Tuberculosis of bones and joints

General consideration

1. Tuberculosis is still endemic disease in developing country

2. It is estimated that India alone has got one fifth global burden of

tuberculosis.

3. India Rank 1 in world total tuberculosis case load

4. After Lung and lymph node, bone and joints is the next most

common site of tuberculosis in the body.

Bone and joints tuberculosis• Spine most commonly affected, 50% of all cases of osteoarticular

tuberculosis.

• Next in order of frequency Hip, Knee, elbow, foot, hand, shoulder, bursal

sheath and others

• Tubercular osteomyelitis affect end of long bone, (unlike pyogenic OM

metaphysis) this is the reason behind early involvement of joints in TB

osteomyelitis.

• Spine/ Pott’s spine

• Joints - Tubercular arthritis (MC Hip)

• Long and flat bones - Tubercular osteomyelitis (MC tibia)

• Short bones – Tubercular dactylitis / spina ventosa

• Tendon sheath ( MC flexor and wrist) & bursae

Etiology

• Common causative organism is Mycobacterium tuberculosis.

• Osteoarticular tuberculosis is always secondary to some primary focus

in lung, lymphnode etc

• Mode of spread from primary focus either haematogenous or by

direct extension from adjacent viscera.

Pathology• Tubercular infection leads to chronic granulomatous inflammation with

caseation necrosis.

• The response to tubercular infection may be proliferative, exudative or both

• Proliferative response:- commoner leads to chronic granulomatous

inflammation, heal with fibrosis.

• Exudative response:- in some cases, malnourished, immunodeficient etc

extensive caseation necrosis without much cellular reaction.

Pathogenesis cont..• Sequestration & peri-osteitis are not very common (unlike pyogenic

infections)

• Ischemic necrosis and end arteritis may result in a very small sequestrum which is usually not visible radiologically (unless calcified)

• Granulation tissue spreads onto the free surface of cartilage eroding it in patches, later causing loosening and separation of the cartilaginous tissue as it proceeds causing necrosis of cartilage with erosion of exposed bone.

Osteolytic lesion with a small sequestrum

• Marginal erosions are common in TB of weight bearing joints (hip,

knee, ankle)

• Necrosed cartilage and fibrinous material form ‘rice bodies’ in synovial

joints, tendon sheaths and bursae.

• Abscesses that form may track along the fascia planes and form sinuses

• Can be divided into 4 pathological stages –

1. Inflammatory edema & exudates (pre-destructive stage)

2. Necrosis & cavitation

3. Destruction & deformation

4. Healing & repair

• Insidious onset

• Low grade fever

Weight loss

Night sweat

• Movement restriction, muscle wasting, regional lymph node involvement and neurologic symptoms

Clinical features

Principles of management

• Relative lymphocytosis, a low level of hemoglobin and a raised ESR are found in active tubercular disease

• The Mantoux test is non-diagnostic in an endemic region and may be negative in an immuno-deficient individuals

• The sensitivity of AFB staining may vary from 25 to 75 %

Laboratory investigations

• Synovial fluid aspiration – routine, microscopy, culture

• Biopsy (needle/open) – culture and histopathology

• Culture of AFB requires a long incubation period of 4 to 6 weeks,

although Bactec radiometric culture takes < 2 weeks

Serological tests

• Non-diagnostic in lesions with a low level of bacilli

• IgG and IgM titres show significant differences between the initiation of treatment and at three months later (can be used for follow up)

• PCR - efficient and rapid method of diagnosis can differentiate between typical and atypical mycobacteria

However, a positive result is not a substitute for culture NOT indicative of the activity of the disease does not differentiate live from dead microorganisms

• Radiography

• USG

• CT

• MRI

• Nuclear imaging

Imaging modalities

AP and lateral views of the involved region radiograph of the chest

Radiological stages – 1. Stage of synovitis2. Stage of arthritis3. Stage of advanced arthritis4. Stage of healing

Radiography

1. Stage of synovitis:

• Soft tissue swelling and joint widening due to effusion and synovial hypertrophy

• The first radiological sign may be juxta-articular osteoporosis.

• If there is secondary superadded infection, subperiosteal reaction may result.

• As a result of localized hyperemia growth plate may show overgrowth, especially in childhood.

2. Stage of arthritis:

• Articular margin and bony cortices become hazy (blurring and fuzzy) giving rise to "washed out appearance“

• Narrowing of joint space (involvement of articular cartilage)

• “Phemister Triad” juxta-articular osteopenia, peripherally located osseous lesions and gradual narrowing of joint space

are considered pathognomonic of tubercular osteoarthritis

Early loss of articular joint space is more typically seen in rheumatoid arthritis and thus helps in differentiating from tuberculosis.

