Orthopaedics Acute suppurative arthritis
The organism may reach a joint either directly: ❶penetrating wound,❷
intra-articular injection, ❸operation or ❹from nearby bone abscess; or
indirectly via blood stream from a distant site.
: usually, Staph.aureus; less often, Strept., E.coli &Proteus. In
infants, H.influenzae is common. In adults, Neisseria gonorrhea is the
commonest. Immune suppressed &AIDS patients: unusual organism.
:
the infection starts in the synovial membrane→ acute inflammatory reaction with serous or
seropurulent exudate. When pus appears, the articular cartilage is eroded &destroyed by:
enzymes released from bacteria, synovium, inflammatory cells &pus. In infants, the
epiphysis may be destroyed or vascular occlusion may lead to avascular necrosis.
Ŗ→ infection may spread to underlying bone or to surrounding soft
tissue forming abscess &sinus.The final result:
1-complete resolution to normal.
2-partial loss of articular cartilage→ joint fibrosis.
3-loss of articular cartilage→ bony ankylosis.
4-bone destruction &permanent joint deformity.
: irritable, refuse to feed &sometimes fever; examine the
joints for tenderness &limitation of mvt.
: ill, feverish, in acute pain &refuse to move the
limb(pseudoparesis); the joint is swollen, hot, red, tender with
limitation of all movements.
: acute joint inflammation; think of gonococcal infection.
Patients with RA or immune suppression are more prone.
early: X-ray: → ❶soft tissue swelling; in children: ❷wide joint
space &❸even subluxation. U/S: joint effusion.
Late: osteoporosis; narrowing &irregularity of joint space.
Very late: bony ankylosis.
↑WBC, ↑ESR, blood culture is +ve in 50%.
Joint aspiration: often yields pus though in early cases, it can be clear. Send for:
1
Orthopaedics Acute suppurative arthritis
1-WBC count→ normal synovial fluid leucocyte count=300/ml;
even >10,000/ml=inflammatory disorder(gout); >50,000/ml suggest infection.
2- Gram stain: Gram +ve cocci are probably Staph.aureus; Gram-ve cocci are
3- either H. influenzae(children) or Gonococcus(adults).
4- Bacteriological culture &AB sensitivity.
: in infants, often both are present.
: pain flits from 1 joint to another, no signs of toxicity.
: may cause joint pain &swelling(traumatic synovitis or hemarthrosis);
aspiration should solve the problem.
5- : is painful with some limitation of mvt but child is not ill.
6- is similar to septic arthritis; history &aspiration is diagnostic.
6- : is very similar to septic arthritis(adults), even the aspirate is
turbid(high leucocyte count); diagnosis needs polarized microscopy.
Septic arthritis is a surgical emergency. joint fluid &blood samples are sent
for direct examination & culture, then start Ŗ without delay:
: analgesia &IV fluids.
2- rest the joint on a splint or in a back-slab; for the hip,
use traction in abduction &some flexion to prevent dislocation.
3- Adults &older children→ 1week IV flucloxacillin+fusidic acid→
orally for 3wks. Children<4years(H.influenzae)→ ampicillin or cephalosporin.
*then change AB according to the results of C&S.
4-
*open drainage: under anesthesia, open the joint through a small incision,
drain &wash with normal saline, close the wound over a small catheter for
suction-irrigation (3days). The indications are : ❶ infants,❷ septic hip &❸if
aspirated pus is thick. For the knee, can use arthroscopic drainage &irrigation.
*repeated closed aspiration is usually successful (if not improve within 48hrs→
open drainage). Indications : ❶older children,❷ early septic arthritis (<3days)
&❸any joint except the hip.
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Orthopaedics Acute suppurative arthritis
Aftercare: if cartilage is preserved→ start movements when pain↓; if
destructed→ continue splinting the joint in the position of function.
1-cartilage destruction: if partial→ fibrous ankylosis; if complete→ bony
ankylosis. In adults, partial cartilage destruction→ secondary OA.
2- bone destruction &(hip ≠).
3- growth disturbance→ deformity or hortening.
Osteomyelitis Septic arthritis
-painful limitation of mvt. -Very painful decrease ROM
- localized tenderness on metaphysis Not present
- reactive arthralgia, less swelling joint effusion and Swelling redness
X-ray after 2 weeks Can Show Squestrum - Not present
Tuberculosis:
Skeletal TB is often seen in the spine & large joints though no bone is
immune.
