with radiolucencies, an elevated periosteum and chronic draining sinus are seen

Complications

General Septicemia Pyemia Metastatic abscess

Local Secondary involvement of joint Spontaneous fracture Deformity Discharging sinus Brodie’ s abscess (chronic Abscess within bone)

Treatment:

Medical and surgical treatments are usually required although in some rare

occasions sole antibiotic treatment may be successful

Principles of Treatment:

Evaluation and correction of compromised host defenses

Gram staining and culture and sensitivity testing Imaging of the region to determine the extend of the

lesion and to rule out the presence of tumors Empirical administration of Gram stain-guided

antibiotics Removal of loose teeth and sequestra Prescription of culture-guided antibiotic therapy Possible placement of irrigating drains/

polymethylmethacrylate –antibiotic beads Sequestrectomy, debridement, decortication,

resection or reconstruction as indicated.

Acute Suppurative Osteomyelitis:

The initial management usually is aided by: Hospitalization to administer high doses

of antibiotic therapy Identify and correct host compromise

factors and treat cause

Chronic Suppurative Osteomyelitis:

Requires Surgical Procedures in addition to antibiotic treatment

Antibiotic therapy should be continued for 4-6 weeks after the patient has no symptoms or from the date of the last debridement.

Closed Wound Irrigation-Suction: Tubes are placed against the bone to allow for drainage of

pus and serum and for irrigation in order to reduce the number of accumulated microorganisms

This type of therapy is esp. helpful when determination of extent of ch. Inf. Of residual bone cannot be determined.

Antibiotic-Impregnated beads: Hyperbaric oxygen therapy.

Surgical Treatment:

In the acute stage it should be limited to removal of severely loose teeth and bone fragments and incision and drainage of fluctuant areas.

This may proceed to sequestrectomy with or without sucerization, decortication resection and then reconstruction

The number and nature of the required surgical procedures increases with the severity of the infection:

Category 1 – Removal of necrotic tissue by extensive debridement Category 2 – Dead space obliteration with flaps, antibiotic beads,

and bone grafts Category 3 – Provision of soft tissue coverage of the bone Category 4 – Stabilization of bone by external or open reduction

and internal fixation

Sequestrectomty:Sequestra are avascular.. Can be cortical or cortico-cancellous. They can be removed with minimal trauma

Sequestrectomy and Saucerization: Saucerization is the unroofing of the bone to expose the medullary cavity. It should be performed as soon as the acute stage has resolved, so to decompress the bone and allow for extrusion of pus, debris and avascular bone.

Saucerization is rarely required for the maxilla

Decortication: Involves removal of chronically infected cortex, usually the buccal and the inferior border are removed 1-2 cm beyond the affected area.