INFECTIONS OF BONE AND JOINTS

DR.Chandrashekar rao

Asst. professor

ACUTE SEPTIC ARTHRITIS

• Definition– Infectious disease of a

joint by bacteria of one of the pyogenic groups

• Typically its acute infection of rapid development but may be sub acute or chronic.

pathogenesis

• 3 Routes of entry by organism– Haematogenous– wound or surgery– adjacent site of osteomyelitis or

cellulitis

pathogenesis

• Synovium is infected, becomes hyperemic and infiltrated with neutrophils.

• Stimulation of T lymphocytes

• Enzymes of inflammatory cells, bacteria and synovium

• Purulent or serous exudate in joint space.

• Erosion and wear of articular cartilage

• Organisms– Staph aureus (M.C)

• H.influenzae• Streptococcus• E.coli

• At risk groups, conditions – Rheumatoid Arthritis (m.c)– Diabetes– IV Drug Us– Hemodialysis– Immunosuppressed Host,

Clinical features

• Infants– Signs of septicaemia– Local signs of warmth , tenderness– Examine umblical card

• In children– Acute pain in joint– Pseudoparesis– Severely ill and fever– Local signs of inflammation– Restriction of joint movements

• In adults– Knee, wrist and finger or toe joints are

involved– Marked local tenderness– Restricted joint movements– Careful history is important

DIAGNOSIS

• Lab investigations– ESR:Elavated in 48 to 72 hrs returns to

baseline in 2 to 4 weeks– CRP:Raises within 6 hrs and peaks 30 to 50

hrs.Good marker for early diag– Bacteriological examination of joint

aspirate:synovial leukocyte >50,000/mm

• X-ray– First few days: may show soft

tissue swelling, joint space widening due to edema

– Later on: joint space narrowing due to destruction of cartilage, rarefaction of adjacent bone and possible destruction

• USG– can detect even small collection

of fluid in joint

• MRI– differentiates b/w bone and soft

tissue infection, and shoes joint effusion.

DIFFERNTIAL DIAGNOSIS

• Acute ostoemylitis:assume that both are present in children

• Traumatic synovitis and haemarthrosis:hx of injury

• Irritable joint:No signs of infection

DIFFERNTIAL DIAGNOSIS

• Haemophilic Bleed:aspiration will resolve the doubt

• Rheumatic Fever:No signs of septicemia• Gout and pseudogout:Joint fluid is

turbid.Microscopic exam by polarized light will show crystals

TREATMENT

• Antibiotics and Supportive Therapy.

• Aspiration and Drainage

• Correction of deformities

• Antibiotics– as per antibiotic sensitivity– Usually administered for 6 weeks– Gram neg and staphylococci respond slowly– Streptococci and Neisseria respond rapidly

SURGERY

• Indications– Hip or Joints difficult to aspirate or monitor– Extensive spread of infection to soft tissues– Inadequate clinical response after 5 to 7 days

• Aspiration and drainage– Early diagnosis,repeated aspirations and

proper antibiotics –good results• Arthroscopic drainage is good alternative

• Deformities– Are corrected with Osteotomies and

arthroplasties

• Prognosis ,poor– RA, prematurity– prosthetic infections– +ve cultures after aspiration after 7 days of anti.bxs

BRUCELLA OSTEOMYELITIS

• Common in mediterranean countries,africa and parts of india

• Organisms– Brucella melitensis– Brucella abortus– Brusella suis

• Source– Infected milk ingetion (mc)– Contact with inf. Meat– Through injured skin and mucosa

• Chance– 50% with chronic brucellosis

• Diff.diagnosis– TB– Reiters disease

• Bones affected– Spine(lumbar)– Hip and– Knee

• Pathology– Cronic inflammatory granuloma with round

cell infiltration and giant cells– May be central necrosis and caseation-

abscess formation

• Clinical features– Fever,headache,weakness– On and off fever(undulant)– Initial illness is acute,– begins insidiously– Then symptoms localize to one joint or spine– Joint become tender and swollen– Movements restricted– Back movements restricted

• Investigations– A positive agglutination test

is diagnostic– Synovial biopsy and culture

• X-ray– Loss of joint space– Slowly progressive bony

erosions– Peri –articular osteoporosis

• Treatment– tetracycline+streptomycin for 4 weeks or– Rifampicin +cephalosporin for 3 weeks– Early diagnosis give good prognosis

TYPHOID OSTEOMYELITIS

• Occurs during convalescent phase• Sub acute osteomyelitis• Occurs in sickle cell anaemia• Common sites

– Ulna, tibia and spine

• Multiple bones may be affected• Some times b/l symmetrical• X-ray

– Diaphyseal sclerosis

MYCOTIC INFECTION

• Divided in to sup. And deep• Superficial

– Infection of skin and mucous membrane– Spread in to bones– Maduromycoses,candida

• Deep– Source is bird droppings and food grains– Entry through lungs– Blastomycoses,histoplasma,cryptococcus and

aspergillus

maduromycoses

• Seen in north america and india

• Through skin cuts• In form workers• Spread to

subcutaneous tissues and bones

• Abscess breaks through multiple sinuses

• Clinical features– Tender sub cut. Nodule in

early stages

– After some years seen with

– Swollen and indurated foot

– With discharging sinuses and ulcers

• X-ray– Multiple bone cavities

• Organism identfied on tissue biopsy

• Treatment– No effective chemotherapy– I.V amphoterecine B is used ,but more toxic– Wide excision – amputation

HYDATID BONE INFECTION

• Caused by ECHINOCOCUS• Definitive host dog or other

carnivore• Cattle or Man is int. host• Infected meat eaten by man

contains cysts• Scolices occasionally settle

in bone• Affected bones are

– Vertebrae– Pelvis– Femur and scapula

• Clinical features– Pain and swelling – Pathological fracture– Spinal cord compression– Symptoms may not be

appear for many years

• X-ray– Solitary or multi loculated

cysts– Moderate cortical

expansion– Paravertebral soft tissue

on CT and MRI

• Casonis test positive• Benign and malignant bone cysts excluded• Albendazole

– 10mg per kg wt– For 3 weeks– In 4 cycles with 1week gap

• Recurrence is common• Curettage and bone grafting• Cavity is cleaned with saline and formalin

SYPHILIS OF BONES and JOINTS

• Caused by treponema pallidum• Sexually transmitted• Can cross placental barrier (congenital)• Primary lesion chancre appears after 1 month• Bone changes occur in the secondary stage

– Periostitis– Osteitis and– Osteochondritis

• In tertiary stage– Gummata in bones– Charcot joints develope

• Congenital, early stage– Joint swelling after 7-10

weeks after birth– Pseudo paralysis– Symmetrical lesions in

tubular bones

• X-ray– Osteochondritis

• Lucent band in metaphyseal region

– Periostitis• Diffuse periosteal new

bone formation

• Congenital; late– Resemble those of adults– Gummata may develop in

adolescents– SABRAE TIBIA dense

edosteal and periostael new bone

– Hutchinson's teeth– Cluttons joints (painless

effusions)– Dactilitis

• Others– Tabes dorsalis– General parasis of insane

• Treatment– Early, benzyl penicillin IM– For 3 weeks– Tertiary lesions will not respond at all– 3rd gen. cephalosporin may work