AS is a seronegative inflammatory disease of unknown etiology characterized by inflammation in the axial skeleton esp; SI joint, principally affecting young males in the 3rd decade.

Course of the disease is said to be one of the relentless progression with periods of exacerbation & remission.

Ankylos – bent or fused, spondylos – vetebrae.

Marie Strumple or Von Bechterew disease It belongs to group of spondyloarthritis. Share certain C/F & an association with HLA

B-27 allele.

M:F 3:1 2nd to 4th decade 6 per 10,000 of G. population Autosomal inheritance, with 70%

penetrance in males, 10% in females. 90% pts have HLA B- 27 antigen. Increased incidence among relatives.

Located in the short arm of chromosome 6 One of the series of closely linked

polymorphic loci in that region. Incidence in N. population – 8% in

caucasians, 4% in blacks. Neither necessary nor sufficient to cause AS Positive individuals tends to have early

onset. No correlation with severity.

Carriers of this gene have a 16% to 50% increased risk of developing AS,

Virtually absent among the aboriginal populations of Australia and South America.

Negative individuals doesn’t have family history.

Susceptibility to AS almost entirely determined by genetic factor with HLA constituting about 1/3 of genetic component.

autoimmune disorder subsequent to a Klebsiella pneumoniae

infection in HLA-B27–positive individuals, Molecular mimicry, incidence of AS in patients with idiopathic

bowel disease is approximately 3.7%.

ENTHESOPATHY , Hall mark of AS. combination of inflammation and bony

destruction at the site of tendon insertion Ass with prominent edema of the adj bone

marrow & is often characterised by erosive lesions that eventually undergoes ossification.

Distribution of lesion: in synovium, articular capsular & ligamentous attachments to bones.

Articular lesions due to 2 primary mech, synovitis, enthesitis

2 subsidary mech, enchondral & trauma. In spine: early, there is inflammatory

granulation tissue at the jn of AF of disc cartilage with the margin of V.B.

Outer AF is replaced by bone – bony osteophytes, fusion of adj V.B.

Aches in buttocks. Lower lumbar aches Bony tenderness. Peripheral jt involvement [girdle jts] Inflammatory back ache.1. < 40 yrs onset2. Insidious onset3. Duration > 3 months4. Morning stiffness5. Improvement with exercise.

Extra articular invoivement Most C. anterior uveitis. [30%] AR, Third degree heart block. Subclinical pulm. Lesion, cardiac dysfn. Cauda equina syn & slow progressive upper

lobe fibrosis in long standing cases. Progression of the diseaseas monitered by

Pt Ht, chest expansion, scoebers test, occiput to wall distance.

Jaw involvement- old pts. Thorax involvement.

Loss of lumbar lordosis Exaggerated kyphosis Head & neck move forwards on the

shoulder Mister punch posture: rounded dorsal spine,

flattened chest & protrubent abdomen. Wide bases stance.

I – phase: Isolated phases characterised by attacks of pain & stiffness occuring in increasingly frequent intervals, corresponding to pre-ankylosing stage.

II- phase: continuous symptoms & constitutional upset.

III- phase: declining disease activity & reduced symptoms with episodic minor relapses.

Early stage of the disease with typical symptoms od spondylitis in absence of definite radiological changes in the SI jt.

Associated with systemic symptoms include anorexia, Wt loss, fatique, low grade quotidion fever.

Iridocyclitis Cardiovascular complications Lung changes Neurological changes Amyloidosis Complication of treatment.

ESR, CRP HLA B-27 Raised globulin fraction Alkaline phosphatase. RA factor negative Rise in CSF protein level Urinary 17- ketosteroid levels increase,

ASCA IgA levels are significantly high in AS & other SpA than in healthy controls & Pt with RA

I Serological marker ass. With SpA Can be marker of radiological damage &

more severe course in A.S

Blurring of cortical margins of subchondral bone sclerosis & erosion pseudowidening of jt space fibrous & bony ankylosis

Shiny corner sign- vetebral squarring Star sign- SI jt. Rail road track lines – zygoapophyseal jts Marginal syndesmophytes Bambo spine

Bone scan MRI – si jt in early stages, more sensitive &

specific DEXA- reduced BMD Falsely elevated reading related to spinal

ossification can be avoided by using lateral projection of L3 vetebrae.

graded 0 (normal), 1suspicious, 2 minimal sacroiliitis 3 moderate sacroiliitis 4 ankylosis

NSAIDS IndomethacinPhenyl butazoneSulphasalazineAnti TNF -alpha

definitive diagnosis of AS; presence of the disease for at least 4

weeks; presence of refractory disease(defined by

the failure of two types of NSAIDs during a single 3-month period);

failure of local corticosteroid injection into inflamed sacroiliac joints;

failure of sulfasalazine in patients with peripheral disease;

no medical contraindications to the initiation of treatment.

Infliximab: anti TNF – alpha monoclonal Ab 5 mg /kg body wt repeated 2 wks later,

again 6 wks later, then at every 8 wks interval.

Etanercept: 25 mg by S.C inj twice weekly

Bisphosphate Pamidronate at a dose of 60 mg monthly IV

Thalidomide 200 mg / day [inhibit TNF] Alpha emitting isotope 224 Ra at a dose of 1

MBq.

Thirty percent to 50% of patients with AS exhibit involvement of the hips; of those, 90% present bilaterally.

THR is the most common surgery done in AS.

Mobilising the hip by THR before spinal osteotomy makes easier to determine desired degree of correction in spine.

AS patients are more prone to anterior dislocation when acetabular components are placed in their normal position relative to the pelvis.

When positioning the acetabular component in a patient with AS, one must account for the relationship of the pelvis to the lumbar spine in the sagittal plane in order to avoid an excessively hyperextended hip once the patient resumes an upright position.

GT – not to be osteotomised Due to osteoporosis & extensive capsular &

pericapsular fibrosis during dislocation of the hip, increased chance of fracture.

Osteotomy of the neck & head can be removed as piecemeal.

Capsulectomy should be adequate. Precautions to avoid postop dislocation.

The level of risk for heterotopic bone formation after THA in patients with AS remains controversial.

The proportion of AS patients with functional ankylosis secondary to HO following THA is likely substantially lower than previously thought.

High-risk patients with preoperative ankylosis, with

previous hip surgery, with previous infection, and/or in whom a transtrochanteric approach to the hip was used should be considered for HO prophylaxis

To improve the erect position there by to balance the effect of gravity

To increase the respiratory function To increase the GI fn. Smith Peterson O. Confined to the laminae & articular facets. Ideally done at L2 & L3 levels.

Surgical intervention also may be indicated for management of deformity, pseudarthrosis, fracture, and spondylodiscitis.