3. Stage of advanced arthritis:

• Collapse• subluxation or dislocation• migration of bone• deformity of joint

4. Healing –

• Re-mineralization

• Cortical and articular margins become distinct

• Fibrous ankylosis may occur during healing phase (pyogenic arthritis – bony ankylosis)

• In contrast to pyogenic arthritis, the development of bone ankylosis is uncommon in tubercular arthritis

• Helpful in the evaluation of large joints

• Demonstrates joint effusion, synovitis and capsular thickening

• Soft tissue abscess like psoas abscess

• Cortical disruption & irregularity of articular margins

• Guided joint fluid aspiration or synovial biopsy is possible

USG

• Lytic areas and marginal erosions seen much before plain radiographs

• Swelling in soft tissues, granulation, exudations, abscess and early calcification can also be demonstrated much earlier

• Joint space better evaluated by CT

• Computed tomography guided aspirations and needle biopsy for difficult areas like sacroiliac joints

CT

• MRI may be helpful in characterizing the lesion as tubercular when the radiographs are normal• MRI helpful in detecting

bone marrow inflammation, Skip lesion in potts spine intra-osseous abscess, sequestrum, cortical destruction, cloaca and sinus tract formation

MRI

• Chondral lesions and subchondral bone erosions may be visible at a stage when the joint space is still well preserved.

• Penumbra sign - A thin intermediate signal intensity rim along the periphery of a bone or soft tissue abscess on unenhanced T1 -weighted images, due to layer of granulation tissue along its wall. It is useful in identifying soft tissue abscesses.

• Tenosynovitis may be seen

• Bursitis may be seen as distended bursa or multiple small abscesses.

• Repeat imaging can be helpful in follow-up and if there is deterioration, then a representative biopsy is mandatory from the area.

• Fluid loculations• Enhancing synovium• erosions

• The pre-destructive stage can be visualized by MRI and also probably by bone scans.

• Isotope bone scan or MRI may reveal subclinical active lesion in 40 % of patients in addition to the presenting lesion.

• Out of technetium-99m, gallium-67 and indium-111 isotopes used in skeletal scintigraphy, technetium-99m is the most sensitive, though not specific.

• Positive scan helps in localizing and for follow-up.

• 18Fluorine fluorodeoxyglucose-positron emission tomography (18F-FDG- PET) has also been found useful in localizing tubercular disease and in differentiating soft tissue infection from osseous infection

Nuclear imaging

Treatment• Aim is to control infection and care of disease part.• Most case respond with conservative therapy few needs surgical

intervention

Conservative treatment• Rest• Traction/ proper positioning of affected part• Antitubercular drugs• Building up the patient resistance

Later- mobilization, physiotherapy, protected weight bearing.

Treatment: Rest • Thomas urged that TB should

be treated by rest – which had to be ‘prolonged, uninterrupted, rigid and enforced’.

Hugh Owen Thomas

Treatment; Rest

• Traction

• Provides rest of the joint

• Relieves muscle spasm

• Prevents and corrects deformity

• Maintains joint space

• Minimises chance of developing deformity

Anti- tubercular drugs• First Line Anti-Tubercular Drugs

• Isoniazide (H) 5mg/kg• Rifampicin (R) 10mg/kg• Pyrazinamide (Z) 30mg/kg• Ethambutol (E) 15-20 mg/kg• Streptomycin (S) 15mg/kg

Second-Line Anti-Tubercular Drugs

Parenteral agent • Kanamycin (Km) 15mg/kg 15m g/kg 1515m g/kg15mg/kg 15mg/kg

• Amikacin (Amk) 15mg/kg• Capreomycin (Cm) 15mg/kg Fluoroquinolones • Levofloxacin (Lfx) 15mg/kg• Moxiflxacin (Mfx) 7.5-10mg/kg• Gatiflxacin (Gfx) 15mg/kg• Oflxacin (Ofx) 15mg/kgOral Bacteriostatic Drugs • Ethionamide (Eto) /Prothionamide (Pto) 15mg/kg• Cycloserine (Cs) Terizidone (Trd) 15mg/kg• p-aminosalicylic acid (PAS) 300mg/kg

• Group 5 Drugs • Clofazimine (Cfz) • Linezolid (Lzd) • Amoxicillin/clavulanate (Amx/Clv) • Thioacetazone (Th) • Clarithromycin (Clr) • Imipenem (Ipm)

•TMC207 (Bedaquiline) &

•OPC-67683 (Delamanid) : Phase III research

TB disease category Intensive phase

Continuation phase

All forms of PTB and EPTB except TB meningitis and osteoarticular TB

2RHZE 4RH

TB meningitis, osteoarticular TB

2RHZE 10RH

New WHO Recommended regimen

Surgical treatment• Aim –• To establish diagnosis• To prevent joint destruction • To decrease bacterial loads (remove necrotic/ infected material )• To correct deformity• To achieve stability• To achieve mobility

Surgical treatment• Biopsy• Curretage of lesion• Joint debridement• Synovectomy• Osteotomy• Decompression and spinal fusion• Arthrodesis • Arthroplasty

Any question???????