Patients with low immunity are more prone like: AIDS, drug abuse,
chronic debilitating disease &prolonged steroid Ŗ. Organism: the
Mycobacterium tuberculosis (human or sometimes bovine) reach the
lung by droplets or the gut by contaminated milk or rarely through the
skin
is the combination of the initial lesion(lung or gut)+
spread to regional lymph node, it is often symptomless. TB bacilli remain in
the LN for many years; if reinfection occurs later, the lesion would be more
destructive because the body has become sensitized to the bacterial toxin.
if the resistance to the initial infection is low, blood
spread may cause miliary TB or meningitis. More often, the spread occurs
years later &the bacilli settled in extrapulmonary tissues forming destructive
lesion called tertiary lesion.
5% occur in the skeleton (bone, joint &spine). The bacilli
cause a chronic inflammatory reaction characterized by tuberculous
granuloma: central necrosis surrounded by giant &epitheloid cells with
lymphocytes at the periphery.
: multiple lesions may coalesce forming bone abscess
containing fragments of necrotic bone. Bone lesion easily spreads into the
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Orthopaedics Acute suppurative arthritis
epiphysis &nearby joint.
the synovium become edematous &thick with marked
effusion. The articular cartilage is slowly destructed with juxta articular bone
erosion. The ↑ vascularity will cause local osteoporosis, sever muscle wasting.
the caseation may spread into surrounding soft tissue forming
'cold' abscess which may open to the skin by sinus or track along tissue plane
&point at distant site.
is by resolution to normal if the disease is arrested early; if the
articular cartilage is destructed, healing is by fibrosis & incomplete
ankylosis with progressive deformity with the possibility of disease flare
up even years later.
a child or young adult may have a history of previous TB; joint pain &swelling;
weight loss &attacks of fever.
O/E: swollen, warm joint with synovial thickening, marked muscle wasting
&limited joint movements.
In TB spine: backache, cold abscess(groin, lumbar or back), localized kyphosis or
neurological deficit in the lower limbs.
soft tissue swelling, periarticular osteoporosis &joint space narrowing.
later: subarticular bone erosion on both sides of the joint; bone cysts with no
periosteal reaction. In the spine: disc space narrowing, end
plate erosion, vertebral collapse ¶vertebral abscess.
↑ESR, relative lymphocytosis & +ve Mantoux test. Synovial fluid aspirate is
cloudy with high protein &WBC count, acid fast bacilli is +ve in 20% & culture is
+ve in 50%.
Synovial biopsy is more reliable→ TB granuloma, acid-fast bacilli &culture is
80% +ve.
1-long history;
2-single joint involvement;
3-marked synovial thickening;
4-marked muscle wasting;
5-periarticular osteoporosis.
Synovial biopsy for histological examination & culture is necessary.
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Orthopaedics Acute suppurative arthritis
1- transient synovitis: is common in children, it always settles down after few weeks rest.
2- monoarticular RA: biopsy should differentiate it from TB.
3- subacute arthritis: like brucellosis, investigations can diagnose it.
4- hemorrhagic arthritis: the history is diagnostic.
5-pyogenic arthritis: in long standing cases, it is difficult to say: it is an old septic or old
tuberculous arthritis.
1-Rest: in bed &rest of the joint in the position of function; when symptoms subside,
movements are encouraged. 2-Chemotherapy: use combination of antituberculous
drugs→ Rifampicin + isoniazid + (streptomycin or ethambutol or pyrazinamide) for 8weeks,
then continue with rifampicin + isoniazid for 6-12 months.
3-operation:
Early: drainage of cold abscess or clearance of TB focus.
Late: osteotomy to correct a deformity;
Arthrodesis or joint replacement for destructed, painful joint.
*at any time &certainly after bone operation, there is a risk of disease reactivation(pre
&postoperative anti-TB is essential).
tb arthritis septic arthritis
Cold abscess joint is swollen, hot, red, tender
Sever muscle weasting No
Multiple lesion Single lesion
Sever osteoporosis Less osteoporosis
incomplete ankylosis Complete incomplete ankylosis
High grade fever Night fever
